A systematic review of single-case experimental design meta-analyses: characteristics of study designs, data, and analyses

Abstract

Given the increasing interest in meta-analyses of Single-Case Experimental Design (SCED) studies mainly in the fields of behavioral, communication disorders, educational, and rehabilitation research, the aim of the present review is to determine the general characteristics of these meta-analyses, namely design characteristics, the kind of data provided in the primary studies and the ones included in meta-analyses, and the type of analyses that were conducted. In this review, 178 meta-analyses were examined for these characteristics. The results indicate that the number of SCED meta-analyses has increased remarkably in recent years. The most frequently used effect size metric was the percentage of non-overlapping data (PND) and the most commonly utilized analysis for synthesizing the results of primary SCEDs was a simple average of effect sizes. The current study provides insights in the characteristics of primary SCED studies and SCED meta-analyses, and therefore can help in further developing methodological techniques and in evaluating whether the currently used techniques are in line with the methodological advancements.

Keywords:

• Single-case experimental design
• meta-analysis
• effect size
• systematic review

Acknowledgement

All the authors are grateful to Emily Rodabaugh, Maries Vissenaeken, and Dimitri Vandersteen for their helpful contribution to the identification of relevant studies and to data extraction.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This project was supported in part by the Institute of Education Sciences, U.S. Department of Education, under grant number: R305D150007. All the content is solely the responsibility of the authors and does not represent views of the Institute of Education Sciences, U.S. Department of Education.