Adaptation of the Evidence Pyramid Diagram developed by the Medical Research Library of Brooklyn, SUNY Downstate Medical Center.
Systematic Review: a comprehensive summary of high-quality studies examining a given topic. Example: Will emergency and surgical patients participate in and complete alcohol interventions? A systematic review
Meta-Analysis: a type of systematic review where results from available high-quality studies are statistically combined to compute a net overall effect. Example: Alcohol drinking and bladder cancer risk: a meta-analysis
Randomized Controlled Trial: a type of epidemiologic study where participants are randomly assigned to receive a given exposure (such as a new drug or therapy) and then followed to examine the effects of the exposure on outcomes. Example: Treating alcohol withdrawal with oral baclofen: A randomized, double-blind, placebo-controlled trial
Cohort: a type pf epidemiologic study design where one or more population groups (called cohorts) are classified according to their level of exposure to a given agent/risk factor and followed over time to determine if this exposure is related to the occurrence of a disease or outcome of interest. Example: Effect of retirement on alcohol consumption: longitudinal evidence from the French Gazel cohort study
Case Control: a type of epidemiologic study that compares individuals who have a disease or outcome of interest (cases) with those who do not (controls). Researchers look retrospectively to evaluate how frequently exposure to a risk factor/agent is present in each group to identify the relationship between the risk factor and the disease or outcome of interest. Example: Risk factors for alcohol dependence: A case-control study
Cross-Sectional: a type of epidemiologic study that observes the relationship between a characteristic/risk factor (the exposure) and the prevalence of the disease or outcome of interest in a specific population at a single point in time. Example: Alcohol involvement in aggression between intimate partners in New Zealand: a national cross-sectional study
Case Series: a summary of a small group of individuals' experience with a similar disease or outcome of interest. Example: Alcohol use in chronic fatigue syndrome
Case Reports: a summary of one individual's experience with the disease or outcome of interest. Example: Acute coronary ischemia during alcohol withdrawal: a case report
Ideas, editorials, opinions: put forth by experts in the field Example: Alcohol brewing and the African tuberculosis epidemic
Animal Research Studies: studies conducted using animal subjects. Example: Renal effects of alcohol withdrawal in five-week alcohol-treated rats
Test-tube lab research: "test tube" experiments conducted in a controlled laboratory setting
