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Background: The South Korean government implemented a multidisciplinary nutritional support team (NST) system to focus on the proper evaluation and supply of nutritional status in hospitalized patients who are at a higher risk of malnutrition. Methods: This nationwide population-based cohort study included patients diagnosed with sepsis who were admitted to hospitals from 2016 to 2020. The NST should consist of four professional personnel (physicians, full-time nurses, full-time pharmacists, and full-time clinical dietitians). The NST group included patients with sepsis admitted to a hospital with an NST system, whereas the non-NST group included patients with sepsis admitted to a hospital without an NST system. Results: A total of 323,841 patients with sepsis were included in the final analysis, and 120,274 (37.1%) admitted to a hospital with an NST system were included in the NST group. In the multivariable Cox regression analysis, the NST group showed a 15% lower 90-day mortality than the non-NST group (hazard ratio [HR]:0.85, 95% confidence interval [CI]:0.83, 0.86; P < 0.001). The NST group shows 11% lower 1-year all-cause mortality than the non-NST group (HR:0.89, 95% CI:0.87, 0.90; P < 0.001). In subgroup analyses, a more evident association of the NST group with lower 90-day mortality was shown in the intensive care unit admission group and age ≥65 years old group. Conclusions: Multidisciplinary NST intervention is associated with improved survival outcomes in patients with sepsis. Moreover, this association was more evident in patients with sepsis aged ≥65 years old who were admitted to the ICU. [ABSTRACT FROM AUTHOR]

Background: Little is known about differences in patient characteristics before and after implementation of the new definition of sepsis (Sepsis-3) and whether the new definition is affecting clinical practice in intensive care units. Objective: To examine and compare the clinicoepidemiologic characteristics of patients with sepsis or septic shock before and after implementation of Sepsis-3. Methods: In this population-based cohort study, a nationwide registration database in South Korea was used to identify patients with sepsis or septic shock. Patients admitted to hospitals from 2012 to 2015 constituted the Sepsis-2 group, and patients admitted from 2017 to 2020 constituted the Sepsis-3 group. Results: The study involved 443 217 patients, of whom 170 660 (38.5%) were in the Sepsis-2 group and 272 557 (61.5%) were in the Sepsis-3 group. The mean (SD) age was 73.3 (14.5) years in the Sepsis-2 group and 75.5 (14.5) years in the Sepsis-3 group. The intensive care unit admission rate was higher in the Sepsis-2 group (34.6%, 59 081 of 170 660) than in the Sepsis-3 group (21.3%, 57 997 of 272 557). Multivariable Cox regression analysis showed that 1-year all-cause mortality was 21% lower in the Sepsis-3 group than in the Sepsis-2 group (hazard ratio, 0.79; 95% CI, 0.78–0.79; P <.001). Conclusions: Implementation of the Sepsis-3 definition was associated with an increased number of patients with sepsis. Other findings suggested that patients in the Sepsis-2 group had more severe illness, with increased 1-year all-cause mortality, compared with those in the Sepsis-3 group. [ABSTRACT FROM AUTHOR]

Purpose: The correlation between perioperative blood transfusions and the prognosis after major cancer surgery remains controversial. We investigated the association between perioperative blood transfusion and survival outcomes following major cancer surgeries and analyzed trends in perioperative blood transfusions. Methods: Data for this population-based cohort study were obtained from the National Health Insurance Service of South Korea. Adult patients who underwent major cancer surgery between January 1, 2016, and December 31, 2020, were included. The primary endpoint was 90-day mortality. Results: The final analysis included 253,016 patients, of which 55,094 (21.8%) received perioperative blood transfusions. In the multivariable logistic regression model, select factors, including neoadjuvant/adjuvant chemotherapy, an increased preoperative Charlson Comorbidity Index, moderate or severe liver disease, liver cancer surgery, and small bowel cancer surgery, were associated with an increased likelihood of blood transfusion. In the multivariable Cox regression model, patients who received blood transfusion had a significantly higher risk of 90-day mortality (hazard ratio: 5.68; 95% confidence interval: 5.37, 6.00; P < 0.001) than those who did not. Conclusion: We identified potential risk factors for perioperative blood transfusions. Blood transfusion is associated with an increased 90-day mortality risk after major cancer surgery. [ABSTRACT FROM AUTHOR]

We aimed to examine the prevalence of, and factors associated with, quality of life (QOL) worsening among coronavirus disease 2019 (COVID-19) survivors. This population-based retrospective cohort study used data from the Korea Disease Control and Prevention Agency and the National Health Insurance Service in South Korea. A total of 325,666 COVID-19 survivors were included in this study. Among them, 106,091 (32.6%) survivors experienced worsening QOL after COVID-19. Specifically, 21,223 (6.5%) participants experienced job loss, 94,556 (29.0%) experienced decreased household income, and 559 (0.2%) acquired new disabilities. In the multivariable logistic regression model, living in rural areas (odds ratio [OR]: 1.02; 95% confidence interval [CI]: 1.01, 1.04; p = 0.009), intensive care unit admission (OR: 1.08, 95% CI: 1.02, 1.15; p = 0.028), and increase in self-payment by 100 USD (OR: 1.02, 95% CI: 1.02, 1.02; p < 0.001) were associated with increased QOL worsening after COVID-19. Old age (OR: 0.99, 95% CI: 0.98, 0.99; p < 0.001), first vaccination (OR: 0.89, 95% CI: 0.86, 0.93; p < 0.001), and second vaccination (OR: 0.95, 95% CI: 0.93, 0.96; p < 0.001) were associated with decreased QOL worsening after COVID-19. Approximately one-third of COVID-19 survivors in South Korea who were admitted to hospitals or monitoring centers experienced QOL worsening. [ABSTRACT FROM AUTHOR]

Rationale: Particulate matter (PM) exposure exacerbates health outcomes by causing lung damage. Objectives: To investigate whether prior exposure to particulate matter ⩽10 μm and ⩽2.5 μm in aerodynamic diameter (PM10 and PM2.5) was associated with clinical outcomes among patients with coronavirus disease (COVID-19). Methods: Data from the nationwide registration database of the National Health Insurance and Korea Disease Control and Prevention Agency in South Korea were used. The study included adult patients who were admitted to monitoring centers or hospitals between October 8, 2020 and December 31, 2021, after COVID-19 confirmation. AirKOREA database, which compiles air pollutant data from 642 stations in 162 cities and counties across South Korea, was used to extract data on PM levels. Average values of monthly exposure to PM10 and PM2.5 from the year previous to hospital admission because of COVID-19 to the date of confirmation of COVID-19 were calculated and used to define PM exposures of patients with COVID-19. Results: In total, 322,289 patients with COVID-19 were included, and 4,633 (1.4%) died during hospitalization. After adjusting for covariates, a 1-μg/m3 increase in PM10 and PM2.5 exposure was associated with 4% (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.03–1.05; P < 0.001) and 6% (OR, 1.06; 95% CI, 1.04–1.07; P < 0.001) increase in the risk of in-hospital mortality, respectively. In addition, a 1-μg/m3 increase in PM10 and PM2.5 was associated with 5% (OR, 1.05; 95% CI, 1.04–1.07; P < 0.001) and 8% (OR, 1.08; 95% CI, 1.06–1.10; P < 0.001) increase in the risks of requiring intensive care unit (ICU) admission and mechanical ventilation, respectively. Conclusions: PM10 and PM2.5 exposure was associated with increased in-hospital mortality and the need for ICU admission and mechanical ventilation among patients with COVID-19 in South Korea. [ABSTRACT FROM AUTHOR]

Objective:This study aimed to evaluate the rate of transfusion for cardiovascular surgeries between 2010 and 2019 in Republic of Korea and the association between blood transfusion and postoperative mortality. Methods: Data were extracted from the National Health Insurance Service database in Republic of Korea. This study includes adult patients who underwent cardiovascular surgery between 1 January 2010 and 31 December 2019. The endpoints were in-hospital mortality and the 1-year all-cause mortality. Results: The analysis included 62,794 cases, with transfusions used in 88.8% of cases. Multivariable logistic regression revealed that older age, comorbidities, hospital admission through the emergency room, aortic procedures (versus coronary artery bypass grafting), cardiopulmonary bypass, repeat procedures, and supportive therapies during the intensive care (extracorporeal membrane oxygenation and mechanical ventilation) were risk factors for blood transfusion. Female sex was associated with a lower risk of transfusion. Perioperative blood transfusion was associated with a 6.87-fold increased risk of in-hospital mortality (odds ratio [OR]: 6.87, 95% confidence interval [CI]: 3.95, 11.93; p < 0.001) and a 3.20-fold increased risk of 1-year all-cause mortality (OR: 3.35, 95% CI: 2.75, 3.93; p < 0.001). Conclusions: Blood transfusion is used at a high rate in cardiovascular surgeries, and it was associated with increases in the risk of in-hospital and 1-year all-cause mortality. However, these correlations should be viewed with caution as emergent phenomena rather than causative. Understanding factors associated with the need for blood transfusion can assist surgeons in predicting the outcomes of cardiovascular surgery and in tailoring procedures as needed to optimize outcomes. [ABSTRACT FROM AUTHOR]

