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In the general population, abdominal aortic aneurysm (AAA) is synonymous with vascular disease and associated with increased mortality. Vascular disease is common in end-stage renal disease (ESRD) patients on dialysis, but there is limited information on AAA in this population. To address this issue, we queried the United States Renal Data System for risk factors associated with a diagnosis of AAA as well as the impact of AAA on ESRD patient survival. Incident dialysis patients from 2005 to 2014 with AAA and other clinical comorbidities were identified using ICD-9 and ICD-10 codes. Time to death was defined using the time from the start of dialysis to the date of death or to December 31, 2015. Cox proportional hazards (CPH) modeling was used to determine the adjusted hazard ratio (aHR) and 95% confidence intervals (CI) for death. From a total cohort of 820,826, we identified 21,631 subjects with a diagnosis of AAA. When compared to patients without AAA, AAA patients were older and more likely to be of white race and male gender, have a higher mean Charlson comorbidity index (CCI), have hypertension as the ESRD etiology, and use tobacco. Although a bivariate CPH model showed that AAA patients had an increased mortality risk compared to patients without the diagnosis, in the final CPH model, AAA patients had a decreased risk of mortality (aHR = 0.83, 95% CI 0.81-0.84) due to confounding with age. These results suggest that AAA is not associated with increased risk of death in ESRD patients after controlling for various demographic and clinical risk factors., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Previous research in the general population suggests that the inflammatory skin disease psoriasis is associated with an increased risk of vascular events, such as stroke. Thus, psoriasis may also represent a risk factor for stroke in end-stage renal disease (ESRD) patients., Methods: We queried the United States Renal Data System for incident dialysis patients between 2004 and 2015. Psoriasis was defined as having at least two international classification of disease (ICD)-9 or ICD-10 diagnosis codes. ICD codes were also used to query the outcome of interest, stroke, as well as other clinical risk factors. Logistic regression was used to examine the association of psoriasis and other risk factors with stroke., Results: Of 966,399 ESRD patients, we identified 89,700 (9.3%) subjects with stroke and 6,286 (0.7%) with psoriasis. Of these psoriasis patients, 796 (0.9%) also had a stroke. Psoriasis was associated with an increased risk of stroke in an unadjusted model [odds ratio (OR)=1.16; 95% confidence interval (CI)=1.08-1.25]. However, after controlling for demographic and clinical risk factors, the final adjusted model showed that psoriasis was not associated with stroke (OR=0.96, CI=0.88-1.04). Congestive heart failure [adjusted OR of 1.79 (CI=1.75-1.83)] was a confounder of the association of psoriasis with stroke., Conclusions: Contrary to prior research in the general population, psoriasis in ESRD patients was not associated with the risk of stroke after controlling for various demographic and clinical parameters. Our finding emphasizes the importance of controlling for a variety of factors in population studies examining associations of diseases and risk factors., Competing Interests: Declaration of Competing Interest The authors declare there is no conflict of interest., (Published by Elsevier Inc.)

Sleep apnea (SA) is highly prevalent in the end-stage renal disease (ESRD) population. However, the impact of SA on mortality in ESRD is unclear. This study investigates the relationship between SA and mortality in ESRD. The United States Renal Data System was queried in a retrospective cohort study to identify ESRD patients aged 18-100 years who initiated hemodialysis between 2005 and 2013. Diagnoses of SA and comorbidities were determined from International Classification of Disease-9 codes and demographic variables from Centers for Medicare and Medicaid Services Form-2728. Cox proportional hazards models were used to examine the association of SA with mortality controlling for multiple variables. Of 858,131 subjects meeting inclusion criteria, 587 were found to have central SA (CSA) and 22,724 obstructive SA (OSA). The SA cohort was younger and more likely to be male and Caucasian compared to the non-SA cohort, with more diagnoses of tobacco and alcohol use, hypertension, heart failure, and diabetes. Both CSA (adjusted hazard ratio (aHR) = 1.42, 95% confidence interval (CI): 1.29-1.56) and OSA (aHR = 1.35, 95% CI: 1.32-1.37) were associated with increased mortality. Other variables associated with increased mortality included age, dialysis initiation with a catheter or graft, alcohol use, hypertension, and cardiovascular disease. Factors associated with decreased mortality included female sex, black race, Hispanic ethnicity, diagnosis of heart failure or diabetes, and an ESRD etiology of glomerulonephritis or polycystic kidney disease. Since a diagnosis of either OSA or CSA increases mortality risk, early identification of SA and therapy in this ESRD population may improve survival.

