Retrospective studies collect data in real time from subjects as events occur, resulting in highly accurate information.

Retrospective studies impose experimental treatments, unlike prospective studies, which simply observe outcomes.

Prospective studies are generally less expensive and quicker because they use data that has already been collected, unlike retrospective studies.

Retrospective studies are often quicker and less expensive but may rely on existing records and subjects’ inaccurate recollections, while prospective studies involve real-time data collection with better accuracy.