Obesity is a major public health problem worldwide and is associated with increased morbidity and mortality. However, studies have shown that obesity has sepsis-related mortality benefits. We aimed to determine whether there is an improved sepsis-related survival rate in patients with obesity in South Korea. We included data from 77,810 adults with sepsis between 1 January 2013 and 31 December 2020, extracted from the National Health Insurance Service database in South Korea. The patients underwent standard health examinations within a year before sepsis, and body mass index (BMI) and waist circumference (WC) were used to reflect obesity. Lower 30-day and 1-year mortality rates were observed in the overweight and obesity groups after adjusting for confounders, including WC. However, there was no difference in mortality between the patients with severe obesity and those with normal BMI. Underweight was associated with higher 30-day and 1-year mortality. Higher 30-day and 1-year mortality was found in the high and very high WC groups. In conclusion, patients with abdominal obesity and overweight and obesity and with sepsis showed reduced mortality, whereas underweight patients with sepsis showed increased mortality in South Korea. [ABSTRACT FROM AUTHOR]

Objectives: The impact of benzodiazepine use on mortality in patients with chronic non‐cancer pain (CNCP) has not been identified. We aimed to examine the factors associated with benzodiazepine use among patients with CNCP and examine whether long‐term benzodiazepine usage is associated with mortality in patients with CNCP. Methods: This study was conducted using data from the National Health Insurance Service database of South Korea. We selected 2.5% of all adult patients diagnosed with musculoskeletal diseases (MSD) in South Korea from 2010 to 2019 using a stratified random sampling technique and included them in the analysis as patients with CNCP. The risk of 10‐year all‐cause mortality in patients with CNCP was investigated using the 2010 cohort of patients with CNCP. Results: The proportion of the study population that used benzodiazepine during the 10‐year study period was 2.1% (390,683/18,770,234). Multivariable logistic regression showed that old age; increased Charlson comorbidity index (CCI); opioid, gabapentin or pregabalin, paracetamol, non‐steroidal anti‐inflammatory drugs, and Z‐drugs usage; and underlying psychiatric comorbidities were associated with increased benzodiazepine use. In addition, benzodiazepine use was associated with increased 10‐year all‐cause mortality (adjusted hazard ratio: 1.03, 95% confidence interval: 1.01, 1.06; p < 0.001). Conclusions: Benzodiazepine was prescribed to 2.1% of the patients with CNCP in South Korea from 2010 to 2019. Old age, increased CCI, underlying psychiatric comorbidities, and use of certain drugs are associated with increased use of benzodiazepines. In addition, benzodiazepine use is associated with 10‐year all‐cause mortality in patients with CNCP. [ABSTRACT FROM AUTHOR]

This study aimed to examine the associated factors of oral glucocorticoid (GC) use in patients with chronic non-cancer pain (CNCP) associated with musculoskeletal diseases (MSDs) in South Korea. Moreover, we examined whether oral GC use was associated with long-term mortality in patients with CNCP. This population-based cohort study used data from the national registration database in South Korea. Using a stratified random sampling technique, we extracted the data from 2.5% of adult patients diagnosed with MSDs in 2010. Patients with CNCP-associated MSDs who were prescribed oral GC regularly for ≥30 days were defined as GC users, while the other patients were considered to be non-GC users. A total of 1,804,019 patients with CNCP were included in the final analysis, and 9038 (0.5%) patients were GC users, while 1,794,981 (95.5%) patients were non-GC users. Some factors (old age, comorbid status, pain medication use, and MSD) were associated with GC use among patients with CNCP. Moreover, in the multivariable time-dependent Cox regression model, GC users showed a 1.45-fold higher 10-year all-cause mortality (hazard ratio: 1.45, 95% confidence interval: 1.36–1.54; p < 0.001) than non-GC users. In South Korea, the 10-year all-cause mortality risk increased in the patients with CNCP using GC. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the association of modifiable lifestyle factors with long-term survival outcomes in patients with chronic non-cancer pain (CNCP) in South Korea. Methods: This population-based cohort study used data from the National Health Insurance Service database in South Korea. We considered three lifestyle factors from the standard health examination (smoking status, alcohol consumption, and physical activity). Results: A total of 1,298,314 patients with CNCP were analyzed; moreover, the 5-year all-cause mortality rate was 3.3% (42,875 patients). In the multivariable Cox regression model, in the previous-smoker and current-smoker groups, it was 5% (hazard ratio [HR]:1.05, 95% confidence interval [CI]:1.02–1.08; P = 0.003) and 65% (HR: 1.65, 95% CI: 1.60–1.69; P < 0.001) higher, respectively, than that in the never-smoker group. The 5-year all-cause mortality was 19% (HR: 1.19, 95% CI: 1.14–1.24; P < 0.001) higher in the heavy-alcohol-consumption group than in the non-alcohol-consumption group. Compared with those without mild physical activity, patients who engaged in mild physical activity for 1–3 (HR: 0.89, 95% CI: 0.87–0.92; P < 0.001), 4–5 (HR: 0.88, 95% CI: 0.86–0.91; P < 0.001), and 6–7 (HR: 0.90, 95% CI: 0.88–0.93; P < 0.001) days per week exhibited a significantly decreased 5-year all-cause mortality. The association between moderate/intensive physical activity and 5-year all-cause mortality yielded similar results. Conclusion: Lifestyle factors, including previous/current smoking, heavy alcohol consumption, and physical activity, were associated with a higher 5-year all-cause mortality risk among patients with CNCP in South Korea. [ABSTRACT FROM AUTHOR]

We aimed to examine whether preoperative psychiatric morbidities affect 30-day postoperative mortality. Using a nationwide registration database in South Korea, the study included all patients who underwent curative cancer surgery from 1 January 2002 to 31 December 2019. Patients underwent surgery for breast, laryngeal, lung, thyroid, gastric, colorectal, esophageal, liver, pancreatic, kidney, bladder, testicular, prostate, vulvar, uterine, or brain cancer. Depression, anxiety disorder, substance abuse, and post-traumatic stress disorder were considered preoperative psychiatric morbidities. Among the 944,794 patients in the final analysis, 5490 (0.6%) died within 30 days of the surgery, and 24,370 (2.6%) had preoperative psychiatric morbidities. Multivariable logistic regression analysis showed that preoperative psychiatric morbidities were associated with a higher (adjusted odds ratio [aOR]: 1.23; 95% confidence interval [CI]: 1.09, 1.39; p = 0.001) 30-day mortality rate than the rate noted for patients without preoperative psychiatric morbidities. This association was significant in the breast (aOR: 3.31, 95% CI: 1.36, 8.07; p = 0.009), lung (aOR: 1.54, 95% CI: 1.19, 2.01; p = 0.001), and kidney (aOR: 1.87, 95% CI: 1.06, 3.31; p = 0.03) cancer groups in the subgroup analyses. In South Korea, preoperative psychiatric morbidities are considered to be associated with increased 30-day postoperative mortality. [ABSTRACT FROM AUTHOR]

Background: Trained intensivist staffing improves survival outcomes in critically ill patients at intensive care units. However, the impact on outcomes of critically ill patients with coronavirus disease 2019 has not yet been evaluated. We aimed to investigate whether trained intensivists affect outcomes among critically ill coronavirus disease 2019 patients in South Korean intensive care units. Methods: Using a nationwide registration database in South Korea, we included adult patients admitted to the intensive care unit from October 8, 2020, to December 31, 2021, with a main diagnosis of coronavirus disease 2019. Critically ill patients admitted to intensive care units that employed trained intensivists were included in the intensivist group, whereas all other critically ill patients were assigned to the non-intensivist group. Results: A total of 13,103 critically ill patients were included, with 2653 (20.2%) patients in the intensivist group and 10,450 (79.8%) patients in the non-intensivist group. In the covariate-adjusted multivariable logistic regression model, the intensivist group exhibited 28% lower in-hospital mortality than that of the non-intensivist group (odds ratio: 0.72; 95% confidence interval: 0.62, 0.83; P < 0.001). Conclusions: Trained intensivist coverage was associated with lower in-hospital mortality among critically ill coronavirus disease 2019 patients who required intensive care unit admission in South Korea. [ABSTRACT FROM AUTHOR]

We aimed to investigate the mortality and associated factors among patients admitted to the intensive care unit (ICU) after transplantation in South Korea. The South Korean National Health Insurance Service database was used as the data source. All adult patients (age ≥18 years) who were admitted to the ICU for organ transplantation-related causes from January 1, 2010 to December 31, 2019 (10 years) were included. Transplantation-associated ICU admissions were defined as admissions to the ward and ICU after transplantation or to the ICU before transplantation. A total of 23,994 ICU admissions after transplantation were included in the analysis (mean [SD] age: 52.7 [10.7] years; men: 67.0%; kidney transplantation: n = 9638; liver transplantation: n = 12,196; heart and/or lung transplantation: n = 1829; pancreas or small bowel transplantation: n = 331). Transplantation-associated ICU admissions gradually increased from 1666 in 2010 to 3014 in 2019. The 1-year mortality rates were 21.2%, 12.3%, 4.2%, and 3.0% after heart and/or lung, liver, pancreas or small bowel, and kidney transplantation, respectively. Invasive life support procedures during ICU stay, comorbidities, and older age were potential risk factors for 1-year mortality after transplantation. Transplantation-associated ICU admissions gradually increased from 2010 to 2019 in South Korea. The 1-year mortality rate after transplantation was the highest in the heart and/or lung transplantation group, followed by those of the liver, pancreas or small bowel, and kidney transplantation groups. [ABSTRACT FROM AUTHOR]

