If properly conducted, Randomized Clinical Trials (RCTs) are the gold standard for the evaluation of drug efficacy. They usually provide evidence of the efficacy of a new drug under strictly controlled conditions, in selected patient groups treated for a defined period of time. Although RCTs represent the key step for the registration of a new drug, they also have significant drawbacks, such as the exclusion of many patients, the limited ability to generalize the results to larger populations followed by less specialized centers and the difficulty in identifying rare adverse events, as well as to evaluate the long-term efficacy of the drugs.

For this reason, observational studies are an important complement to RCTs.

If properly designed and conducted, observational studies are apparently the only way to answer key questions about the efficacy and long-term safety of a drug, as well as its use appropriateness in clinical practice. Large observational studies also allow the assessment of efficacy and safety in specific subgroups, such as those characterized by particularly high disease duration, specific concomitant medications or comorbidities presence, etc.

All that considered, the course is aimed at increasing the knowledge of participants on the strengths and limitations of observational studies, the most innovative and appropriate statistical methods to analyze the results, and the implications for clinical practice and research derived.


  • Introduction: clinical practice and clinical epidemiology
  • Identifying a research question
  • Groups exercise: identification of the most relevant research questions for participants
  • The formulation of a research question: PICO
  • Groups exercise: reformulation of the questions identified by PICO method
  • The main clinical study design: observational studies and experimental studies
  • Cross-sectional studies
  • Longitudinal studies
  • Case-control studies
  • Groups exercise: identification of the most appropriate study design for the identified question
  • Observational studies: statistical aspects and interpretation of results