(From : Oxford Handbook of Medical Statistics, Janet L. Peacock, Philip J. Peacock, P:5)
❓What is the prevalence of diabetes mellitus in the population?
๐ดThis is a simple descriptive study
❓How effective is influenza vaccination in the community-based elderly?
๐ดThis is a comparative study, comparing individuals who had vaccines with those who did not
❓Does lowering blood pressure reduce the risk of coronary heart disease?
๐ดThis is an evaluative study, investigating the effi cacy of lowering blood pressure
❓Is prognosis following stroke dependent on age at the time of the event?
๐ดThis is an observational study
❓Why does smoking increase the risk of heart disease?
๐ดThis is an explanatory study investigating the mechanism behind an observed relationship
❓What evidence is there for the effectiveness of antidepressants in treating depression?
๐ดThis study is a meta-analysis of existing interventional studies
