Hypothesis: hierarchical levels of evidence based medicine are incorrect.

<p><strong>ABSTRACT</strong></p> <p><strong>Hypothesis</strong></p> <p>Hierarchical levels of evidence based medicine are incorrect.</p> <p><strong>Objectives</strong></p> <p>To evaluate the scientific output (i.e., publication trends) of evidence based medicine (EBM) in peer-review biomedical journals.</p> <p>To collect data about hierarchical levels of different types of study designs according to their strenght of evidence.</p> <p><strong>Methods</strong></p> <p>1. PubMed publication trends: EBM, clinical trials, observational studies (i.e., case-control, cohort, and cross-sectional designs), and clinical practice guidelines (CPG).</p> <p>2. Analysis of Google Trends: EBM (Spanish, English, and French) & CPG</p> <p>3. Supplementary analysis of the available evidence using different variables: geographical locations, sponsors, diseases, interventions (pharmacological & non-pharmacological).</p> <p><strong>Results</strong></p> <p>Data and analysis support the hypothesis described in the title of this abstract.</p> <p><strong>Conclusions</strong></p> <p>Human pharmacology is a non-linear science created by multiple variables at different levels of complexity:</p> <p>1. Drug effects at molecular and cellular levels</p> <p>2. Effects of drugs on human health and disease</p> <p>3. Effects of drugs in the society</p> <p>Hierarchical levels of evidence-based medicine (EBM) are over-simplistic to understand complex relationships involved in human pharmacology.</p> <p>The 1st EBM paper in the PubMed search query was published in 1992. Opinions (i.e., narrative evidence) instead of data supports classic (e.g., McMaster) and current (e.g., Oxford Centre of EBM) hierarchical levels of EBM. The model of drug approval into the market, as well as our methods for appraisal of the evidence involving therapeutic interventions in humans, are supported by opinions but not data (i.e., evidence).