Background: The difference in survival outcomes between closed and open intensive care unit (ICU) designs with respect to trained intensivist coverage remains unknown. We aimed to investigate whether trained intensivist coverage is associated with mortality in critically ill patients admitted to the ICU in South Korea. Methods: This population-based cohort study used nationwide registration data from South Korea. This study enrolled all adult patients admitted to the ICU between January 1, 2016, and December 31, 2019. Patients, who were admitted ICU in a hospital that employed trained intensivists, were designated as the intensivist group. Results: This study included 1,147,493 critically ill patients admitted to the ICU. The intensivist and non-intensivist groups consisted of 484,004 (42.2%) and 663,489 (57.8%) patients, respectively. Mixed effect logistic regression revealed a 22% lower in-hospital mortality rate (odds ratio: 0.78. 95% confidence interval: 0.74, 0.81; P < 0.001) than that in the non-intensivist group. Mixed effect Cox regression revealed a 15% lower 1-year mortality rate (hazard ratio: 0.85. 95% confidence interval: 0.83, 0.89; P < 0.001) in the intensivist group than that in the non-intensivist group. Moreover, the in-hospital mortality was significantly lower in the intensivist group than that in the non-intensivist group, irrespective of age, Charlson comorbidity index, surgery or non-surgery associated admission, and invasive treatment during ICU stay. Conclusions: A closed ICU design with trained intensivist coverage was associated with lower in-hospital and 1-year mortality rates. Our results suggest that hospitals should employ trained intensivists to improve both short-term and long-term survival outcomes of critically ill patients. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to investigate trends in extracorporeal membrane oxygenation (ECMO) treatment during 2005–2018 and examine factors associated with in-hospital mortality. Methods: We conducted a population-based cohort study based on health records obtained from the National Health Insurance Service database in South Korea. All adult patients (⩾18 years old) who received ECMO treatment in the intensive care unit after hospitalization from 2005 to 2018 were enrolled. Results: We analyzed data for 21,129 adult ECMO patients from 128 hospitals. The prevalence of ECMO treatment gradually and continuously increased from 4 per 100,000 individuals (95% confidence interval [CI]: 3–4) in 2005 to 67.4 per 100,000 individuals (95% CI: 65–68) in 2018. There was a significant increase in ECMO treatment for acute respiratory distress syndrome (ARDS) or respiratory failure (from 2.5% during 2005–2008 to 14.5% during 2016–2018). The overall in-hospital and 30-day mortality rates of the patients were 48.4% and 53.5%, respectively. The in-hospital mortality rate was highest among patients with shock (62.1%) and lowest among ECMO patients with liver failure (21.6%). On multivariable logistic regression, a higher hospital case volume was associated with improvement in in-hospital mortality (p < 0.001). Conclusions: In South Korea, the prevalence of ECMO treatment has increased gradually and continuously between 2005 and 2018. There was a significant increase in the prevalence of ECMO treatment for ARDS or respiratory failure. Our results support that ECMO treatment indications have been expanding, and ECMO will become vital for treating critically ill patients in the future. [ABSTRACT FROM AUTHOR]

Aim: This study investigated the changes in quality of life (QOL) after in-hospital cardiopulmonary arrest (IHCA) among survivors and examined the association between worsening QOL and 3-year all-cause mortality.Methods: This population-based cohort study used data from the National Health Insurance Service database in South Korea. Adult survivors who experienced IHCA between January 1, 2010, and December 31, 2018, and were alive for over 1 year after IHCA were included. Worsening QOL among IHCA survivors was determined using three criteria: decreased household income, unemployment, and acquired disability.Results: A total of 22,611 IHCA survivors from 903 hospitals were included in the final analysis, and 7,796 (34.5%) experienced worsening QOL. Specifically, 5,595 (24.7%), 1,694 (7.5%), and 1,617 (7.2%) survivors experienced decreased household income, unemployment, and acquired disability, respectively. The proportion of brain lesion disability increased from 6.3% to 10.8% after IHCA. In multivariable Cox regression, worsening QOL was not associated with 3-year all-cause mortality (adjusted hazard ratio [aHR]: 1.03, 95% confidence interval [CI]: 0.96, 1.11; P = 0.372). However, among the QOL factors, acquired disability was associated with a 1.29-fold higher risk of 3-year all-cause mortality among IHCA survivors (aHR: 1.29, 95% CI: 1.15, 1.46; P < 0.001).Conclusion: Approximately one-third of IHCA survivors experienced worsening QOL (decreased household income, unemployment, and acquired disability) at 1-year follow-up after IHCA in South Korea. Although overall worsening of QOL was not associated with 3-year all-cause mortality, acquired disability was associated with increased 3-year all-cause mortality among IHCA survivors. [ABSTRACT FROM AUTHOR]

Background The impact of HIV infection on survival outcomes after in-hospital cardiopulmonary resuscitation (ICPR) remains controversial. This study aimed to investigate the impacts of HIV infection on both short-term and long-term outcomes after ICPR. Methods This nationwide, population-based cohort study used data taken from the South Korean National Health Insurance Service database. All adult (≥18 years old) patients who experienced ICPR between January 1, 2010, and December 31, 2019, were included. Results A total of 298 676 adult patients who underwent ICPR were initially included in the analysis. Among them, 586 (0.2%) patients were assigned to the patients with symptomatic HIV infection (PWH) group, while 298 090 (99.8%) patients were assigned to the control group. After 1:10 propensity score (PS) matching, 586 patients in the PWH group and 5845 patients in the control group were included in the analysis. Logistic regression analysis after PS matching showed that the PWH group had a 20% lower live discharge rate after ICPR compared with the control group (odds ratio, 0.80; 95% CI, 0.65–0.97; P  = .024). However, Cox regression analysis after PS matching showed that the risks of 6-month survival (hazard ratio [HR], 1.01; 95% CI, 0.93–1.11; P  = .768) and 1-year survival (HR, 1.02; 95% CI, 0.93–1.11; P  = .702) were not significantly different between the PWH and control groups. Conclusions Although the PWH group showed lower live discharge rates compared with the control group after ICPR, long-term survival outcomes from 6 months and 1 year were not significantly different. [ABSTRACT FROM AUTHOR]

Background: This study aimed to investigate the prevalence of 7‐, 30‐, 60‐, and 365‐day overall and cause‐specific mortality following extracorporeal membrane oxygenation (ECMO) support. Methods: The National Health Insurance claims database in South Korea was the data source for this population‐based cohort study. We enrolled all adult patients aged ≥18 years receiving intensive care unit ECMO support from January 1, 2005 to December 31, 2018. The study population was divided into three groups based on the main diagnoses during ECMO support: (1) cardiovascular, (2) respiratory, and (3) other diagnoses group (all other main diagnoses rather than cardiovascular or respiratory diseases). Results: A total of 18 697 patients were included in the final analysis (64.5%, 10.9%, and 24.6% in the cardiovascular, respiratory, and other groups, respectively). The corresponding 7‐, 30‐, 60‐, and 365‐day mortality rates in these groups were 33.1%, 56.1%, 62.4%, and 67.7%. Kaplan–Meier curves demonstrated that the median survival time was shortest in the cardiovascular group (12.0 days, 95% confidence interval [CI]: 11.3–12.7), with 31.0 (95% CI: 28.5–33.6) and 49.0 (95% CI: 44.4–57.6) day survival in the respiratory and other diagnoses groups (p < 0.001). Conclusions: Approximately one‐third of patients died within 7 days, half of the patients died within 30 days, and two‐thirds died within 365 days of ECMO support. Overall survival time was shortest in the cardiovascular group, followed by that of the respiratory group. [ABSTRACT FROM AUTHOR]

Summary: We investigated the prevalence of insomnia in extracorporeal membrane oxygenation (ECMO)‐treated patients and examined the association between post‐ECMO insomnia disorder and long‐term mortality. In the present population‐based cohort study, we used data from the National Health Insurance Claims database in South Korea. All adult patients who underwent ECMO between 2006 and 2014 were included, and ECMO‐treated patients were defined as those who survived >365 days after ECMO. Insomnia disorder was identified using the International Classification of Diseases 10th Revision codes G47.0 and F51.0. Overall, 3,055 ECMO‐treated patients were included in the final analysis: 431 (14.1%) had pre‐ECMO insomnia disorder, while 148 (4.8%) were newly diagnosed with insomnia disorder up to 1 year after ECMO. In multivariable Cox regression model, patients with post‐ECMO insomnia disorder had higher 5‐year all‐cause mortality (ACM) than controls (hazard ratio [HR] 1.71, 95% confidence interval [CI] 1.21–2.42; p = 0.003); however, those with pre‐ECMO insomnia disorder did not (p = 0.655). In sensitivity analysis, post‐ECMO insomnia disorder with underlying psychiatric illness was associated with a 2.39‐fold higher 5‐year ACM in ECMO‐treated patients (HR 2.39, 95% CI 1.52–3.75; p < 0.001). In conclusion, at 1‐year after ECMO, 4.8% of ECMO‐treated patients were newly diagnosed with insomnia disorder, and post‐ECMO insomnia disorder was associated with higher 5‐year ACM, especially in those with underlying psychiatric illness. Our present results suggest that the development of insomnia disorder might be related to poorer long‐term survival in ECMO‐treated patients, especially in case of underlying psychiatric illness. [ABSTRACT FROM AUTHOR]

