Prospective Cohort Studies
Strengths
- Powerful strategy for defining the incidence and investigate the potential causes of a condition.
- Time sequence strengthens the inference that the factor may be a cause of the outcome.
- To be able to measure important variables completely and accurately.
- To study antecedents of fatal diseases
Weaknesses
- Expensive and inefficient
- Cannot be used for studying rare diseases. (CHD 1%!)
- Associations found in cohort studies can sometimes be misleading, if they are due to confounding variables (associated with both the predictor and outcome variables of interest).
- Inferences about the cause and effect can be strengthened by measuring all potential confounding variables and adjusting for their effects in statistical analyses.