Related Experiment Video
Updated: Aug 7, 2026

Observational Study Protocol for Repeated Clinical Examination and Critical Care Ultrasonography Within the Simple Intensive Care Studies
Published on: January 16, 2019
Quality assessment of observational studies is not commonplace in systematic reviews
Christian Mallen1, George Peat, Peter Croft
1Primary Care Sciences Research Centre, Keele University, Keele University, Keele, Staffordshire ST5 5BG, United Kingdom. c.d.mallen@cphc.keele.ac.uk
Background And Objective:
To review current practice in the assessment of the quality of original observational studies included in systematic reviews.
Materials And Methods:
Examination of all systematic reviews identified by a basic PubMed search for the years 1999-2000 (32 reviews) and 2003-2004 (98 reviews). English language systematic reviews published in peer-reviewed journals was the setting. Each review was evaluated for the use of quality assessment of original observational studies and if quality assessment occurred, what type of assessment was used.
Results:
Quality assessment occurred in 22% of systematic reviews identified in 1999-2000 compared with 50% of reviews identified from 2003-2004. All earlier reviews devised their own quality assessment criteria, whereas in 2003-2004 10 different quality assessment techniques were identified.
Conclusions:
Quality assessment does not routinely occur in systematic reviews of observational studies. Where it does occur, there is no clear consensus in the method used.
Related Concept Videos
Observational Studies
There are three types of observational studies – Prospective, retrospective, and cross-sectional.
Prospective Study
Prospective studies, also known as longitudinal or cohort studies, are carried out by collecting future data from groups sharing similar characteristics. One example of...
Naturalistic Observations
Data Collection by Observations
An astronomer viewing the motion and brightness of stars in the sky and recording the data is an example of observational data collection. A botanist recording...
Bias in Epidemiological Studies
Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast, controlled...
Study Designs in Epidemiology
Observational studies are those where the researcher does not intervene but rather observes natural variations. They include cross-sectional, cohort, and case-control studies.