Quantitizing findings from qualitative studies for inclusion in a mixed studies review: an update of the quantitizing proposition


Oral session: Qualitative evidence synthesis methodology (1)


Tuesday 22 October 2019 - 16:00 to 17:30


All authors in correct order:

Van Grootel L1
1 Tilburg University, The Netherlands
Presenting author and contact person

Presenting author:

Leonie Van Grootel

Contact person:

Abstract text
Background: In mixed studies reviewing, data from quantitative and qualitative studies are combined at the review level. One possible way to combine findings of quantitative and qualitative studies is to quantitize qualitative findings prior to their incorporation in a meta-analysis. There are only few examples of the quantification of qualitative findings within this context. The examples that are currently available provide a way to estimate the mean of the strength of a relationship between a predictor and an outcome, but lack methods for estimating the variance accompanying this mean. This study adds to current research on mixed studies review methodology by presenting a pilot implementation of a method to extract and quantitize the strength of relationships found in qualitative studies providing a corresponding measure of variability. This presentation will build on an earlier version of the quantitizing idea, discussing some improvements of the proposed method.

Method: the paper to be presented describes four steps conducted in the pilot implementation:
1) how the analysis is prepared;
2) how vague quantifiers in text fragments are organized and transformed to numerical values;
3) how qualitative studies as a whole are assigned mean effect sizes and variances; and
4) how the overall mean effects size and variance can be calculated.

An example shows how findings from 26 primary qualitative studies are transformed into mean effect sizes and corresponding variances.

Results: the results of the presentation provide an overall weighted average effect size and corresponding variance for the qualitative studies, but focus mostly on the challenges faced during the implementation of the pilot, and how we overcame those.

Conclusion: the pilot has shown that the method is promising, and we invite other researchers to build on our idea. We list some issues with the method that require further investigation.

Patient or healthcare consumer involvement: as this was a pure methodological study, patients or healthcare consumers were not involved - substantive researchers in healthcare were.