Development of the short form Endometriosis Health Profile questionnaire: The EHP-5

Objective: To develop and validate a short form version of the Endometriosis Health Profile-30 questionnaire which consists of a 30-item core questionnaire and a 23 item modular questionnaire. Methods: Three studies were carried out to develop the Endometriosis Health Profile-5. Study 1: a short form version of the Endometriosis Health Profile-30 core questionnaire was developed. Study 2: the results were verified in a new data set. Study 3: a short form version of the 23 item modular questionnaire was produced. The modular questionnaire contains six dimensions which may not be applicable to every woman with endometriosis and is used to supplement the five scales on the core questionnaire when required. Results: The final instrument contained 11 items:five items from the core questionnaire and six items from the modular questionnaire. The 95% confidence intervals for Study 1 indicated that the scale scores overlapped with each item score and were confirmed in the second analysis ( study 2). Each item was most highly correlated to its parent scale and less with the remaining four core questionnaire scales which was verified in study 2. In both studies all correlations were significant at the 0.01 level ( two tailed test). Conclusion: The Endometriosis Health Profile-5 is a reliable and valid short form questionnaire which can also be supplemented with a short form version of the modular questionnaire when required. It will be especially useful in clinical settings where a short and economical endometriosis health status measure is required.