An investigation in which the data are collected for the first time directly from patients (randomized controlled trial, observational study, case series, etc.).
Note: The term “primary research” is often used to distinguish this type of research from “secondary research,” which is synthesis research (re-analysis of previously collected data), meta-analyses and other ways of combining studies (such as economic analysis and decision analysis).
Related concept: secondary research
Syn.: primary study, original study.