Background: Previous research in non-dialysis patients suggests that the inflammatory skin disease psoriasis is associated with an increased risk of severe vascular events like myocardial infarction (MI). Thus, we determined whether psoriasis represents a significant risk factor for MI in end-stage renal disease (ESRD) patients., Methods: We queried the United States Renal Data System for ESRD patients starting dialysis between 2004 and 2015. ICD-9 and ICD-10 codes were used to identify those with at least two diagnoses of psoriasis, a diagnosis of MI, and other clinical risk factors. Logistic regression was used to examine the association of psoriasis and various risk factors with MI., Results: Of a cohort of 1,062,693, we identified 6823 (0.6%) subjects with psoriasis and 181,960 (17.1%) with MI. Of the 6823 patients with psoriasis, 1671 (24%) developed an MI. Psoriasis was associated with an increased risk of MI in an unadjusted model [odds ratio (OR) = 1.34; confidence interval (CI) = 1.26-1.42]. However, after controlling for demographics, dialysis modality, access type, and various conditions related to the Charlson Comorbidity Index, psoriasis was not associated with MI (OR = 0.95, CI = 0.89-1.01). Confounders of the association of psoriasis with MI included congestive heart failure (OR = 5.26, CI = 5.17-5.36), pulmonary disease (OR = 1.25, CI = 1.23-1.26), and diabetes with complications (OR = 1.82, CI = 1.79-1.85)., Conclusions: Contrary to prior research in the general population, in the ESRD population psoriasis was not associated with an increased risk of MI after controlling for various demographic and clinical parameters. These data emphasize the importance of an integrated approach since comorbidities may influence the choice of therapy for psoriasis and outcomes., Competing Interests: Declaration of Competing Interest None declared., (Published by Elsevier Inc.)

Background: In the general population, cutaneous squamous cell carcinoma (cSCC) is associated with increased all-cause mortality. Transplant patients have been shown to have an increased risk of developing cSCC, and their cSCC is associated with an increased risk for mortality. In end-stage renal disease (ESRD) patients, there is extensive mortality and immune dysfunction. Because of this immune system dysfunction, we examined whether cSCC is associated with increased risk of all-cause mortality among ESRD patients, as well as the risk factors for cSCC., Methods: We analyzed ESRD patients in the United States Renal Data System from 2004-2014, excluding organ transplant recipients. We assessed mortality using a Cox Proportional Hazards (CPH) model to control for various demographic and clinical parameters, identified using international classification of diseases (ICD)-9 codes., Results: Of the 1,035,193 patients included, 624 (0.1%) were diagnosed with cSCC. The median survival time for those with cSCC was 3.91 years [95% confidence interval (CI) = 3.67-4.15], versus 2.92 years [95%CI = 2.92-2.93] for patients without cSCC. ESRD patients with cSCC were at lower risk of death [adjusted hazard ratio = 0.75; 95%CI = 0.69-0.82] compared to those without. Decreased risk of death was also associated with parameters such as black race, Hispanic ethnicity, tobacco dependence and actinic keratosis. Increased mortality risk was associated with increasing age, male sex, hemodialysis (versus peritoneal dialysis) and alcohol dependence., Conclusions: Contrary to expectations, ESRD patients with a cSCC diagnosis showed reduced all-cause mortality risk relative to those without. The reason for this discrepancy remains unclear, suggesting the need for further study., Competing Interests: Declaration of Competing Interest None declared. There are no conflicts of interest related to this project. Results in this paper have not been published previously in whole or part, except in abstract format., (Published by Elsevier Inc.)

Background: Psoriasis is a common chronic inflammatory skin disease associated with an increased risk for acute infections. Because chronic kidney disease is a risk factor for pneumonia, end-stage renal disease (ESRD) patients with psoriasis may have an increased risk for acquiring pneumonia., Material and Methods: A retrospective cohort analysis was performed using the United States Renal Data System, a medical claims database of all ESRD patients undergoing dialysis in the US. Logistic regression analysis was used to investigate the association of psoriasis with pneumonia in ESRD patients., Results: A total of 6841 (0.7%) ESRD patients were diagnosed with psoriasis; 385,976 (36%) ESRD patients had pneumonia. Although simple models showed that psoriasis was associated with an increased risk of pneumonia in the ESRD population (odds ratio (OR) = 1.14), the final multivariable model found that psoriasis was protective for pneumonia (OR = 0.56) when controlling for age, race, sex, ethnicity, dialysis modality, Charlson Comorbidity Index (CCI), multiple sclerosis, tobacco use and alcohol use. This is due to both the CCI and tobacco use being strong confounders of the association of psoriasis and pneumonia. Black, other race and Hispanic ethnicity were also protective for pneumonia, while increasing age and CCI, female sex, hemodialysis, multiple sclerosis and tobacco and alcohol use were associated with increased risk., Conclusions: When controlling for multiple factors, psoriasis does not increase the risk for pneumonia in ESRD patients. In this cohort, other factors, such as the CCI and tobacco use, were more strongly associated with increased risk for pneumonia than psoriasis., Competing Interests: Conflict of Interest Statement None declared., (Published by Elsevier Inc.)

