Table 1.

Advantages and disadvantages of a case-control study, cohort study, case-control study within a defined cohort, and cross-sectional study

Study type	Advantage	Disadvantage
Case-control study	Less expensive, less time-consuming	Vulnerable to bias (recall bias, selection bias, confounding bias)
	Good for the study of rare disease
	Can assess multiple risk factors at once
Cohort study	Effective to establish cause and effect	Possibility of selection bias, information bias
	Useful to identify the timelines over which certain exposures can contribution to outcome	More expensive, more time-consuming (prospective cohort study)
	Can collect a wide variety of data	Risk bias in sampling the cohort (retrospective cohort study)
Nested case-control study	Can reduce the cost to perform the study	Require the selection of a new set of controls for each distinct disease
	Confounders can be matched in matching process
Case-cohort study	The ability to study several diseases using the same subcohort	Require a more complicated statistical analysis
Cross-sectional study	Useful to assess the prevalence of disease	Cannot infer causality
	Can suggest a natural progression with less cost	Cannot estimate incidence rate
		Not good for studying rare disease
		Susceptible to nonresponse bias and recall bias