A systematic review highlighting poor quality of evidence for content validity of quality of life instruments in female chronic pelvic pain

Objectives: To evaluate the content validity of 19 patient-reported outcome measures (PROMs) used to measure quality of life (QoL) in women with chronic pelvic pain (CPP).

Study design and setting: We searched Embase, MEDLINE, PsycINFO databases and Google Scholar from inception to August 2020. We included records describing the development or studies assessing content validity of PROMs. Two reviewers independently assessed the methodological quality of PROMs using the Consensus-based Standards for the Selection of Health Measurement Instruments checklist. Evidence was synthesized for relevance, comprehensiveness, and comprehensibility. Quality of evidence was rated using a modified Grading of Recommendations, Assessment, Development, and Evaluations approach.

Results: PROM development was inadequate for all instruments included in this review. No high-quality evidence ratings were found for relevance, comprehensiveness, and comprehensibility. QoL was measured using generic instruments (68.42%, 13/19) rather than those specific to chronic pain (21.04%, 4/19) or pelvic pain (10.53%, 2/19). Quality of concept elicitation was inadequate for 90% of PROMs. Half of PROMs did not include patients in their development and only 40% were devised using a sample representative of the target population for which the PROM was developed. Cognitive interviews were conducted in one-fifth of PROMs and were mostly of inadequate/doubtful quality.

Conclusion: There is poor quality of evidence for content validity of PROMs used to measure QoL in women with CPP.