Background: Using qualitative-evidence synthesis (QES) findings to supplement findings from review of the effectiveness of interventions is a relatively new approach, and the most appropriate methods for doing this are still unclear.
Objectives: To use a matrix table to integrate the findings from a QES on vaccination communication with those from related Cochrane reviews on the effectiveness of vaccination-communication interventions.
To create the matrix we did the following:
• We went through each of the QES findings and identified features of communication interventions that parents perceived as facilitators, including features tied to information timing, availability, amount, source and content.
• We organised these features into groups and created 8 questions reflecting key issues. These questions, which can be answered as yes, no or unclear, allowed us to assess the alignment between the issues identified in the QES and the interventions assessed in the effectiveness reviews.This alignment was expressed in a matrix table (Table 1).
• We assessed whether there was a full or partial match between each of the questions and the intervention components from each trial and added these to the table.
Results: Most of the matrix-table questions were not addressed by the effectiveness trials (Table 1). Poor reporting in the trials made this assessment difficult.
Conclusions:Using a matrix-table analysis to compare the QES findings to the interventions used in the studies in the related effectiveness reviews allowed us to identify gaps in the trial interventions in relation to the issues that parents see as important. QES can play a unique part in complementing reviews of effectiveness by synthesising evidence that helps to unpack and explain effectiveness findings, and by contributing to identifying further research questions.