Content validation of the SF-36v2® Health Survey Acute for use in hypoparathyroidism

PURPOSE: The purpose of this study was to conduct cognitive debriefing (CD) interviews with adults diagnosed with chronic hypoparathyroidism (HP) to assess the content validity of the SF-36v2® Health Survey Acute (SF-36v2) measure in this population. METHODS: CD interviews were conducted with adults with HP in the United States (US). Interviews were conducted by a trained moderator using a semi-structured interview guide, employing a think-aloud method in conjunction with verbal probing. Participants were asked whether each item was understandable, relevant, important, and sensitive to change in relation to HP. Additionally, comprehension of instructions, response options, and the appropriateness of a 1-week recall period was assessed. RESULTS: Sixteen adults with HP participated in individual CD telephone interviews. All items in the SF-36v2 were reported to be understood, relevant, important, and sensitive to change by at least half, and in most cases, by a strong majority of study participants. Most of the study sample confirmed comprehension of the instructions and the entire sample understood all response options. CONCLUSION: The study findings show that the items in the SF-36v2® are applicable to adults with HP. The overall high levels of endorsement of items provide strong evidence of the measure’s content validity for this population. The SF-36v2 is therefore recommended for usage in clinical trials examining adults with HP, although it is recommended that this generic measure be supplemented with disease-specific instruments such as the recently developed Hypoparathyroidism Patient Experience Scale—Symptom (HPES-Symptom) and Hypoparathyroidism Patient Experience Scale—Impact (HPES-Impact) measures.