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When faced with missing data in a statistical survey or administrative sources, imputation is frequently used in order to fill the gaps and reduce the major part of bias that can affect aggregated estimates as a consequence of these gaps. This paper presents research on the efficiency of model–based imputation in business statistics, where the explanatory variable is a complex measure constructed by taxonomic methods. The proposed approach involves selecting explanatory variables that fit best in terms of variation and correlation from a set of possible explanatory variables for imputed information, and then replacing them with a single complex measure (meta–feature) exploiting their whole informational potential. This meta–feature is constructed as a function of a median distance of given objects from the benchmark of development. A simulation study and empirical study were used to verify the efficiency of the proposed approach. The paper also presents five types of similar techniques: ratio imputation, regression imputation, regression imputation with iteration, predictive mean matching and the propensity score method. The second study presented in the paper involved a simulation of missing data using IT business data from the California State University in Los Angeles, USA. The results show that models with a strong dependence on functional form assumptions can be improved by using a complex measure to summarize the predictor variables rather than the variables themselves (raw or normalized).

PurposeThe aim of this study is to evaluate five job qualification programs for young apprentices, in Goiás, a Brazilian State. We expect to contribute to the improvement and strengthening of the job training programs in developing countries.Design/methodology/approachWe applied propensity score matching and extensions such as the generalized propensity score method (dose–response effect).FindingsWe found evidence of the heterogenous effects of the five job qualification programs on employability. We found that the duration of the programs influences employability in up to two years after the program.Research limitations/implicationsThis research is based on secondary data provided by the responsible institutions. The evidence is obtained through a nonexperimental method.Practical implicationsThe research has implications for public or private institutions dedicated to the professional qualification of young apprentices.Social implicationsThe findings of the study provide some ways of comparing training programs, for young workers, that can be applied in different types of institutions.Originality/valueThis study provides new insight about the professional qualification of young apprentices, by comparing fives programs in Midwest Brazil.

OBJECTIVE: This study aimed to examine the relationship between electronic cigarette use and subsequent combustible cigarette use, controlling for confounding by using a propensity score method approach. METHODS: Data from the first three annual waves of the Population Assessment of Tobacco and Health study were analyzed (n = 6309). Participants were tobacco naïve at Wave 1, had used e-cigarettes exclusively (n = 414), used combustible cigarettes exclusively (n = 46), or not used any tobacco products (n = 5849) at Wave 2. We conducted entropy balancing propensity score analysis to examine the association between exclusive e-cigarette or cigarette initiation and subsequent cigarette use at Wave 3, adjusting for nonresponse bias, sampling bias, and confounding. RESULTS: Among tobacco naïve youth, exclusive e-cigarette use was associated with greater risk for subsequent combustible cigarette smoking initiation (OR = 3.42, 95% CI = (1.99, 5.93)) and past 30-day combustible cigarette use (OR = 2.88, 95% CI = (1.22, 6.86)) in the following year. However, the latter risk was comparatively lower than the risk if youth started with a combustible cigarette (OR = 25.79, 95% CI = (9.68, 68.72)). Results of sensitivity analyses indicated that estimated effects were robust to unmeasured confounding. CONCLUSIONS: Use of e-cigarettes in tobacco-naïve youth is associated with increased risk of subsequent past 30-day combustible cigarette use but the risk is an order of magnitude higher if they start with a combustible cigarette.

Focus of Presentation Cohort study recruitment can be complex, often requiring extensive pre-screening to recruit sufficient numbers of exposed and unexposed participants. We discuss a prospective study of the impact of racism on adult health in New Zealand (NZ), with emphasis on propensity-score based sampling and recruitment methods accessing participants from a national survey (NZ Health Survey 2017/18, n = 12,530 eligible adults). Discussion will cover sampling design, response rate, and confounder balance in the final sample. Key empirical results will be summarised. Findings The NZHS provided a sampling frame with complete baseline exposure and covariate data, giving n = 2,099 exposed individuals (reported racial discrimination on NZHS). A propensity-score model (stratified by ethnicity) allowed invitation of unexposed individuals balanced on key sociodemographic confounders. Recruitment used postal invitations with telephone follow-up: individuals could respond by paper survey, online questionnaire or telephone interview. Response rate was 54%, with comparable rates in exposed/unexposed individuals, with key sociodemographic factors well-balanced by exposure status. Conclusions/Implications Racism is an important determinant of health inequity, with limited prospective research in New Zealand. Our approach enabled appropriate recruitment from a sampling frame with baseline exposure status (NZHS), including allowance for exposure variability by ethnicity. Propensity-score matching on baseline covariates allowed for balance on key confounders at invitation, with balance maintained in the final sample. Key messages Secondary sampling from large national surveys can provide efficient recruitment for prospective studies. We achieved a highly satisfactory response rate, and propensity-score based sampling substantially balanced confounders between exposed and unexposed groups, enhancing study validity.

