Methodologic Issues of Case-Control Studies: A Review of Established and Newly Recognized Limitations

Abstract

EXCERPT The case–control study design is used extensively to identify risk factors associated with patients’ harboring antimicrobial†resistant pathogens. Although case–control studies have numerous strengths, this editorial reviews and discusses their current limitations. Three articles in this issue of Infection Control and Hospital Epidemiology, which provide further insight and potential solutions to the limitations of this study design, are also reviewed.1†3 The main strength of a case–control study design is the analysis of risk factors associated with outcomes that occur infrequently. Case–control studies, in contrast to cohort studies, allow the rapid and efficient investigation of a hypothesis because the outcome of interest has already occurred. This design is therefore frequently used for the study of risk factors associated with antimicrobial†resistant pathogens, an infrequent outcome that is predominantly identified by clinical or surveillance cultures.