Skip to main content

Table 1 The advantages and disadvantages of different observational study types

From: What can cohort studies in the dog tell us?

Study type Potential goals Advantages Disadvantages
Cross-sectional - Population prevalence of exposure and/or outcome - Relatively simple - Poor for rarer exposures and outcomes
- Associations between exposures and outcomes - Relatively cheap - No causality may be inferred as exposures and outcomes are measured contemporaneously
- Relatively quick - Highly susceptible to information bias
- Good for common conditions and exposures
- May assess multiple exposures and outcomes
- Good for initial assessment of an exposure or outcome
Case–control - Associations between exposures and outcome - Relatively cheap - Choice of controls notoriously difficult
- Strength of association in the form of odds ratio between exposure(s) in controls and exposure(s) in cases - Relatively quick - May only examine one outcome
- May assess long latent periods - Odds ratio not an intuitive measure
- Good for rarer outcomes - Highly susceptible to selection and information bias and population stratification
Cohort - Incidence rates - Good for rare exposures - Not simple
- Temporal associations between exposures and outcomes - May examine multiple exposures and outcomes - Not cheap
- May assess long latent periods - Not quick (unless retrospective)
- May assess temporal relationship between exposure and outcome inferring causality - Highly susceptible to retention bias
- Susceptible to sampling bias