Practicing evidence-based psychiatry- 2. Interpreting integrative literature: Systematic reviews and meta-analyses

The practice of evidence-based medicine (EBM) requires the ability to adequately appraise relevant clinical evidence with the intention of making an evidence-based treatment decision. Broadly, there are three available sources of information available to the practicing clinician: individual studies, reviews of the literature, and practice guidelines. In the first article in the series, we described the threats to validity (T2V) approach in evaluating evidence and specifically discussed the different threats to validity in applying the findings of a single study to an individual patient. In this article, we describe the five steps of a systematic review and evaluate threats to validity at each of these steps. We illustrate the method by evaluating a review relevant to the treatment question presented in a clinical vignette. We discuss results of the meta-analytic review about comparative antipsychotic effectiveness in patients with schizophrenia and consider application of its conclusions to the question of which antipsychotic to select for the particular patient with schizophrenia utilizing the T2V approach.