This study introduces a novel differential item functioning (DIF) method based on propensity score matching that tackles two challenges in analyzing performance assessment data, that is, continuous task scores and lack of a reliable internal variable as a proxy for ability or aptitude. The proposed DIF method consists of two main stages. First, propensity score matching is used to eliminate preexisting group differences before the test, ideally creating equivalent groups as in a randomized experimental study. Then, linear mixed effects models are adopted to perform DIF analysis based on the matched data set. We demonstrate this propensity DIF method using a high-stakes functional English language proficiency test. DIF due to education was investigated in the writing component, which consists of two continuously scored performance-based tasks. Although the proposed method is demonstrated in the context of language testing, it can be applied to other types of performance assessments.

Purpose The number of patients on antiplatelet therapy (APT) who need surgery is increasing; however, it is unclear whether APT should be continued for abdominal surgery, particularly laparoscopic colorectal surgery. We investigated the safety of continuing APT for patients undergoing laparoscopic colorectal surgery. Methods We collected retrospective data from 529 patients who underwent laparoscopic colorectal surgery at Hiroshima University between January, 2013 and December, 2018. We analyzed information related to APT. Thirty-six pairs were matched by the propensity score method between patients on APT (APT+) and those not on APT (APT−). We compared the surgical outcomes of both groups. Results Among 463 patients eligible for the study, 48 were on APT for cerebrovascular or cardiovascular disease, and 36 continued to take aspirin. In the case-matched comparison, the amount of intraoperative blood loss in the APT+ group was not significantly higher than that in the APT− group, and the incidences of bleeding complications, thromboembolic complications, and other complications were not significantly different between the groups. Conclusion In a case-matched comparison, continuation of aspirin during laparoscopic colorectal surgery did not increase perioperative complications. In laparoscopic colorectal surgery, continuation of aspirin is an acceptable strategy for patients with thromboembolic risk caused by interruption of APT.

Funding Acknowledgements Type of funding sources: None. Background Among patients undergoing transvenous lead extraction (TLE), differences in complication rate and 1-year mortality has been explored in patients with cardiac resynchronisation therapy (CRT) devices. Longer term outcomes and the influence of timing of reimplantation of device, with respect to rehospitalisation and longer-term mortality is poorly understood. Purpose The purpose of this study was to evaluate whether early reimplantation following TLE in patients with CRT devices influenced survival and rehospitalisation. Methods Clinical data from consecutive patients undergoing TLE in the reference centre between the years 2000 to 2019 were prospectively collected. Patients surviving to discharge who were re-implanted with the same device were included. The cohort was split depending on whether or not they had a CRT device at time of explant. The association between TLE in CRT patients and all-cause mortality and re-hospitalisation was assessed by Kaplan Meier estimates in a 1:1 propensity-score matched cohort, with a calliper of 0.10. Early reimplantation was defined as reimplantation within 7 days of TLE, and late reimplantation as reimplantation after greater than 7 days of TLE. Results Of 1005 patients included in the analysis, 285 (25%) had a CRT device. After matching, 192 CRT patients were compared with 192 non-CRT patients. Propensity scores were calculated using 39 baseline characteristics, including age, gender, co-morbidities, TLE indication, left ventricular ejection fraction, baseline creatinine and technical extraction data. Mean follow up was 53.5 ± 38.3 months, mean age at explant was 67.7 ± 12.1 years, 83.3% were male and 54.4% had an infective indication for TLE. In the matched cohort, there was no significant difference between the CRT and non-CRT group with respect to long-term mortality (hazard ratio [HR] = 1.01, 95% confidence interval [CI] [0.74-1.39], p = 0.093) or rehospitalisation (HR = 1.2 [0.87-1.66], p = 0.265). A similar proportion of patients were reimplanted within 7 days in the CRT and non-CRT groups (59.4% vs 61.5%, p = 0.754). In the matched non-CRT group, late reimplantation was associated with similar mortality to early reimplantation (HR = 1.33 [0.86-2.05], p = 0.208) and rehospitalisation (HR = 0.88 [0.53-1.45], p = 0.603). In the matched CRT group, late reimplantation was associated with higher mortality (HR = 1.64 [1.04-2.57], p = 0.032) and rehospitalisation (HR = 1.57 [1.00-2.46], p = 0.049] (see figure). Conclusion In this closely matched population, TLE in CRT patients resulted in similar long-term outcomes compared with non-CRT patients. Early reimplantation post CRT explant was associated with reduced long-term mortality and rehospitalisation. This suggests a longer duration without biventricular pacing post TLE may induce negative reverse-remodelling and should be avoided in a CRT population. Abstract Figure. Kaplan-Meier survival curves