Purpose: Worsening quality of life (QOL) is an important health issue in acute respiratory distress syndrome (ARDS) survivors. We aimed to investigate the prevalence of worsening QOL among ARDS survivors and their association with mortality. Methods: South Korean National Health Insurance database information for all adults admitted to intensive care units for ARDS from January 1, 2010 to December 31, 2018 who survived ≥ 365 days were included in this study. Results: A total of 4452 ARDS survivors were included in the final analysis. Total QOL had worsened in 1667 (37.4%) of the survivors at the follow-up 1 year after being diagnosed with the syndrome. Specifically, 1298 patients (29.2%) experienced decreased income, 334 (7.5%) lost their jobs, and 327 (7.3%) had newly acquired disabilities. In the multivariable Cox regression analysis, worsening QOL was not associated with 2-year all-cause mortality among survivors (P = 0.140). However, newly acquired disability was associated with 1.74-fold (hazard ratio [HR]: 1.74, 95% confidence interval [CI] 1.31–2.33; P < 0.001) higher 2-year all-cause mortality, while decreased income (P = 0.571) and unemployment (P = 0.952) were not associated with it. In addition, newly acquired respiratory disability was associated with a 6.61-fold higher risk of 2-year respiratory mortality (HR: 6.61, 95% CI 3.14–13.90; P < 0.001). Conclusions: At the 1-year follow-up period, one-third of ARDS survivors experienced worsening QOL in South Korea. Specifically, newly acquired disability was associated with a higher risk of 2-year all-cause and respiratory mortality among patients who survived ARDS. [ABSTRACT FROM AUTHOR]

The dynamic aspartate‐to–alanine aminotransferase ratio (dAAR) was developed recently to predict the risk of incident chronic liver disease among the Nordic adult population; however, the dAAR has not been externally validated in other ethnic cohorts. Therefore, we aimed to examine the predictive ability of dAAR for liver disease mortality in the South Korean adult population. As a population‐based cohort study, we used the National Health Screening Cohort database, which included adult individuals who underwent standardized medical examinations between 2002 and 2003 in South Korea. The primary endpoint was liver disease mortality, defined as death due to liver disease. Liver disease mortality was evaluated between 2004 and 2015 (12 years). Analysis of data from 512,749 adults showed that 4,052 (0.8%) individuals died due to liver disease. On receiver operating characteristic (ROC) analyses, the area under curve for alanine aminotransferase (ALT), aspartate‐to‐ALT ratio (AAR), and dAAR for liver disease mortality were 0.74, 0.55, and 0.81, respectively. The cutoff point of dAAR was determined to be 0.72 on ROC analysis, using the Youden index method. On competing risk analysis using the Fine and Gray model, the dAAR > 0.72 group demonstrated a 4.43‐fold higher rate of liver disease mortality (subdistribution hazard ratio: 4.43, 95% confidence interval: 4.11, 4.77; P < 0.001) after adjustment for covariates. Conclusion: The performance of dAAR in predicting liver disease mortality was better than that of AAR or ALT in South Korea. Our study suggests that dAAR scores can potentially be used for screening and predicting liver disease mortality among the general Korean population. [ABSTRACT FROM AUTHOR]

We examined and compared the clinical characteristics of acute respiratory distress syndrome (ARDS) patients who received and did not receive extracorporeal membrane oxygenation (ECMO) support. The national health insurance database of South Korea was used to obtain real-world data. All adult patients admitted to intensive care units for ARDS treatment between 1 January 2014 and 31 December 2019 were included in this study. Of the 10,173 patients with ARDS included in the analysis, 740 (7.3%) received ECMO support for a mean duration of 1.6 days (standard deviation [SD]: 2.8 days) and were assigned to the ECMO group. The ECMO group had a significantly lower mean age at 57.0 years (SD: 15.7 years) than the non-ECMO group (71.8 Â years [SD: 15.1 Â years], P < 0.001). In multivariable logistic regression, a 1-year increase in age was associated with a 5% lower prevalence of ECMO support. The annual case volume was classified into four groups by quartile ratio (Q1 [lowest], Q2, Q3, and Q4 [highest]), and Q2, Q3, and Q4 groups showed a higher prevalence of ECMO support than the Q1 group. ECMO support was also performed more frequently in high case volume centers than in low case volume centers for ARDS patients. [ABSTRACT FROM AUTHOR]

We aimed to examine recent trends in in-hospital cardiopulmonary resuscitation in South Korea from 2010 to 2019. A population-based sample of all adult patients who experienced in-hospital cardiopulmonary resuscitation between 1 January 2010 and 31 December 2019, was included. In all, 298,676 patients who received in-hospital cardiopulmonary resuscitation were included in the survival analysis. In 2010, 60.7 per 100,000 adults experienced in-hospital cardiopulmonary resuscitation. A similar rate was observed until 2015. The rate increased to 83.5 per 100,000 adults in 2016 and gradually increased to 92.1 per 100,000 adults in 2019. Among all patients, 78,783 (26.2%) were discharged alive after in-hospital cardiopulmonary resuscitation. The 6-month and 1-year survival rates were 9.8% and 8.7%, respectively. In 2010, the mean total cost of hospitalization was USD 5822.80 (United States Dollar) (standard deviation; SD: USD 7493.4), which increased to USD 7886.20 (SD: USD 13,071.6) in 2019. The rate of in-hospital cardiopulmonary resuscitation and cost of care have significantly increased since 2010, while the 6-month and 1-year rates of survival post in-hospital resuscitation remain low. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to investigate the prevalence of quality-of-life deterioration and associated factors in patients who underwent craniotomies for brain tumor removal. Additionally, we examined whether deteriorating quality of life after surgery might affect mortality. Methods: As a national population-based cohort study, data were extracted from the National Health Insurance Service database of South Korea. Adult patients (≥ 18 years old) who underwent craniotomy for excision of brain tumors after diagnosis of malignant brain tumor between January 1, 2011, and December 31, 2017, were included in this study. Results: A total of 4852 patients were included in the analysis. Among them, 2273 patients (46.9%) experienced a deterioration in quality of life after surgery. Specifically, 595 (12.3%) lost their jobs, 1329 (27.4%) experienced decreased income, and 844 (17.4%) patients had newly acquired disabilities. In the multivariable Cox regression model, a lower quality of life was associated with a 1.41-fold higher 2-year all-cause mortality (hazard ratio: 1.41, 95% confidence interval: 1.27–1.57; P < 0.001). Specifically, newly acquired disability was associated with 1.80-fold higher 2-year all-cause mortality (hazard ratio: 1.80, 95% confidence interval: 1.59–2.03; P < 0.001), while loss of job (P = 0.353) and decreased income (P = 0.599) were not significantly associated. Conclusions: At 1-year follow-up, approximately half the patients who participated in this study experienced a deterioration in the quality-of-life measures of unemployment, decreased income, and newly acquired disability after craniotomy for excision of brain tumors. Newly acquired disability was associated with increased 2-year all-cause mortality. [ABSTRACT FROM AUTHOR]

Background: We aimed to investigate the prevalence and associated factors of newly developed depression in patients who underwent craniotomy for brain tumor removal, as well as its effect on long-term mortality.Methods: Using a nationwide cohort database in South Korea, we included adult patients diagnosed with brain tumors who underwent craniotomy for brain tumor removal from January 1, 2011, to December 31, 2017. We excluded patients with a preoperative history of depression.Results: Among 4,275 patients, 727 (17.0%) patients were newly diagnosed with depression within one year, postoperatively. Two-year all-cause mortality and mortality due to brain cancer occurred in 1,233 (28.8%) and 1,099 (25.7%) patients, respectively. In the multivariable logistic regression model, older age, living in rural areas, newly acquired brain disability, underlying other psychiatric disorders, and longer length of hospital stay were associated with a higher incidence of newly developed depression. In the multivariable Cox regression model, newly acquired depression was associated with a 1.58-fold higher 2-year all-cause mortality compared with that in other patients (hazard ratio: 1.58, 95% confidence interval: 1.38-1.80; P < 0.001).Limitation: Lack of information regarding severity and pathologic tumor type.Conclusion: Within one follow-up year, 17.0% of patients were newly diagnosed with depression after craniotomy for brain tumor removal. Some factors (old age, living in rural areas, newly acquired brain disability, longer length of hospital stay, and underlying other psychiatric illnesses) could be risk factors for newly diagnosed depression. Furthermore, newly developed depression was associated with an increased 2-year all-cause mortality. [ABSTRACT FROM AUTHOR]

Background: The prevalence of delirium, its associated factors, and its impact on long-term mortality among survivors of acute respiratory distress syndrome (ARDS) is unclear.Methods: Since this was a population-based study, data were extracted from the National Health Insurance database in South Korea. All adults who were admitted to intensive care units with a diagnosis of ARDS between January 1, 2010, and December 31, 2019, and who survived for ≥ 60 days were included. The International Statistical Classification of Diseases and Related Health Problems, tenth revision code of delirium (F05) was used to extract delirium cases during hospitalization.Results: A total of 6809 ARDS survivors were included in the analysis, and 319 patients (4.7%) were diagnosed with delirium during hospitalization. In the multivariable logistic regression analysis after covariate adjustment, male sex (odds ratio [OR] 1.60, 95% confidence interval [CI] 1.23, 2.08; P < 0.001), longer duration of hospitalization (OR 1.02, 95% CI 1.01, 1.03; P < 0.001), neuromuscular blockade use (OR 1.50, 95% CI 1.12, 2.01; P = 0.006), benzodiazepine (OR 1.55, 95% CI 1.13, 2.13; P = 0.007) and propofol (OR 1.48, 95% CI 1.01, 2.17; P = 0.046) continuous infusion, and concurrent depression (OR 1.31, 95% CI 1.01, 1.71; P = 0.044) were associated with a higher prevalence of delirium among ARDS survivors. In the multivariable Cox regression analysis after adjustment for covariates, the occurrence of delirium was not significantly associated with 1-year all-cause mortality, when compared to the other survivors who did not develop delirium (hazard ratio: 0.85, 95% CI 1.01, 1.71; P = 0.044).Conclusions: In South Korea, 4.7% of ARDS survivors were diagnosed with delirium during hospitalization in South Korea. Some factors were potential risk factors for the development of delirium, but the occurrence of delirium might not affect 1-year all-cause mortality among ARDS survivors. [ABSTRACT FROM AUTHOR]

