Study selection in a Qualitative Evidence Synthesis (QES) can be more complex than in a systematic review of trials. The review team needs to decide whether to include all studies or to select a sample of studies, and whether to take an aggregative or configurative approach to study selection. As a QES seeks to provide an interpretation of the evidence it is not essential to identify and include every available relevant study. One way of approaching study selection in a QES to limit the number of included studies is sampling from the studies that meet the inclusion criteria. This webinar introduced participants to the concept of purposive sampling in qualitative evidence synthesis. Through worked examples the webinar explored different approaches to sampling and when QES teams can consider sampling in their reviews.
Dr Heather Ames is currently a researcher at the Norwegian Institute of Public Health and an editor with the Cochrane Consumer and Communications group. She is authoring the chapter on study selection and sampling in the new Cochrane and Campbell Qualitative Evidence Synthesis Handbook. She has been working with QES for ten years and developed a purposive sampling approach as part of her PhD work.