Funding Acknowledgements Type of funding sources: None. BACKGROUND Upgrade to resynchronization therapy (CRT) is common practice in Europe. However, guideline recommendations are discordant and randomized trials are lacking. Previous studies have shown worse outcomes in upgraded patients. AIM To compare clinical outcomes in a cohort of patients receiving de novo or upgrade to CRT. METHODS Single-center retrospective study of consecutive patients submitted to CRT implantation (2007-2018). Major adverse cardiac events (MACE) included heart failure hospitalization or all-cause mortality. Clinical response was defined as NYHA class improvement without MACE in the 1st year of follow-up (FU). Left ventricle end-systolic volume reduction of >15% designated echocardiographic (echo) response. Survival analysis with Kaplan-Meier method and Log-rank test was performed. Propensity-score matching (PSM) analysis was performed to adjust for possible confounder variables. RESULTS 295 CRT patients (70.5% male, mean age 67 ± 11 years, 72.5% non-ischemic cardiomyopathy, 54.6% implanted with CRT-D) were included. Fifty-six patients (19%) underwent an upgrade: 43 (78.2%) from a pacemaker and 12 (21.8%) from a defibrillator device. Indications for upgrade were mainly pacemaker dependency or pacing-induced LV dysfunction (76.6%) and de novo left bundle branch block (23.4%). Upgraded patients were older (70 vs 66 years, p=.034), with larger baseline QRS (185 ± 25 vs 163 ± 30 ms, p PSM analysis identified 106 matched pairs (56 upgrade/50 de novo patients), without baseline statistical differences. All-cause mortality (Log-rank test, p=.555) and MACE (Log-rank test, p=.574) were comparable between groups. CONCLUSION In this cohort, upgrade to CRT was comparable to de novo implantation in terms of clinical and echo response. Moreover, upgrade to CRT was not associated with higher complication rates. All-cause mortality and MACE were similar between groups.

To explore trends of ovarian conservation (OCN) over time in young women with early stage leiomyosarcoma (LMS) and examine the association between OCN and survival.Patients under the age of 50 who were diagnosed with stage I LMS who underwent hysterectomy with and without oophorectomy between 2010 and 2016 were identified in the National Cancer Database (NCDB). Performance of oophorectomy vs. OCN was determined using surgery codes. Trends of OCN were reported. Multivariable regression models were fit to estimate predictors of OCN. An inverse probability of treatment weighted propensity score method was used to examine the association between all-cause mortality and OCN.Overall, 225 patients (28%) underwent OCN. Rates of OCN decreased from 41.2% (2010) to 14.3% (2016); this finding was consistent across age groups:35, 35-39, 40-44, and 45-49 years. Race, insurance, and stage did not affect performance of OCN. Women with poorly differentiated tumors were less likely to undergo OCN compared to well-differentiated tumors (aRR 0.59; 95% CI 0.40-0.86). After propensity score weighting, there was no association between OCN and mortality (HR 1.19, 95% CI 0.80-1.77). Five-year survival for the OCN group was 67.1% (95% CI 59.8-75.2%) compared to 72.2% for the oophorectomy group (95% CI 67.2-77.5%).OCN for early stage LMS in premenopausal women has decreased over time. There was no association between OCN and mortality among women with stage I LMS. OCN should be considered in premenopausal women with stage I LMS given the health benefits.

