Study designs
Epidemiologic study designs organize how exposure, outcomes and comparison groups are measured. Study design influences what conclusions the data can support.
Open interactive lesson & self-check ↗Study designs: where do you start?
Original conceptual SVG · scalableA simplified decision map; study ethics, temporal sequence, feasibility and bias safeguards before selecting a design.
Observational studies
Cross-sectional designs measure exposure and outcome around the same time. Case–control designs begin by selecting outcome groups, then investigate prior exposures. Cohort designs follow exposure groups to compare outcomes.
Experimental designs
Randomized trials allocate interventions by a random process to reduce some forms of confounding; analysis still must address bias, adherence and uncertainty.
Read critically
No design removes all bias. Check sampling, measurement, selection effects, confounding, effect estimates and confidence intervals before interpreting conclusions.
Reference and next reading
Explore the original curriculum and publisher-hosted resources for full-depth reading; this note is an original schematic introduction, not an exhaustive chapter.