Outcome Measurement Instruments and Evidence-based Recommendations for Measurement of the Pelvic Girdle Pain Core Outcome Set (PGP-COS): A Systematic Review and Consensus Process.

This study provides evidence- and consensus-based recommendations for the instruments to measure the five Pelvic Girdle Pain Core Outcome Set (PGP-COS): pain frequency, pain intensity/severity, function/disability/activity limitation, health-related quality of life and fear avoidance. Studies evaluating measurement properties of instruments measuring any PGP-COS outcome in women with PGP were identified through a systematic search of MEDLINE, EMBASE and PEDro databases (inception-July 2021). The methodological quality of studies and quality of measurement properties were evaluated using the COnsensus-based Standards for the selection of health status Measurement Instruments (COSMIN) checklist. Quality criteria and the synthesized evidence were graded using the modified grading of recommendations, assessment, development, and evaluation (GRADE) approach. A consensus meeting with PGP stakeholders was then held to establish recommendations, based on the evidence, for the instruments that should be used to measure the PGP-COS. Ten instruments were identified from 17 studies. No instrument showed high quality evidence for all measurement properties and/or measured all PGP-COS outcomes. Based on current evidence and consensus, the Pelvic Girdle Questionnaire (PGQ), the Short Form-8 (SF-8) and the Fear Avoidance Beliefs Questionnaire (FABQ) are recommended for measuring the PGP-COS. Future research should establish additional measurement properties of instruments and to substantiate these recommendations.