Article type
Year
Abstract
Background: Reviews of qualitative research, or qualitative evidence synthesis (QES), are increasingly common and are now being done by Cochrane. Identifying and including all possible studies is a goal for reviews of intervention effectiveness, but is not necessarily the best approach for QES. Too much data due to a large number of studies may threaten the quality of the analysis. Using purposive sampling of included studies is one way of reducing the number of articles to be analysed.
Objectives: To describe an approach to purposively sampling included studies in a QES.
Methods: We searched electronic databases to identify studies that met the following inclusion criteria: 1) qualitative methods of data collection and analysis; 2) parents or carers as participants; and 3) a focus on views and experiences of vaccination information. For studies that met the inclusion criteria, we extracted information regarding study country and focus and assessed data 'richness' on a 1-5 scale. Studies meeting the inclusion criteria were sampled using a three-step purposive process: 1) We sampled any study from a low- or middle-income country (LMIC) to help ensure geographic spread, as the majority of studies on the topic were from high-income settings; 2) We sampled all studies that scored 3 or more on the data richness scale; 3) We reviewed the abstracts of the remaining studies and sampled those that answered the review question most closely and in the most detail.
Results: Sixty studies met our inclusion criteria. We sampled seven studies from LMIC settings; 14 studies that scored more than 3 on the data richness scale; and five studies that answered the review question best, leaving 26 studies for data analysis.
Conclusions: This systematic, three-step approach may prove useful to other researchers attempting to synthesise qualitative literature from a large number of studies. Strengths included that it allowed us to achieve a geographic spread of articles together with rich data that closely answered the review question. The weakness is that we may have overlooked articles that did not meet our sampling criteria, but would have contributed to the synthesis.
Objectives: To describe an approach to purposively sampling included studies in a QES.
Methods: We searched electronic databases to identify studies that met the following inclusion criteria: 1) qualitative methods of data collection and analysis; 2) parents or carers as participants; and 3) a focus on views and experiences of vaccination information. For studies that met the inclusion criteria, we extracted information regarding study country and focus and assessed data 'richness' on a 1-5 scale. Studies meeting the inclusion criteria were sampled using a three-step purposive process: 1) We sampled any study from a low- or middle-income country (LMIC) to help ensure geographic spread, as the majority of studies on the topic were from high-income settings; 2) We sampled all studies that scored 3 or more on the data richness scale; 3) We reviewed the abstracts of the remaining studies and sampled those that answered the review question most closely and in the most detail.
Results: Sixty studies met our inclusion criteria. We sampled seven studies from LMIC settings; 14 studies that scored more than 3 on the data richness scale; and five studies that answered the review question best, leaving 26 studies for data analysis.
Conclusions: This systematic, three-step approach may prove useful to other researchers attempting to synthesise qualitative literature from a large number of studies. Strengths included that it allowed us to achieve a geographic spread of articles together with rich data that closely answered the review question. The weakness is that we may have overlooked articles that did not meet our sampling criteria, but would have contributed to the synthesis.