What is cohort study?
cohort study is An observational study in which outcomes in a group of participants that received an intervention are compared with outcomes in a similar group (i.e. the cohort) of participants, either contemporary or historical, that did not receive the intervention. In an adjusted (or matched) cohort study, investigators identify (or make statistical adjustments to provide) a cohort group that has characteristics (e.g. age, gender, disease severity) that are as similar as possible to the group that experienced the intervention.
source: A GLOSSARY OF TERMS FOR COMMUNITY HEALTH CARE AND SERVICES FOR OLDER PERSONS. World Health Organization, 2004.