Meta-Analysis
A way of combining data from many different research studies. A meta-analysis is a statistical process that combines the findings from individual studies.
Example:
Conn, V. S. (2010). Anxiety outcomes after physical activity interventions: meta-analysis findings. Nursing research, 59(3), 224.
Adapted from Study Designs; in NICHSR Introduction to Health Services Research: a Self-Study Course
Systematic Review
A summary of the clinical literature. A systematic review is a critical assessment and evaluation of all research studies that address a particular clinical issue. The researchers use an organized method of locating, assembling, and evaluating a body of literature on a particular topic using a set of specific criteria. A systematic review typically includes a description of the findings of the collection of research studies. The systematic review may also include a quantitative pooling of data, called a meta-analysis.
Adapted from Study Designs; in NICHSR Introduction to Health Services Research: a Self-Study Course
Randomized Controlled Trial
A controlled clinical trial that randomly (by chance) assigns participants to two or more groups. There are various methods to randomize study participants to their groups.
Example:
Adapted from Study Designs; in NICHSR Introduction to Health Services Research: a Self-Study Course
Cohort Study (Prospective Observational Study)
A clinical research study in which people who presently have a certain condition or receive a particular treatment are followed over time and compared with another group of people who are not affected by the condition.
Example:
Adapted from Study Designs; in NICHSR Introduction to Health Services Research: a Self-Study Course
Case-control Study
Case-control studies begin with the outcomes and do not follow people over time. Researchers choose people with a particular result (the cases) and interview the groups or check their records to ascertain what different experiences they had. They compare the odds of having an experience with the outcome to the odds of having an experience without the outcome.
Example:
Adapted from Study Designs; in NICHSR Introduction to Health Services Research: a Self-Study Course
Cross-sectional study
The observation of a defined population at a single point in time or time interval. Exposure and outcome are determined simultaneously.
Example:
Adapted from Study Designs; in NICHSR Introduction to Health Services Research: a Self-Study Course
Case Reports & Series
A report on a series of patients with an outcome of interest. No control group is involved.
Example:
Adapted from Study Designs; in NICHSR Introduction to Health Services Research: a Self-Study Course
Ideas, Editorials, Opinions
Put forth by experts in the field.
Example:
Adapted from Study Designs; in NICHSR Introduction to Health Services Research: a Self-Study Course
Animal Research Studies
Studies conducted using animal subjects.
Example:
Adapted from Study Designs; in NICHSR Introduction to Health Services Research: a Self-Study Course
Test-Tube Lab Research
"Test tube" experiments conducted in a controlled laboratory setting.
Adapted from Study Designs; in NICHSR Introduction to Health Services Research: a Self-Study Course
The Evidence Pyramid is often used to illustrate the development of evidence. At the base of the pyramid is animal research and laboratory studies - this is where ideas are first developed. As you progress up the pyramid the amount of information available decreases in volume, but increases in relevance to the clinical setting.
http://libraryguides.unh.edu/health-literacy. Adaptation of the Evidence Pyramid Diagram
developed by the Medical Research Library of Brooklyn, SUNY Downstate Medical Center
What type of question are you asking and which would be best to support the evidence?
Type of Question | Type of Study/Methodology to Look at |
Therapy |
Double-Blind Randomized Controlled Trial; |
Diagnosis | Controlled Trial; Systematic Review/Meta Analysis of Controlled Trial |
Harm | Cohort studies |
Prognosis | Cohort Studies; Case control, case studies |
Etiology | Cohort studies |
Prevention | Randomized Controlled Trial; Cohort studies |
Quality Improvement | Randomized Controlled Trial |
Quality of Life | Qualitative Study |
Cost Effectiveness | Economic Evaluation |
Clinical Exam | Prospective, blind comparison to gold standard |