> Called the high-dimensional propensity score algorithm (hd-PS), it is a tool for improving not randomized clinical trials but broader observational studies, in which researchers watch a large pool of participants and look for correlations—like the fact that wine drinkers live longer than other drinkers.
Observational studies are cheaper and easier than clinical trials. Unfortunately, the data they yield are rife with confounder problems, but researchers can improve the data by adjusting for suspected confounders and removing the bias they introduce.