title: Study design.
abstract: A brief survey is provided of common designs for medical studies and important issues in their implementation. The designs discussed include those for laboratory studies, clinical trials, cohort studies, case-control and related studies, and diagnostic studies.
authors: Programme Leader, MRC Biostatistics Unit, Cambridge Institute of Public Health, Cambridge, UK. Conflicts of interest: None.
authors: Vernon T
authors: VT
authors: Farewell
authors: Programme Leader, MRC Biostatistics Unit, Cambridge Institute of Public Health, Cambridge, UK. Conflicts of interest: None.
authors: Daniel M
authors: DM
authors: Farewell
keywords: clinical trials; diagnostic tests; epidemiology; experimental studies; observational studies; randomization