Background The aim of this study was to evaluate feasibility of integrated table motion (ITM), comparing perioperative outcomes of patients with diagnosed endometrial endometrioid cancer who underwent total robotic hysterectomies (TRHs) and case-related staging procedures with and without ITM. Methods Five patients underwent surgery with da Vinci Xi system and ITM technology. ITM feasibility, efficacy and safety was compared with a second group of 56 patients, reduced to 10 with propensity score method, who underwent same procedures with da Vinci Xi System without ITM system. Results We report safety of robotic surgery with new ITM even in a preliminary experience of oncologic procedures. No significance in any analysed data between groups TRH with ITM and TRH without ITM are described. Conclusion This preliminary study demonstrated the feasibility of ITM in performing da Vinci Xi TRH even in the first cases of surgery for malignancy such as early stage endometrial endometrioid cancer.

BACKGROUND The cost profiles of stent-assisted coiling (SAC) vs Pipeline embolization device (PED) in small unruptured anterior circulation aneurysms have not been studied. OBJECTIVE To compare the 2 modalities cost profiles in a propensity-matched cohort controlling for potential technical complexity confounders including size and location. METHODS Patients treated with either SAC or PED at our institution were identified. Following propensity-score algorithm, 46 patients, 23 in each group were matched. The procedural and follow-up costs in each group were analyzed and compared. RESULTS Median maximal aneurysm size in the SAC and PED cohort were 5.3 vs 5.1 mm, respectively. Costs of access guide materials were significantly higher in the SAC group (P

Background Propensity scores are widely used to deal with confounding bias in medical research. An incorrectly specified propensity score model may lead to residual confounding bias; therefore it is essential to use diagnostics to assess propensity scores in a propensity score analysis. The current use of propensity score diagnostics in the medical literature is unknown. The objectives of this study are to (1) assess the use of propensity score diagnostics in medical studies published in high-ranking journals, and (2) assess whether the use of propensity score diagnostics differs between studies (a) in different research areas and (b) using different propensity score methods. Methods A PubMed search identified studies published in high-impact journals between Jan 1st 2014 and Dec 31st 2016 using propensity scores to answer an applied medical question. From each study we extracted information regarding how propensity scores were assessed and which propensity score method was used. Research area was defined using the journal categories from the Journal Citations Report. Results A total of 894 papers were included in the review. Of these, 187 (20.9%) failed to report whether the propensity score had been assessed. Commonly reported diagnostics were p-values from hypothesis tests (36.6%) and the standardised mean difference (34.6%). Statistical tests provided marginally stronger evidence for a difference in diagnostic use between studies in different research areas (p = 0.033) than studies using different propensity score methods (p = 0.061). Conclusions The use of diagnostics in the propensity score medical literature is far from optimal, with different diagnostics preferred in different areas of medicine. The propensity score literature may improve with focused efforts to change practice in areas where suboptimal practice is most common.

Background Upgrade to resynchronization therapy (CRT) from conventional pacemaker (P) or defibrillator (D) is common practice in Europe. However, guidelines (GL) are discordant: Pacing GL give a class I recommendation, while Heart Failure (HF) GL provide a class IIb indication. Previous studies suggested worse outcomes in upgraded patients (pts). Aim To compare response rate and clinical outcomes in a cohort of pts receiving de novo or upgrade to CRT. Methods Single-center retrospective study of consecutive pts submitted to CRT implantation (2007–2017). Major adverse cardiac events (MACE) included HF hospitalization (HHF) or all-cause mortality. Clinical response was defined as New York Heart Association class improvement without MACE in the first year of follow-up (FU). Left ventricle end-systolic volume reduction of >15% denoted echocardiographic (echo) response. Survival analysis with Kaplan-Meier method and Log-rank test was performed. Propensity-score matching (PSM) analysis was made to adjust for possible confounder variables. Results 230 CRT recipients (70.9% male, mean age 67±11 years, 71.5% non-ischemic cardiomyopathy, 39.6% CRT-P) were included, of whom 46 (20%) underwent an upgrade. Upgraded pts were older (69.8 vs 65.9 years, p=0.015), with higher rates of permanent atrial fibrillation (37.0% vs 12.7%, p=0.001), moderate to severe valve disease (45.7% vs 22.3%, p=0.002), chronic kidney disease (37.0% vs 17.2%, p=0.005) and treatment with mineralocorticoid receptor antagonists (79.1% vs 52.0%, p=0.002). They were more likely to receive CRT-P (65.2% vs 33.2%, p During a median FU of 3±4 years, all-cause mortality was similar among groups (Log Rank test, p=0.522, unadjusted hazard ratio [HR] 1.25, confidence interval [CI] 95% 0.62–2.49, p=0.534). There was a statistical tendency for higher MACE rate in the upgrade group (Log Rank test, p=0.064, HR 1.66, CI 95% 0.95–2,91, p=0.076). No differences were found in lead dislodgement (10.9% vs 7.1%, p=0.368) or endocarditis (2.2% vs 4.3%, p=0.692) rates. PSM analysis identified 88 matched pairs (46 upgrade/42 de novo pts). In this cohort, all-cause mortality (Log Rank test, p=0.77, HR 0.89, CI 95% 0.39–2.03, p=0.78) and MACE (Log Rank test, p=0.36, HR 1.38, CI 95% 0.68–2.81, p=0.37) were comparable between groups [graph no. 1]. Conclusion Upgrade to CRT was similar to de novo implantation in terms of complications and clinical and echo response, in this cohort. The risk for MACE and mortality was also comparable. Graph 1 Funding Acknowledgement Type of funding source: None