Background: Previous studies reported that patients with acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT) after cardiac surgery were at a higher risk of postoperative mortality. However, the impact of AKI and CRRT on long-term mortality has not yet been identified. Therefore, we investigated whether postoperative AKI requiring CRRT was associated with one-year all-cause mortality after coronary artery bypass grafting (CABG).Methods: For this population-based cohort study, we analyzed data from the National Health Insurance Service database in South Korea. The cohort included all adult patients diagnosed with ischemic heart disease who underwent isolated CABG between January 2012 and December 2017.Results: A total of 15,115 patients were included in the analysis, and 214 patients (1.4%) required CRRT for AKI after CABG during hospitalization. They received CRRT at 3.1 ± 8.5 days after CABG, for 3.1 ± 7.8 days. On multivariable Cox regression, the risk of 1-year all-cause mortality in patients who underwent CRRT was 7.69-fold higher. Additionally, on multivariable Cox regression, the 30-day and 90-day mortality after CABG in patients who underwent CRRT were 18.20-fold and 20.21-fold higher than the normal value, respectively. Newly diagnosed chronic kidney disease (CKD) requiring renal replacement therapy (RRT) 1 year after CABG in patients who underwent CRRT was 2.50-fold higher. In the generalized log-linear Poisson model, the length of hospital stay (LOS) in patients who underwent CRRT was 5% longer.Conclusions: This population-based cohort study showed that postoperative AKI requiring CRRT was associated with a higher 1-year all-cause mortality after CABG. Furthermore, it was associated with a higher rate of 30-day and 90-day mortality, longer LOS, and higher rate of CKD requiring RRT 1 year after CABG. Our results suggest that CRRT-associated AKI after CABG may be associated with an increased risk of mortality; hence, there should be interventions in these patients after hospital discharge. [ABSTRACT FROM AUTHOR]

Background: Anemia, which is a condition with reduced healthy red blood cells, is reported to be closely related to the development of infectious diseases. We aimed to investigate the association between history of anemia and 12-year mortality rate due to infections, and compare it with that among non-anemic individuals.Methods: Data from the National Health Insurance Service Health Screening Cohort were used in this population-based cohort study. Adults who underwent standardized medical examination between and 2002-2003 were included, and the mortality rate due to infection between 2004 and 2015 was analyzed. Individuals were considered to have a history of anemia if the serum hemoglobin level in 2002-2003 was < 12 g/dL for women and < 13 g/dL for men. The severity of anemia at that time was categorized as mild (12 g/dL > hemoglobin ≥11 g/dL in women and 13 g/dL > hemoglobin ≥11 g/dL in men), moderate (hemoglobin 8-10.9 g/dL), or severe (hemoglobin < 8 g/dL). Propensity score (PS) matching and Cox regression analysis were used as statistical methods.Results: Overall, 512,905 individuals were included in this study. The mean age of the participants was 54.5 years old (range: 40-98), and 49,042 (9.6%) individuals were classified in the anemic group, which comprised of 36,383 (7.1%), 11,787 (2.3%), and 872 (0.2%) participants in the mild, moderate, and severe sub-groups, respectively. After PS matching, 49,039 individuals in each group were included in the analysis. The risk of mortality due to infection in the anemic group was 1.77-fold higher (hazard ratio [HR]: 1.77, 95% confidence interval [CI]: 1.52-2.60; P < 0.001) than that in the non-anemic group. In the subgroup analysis, the mild and moderate anemia groups had 1.38-fold (HR: 1.38, 95% CI: 1.23 to 1.55; P < 0.001) and 2.02-fold (HR: 2.02, 95% CI: 1.62 to 2.50; P < 0.001) risk of mortality due to infection compared to that of the non-anemic group, respectively. The severe anemia group did not have a significantly different risk of mortality due to infection (P = 0.448).Conclusions: History of anemia was associated with increased mortality rate due to infection at 12-year follow-up. [ABSTRACT FROM AUTHOR]

Background: Quality of life following extracorporeal membrane oxygenation (ECMO) therapy is an important health issue. We aimed to describe the characteristics of patients who developed chronic respiratory disease (CRD) following ECMO therapy, and investigate the association between newly diagnosed post-ECMO CRDs and 5-year all-cause mortality among ECMO survivors.Methods: We analyzed data from the National Health Insurance Service in South Korea. All adult patients who underwent ECMO therapy in the intensive care unit between 2006 and 2014 were included. ECMO survivors were defined as those who survived for 365 days after ECMO therapy. Chronic obstructive pulmonary disease (COPD), asthma, interstitial lung disease, lung cancer, lung disease due to external agents, obstructive sleep apnea, and lung tuberculosis were considered as CRDs.Results: A total of 3055 ECMO survivors were included, and 345 (11.3%) were newly diagnosed with CRDs 365 days after ECMO therapy. The prevalence of asthma was the highest at 6.1% (185). In the multivariate logistic regression, ECMO survivors who underwent ECMO therapy for acute respiratory distress syndrome (ARDS) or respiratory failure had a 2.00-fold increase in post-ECMO CRD (95% confidence interval [CI]: 1.39 to 2.89; P < 0.001). In the multivariate Cox regression, newly diagnosed post-ECMO CRD was associated with a 1.47-fold (95% CI: 1.17 to 1.86; P = 0.001) higher 5-year all-cause mortality.Conclusions: At 12 months after ECMO therapy, 11.3% of ECMO survivors were newly diagnosed with CRDs. Patients who underwent ECMO therapy for ARDS or respiratory failure were associated with a higher incidence of newly diagnosed post-ECMO CRD compared to those who underwent ECMO for other causes. Additionally, post-ECMO CRDs were associated with a higher 5-year all-cause mortality. Our results suggest that ECMO survivors with newly diagnosed post-ECMO CRD might be a high-risk group requiring dedicated interventions. [ABSTRACT FROM AUTHOR]

We aimed to investigate the association between sleep disorders and 5-year all-cause and disease-specific mortality. In this population-based cohort study, data from the sample cohort of the National Health Insurance Service, that was developed as a representative of the South Korean population were extracted. Sleep disorder was defined based on the 10th edition of the International Classification of Diseases (ICD-10; codes G47*). Multivariate Cox regression modeling was used for statistical analysis. In the sample cohort of 2010, 822,214 adults (≥ 18 years) were included for analysis. Among them, 27,515 (3.3%) individuals had sleep disorders, of which insomnia was most common (17,864 individuals, 2.2%). Compared with the control group, the sleep disorder group showed a 1.23-fold higher 5-year all-cause mortality (hazard ratio [HR]: 1.23, 95% confidence interval: 1.18–1.28; P < 0.001). On competing risk analysis, compared with the control group, the sleep disorder group demonstrated the highest risk of 5-year injury- and poisoning-related mortality (HR: 1.61) followed by 5-year nervous system disease mortality (HR: 1.35). On subgroup analyses according to age, sleep disorders conferred a 2.05-fold higher risk for all-cause mortality (HR: 2.05) in the group aged 18–40 years; sleep disorders in the 41–60 and > 60 years groups showed 1.58-fold (HR: 1.58) and 1.48-fold (HR: 1.48) higher risk, respectively. Increased 5-year all-cause mortality was associated with sleep disorders, particularly for deaths owing to injury or poisoning, and nervous system disease. This association was more evident in the young adult population (aged 18–40 years). [ABSTRACT FROM AUTHOR]

Aims: The relationship between metformin therapy and the risk of coronavirus disease (COVID-19) has not been reported among patients with type 2 diabetes mellitus (DM). We aimed to investigate whether metformin therapy was associated with the incidence of COVID-19 among type 2 DM patients in South Korea. Methods: The National Health Insurance Service-COVID-19 cohort database, comprising COVID-19 patients from 1 January 2020 to 4 June 2020, was used for this study. Among them, adult patients with type 2 DM were included in this study. Metformin users were defined as those who had been prescribed continuous oral metformin for over a period of ≥ 90 days, and the control group was defined as all other patients. Results: Overall, 27,493 patients with type 2 DM (7204, metformin user group; 20,289, control group) were included. After propensity score matching, 11,892 patients (5946 patients in each group) were included in the final analysis. In the logistic regression analysis, the odds of metformin users developing COVID-19 was 30% lower than that of the control group [odds ratio (OR): 0.70, 95% confidence interval (CI): 0.61–0.80; P < 0.001]. However, in the multivariate model, metformin use was not associated with hospital mortality when compared with that of the control group (OR: 1.26, 95% CI: 0.81–1.95; P = 0.301). Conclusions: Metformin therapy might have potential benefits for the prevention of COVID-19 among patients with type 2 DM in South Korea. However, it did not affect the hospital mortality of type 2 DM patients diagnosed with COVID-19. [ABSTRACT FROM AUTHOR]

