Is the 30-item Endometriosis Health Profile (EHP-30) suitable as a self-report health status instrument for clinical trials? This prospective study aimed to evaluate the suitability of the Endometriosis Health Profile–30 Questionnaire (EHP-30) as a self-report health status instrument. We compared our results with those from the U.K. and the U.S. and discovered relationships between the EHP-30 and patient characteristics. The results showed that the EHP 30 questionnaire is a user-friendly self-report tool suitable for use in endometriosis-related clinical research. (Fertil Steril 2010;94:1928–32. 2010 by American Society for Reproductive Medicine.)
Endometriosis is a common gynecologic disease which can affect many different aspects of life of women of reproductive age (1). Advances in the treatment of this disease, however, have been hampered by great difficulty in understanding and comparing results of clinical trials within one center over a period of time or between different centers which used different instruments to measure health status and quality of life. In addition, most published studies have used generic instruments, such as the Short Form–36 (SF-36) (2) and the Nottingham Health profile (3), which may not address issues which are important and unique to women with endometriosis. To overcome many of these difficulties, a group of researchers developed the 30-item Endometriosis Health Profile (EHP-30) in 2001 (4). This was the first healthrelated quality-of-life (HRQoL) questionnaire developed with the help of patients with endometriosis via in-depth interviews to specifically address the impact of the disease on the physical, psychologic, and social aspects of their lives. The EHP-30 questionnaire comprises two parts. A core questionnaire which consists of five scales (pain, control and powerlessness, emotional well-being, social support, and self-image) contains a total of 30 items. This section is applicable to all women with endometriosis. And a modular questionnaire, which does not Su-Yen Khong, M.R.C.O.G.a Alan Lam, F.R.A.N.Z.C.O.G.a Georgina Luscombe, Ph.D.b a Centre for Advanced Reproductive Endosurgery, St. Leonards, New South Wales, Australia b Department of Obstetrics and Gynaecology, Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia Received September 11, 2009; revised January 13, 2010; accepted January 15, 2010; published online February 27, 2010. S.-Y.K. has nothing to disclose. A.L. has nothing to disclose. G.L. has nothing to disclose. Reprint requests: Alan Lam, F.R.A.N.Z.C.O.G., Centre for Advanced Reproductive Endosurgery, AMA Building, Suite 408, Level 4, 69 Christie Street, St. Leonards, NSW 2065, Australia (FAX: þ612 99669126; E-mail:
[email protected]).
1928
necessarily apply to all women with endometriosis, consists of six scales (work, relationship with children, sexual intercourse, infertility, medical profession, and treatment) and contains a total of 23 items. Items within scales are summed to create a raw score, and then each scale is translated into a score ranging from 0 (best health status) to 100 (worst health status). This scaled score is equal to the total of the raw scores of each item in the scale divided by the maximum possible raw score of all the items in the scale, multiplied by 100. The aims of the present study were: 1) to evaluate the suitability of the EHP-30 as a self-report health status instrument; 2) to compare our results with those from the U.K. and the U.S.; and 3) to explore the relationships between the EHP-30 and patient characteristics. Data were collected prospectively from patients seen at a tertiary referral center between August 2006 and August 2008. All patients presented with pelvic pain, with or without infertility, and all were either suspected of having endometriosis or referred with a known history of endometriosis confirmed by earlier laparoscopy. Each patient was given an EHP-30 questionnaire to self-complete at her first visit. The information from the returned questionnaires was then entered into a computer database and analyzed using the Statistical Package for Social Sciences (SPSS) for Windows version 15. The suitability of the EHP-30 form for use in the Australian population was assessed by examining item and scale completion. In turn, the results were compared with those reported from U.K. (5) and U.S. studies (6). One-sample t tests were used to compare mean scores in the present study against previously published means, and effect sizes (Cohen d) were calculated to estimate the size and direction of these differences. Any relationships between the EHP-30 scores and the patient characteristics were explored using Pearson correlation (for normally distributed data) or Spearman rho (denoted by rs) for skewed data calculations. Alpha was set at .05. There were a total of 195 women in this study. The mean age of the respondents was 34.6 years (SD 7.6, range 19–56 years). The
Fertility and Sterility Vol. 94, No. 5, October 2010 Copyright ª2010 American Society for Reproductive Medicine, Published by Elsevier Inc.
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TABLE 1 Data completeness for core scales and items of the EHP-30. Question Pain Been unable to go to social events because of the pain? Been unable to do jobs around the home because of the pain? Found it difficult to stand because of the pain? Found it difficult to sit because of the pain? Found it difficult to walk because of the pain? Found it difficult to exercise or do the leisure activities you would like to do because of the pain? Lost the appetite and/or been unable to eat because of the pain? Been unable to sleep properly because of the pain? Had to go to bed/lie down because of the pain? Been unable to do the things you want to do because of the pain? Felt unable to cope with the pain? Control and powerlessness Generally felt unwell? Felt frustrated because your symptoms not getting better? Felt frustrated because you are not able to control your symptoms? Felt unable to forget your symptoms? Felt as though your symptoms are ruling your life? Felt your symptoms are taking away your life? Emotion Felt depressed? Felt weepy/tearful? Felt miserable? Had mood swings? Felt bad-tempered or short-tempered? Felt violent or aggressive? Social support Felt unable to tell people how you feel? Felt others do not understand what you are going through? Felt as though others think you are moaning? Felt alone? Self-image Felt frustrated as you can not always wear the clothes you would choose? Felt your appearance has been affected? Lacked confidence?
No. missing
% missing data (n [ 195)
6 1 1 1 0 0 0
3.1 0.5 0.5 0.5 0.0 0.0 0.0
0 1 0 2 1 3 1 0 0 2 1 0 5 1 1 2 1 1 0 2 0 1 0 1 0 0 0 0
0.0 0.5 0.0 1.0 0.5 1.5 0.5 0.0 0.0 1.0 0.5 0.0 2.6 0.5 0.5 1.0 0.5 0.5 0.0 1.0 0.0 0.5 0.0 0.5 0.0 0.0 0.0 0.0
Khong. Correspondence. Fertil Steril 2010.
average age at symptom onset was 24.3 years (SD 8.1, range 10.8 to 46.0 years; n ¼ 144). The average time since onset of symptoms to first consultation at our unit was 9.8 years (SD 8.5, range 0 to 38.7 years; n ¼ 145), although the average time from symptom onset to first diagnosis of endometriosis was 4.5 years (SD 6.3, range 0 to 30.2 years; n ¼ 111). The period from diagnosis of endometriosis to first consultation at our unit was 6.3 years (SD 5.6, range 0 to 20.5 years; n ¼ 129). Data completeness was very high, with 99.5% of patients (195 out of 196) returning completed questionnaires. Item response rates were also high ,with 94.4% (184 out of 195) completing all of the items within the core questionnaire. The missing response rates for each item in the core section ranged from 0.5% to 1.0%; data were complete except for 16 items, 13 of which were missing for only one subject (0.5%) and 3 missing for two subjects (1%; Table 1). Data from 193 out of the 195 patients were considered for the modular component when assessing data completeness (two patients answered