Background Atrial Fibrillation (AF) is common and is caused and predisposed to by a complex pathophysiology. Aging is among the most important risk factors for AF. Yet, some individuals develop AF in early years, whereas elderly individuals may remain free of AF. Aside from measurable concomitant risks, we hypothesized that a pathophysiologically relevant biological age exists, which outweighs a patient's calendar age. Telomere length is a measurable marker of age, which might reflect biological age. AF and telomere length have previously been associated, but results remained controversial. Here, we tested the relation between AF and telomere length in a well-characterized and so far largest cohort. Methods Since 2005, we enrolled 2475 patients with AF from the prospective AFLMU cohort, preferentially if they developed AF before age 65 years, and 3077 control individuals free of AF from the community-based KORA Study between 2006–08. All participants received a detailed clinical characterization, an electrocardiogram, and a blood draw for biomarker analyses. In all participants, we determined telomere length using a qPCR-based method. In a 384 well format, we employed a multiplex TaqMan assay to determine both telomere length and the single copy gene 36B4. Telomere length was expressed by the delta-CT method and was reformatted to have lower CT values indicate shorter telomere length. We compared telomere length between cases and controls using multi-variably corrected logistic regression models. Results Our cohort's mean age was 58 years in AFLMU and 56 years in KORA F4. Men were enrolled more commonly, with 72.3% in AFLMU and 51.7% in KORA F4. For consistency with available information, we confirmed that telomere length is continuously decreasing with age and that men have shorter telomere length compared to women. As a main result we found that AF patients have significantly shorter telomere length compared to controls (controls: telomere length 13,10 [12.60, 13.63] versus AF: 9.81 [5.98, 13.1], p Conclusion AF is significantly associated with telomere length in one of the largest cohorts to date. Assessment of telomere length may adjudicate patients with AF due to premature biological aging. The underlying reasons for such premature aging remain to be identified. Funding Acknowledgement Type of funding source: Public grant(s) – EU funding. Main funding source(s): European Commission - Horizon 2020

Background The Systolic Blood Pressure Intervention Trial (SPRINT) evaluated whether a blood pressure (BP) goal of less than 120mmHg versus less than 140mmHg would reduce cardiovascular outcomes in subjects with at least one cardiovascular risk factor and without heart failure. Participating investigators were encouraged to use any antihypertensive medication class with a strong evidence base. The SPRINT trial was halted early due to a lower rate of the composite primary outcome in the 120mmHg group, which was mainly driven by a reduction in heart failure (HF). Objective As there is a concern that beta-blocker use may be associated with an excess risk for incident HF in subjects with a normal left ventricular systolic function, we evaluated the association between beta-blocker use and HF. Beta-blockers were compared with other major classes of antihypertensive medications. We also studied the association of antihypertensive class with loop-diuretic initiation. Methods and results In the 9,012 subjects, without HF at baseline, the association of beta-blocker exposure and incident HF was examined using time-variant competing risk analysis. Beta-blocker exposure was associated with an increased HF risk (HR 1.18; CI 1.07–1.30; p Conclusions Beta-blocker exposure was associated with a higher incidence of HF in hypertensive subjects without HF at baseline. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Institutes of Health

