Survivor Treatment Selection Bias and Outcomes Research

Publisher Website
Google Scholar
Abstract
Background— Recent studies in infective endocarditis have suggested an association between surgery and reduced mortality. However, these studies did not account for survivor treatment selection bias, which is an underrecognized source of error in observational studies. Therefore, we sought to evaluate the effects of survivor bias on surgical outcomes in infective endocarditis. Methods and Results— We studied 223 patients admitted with left-sided infective endocarditis between 1996 and 2006 and compared all-cause mortality between surgically treated and medically treated patients using Cox regression analysis. Propensity scores were used to account for selection bias, and time-dependent analyses were performed to account for survivor bias. Compared with medical patients (n=161), surgical patients (n=62) had lower mortality during a median follow-up of 5.2 years (32% versus 51%; P=0.02) with an unadjusted hazard ratio of 0.54 (95% CI, 0.33 to 0.88, P=0.01). After adjustment for baseline differences in prope...

This publication has 20 references indexed in Scilit: