title: Case-control study design.
authors.forename: Maher M
authors.initials: MM
authors.lastname: El-Masri
mesh_terms: D035843:Biomedical Research / Q000458:organization & administration*; D016022:Case-Control Studies; D015331:Cohort Studies; D006801:Humans; D064887:Observational Studies as Topic; D012107:Research Design; D012189:Retrospective Studies