Renal transplant patients are immunosuppressed and are at increased risk of opportunistic infections, including Nocardia infection. In renal transplant patients, information on the incidence and risk factors associated with nocardiosis is limited. To address the incidence and risk factors associated with nocardiosis in a large renal transplant population, we used the US Renal Data System (USRDS). Sequelae of allograft failure or rejection after infection were also examined. Demographics, clinical risk factors, Nocardia diagnosis, and allograft failure following Nocardia infection were queried in USRDS renal transplant patients using International Classification of Diseases, Ninth Revision (ICD-9) codes in billing claims and Centers for Medicare and Medicaid Services Form 2728. Generalized linear models were used to determine the risk factors associated with nocardiosis, and Cox proportional hazards models were used to examine the association of risk factors with graft failure among patients with Nocardia infection. Of 203,233 renal transplant recipients identified from 2001 to 2011, 657 (0.32%) were diagnosed with Nocardia infection. Pneumonia was the most frequent presentation (15.2%), followed by brain abscess (8.4%). Numerous factors associated with increased Nocardia infection included age >65 years (OR=2.10, 95% CI 1.71 to 2.59), history of transplant failure (OR=1.28, CI 1.02 to 1.60) or history of rejection (OR=4.83, CI 4.08 to 5.72), receipt of a deceased donor transplant (OR=1.23, CI 1.03 to 1.46), and treatment with basiliximab (OR=1.25, CI 1.00 to 1.55), cyclosporine (OR=1.30, CI 1.03 to 1.65), tacrolimus (OR=2.45, CI 2.00 to 3.00), or thymoglobulin (OR=1.89, CI 1.59 to 2.25). In patients with nocardiosis administration of antithymocyte globulin (HR=2.76), chronic obstructive pulmonary disease (HR=2.47), and presentation of Nocardia infection with brain abscess (HR=1.85) were associated with an increased risk of graft failure. This study provides new information to enhance early recognition and targeted treatment of nocardiosis in renal transplant patients., Competing Interests: Competing interests: None declared., (© American Federation for Medical Research 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Spinal epidural abscess (SEA) is an uncommon and highly morbid infection of the epidural space. End-stage renal disease (ESRD) patients are known to be at increased risk of developing SEA; however, there are no studies that have described the risk factors and outcomes of SEA in ESRD patients utilizing the United States Renal Data System (USRDS)., Methods: To determine risk factors, morbidity, and mortality associated with SEA in ESRD patients, a retrospective case-control study was conducted using the USRDS. ESRD patients diagnosed with SEA between 2005 and 2010 were identified, and logistic regression was performed to examine correlates of SEA, as well as risk factors associated with mortality in SEA-ESRD patients., Results: The prevalence of SEA amongst ESRD patients was 0.39% (n = 1,697). Patients with SEA were more likely to be male [adjusted Odds Ratio (OR) = 1.22], black (OR = 1.19), diabetic (OR = 1.26), with catheter access (OR = 1.29), and less likely to be ≥65 years old (OR = 0.64). Osteomyelitis, bacteremia/septicemia, MRSA, and endocarditis were all significantly associated with increased risk of SEA (OR = 1.54-5.14). Age ≥65 years (HR = 1.45), urinary tract infections (HR = 1.26), decubitus ulcers (HR=1.37), and post-SEA paraplegia (HR = 1.25) were significantly associated with mortality among those with SEA., Conclusions: As described in previous literature, risk factors for SEA included infections, diabetes, and indwelling catheters. Additionally, clinicians should be aware of the risk factors for mortality in SEA-ESRD patients. As the largest study of SEA to date, our report identifies important risk factors for SEA in ESRD patients, and novel data regarding their mortality-associated risk factors., (Published by Elsevier Inc.)