Patients included in randomised controlled trials do not represent those seen in clinical practice: focus on antimicrobial agents

Abstract 

Clinicians rely on the findings of randomised controlled trials (RCTs) to formulate clinical decisions regarding individual patients. We examined whether patients included in RCTs focusing on antimicrobial agents are representative of those encountered in real-life clinical situations. PubMed was searched for RCTs referring to the field of infectious diseases. Data regarding the exclusion criteria of the identified RCTs were extracted and critically evaluated. In total, 30 trials (17 referring to respiratory tract, 5 to skin and soft-tissue, 4 to intra-abdominal, 2 to gynaecological and 2 to bloodstream infections) were included in the study. All retrieved RCTs reported extensive exclusion criteria. After comparing in a qualitative manner (based on our clinical experience) the eligible patient population in the identified RCTs with the respective population that would be encountered in general practice, it was observed that the abovementioned patient populations differ considerably. In conclusion, RCTs in the field of infectious diseases use extensive and stringent exclusion criteria, a fact that may lead to considerable difference between the patient populations of RCTs and those viewed in clinical practice. The application of the findings of RCTs to the care of individual patients should be performed cautiously.

Keywords: Evidence-based medicine, External validity