Evidence-Based Practice: Study Design

The use of statistical techniques in a systematic review to integrate the results of included studies.²

A review of a clearly formulated question that uses systematic and explicit methods to identify, select, and critically appraise relevant research, and to collect and analyse data from the studies that are included in the review.2

An experimental study in which participants are randomly allocated to treatment/intervention or control/placebo groups.1

An observational study in which the experimental group is selected on basis of exposure and carefully matched to a control group which is not exposed. The outcome status is examined prospectively. Cohort studies observe groups of individuals before they develop a disease or a particular outcome.^{1 2}

An observational study where cases are selected on the basis of outcome (e.g. disease) and carefully matched to a control group which does not experience the outcome. The exposure is examined retrospectively.^{1 2}

A descriptive study which reports on the profile of a single patient. ¹

A descriptive study which reports on the profiles of a series of patient with an outcome of interest.¹

A descriptive study that measures the prevalence of disease, both exposure and disease is assessed at the same point in time. The units of analysis are individuals. ¹