Propensity scores in cardiovascular research

Propensity scores are being widely used in statistical analyses, particularly in the area of cardiovascular disease research. Their use is likely to continue to increase as the cost for randomized clinical trials rises and more investigators turn to observational studies as a method of research. The propensity score methodology appears to produce the greatest benefits when it can be incorporated into the design stages of studies (through matching or stratification). These benefits include providing more precise estimates of the true treatment effects as well as saving time and money. This savings results from an ability to avoid recruitment of subjects who may not be appropriate for particular studies. The propensity score is not the only tool that can be used in analysis of data from observational studies; rather, it should be thought of as an additional tool available to investigators as they try to estimate the effects of treatments in studies where potential bias may exist. © 2007 American Heart Association, Inc.