Background: This study aimed to investigate whether weekend admission was associated with a higher risk of 90‐day mortality in patients with sepsis. Methods: This population‐based cohort study was based on health records from the National Health Insurance Service database in South Korea. All adult patients (age ≥ 18 years) admitted for sepsis (A40, A41) or septic shock (R65.2) as diagnosed according to the International Classification of Diseases, 10th revision codes, during 2010‐2018 were screened. Weekend admission was defined as admission for sepsis on weekends. Results: In all, 251 837 patients were enrolled, of which 43 327 (17.2%) were in the weekend admission group and 208 510 (82.8%) in the weekday admission group. After propensity score matching, 86 654 patients with sepsis (43 327 patients with sepsis in each group) were included in the analysis. The 90‐day mortality rates in the weekend admission and weekday admission groups were 44.3% (19 204/43 327) and 41.9% (18 157/43 327), respectively. On Cox regression analysis, the risk of 90‐day mortality in the weekend admission group was 1.09‐times higher than that in the weekday admission group (hazard ratio: 1.09, 95% confidence interval: 1.07‐1.12; P <.001). Conclusion: Using the national health claims database in South Korea, we showed that weekend admission for diagnosed sepsis was associated with an increased risk of 90‐day mortality, compared to that for weekday admission. This might be due to the higher severity of illness in patients with sepsis admitted during the weekend or relatively lesser hospital staff during the weekend. [ABSTRACT FROM AUTHOR]

Background We compared all-cause mortality between individuals in South Korea with and without coronavirus disease 2019 (COVID-19) using propensity score (PS) matching. Methods This population-based cohort study used data from the National Health Insurance Service COVID-19 cohort database. In the database, we included individuals (COVID-19 patients, control population, and test-negative individuals) aged 20 years or older, regardless of hospitalization. The primary end point was all-cause mortality between January 1, 2020, and August 27, 2020. Results A total of 328 374 adults were included in the study: 7713 and 320 660 in the COVID-19 group and the control group. After PS matching, a total of 15 426 individuals (7713 per group) were included in the analysis. All-cause mortality was 3.2% (248/7713) and 1.6% (126/7713) in the COVID-19 group and the control group, respectively. In Cox regression analysis after PS matching, the risk of death in the COVID-19 group was twice as high (hazard ratio, 2.00; 95% CI, 1.61–2.48; P  < .001) as that in the control group. Among patients aged ≥60 years, the COVID-19 group had a 2.32-fold higher all-cause mortality compared with the control group, while statistically significant differences were not observed in the age groups 20–39 years (P  = .339) and 40–59 years (P  = .562). Conclusions In South Korea, all-cause mortality was twice as high among individuals with COVID-19 as among those with similar underlying risks, primarily because of the elevated COVID-19-associated mortality in those aged ≥60 years. Our results highlight the need for prevention of COVID-19 with respect to mortality as a public health outcome. [ABSTRACT FROM AUTHOR]

Background: Postoperative mortality associated with elective coronary artery bypass graft (CABG) surgery may reportedly increase as the weekday of surgery approaches the weekend. We aimed to investigate the potential effect of the weekday of CABG surgery on the 30‐day mortality. Methods: This population‐based cohort study analyzed data obtained from the South Korea national health insurance service database. The cohort included all adult patients diagnosed with ischemic heart disease (International Classification of Diseases‐10 codes I20*–I25*) who underwent isolated and elective CABG surgery from January 2012 to December 2017. Results: Of the 13,556 patients included in the analysis, 595 (4.4%) died within 30 days after CABG surgery. In a multivariable Cox model, the 30‐day mortality of patients who underwent CABG surgery later in the week (Wednesday–Friday) was not significantly associated with the weekday of surgery as similar to those who underwent surgery early in the week (Monday–Tuesday) (hazard ratio [HR]: 1.14, 95% confidence interval [CI]: 0.97–1.34; p =.109). Multivariable sensitivity analysis revealed that CABG surgery on Friday was associated with a 1.40‐fold higher hazard of 30‐day mortality (HR: 1.40; 95% CI: 1.09–1.80; p =.008) than CABG surgery on Monday. Conclusions: This South Korean population‐based cohort study revealed that relative to surgery early in the week (Monday–Tuesday), CABG surgery later in the week (Wednesday–Friday) was not associated with higher 30‐day mortality. However, using surgery on Monday as a reference, CABG surgery on Friday was associated with higher 30‐day mortality. Future studies must confirm these findings. [ABSTRACT FROM AUTHOR]

Purpose: Peripheral gangrene (PG) is a known complication requiring limb amputation among sepsis survivors; however, its incidence and associated risk factors remain controversial. We aimed to examine the incidence of limb amputation among sepsis survivors, and to investigate factors independently associated with limb amputation. Methods: In this population-based cohort study, data obtained from the South Korean national health insurance service database between 2015 and 2016 were analyzed. A sepsis survivor was defined as someone having survived > 90 days after initiation of treatment for sepsis. Results: Of 19,906 sepsis survivors, 163 (0.8%) had undergone surgical limb amputation. In a multivariable model, male sex (odds ratio [OR] 1.74, 95% confidence interval [CI] 1.26–2.40; P = 0.001), dopamine infusion (OR 1.78, 95% CI 1.22–2.60; P = 0.003), epinephrine infusion (OR 2.04, 95% CI 1.30–3.20; P = 0.002), continuous renal replacement therapy (OR 3.34, 95% CI 2.01–3.20; P < 0.001), diabetes mellitus (DM) without chronic complication (OR 1.73, 95% CI 1.19–2.51; P = 0.004), DM with chronic complication (OR 3.49, 95% CI 2.32–5.26; P < 0.001), and peripheral arterial disease (OR 6.79, 95% CO 3.70–12.46; P < 0.001) were associated with a higher incidence of limb amputation among sepsis survivors. Conclusions: In South Korea, 0.8% of sepsis survivors underwent limb amputation for the treatment of PG. Furthermore, the incidence of limb amputation was higher among the sepsis survivors having some underlying diseases (DM and peripheral arterial diseases) or receiving certain vasopressor treatments (epinephrine and dopamine). [ABSTRACT FROM AUTHOR]

Background: The effect of prior statin therapy on mortality in patients with acute respiratory distress syndrome (ARDS) remains controversial. This study aimed to investigate whether prior statin therapy was associated with lower 30‐day mortality compared to non‐statin use. Methods: This population‐based cohort study used nationwide data procured from the National Health Insurance service in South Korea, and included all the adult patients admitted to a hospital for ARDS treatment between January 1, 2013 and December 31, 2017. Results: In total, 14,600 patients with ARDS were included: 4,319 were statin users and 10,281 were non‐statin users. After propensity score matching, 6,046 patients with ARDS (3,023 patients in each group) were included in the analysis. The 30‐day mortality of statin users was 44.4% (1,331 of 3,023), while that of non‐statin users was 45.2% (1,331 of 3,023). On Cox regression analysis in the propensity score matched cohort, 30‐day mortality was not significantly associated with statin use compared to non‐statin use (hazard ratio: 0.95, 95% confidence interval: 0.88 to 1.02; P =.165). On Kaplan‐Meier estimation, the median survival time in statin users was 45 days (95% CI: 39 to 50), while that in non‐statin users was 42 days (95% CI: 37 to 47) after propensity score matching, and there was no statistical difference with the log‐rank test (P =.215). Conclusion: This population‐based cohort study in South Korea showed that prior statin therapy was not significantly associated with 30‐day mortality in patients with ARDS. Our findings should be confirmed in future prospective studies. [ABSTRACT FROM AUTHOR]

Background: We sought to investigate the risk of psychological diseases among coronavirus disease‐2019 (COVID‐19) survivors in South Korea. Methods: The National Health Insurance Service (NHIS) COVID‐19 cohort database, comprising COVID‐19 patients and a control population from January 1, 2020 to June 4, 2020, was used in this study. COVID‐19 patients were defined as individuals who were confirmed as COVID‐19 positive, regardless of disease severity, and COVID‐19 survivors were defined as individuals who recovered from COVID‐19. The control population was extracted using stratification methods according to the age, sex, and residence of COVID‐19 patients. Individuals previously diagnosed with any psychological disease were excluded from the analysis. The primary endpoint was a new diagnosis of psychological disease. Multivariable logistic modeling was used for statistical analyses. Results: A total of 99,742 individuals (5879 [5.9%] COVID‐19 survivors and 93,863 [94.1%] controls) were included in the final analysis. The incidence of newly diagnosed psychological disease, depression, psychosis, alcohol abuse, and drug abuse was 1438 (1.4%), 1268 (1.3%), 44 (0.0%), 173 (0.2%), and 2 (0.0%), respectively. In the multivariable model after adjusting for confounders, the COVID‐19 survivors had a 2.98‐fold higher probability of developing the psychological disease compared with the control group. Specifically, the odds of depression and psychosis in the COVID‐19 survivors were 3.34‐fold and 2.49‐fold higher than that in the control group, respectively. Conclusion: COVID‐19 survivors had a higher risk of experiencing psychological disease than the control population in South Korea. Particularly, COVID‐19 may increase the risk of developing depression and psychosis. [ABSTRACT FROM AUTHOR]

