1) The hierarchical levels of evidence in evidence-based medicine are incorrect according to an analysis of studies. 2) Data and analyses support the hypothesis that evidence-based medicine rankings of randomized controlled trials, observational studies, and other research designs may be too simplistic. 3) Evidence-based medicine itself is not truly evidence-based, as its foundations are more based on opinions than real data and it fails to consider the complex relationships involved in human pharmacology.

1. Hierarchical levels of evidence based medicine are incorrect.

2. Background
“Evidence based medicine insists on rigorous standards to appraise clinical interventions. Failure to apply the same rules to its own tools could be equally damaging” - Joseph L,
Ioannidis JPA, Norma T, et al. The case of the misleading funnel plot BMJ 2006; 333:597.
Aims
Hypothesis: Hierarchical levels of evidence based medicine are incorrect.
Objective
To analyze the strength of evidence provided by different types of study designs: systematic reviews and meta-analysis, controlled clinical trials, and observational studies (case-
control, cohort, and cross-sectional).
Methods
Analysis of public databases (e.g., ClinicalTrials.gov, PubMed, ISI Web of Knowledge, Embase, and WHO ICTRP) according to the following variables: geographical locations, sponsors
(i.e., industry and non-industry), study designs, conditions (diseases), and interventions (pharmacological and non-pharmacological).
Estimation of unpublished clinical trials according to the variables listed above.
Analysis of publication bias in systematic reviews and meta-analysis.
Results
Data and analysis supports the hypothesis in the title of this abstract.
Conclusions
Human pharmacology is a non-linear science created by multiple variables at different levels of complexity:
1. Drug effects at molecular and cellular levels: drug-receptor interaction (pharmacodynamics) and drug disposition (pharmacokinetics)
2. Effects of drugs on human health and disease: safety, efficacy, and effectiveness
3. Effects of drugs in the society: economical aspects (i.e., pharmacoeconomics), epidemiology (i.e., pharmacological surveillance), healthcare systems (i.e., definitions of essential
medicines), over the counter availability of medicines, drug addiction, and many other variables.
Hierarchical levels of evidence-based medicine (EBM) are over-simplistic to understand complex relationships involved in human pharmacology. The first EBM article matching search
terms in PubMed was published in 1992. 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 instead of real data (i.e., evidence).
Evidence-based medicine is not "evidence-based".
References
http://www.bmj.com/content/348/bmj.g3725/rr/762595
http://dx.doi.org/10.6084/m9.figshare.1093997