Background In the last two decades, catheter ablation (CA) for atrial fibrillation (AF) including pulmonary vein isolation (PVI) has been developed as a standard and effective treatment for atrial fibrillation (AF). In patients with chronic heart failure with reduced left ventricular ejection fraction (LVEF) (HFrEF), PVI CA for AF dramatically improves LVEF, resulting in better clinical prognoses. On the contrary, there still has been no data that PVI CA for AF improves the prognosis in heart failure patients with preserved LVEF (HFpEF). Purpose The aim of this study was to evaluate the prognostic impact of PVI CA for AF after the hospitalization due to decompensation of heart failureHF, focusing on LVEF. Methods From the database including 1,793 consecutive patients who were hospitalized due to congestive HF, we ultimately analyzed 624 AF patients who were discharged alive. They were assigned into two groups due that PVI CA for AF procedure done after the index hospitalization for HF; the PVI CA group (n=62) and Non-PVI CA group (n=562). For the two groups, we performed propensity-score (PS) matching using variables as follows: age, sex, LVEF, brain natriuretic peptide (BNP), blood urea nitrogen (BUN) and estimated glomerular filtration rate (eGFR) at discharge. Further analysis was performed separately in HFrEF (LVEF 50%). The primary endpoint of this study was death from any cause. Results In unmatched patients, Kaplan-Meier analysis showed that patients in the PVI CA group had a significantly lower all-cause mortality than those in the Non-PVI CA group during 678 median follow-up period (Log-rank test: P=0.003, Figure A). In 96 PS-matched patients, patients in the PVI CA group still had lower mortality rate than those in the Non-PVI CA group (hazard ratio 0.28, 95% confidence interval 0.09–0.86, p=0.018, Figure B). When the whole study population was classified into HFrEF and HFpEF, HFrEF patients who received PVI showed a significantly lower mortality than those who did not (p=0.007); whereas, in HFpEF patients, PVI CA for AF did not make statistical difference in all-cause mortality (p=0.061). Conclusions In this observational study, PVI CA for AF may improve the mortality in HF patients with reduced LVEF. However, the prognostic impact of PVI CA for AF was not observed in HF patients with preserved LVEF. Funding Acknowledgement Type of funding source: None

Background Numerous cardiac rehabilitation (CR) studies have demonstrated functional benefits, improvement in quality of life and clinical outcomes from exercise training in patients with heart failure (HF), so CR is consistently recommend for HF patients. However its influence on survival in HF population is unknown. Purpose To assess the influence of CR on survival rate in HF patients. Methods It is a retrospective analysis of 1 620 686 HF patients in Poland in years 2013–2018, based on nationwide Polish Ministry of Health registry, that provides public universal healthcare coverage to all residents and collects detailed information for the entire Polish population (38,495,659 in 2013) since 2009. Within registry, we identified the experimental group of 11 512 HF patients ≥18 years old who underwent CR in 2013–2018. From entire HF population we identified a 1:1 propensity score matched cohort of HF patients, who did not get CR. Results After propensity-score matching, we identified 11,512 patient pairs who underwent/not CR. Average age was approximately 66 years (18–39: 2.1 vs 2.0%; 40–49: 491 – 4.3 vs 4.2%; 50–59: 17.0 vs 17.1%; 60–69: 34.9 vs 35.2%; 70–79: 31.3 vs 31.4%; 80+: 10.4 vs 10.3% respectively), 61% of the participants were males, mainly urban residence nearly 70%, with HF diagnose put during hospitalization 74.5%. Both groups were similar also by comorbidities evaluated by Charlson Comorbidity Index. Patients subjected to CR compared CR negative significantly increased survival risk at 1st, 2nd, 3rd, 4th and 5th year (CR vs CR negative 97.4% vs. 84.9%; 93.9% vs. 77.9%; 89.9% vs. 71.9%; 85.2% vs 66.0%; 81.8% vs 62.1% respectively) – Figure 1. Conclusion Our analysis showed that in heart failure patients, CR was associated with an increased survival rate among HF patients as treated in routine health care system. Figure1 Funding Acknowledgement Type of funding source: Other. Main funding source(s): European Union from the European Social Fund

