Skip to Main Content

Critical Appraisal Resources for Evidence-Based Nursing Practice

What is a Quasi-Experimental Study?

Quasi-experimental studies are a type of quantitative research used to investigate the effectiveness of interventions or treatments.  These types of studies involve manipulation of the independent variable, yet they lack certain elements of a fully experimental design.  Quasi-experimental studies have no random assignment of study subjects and lack a control group (Schmidt & Brown, 2019, p. 177).  However, they may have a non-equivalent comparison group (Krishnan, 2019). 

Krishnan P. (2019). A review of the non-equivalent control group post-test-only designNurse Researcher26(2), 37–40.

Schmidt N. A. & Brown J. M. (2019). Evidence-based practice for nurses: Appraisal and application of research (4th ed.). Jones & Bartlett Learning. 

PRO TIPS: Quasi-Experimental Checklist

Each JBI Checklist provides tips and guidance on what to look for to answer each question.  These tips begin on page 4. 

Below are some additional Frequently Asked Questions about the Quasi-Experimental Checklist that have been asked students in previous semesters. 

Frequently Asked Question Response
In Question 1, the checklist asks whether the 'cause' and 'effect' is clear.  How do I find the cause and effect? The 'cause' refers to the independent variable that is being manipulated to observe an 'effect.' The 'effect' is the dependent variable, or the outcome. You will often find this information in the beginning of the study in the objectives/purpose/aim/research question section. Is this information clearly stated? For example: "The purpose of this study is to identify whether mindfulness-based stress reduction ('the cause') reduces anxiety ('the effect') in cancer patients."
For Question 8, how can I tell whether outcomes were reliably measured?  Check for information about the internal reliability or internal consistency of the research instruments (scales, questionnaires, surveys, tools, etc.) used in the study. Look for the Cronbach's alpha statistic which is used to indicate internal reliability of an instrument. 

Articles on Quasi-Experimental Design and Methodology

Krishnan P. (2019). A review of the non-equivalent control group post-test-only designNurse Researcher26(2), 37–40.

Maciejewski, M. L. (2020). Quasi-experimental design. Biostatistics & Epidemiology, 4(1), 38-47. doi:10.1080/24709360.2018.1477468

Maciejewski, M. L., Curtis, L. H., & Dowd, B. (2013). Study design elements for rigorous quasi-experimental comparative effectiveness researchJournal of Comparative Effectiveness Research2(2), 159–173.

Miller, C. J., Smith, S. N., & Pugatch, M. (2020). Experimental and quasi-experimental designs in implementation researchPsychiatry Research283, 112452.

Siedlecki S. L. (2020). Quasi-experimental research designsClinical Nurse Specialist34(5), 198–202.