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Evidence-Based Practice: Study Design

Study Types

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

Systematic Review:
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

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

Cohort Study:
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

Case-Control Study:
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
 
Case Report:
A descriptive study which reports on the profile of a single patient. 1
 
Case Series:
A descriptive study which reports on the profiles of a series of patient with an outcome of interest.1

Cross-Sectional:
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

Definitions come from the following sources:

1. Evidence-Based Answers to Clinical Questions for Busy Clinicians. (2011) The Centre for Clinical Effectiveness, Southern Health, Melbourne, Australia.
 
2. Glossary of Terms in The Cochrane Collaboration. (2005). Cochrane Collaboration. Also see here.

Study Design 101

Study Design 101. Himmelfarb Health Sciences Library. License: Creative Commons BY-NC-ND 3.0

Glossaries and Study Design Resources

Classification of Scientific Literature

Primary Literature
(Original Research)
Experimental/Interventional Studies
Observational Studies
Analytical
Descriptive
  • Randomized controlled trials
  • Controlled trials
  • Case control studies
  • Cohort studies
  • Cross sectional (analytic)
  • Case reports
  • Case series
  • Cross sectional studies
  • Qualitative studies
  • Correlational studies
Secondary Literature
(Evaluative Studies of Primary Research)
  • Systematic reviews
  • Meta-analyses
  • Practice guidelines
  • Decision analyses
  • Critically appraised topics

Identifying Study Type: Method 1

Study Design Table from:
Evidence-Based Answers to Clinical Questions for Busy Clinicians. (2011) The Centre for Clinical Effectiveness, Southern Health, Melbourne, Australia. Permission for use granted. 

Identifying Study Type: Method 2

Study table from:
”Research Designs.” AFMC Primer on Population Health, The Association of Faculties of Medicine of Canada Public Health Educators’ Network. License: Creative Commons BY-NC-SA 3.0.
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