In recent years, with the rapid increase in the volume and accessibility of Real-World-Data (RWD) and Real-World-Evidence (RWE), we have seen the unprecedented opportunities for their use in drug clinical development and life-cycle management. RWD and RWE have demonstrated the significant potential to improve the design, planning, and execution of clinical development. Furthermore, they can feature in the designs as either a substitute or compliment to traditional clinical trials. However, to utilize RWD and RWE appropriately and wisely, it is critical to apply rigorous statistical methodologies that enable the robustness of results to be characterized and ascertained. Several statistical methodologies including exact matching, propensity score methods, matching-adjusted indirect comparisons and meta-analysis have been proposed for analyzing RWD. Among them, propensity score method is one of the most commonly used methods for non-randomized trials with indirect comparison. Although massive methodologies and examples have been published and discussed since propensity score methods were introduced, systematic review and discussion of how to rigorously use propensity score methods in the practical clinical development is still deficient. This paper introduces commonly used and emerging propensity score methods with detailed discussions of their pros and cons. Three different case studies are presented to illustrate the practical considerations of utilizing propensity score methods in the study design and evaluation using real-world and historical data. Additional considerations including selection of patient populations, endpoints, baseline covariates, propensity score methods, sensitivity analysis and practical implementation flow in clinical development will be discussed.

Propensity scores are often used to adjust for between-group variation in covariates, when individuals cannot be randomized to groups. There is great flexibility in how these scores can be appropriately used. This flexibility might encourage p-value hacking – where several alternative uses of propensity scores are explored and the one yielding the lowest p-value is selectively reported. Such unreported multiple testing must inevitably inflate type I error rates – our focus is on exploring how strong this inflation effect might be. Across three different scenarios, we compared the performance of four different methods. Each taken individually gave type I error rates near the nominal (5%) value, but taking the minimum value of four tests led to actual error rates between 150% and 200% of the nominal value. Hence, we strongly recommend pre-selection of the details of the statistical treatment of propensity scores to avoid risk of very serious over-inflation of type I error rates. Postprint

Introduction: Anemia in women of reproductive age is a common health problem in Senegal. The objective of this research was to study the contribution of dietary diversity in the fight against anemia in women of reproductive age in two regions of Senegal using the propensity score method. Methodology: An observational, cross-sectional and analytical study of women of reproductive age and their households was conducted in the Kolda and Kedougou regions in 2015. This was a three-stage random sample survey. The data was collected during an individual interview. Conditional logistic regression was used to identify the risk factor for this anemia. Results: In this study, 1926 women of reproductive age were surveyed. The average age of women of reproductive age surveyed was 27.2 years with a standard deviation of 7.6 years. The median age was 26 years old. Married women were in the majority. Pregnant and lactating women were 43.8%. The percentage of women with adequate diets was 31.5%. The proportion of women with anemia was 51.8%, or 998 women of reproductive age. Adequate dietary diversity is the main factor associated with anemia in these women (OR = 0.75 (0.59 - 0.96)). Conclusion: The prevalence of anemia in women of reproductive age is still high in the southern regions of Senegal. To combat this phenomenon, it is therefore necessary to intensify interventions on the balance of diet, iron and folic acid supplementation in pregnant and lactating women and to strengthen the empowerment of women.

This comparative effectiveness research study examines propensity scores adjustment in multiple sclerosis studies comparing disease-modifying treatments.

Background: To assess early and mid-term efficacy of transcatheter aortic valve replacement (TAVR) using the new-generation CoreValve Evolut R (Medtronic Inc., Galway, Ireland).Methods: This is a prospective, single-center study. All consecutive patients undergoing TAVR with 23-, 26-, 29-, 34-mm Evolut R valve were included. In a secondary analysis, patients undergoing Evolut R implantation were compared using the propensity score method with a historical cohort of patients who underwent CoreValve implantation in our institution.Results: From March 2015 to September 2017, a total of 320 patients with a median age of 81.1 years (IQR 77–84) and mean STS score of 4.9 ± 3.1% were treated. Device success was obtained in 300 patients (93.8%). Effective recapture and repositioning of the valve due to initial suboptimal deployment was accomplished in 40 patients (12.5%). Post-TAVR transthoracic echocardiogram showed a reduction in mean gradient from 49.1 ± 18.2 mmHg to 7.6 ± 0.4 mmHg (p