Background: The relationship between socioeconomic status and the risk of contracting coronavirus disease (COVID-19) remains controversial. We aimed to investigate whether socioeconomic status affected the risk of contracting COVID-19 in the South Korean population.Methods: The NHIS-COVID-19 database cohort was used in this population-based study. We collected the data of COVID-19 patients who were diagnosed between January 1, 2020 and June 4, 2020 and those of the control population. The income levels of all individuals as of February 2020 were extracted, and study participants were classified into four groups based on quartiles: Q1 (the lowest) to Q4 (the highest). Data were statistically analyzed using multivariable logistic regression modeling.Results: In total, 122,040 individuals-7669 and 114,371 individuals in the COVID-19 and control groups, respectively-were included in the final analysis. The multivariable logistic regression model showed that the Q1 group had a 1.19-fold higher risk of contracting COVID-19 than the Q4 group, whereas the Q2 and Q3 groups showed no significant differences. In the 20-39 years age group, compared with the Q4 group, the Q3 and Q2 groups showed 11 and 22% lower risks of contracting COVID-19, respectively. In the ≥60 years age group, compared with the Q4 group, the Q1, Q2, and Q3 groups showed a 1.39-, 1.29-, and 1.14-fold higher risks of COVID-19, respectively.Conclusions: Lower socioeconomic status was associated with a higher risk of contracting COVID-19 in South Korea. This association was more evident in the older population (age ≥ 60 years), whereas both lower and higher socioeconomic statuses were associated with higher risks of contracting COVID-19 in the young adult population (in the 20-39 year age group). Strategies for the prevention of COVID-19 should focus on individuals of lower socioeconomic status and on young adults of higher and lower socioeconomic status. [ABSTRACT FROM AUTHOR]

Background: The impact of underlying chronic respiratory diseases (CRDs) on the risk and mortality of patients with coronavirus disease 2019 (COVID-19) remains controversial. We aimed to investigate the effects of CRDs on the risk of COVID-19 and mortality among the population in South Korea.Methods: The NHIS-COVID-19 database in South Korea was used for data extraction for this population-based cohort study. Chronic obstructive pulmonary disease (COPD), asthma, interstitial lung disease (ILD), lung cancer, lung disease due to external agents, obstructive sleep apnea (OSA), and tuberculosis of the lungs (TB) were considered CRDs. The primary endpoint was a diagnosis of COVID-19 between January 1st and June 4th, 2020; the secondary endpoint was hospital mortality of patients with COVID-19. Multivariable logistic regression modeling was used for statistical analysis.Results: The final analysis included 122,040 individuals, 7669 (6.3%) were confirmed as COVID-19 until 4 June 2020, and 251 patients with COVID-19 (3.2%) passed away during hospitalization. Among total 122,040 individuals, 36,365 individuals were diagnosed with CRD between 2015 and 2019: COPD (4488, 3.6%), asthma (33,858, 27.2%), ILD (421, 0.3%), lung cancer (769, 0.6%), lung disease due to external agents (437, 0.4%), OSA (550, 0.4%), and TB (608, 0.5%). Among the CRDs, patients either with ILD or OSA had 1.63-fold (odds ratio [OR] 1.63, 95% confidence interval [CI] 1.17-2.26; P = 0.004) and 1.65-fold higher (OR 1.65, 95% CI 1.23-2.16; P < 0.001) incidence of COVID-19. In addition, among patients with COVID-19, the individuals with COPD and lung disease due to external agents had 1.56-fold (OR 1.56, 95% CI 1.06-2.2; P = 0.024) and 3.54-fold (OR 3.54, 95% CI 1.70-7.38; P < 0.001) higher risk of hospital mortality.Conclusions: Patients with OSA and ILD might have an increased risk of COVID-19. In addition, COPD and chronic lung disease due to external agents might be associated with a higher risk of mortality among patients with COVID-19. Our results suggest that prevention and management strategies should be carefully performed. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to determine trends in the prevalence of chronic opioid users among patients with chronic gout in South Korea from 2002 to 2015 and to investigate the factors associated with chronic opioid use among patients with chronic gout. Methods: We performed a population-based cohort study and extracted data from the National Health Insurance Service database in South Korea. We included all adult patients (age ≥ 18 years) with a diagnostic code of M1A* (chronic gout) according to the International Classification of Disease (10th revision). Results: The prevalence of chronic opioid users among patients with chronic gout has gradually increased from 4.0% in 2002 to 19.4% in 2015. After excluding the patients who had a history of cancer or other rheumatic diseases, a total of 18,042 patients with chronic gout were included in this cross-sectional cohort study in 2015, of which 993 (5.5%) were long-term opioid users. In a multivariable model, older age, female sex, Charlson Comorbidity Index > 2, long-term use of other analgesics, such as pregabalin, gabapentin, paracetamol, and glucocorticoids, and the use of other gout medication (colchicine) were independently associated with higher rates of long-term opioid use among patients with chronic gout. Conclusion: Chronic opioid users among patients with chronic gout increased from 2002 to 2015 in South Korea. Female sex, older age, comorbid status, and the use of other non-opioid analgesics were independently associated with higher rates of long-term opioid use among patients with chronic gout. Key Points • Chronic opioid users among patients with chronic gout have increased from 2002 to 2015 in South Korea. • Among patients with chronic gout, 5.5% were long-term opioid users. • Female sex, older age, comorbid status, and the use of other non-opioid analgesics were associated with higher rates of long-term opioid use. [ABSTRACT FROM AUTHOR]

Purpose: There have been no large-scale studies on whether metformin therapy might have a potential benefit for lowering mortality. Thus, this study aimed to investigate the association between prior metformin therapy and the development of sepsis as well as the association between prior metformin therapy and 30-day mortality in sepsis patients. Methods: We evaluated adult diabetes patients registered in the 2010 sample cohort database of the National Health Insurance Service in South Korea. Diabetes was identified according to the International Classification of Disease-10 diagnostic system (E10–E14). The cohorts were divided into the metformin user group (i.e., those who had been prescribed continuous oral metformin over a period of ≥ 90 days) and the control group (i.e., all other individuals). The primary endpoint was the development of sepsis between 2011 and 2015, and the secondary endpoint was 30-day mortality among diabetes patients diagnosed with sepsis. Results: In total, 77,337 patients (34,041 in the metformin user group and 43,296 in the control group) were included in the analysis, among whom 2512 patients (3.2%) were diagnosed with sepsis between 2011 and 2015. After propensity score adjustment, metformin use was not significantly associated with both the risk of sepsis (OR: 0.92, 95%CI 0.82–1.03; P = 0.143) and the risk of 30-day mortality after diagnosis of sepsis (OR: 0.94, 95%CI 0.75–1.17; P = 0.571). Conclusions: Prior metformin therapy was not significantly associated with the risk of sepsis and 30-day mortality after diagnosis of sepsis among diabetes patients. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to investigate the association of chronic opioid usage with 90-day mortality in critically ill patients after admission to the ICU.Methods: This retrospective cohort study analysed the medical records of adult patients admitted to ICUs in a tertiary academic hospital between January 2012 and December 2017. Patients taking opioids regularly for more than 4 weeks before ICU admission were defined as chronic opioid users, whereas the others were defined as opioid-naïve patients.Results: We selected 18 409 patients for this study, including 757 (4.1%) chronic opioid users. After propensity matching, 2990 patients (chronic opioid users, 757; opioid-naïve, patient: 2233) were included in the analysis. The odds of 90-day mortality were higher in chronic opioid users than in opioid-naïve patients using both the generalised estimating equation model for the propensity-matched cohort (odds ratio=1.90; 95% confidence interval, 1.57-2.31; P<0.001) and the multivariable logistic regression model for the entire cohort (odds ratio=2.20; 95% confidence interval, 1.81-2.66; P<0.001). Additionally, this association was significant in cancer patients and non-chronic kidney disease (CKD) patients and was not significant in non-cancer and CKD patients.Conclusions: Our results suggest that in a cohort of critically ill adult patients, chronic opioid use is associated with an increase in 90-day mortality. This association was more evident in cancer patients and non-CKD patients. [ABSTRACT FROM AUTHOR]

Abstract: Aims: To determine the need for care robots among nurses and to suggest how robotic care should be prioritized in integrated nursing care services. Background: Korea is expected to be a super‐aged society by 2030. To solve care issues with elderly inpatient caused by informal caregivers, the government introduced “integrated nursing care services”; these are comprehensive care systems staffed by professionally trained nurses. To assist them, a care robot development project has been launched. Design: The study applied a cross‐sectional survey. Methods: In 2016, we conducted a multicentre survey involving 302 Registered Nurses in five hospitals including three tertiary and two secondary hospitals in Korea. The questionnaire consisted of general characteristics of nurses and their views on and extents of agreement about issues associated with robotic care. Results: Trial centre nurses and those with ≥10 years of experience reported positively on the prospects for robotic care. The top‐three desired primary roles for care robots were “measuring/monitoring”, “mobility/activity” and “safety care”. “Reduction in workload”, especially in terms of “other nursing services” which were categorized as nonvalue‐added nursing activities, was the most valued feature. The nurses approved of the aid by care robots but were concerned about device malfunction and interruption of rapport with patients. Conclusion: Care robots are expected to be effective in integrated nursing care services, particularly in “measuring/monitoring”. Such robots should decrease nurses’ workload and minimize nonvalue‐added nursing activities efficiently. No matter how excellent care robots are, they must cooperate with and be controlled by nurses. [ABSTRACT FROM AUTHOR]

We aimed to investigate whether coronavirus disease (COVID-19) survivors were at a higher risk of dementia diagnosis compared to controls at 6 months follow-up. Data pertaining to the period between 1 January and 4 June 2020, were extracted from the National Health Insurance Service (NHIS)-COVID-19 database in South Korea. Data on adults (≥20 years old) with no history of dementia, obtained from the NHIS-COVID-19 database, were included in the study. The endpoint of this study was the development of dementia, which was evaluated from 1 January to 1 December 2020. A total of 306,577 adults were included in the analysis, comprising 7133 COVID-19 survivors and 299,444 individuals in the control group. Among the subjects, new-onset dementia diagnosed in 2020 was recorded in 1.2% (3546 of 306,577). In the covariate-adjusted multivariable Cox regression model, the incidence of dementia among COVID-19 survivors was 1.39-fold higher (hazard ratio: 1.39, 95% confidence interval: 1.05–1.85; p = 0.023) than that in the control group. At approximately 6 months of follow-up, COVID-19 survivors were at a higher risk of dementia compared to other populations in South Korea. [ABSTRACT FROM AUTHOR]

