title: Analytical study designs--I.
authors.affiliation: Department of Community Health Sciences, Aga Khan University, Karachi.
authors.forename: M A
authors.initials: MA
authors.lastname: Lobo
authors.forename: A F
authors.initials: AF
authors.lastname: Qureshi
mesh_terms: D015982:Bias; D016022:Case-Control Studies; D015986:Confounding Factors, Epidemiologic; D003627:Data Interpretation, Statistical; D006801:Humans; D016017:Odds Ratio; D012107:Research Design