A systematic review to determine use of the Endometriosis Health Profiles to measure quality of life outcomes in women with endometriosis.

Background: The Endometriosis Health Profiles (EHPs), the EHP-30 and EHP-5, are patient-reported outcome measures that were developed to measure the health-related quality of life (HRQoL) of women living with endometriosis. Prior to their development, a systematic review was undertaken which identified that the HRQoL of women living with endometriosis was poorly understood, with only three medical and one surgical study identified.

Objective and rationale: The 20-year anniversary of the EHP-30 provided a timely opportunity to assess how the tools have been used and explore what the findings tell us about the impact of endometriosis and its associated treatments upon women's QoL. Applying robust systematic review methodology, following PRISMA guidelines, we sought to answer: How many studies have used the EHP and for what purpose?; What are the demographic characteristics and international context of the studies?; What is the methodological nature and quality of the studies?; Which interventions have been assessed and what are the reported EHP outcomes?; and Can the EHP outcomes of these interventions be analysed using a meta-analysis and, if so, what do the results show?

Search methods: The electronic databases MEDLINE, CINAHL, PsycINFO, PubMed, and Google Scholar were searched from the year the EHP was first published, in 2001 to 26 February 2020 using the search terms 'EHP30', 'EHP5', 'EHP-30', 'EHP-5', 'endometriosis health profile 30', and 'endometriosis health profile 5'. We updated the searches on 9 April 2021. All included studies were quality assessed using the Mixed Methods Appraisal Tool (MMAT).

Outcomes: The review included 139 papers. In clinical intervention studies, the EHPs were deployed most frequently to measure the outcomes of medical (n = 35) and surgical (n = 21) treatment. The EHPs were also used in 13 other intervention studies, 29 non-interventional studies, 32 psychometric/cross cultural validation studies; six diagnostic studies, and in three other studies to measure outcomes in related conditions. They were mainly deployed in studies undertaken in Europe and North America. Overall, regardless of the nature of the intervention, most women reported improvements in HRQoL after treatment. Surgical interventions generally resulted in significant improvements for the longest amount of time. There was also evidence that when participants stopped taking medication their EHP scores worsened, perhaps reinforcing the temporary impact of medical treatment. Younger patients reported more negative impact upon their HRQoL. Further evidence using classical test theory to support the EHPs' robust psychometric properties, including acceptability, dimensionality, reliability, validity (including cross-cultural), and responsiveness, was demonstrated, particularly for the EHP-30. Strikingly, using anchor-based methods, EHP-30 responsiveness studies demonstrate the largest mean changes in the 'control and powerlessness' domain post-intervention, followed by 'pain'. MMAT outcomes indicated the quality of the papers was good, with the exception of five studies. A meta-analysis was not undertaken owing to the heterogeneity of the interventions and papers included in this review.

Wider implications: Women with endometriosis face a lifetime of surgical and/or medical interventions to keep the condition under control. Less invasive treatments that can lead to improved longer term physical and psycho-social outcomes are needed. The EHPs are reliable, valid, acceptable, and responsive tools, but more assessment of EHP outcomes using modern psychometric methods and in the context of women from ethnically diverse backgrounds and in routine clinical care would be beneficial. Given the brevity of the EHP-5, it may be the most appropriate version to use in routine clinical practice, whereas the longer EHP-30, which provides more granularity, is more appropriate for research.