Aim: We aimed to investigate whether trained intensivist coverage affects survival outcomes following in-hospital cardiopulmonary resuscitation (ICPR) for in-hospital cardiac arrest (IHCA).Methods: All adult patients who received ICPR for IHCA between January 1, 2016 and December 31, 2019 in South Korea were included. Patients who received ICPR in hospitals with trained intensivist coverage for ICU staffing were defined as the intensivist group, whereas other patients were considered the non-intensivist group.Results: In total 68,286 adult patients (36,025 [52.8%] in the intensivist group and 32,261 [47.2%] in the non-intensivist group) were included in the analysis. After propensity score (PS) matching 40,988 patients (20,494 in each group) were included. In logistic regression after PS matching, the intensivist group showed a 17% (odds ratio: 1.17; 95% confidence interval [CI]: 1.12-1.22; P < 0.001) higher live discharge rate after ICPR than the non-intensivist group. In Cox regression after PS matching, the 6-month and the 1-year mortality rates in the intensivist group after ICPR were 11% (hazard ratio [HR]: 0.89; 95% CI: 0.87-0.91; P < 0.001) and 10% (HR: 0.90; 95% CI: 0.88-0.92; P < 0.001) lower than those in the non-intensivist group, respectively. In Kaplan-Meir estimation the median survival time after ICPR in the intensivist group was 12.0 days (95% CI: 11.6-12.4) while that in the non-intensivist group was 8.0 days (95% CI: 7.7-8.3).Conclusions: Trained intensivist coverage in the ICU was associated with improvements in both short and long-term survival outcomes after ICPR for IHCA. [ABSTRACT FROM AUTHOR]

Background: We aimed to examine the prevalence and associated factors of newly developed psychiatric morbidity among survivors of in-hospital cardiopulmonary resuscitation (ICPR). Additionally, we investigated whether pre-existing and newly developed psychiatric morbidities affect long-term mortality.Methods: We extracted data from the National Health Insurance Service database in South Korea. Adult ICPR survivors who underwent ICPR from January 1, 2010, to December 31, 2018, and who were alive for more than 1 year after ICPR were enrolled. Depression, anxiety, substance abuse, and post-traumatic stress disorder (PTSD) were evaluated as psychiatric morbidity.Results: A total of 22,611 survivors of ICPR from 615 hospitals in South Korea were included in the final analysis. Among them, 7825 (34.6%) had pre-existing psychiatric morbidity before ICPR, while 2524 (11.2%) had newly developed psychiatric morbidity after ICPR. In multivariable Cox regression analysis, compared to the no psychiatric morbidity group, the pre-existing psychiatric morbidity group (adjusted hazard ratio, 1.02; 95% confidence interval, 0.94, 1.11; P = 0.629) and the newly developed psychiatric morbidity group (adjusted hazard ratio, 1.02; 95% confidence interval, 0.90, 1.15; P = 0.798) were not associated with 1-year all-cause mortality among 1-year survivors of ICPR.Limitation: Retrospective cohort design.Conclusions: In South Korea, 11.2% of ICPR survivors had newly developed psychiatric morbidity such as depression, anxiety disorder, substance abuse, and PTSD within 1 year after ICPR. However, both pre-existing and newly developed psychiatric morbidities were not associated with 1-year all-cause mortality among 1-year survivors of ICPR. [ABSTRACT FROM AUTHOR]

We aimed to investigate whether statin therapy is associated with the incidence of coronavirus disease 2019 (COVID-19) among the South Korean population. In addition, we examined whether statin therapy affects hospital mortality among COVID-19 patients. The National Health Insurance Service (NHIS)-COVID-19 database in South Korea was used for data extraction for this population-based cohort study. A total of 122,040 adult individuals, with 22,633 (18.5%) in the statin therapy group and 101,697 (91.5%) in the control group, were included in the analysis. Among them, 7780 (6.4%) individuals were diagnosed with COVID-19 and hospital mortality occurred in 251 (3.2%) COVID-19 cases. After propensity score matching, logistic regression analysis showed that the odds of developing COVID-19 were 35% lower in the statin therapy group than in the control group (odds ratio: 0.65, 95% confidence interval: 0.60 to 0.71; p < 0.001). Regarding hospital mortality among COVID-19 patients, the multivariable model indicated that there were no differences between the statin therapy and control groups (odds ratio: 0.74, 95% confidence interval: 0.52 to 1.05; p = 0.094). Statin therapy may have potential benefits for the prevention of COVID-19 in South Korea. However, we found that statin therapy does not affect the hospital mortality of patients who are diagnosed with COVID-19. [ABSTRACT FROM AUTHOR]

We investigated the association between physician turnover and survival outcomes after in-hospital cardiopulmonary resuscitation (ICPR) in South Korea. This population-based cohort study used the South Korean national registration database as the data source. All adult patients admitted to the hospital and who underwent ICPR between 1 January 2010 and 31 December 2019, were included. Patients who underwent ICPR in March were included in the turnover group, while those who underwent ICPR in the other months were included in the non-turnover group. Propensity score (PS) matching was performed. Overall, 298,676 adult patients who underwent ICPR in 2,553 South Korean hospitals were included in the analysis. Among them, 26,342 (8.8%) and 272,334 (91.2%) were included in the turnover and non-turnover groups, respectively. In total, 7,009 (26.6%) and 6,903 (26.2%) of the 26,342 patients each in the turnover and non-turnover groups, respectively, were discharged alive after ICPR. Using logistic regression analysis in the PS-matched cohort, the two groups did not show any significant association in the live discharge rate after ICPR (odds ratio: 1.02, 95% confidence interval: 0.98, 1.06; P = 0.295). This non-significant association was also observed in patients who underwent ICPR in tertiary general hospitals that had cardiopulmonary resuscitation teams for ICPR (P = 0.136). Moreover, the median survival time in the turnover and non-turnover groups was 4.0 days (95% confidence interval: 3.8 days, 4.2 days; log-rank test, P = 0.796). Significant association between physician turnover and survival outcomes was not observed after ICPR in South Korea. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the potential association of exposure to metformin therapy with the risk of hip fracture in adult patients with type II diabetes. We included patients with diabetes who were registered in the 2010 sample cohort database of the National Health Insurance Service in South Korea. The patients who had been prescribed continuous oral metformin therapy for a 1-year period in 2010 were defined as the metformin group, while those who were not prescribed metformin during the same period were classified as the control group. The primary endpoint of this study was the development of hip fracture between January 2011 and December 2015. A total of 64,878 patients (31,300 patients in the metformin group and 32,439 patients in the control group) were included in this study. Among those, 1655 patients (2.6%) had experienced a hip fracture. After a propensity score matching, a total of 37,378 patients (18,689 patients in each group) were included in the analysis. Using a time-dependent Cox regression analysis on the propensity score-matched cohort, the exposure to metformin was not significantly associated with the development of hip fracture compared to the control group (hazard ratio: 1.00, 95% confidence interval: 0.86 to 1.16; P = 0.985). Similar results were observed using sensitivity analysis of a multivariable time-dependent Cox regression model of the entire cohort (hazard ratio: 0.78, 95% confidence interval: 0.36 to 1.69; P = 0.525). This population-based cohort study in South Korea showed that there was no significant association between the exposure to metformin therapy and hip fracture in patients with type II diabetes mellitus. • Hip fracture is among the most fatal types of injury, particularly in older people. • Diabetes mellitus is associated with a decrease in bone quality. • Prevention of hip fracture is an important issue in patients with diabetes. • Metformin is the most commonly prescribed for treating type 2 diabetes mellitus. • No significant association between exposure to metformin and hip fractures. [ABSTRACT FROM AUTHOR]

It has been reported that survivors of acute respiratory distress syndrome (ARDS) experience depression. However, the relationship between newly developed depression and mortality among survivors of ARDS has not been elucidated. Thus, the aim of this study was to investigate the prevalence and associated factors of depression among survivors of ARDS and determine whether newly developed depression is associated with long-term mortality among them. The data used for this study were extracted from the national health insurance database of South Korea. All adult patients who were admitted into intensive care units for ARDS between January 1, 2010, and December 31, 2018, and survived for ≥1 year after treatment were defined as ARDS survivors and included in this study. A total of 4,452 ARDS survivors were included in the final analysis. Of these, 581 (13.4%) were newly diagnosed with depression within 1 year after ARDS diagnosis. Multivariable logistic regression showed that underlying anxiety disorder (odds ratio [OR], 2.35; 95% confidence interval [CI], 1.93–2.86; P < 0.001), substance abuse (OR, 2.18; 95% CI, 1.48–3.20; P < 0.001), and post-traumatic stress disorder (OR, 15.52; 95% CI, 2.57–93.51; P = 0.003) were associated with a higher prevalence of post-ARDS depression among survivors. Multivariable Cox regression analysis showed that post-ARDS depression was associated with a 1.49-fold increased risk of 2-year all-cause mortality (hazard ratio, 1.49; 95% CI, 1.18–1.88; P = 0.001). Underlying psychiatric illness is a potential risk factor for the development of depression among ARDS survivors. Post-ARDS depression is associated with an increased risk of 2-year all-cause mortality. [ABSTRACT FROM AUTHOR]