Outcomes and outcomes measurements used in intervention studies of pelvic girdle pain and lumbopelvic pain: a systematic review

BACKGROUND: Pelvic girdle pain is a common problem during pregnancy and postpartum with significant personal and societal impact and costs. Studies examining the effectiveness of interventions for pelvic girdle pain measure different outcomes, making it difficult to pool data in meta-analysis in a meaningful and interpretable way to increase the certainty of effect measures. A consensus-based core outcome set for pelvic girdle pain can address this issue. As a first step in developing a core outcome set, it is essential to systematically examine the outcomes measured in existing studies. OBJECTIVE: The objective of this systematic review was to identify, examine and compare what outcomes are measured and reported, and how outcomes are measured, in intervention studies and systematic reviews of interventions for pelvic girdle pain and for lumbopelvic pain (which includes pelvic girdle pain). METHODS: We searched PubMed, Cochrane Library, PEDro and Embase from inception to the 11th May 2018. Two reviewers independently selected studies by title/abstract and by full text screening. Disagreement was resolved through discussion. Outcomes reported and their outcome measurement instruments were extracted and recorded by two reviewers independently. We assessed the quality of reporting with two independent reviewers. The outcomes were grouped into core domains using the OMERACT filter 2.0 framework. RESULTS: A total of 107 studies were included, including 33 studies on pelvic girdle pain and 74 studies on lumbopelvic pain. Forty-six outcomes were reported across all studies, with the highest amount (26/46) in the ‘life impact’ domain. ‘Pain’ was the most commonly reported outcome in both pelvic girdle pain and lumbopelvic pain studies. Studies used different instruments to measure the same outcomes, particularly for the outcomes pain, function, disability and quality of life. CONCLUSIONS: A wide variety of outcomes and outcome measurements are used in studies on pelvic girdle pain and lumbopelvic pain. The findings of this review will be included in a Delphi survey to reach consensus on a pelvic girdle pain - core outcome set. This core outcome set will allow for more effective comparison between future studies on pelvic girdle pain, allowing for more effective translation of findings to clinical practice. SUPPLEMENTARY INFORMATION: Supplementary information accompanies this paper at 10.1186/s12998-019-0279-2.