Assessing the Patient Experience of Hypoparathyroidism Symptoms: Development of the Hypoparathyroidism Patient Experience Scale-Symptom (HPES-Symptom)

BACKGROUND AND OBJECTIVE: Hypoparathyroidism is a rare endocrine disorder characterized by absent or inappropriately low levels of circulating parathyroid hormone. Patients with hypoparathyroidism receiving standard-of-care therapy report debilitating physical and cognitive symptoms, which may indicate a reduced health-related quality of life. The purpose of this study was to develop a new disease-specific measure of the signs and symptoms of hypoparathyroidism, the Hypoparathyroidism Patient Experience Scale-Symptom (HPES-Symptom), and provide evidence for the content validity of items in the measure based on rigorous qualitative research methodologies for patient-reported outcome development. METHODS: Semi-structured, individual concept elicitation interviews were conducted with five clinical experts and 42 adults with hypoparathyroidism in the USA to identify the signs and symptoms of relevance and importance to those with the condition. Transcripts were coded and analyzed using an adapted grounded theory approach. Following item generation, cognitive debriefing interviews of the draft measure were conducted in an independent sample of 16 adults with hypoparathyroidism. RESULTS: One hundred percent of the concept elicitation patient sample reported experiencing physical symptoms that were attributed to hypoparathyroidism, including tingling/numbness/paresthesia (n = 37, 88%), muscle cramping (n = 36, 86%), and physical fatigue (n = 35, 83%). The majority of patients (n = 36, 86%) further reported experiencing cognitive dysfunction, including impaired memory (n = 24, 57%), impaired ability to have a conversation (n = 21, 50%), and lack of concentration/focus (n = 18, 43%). Seventeen major signs and symptoms were identified during item generation and included in the preliminary measure. After the cognitive debriefing, the 17-item HPES-Symptom was generated. CONCLUSIONS: The findings provided evidence of content validity for the HPES-Symptom in US adults with hypoparathyroidism. Additional research is needed to validate the measure in patients with hypoparathyroidism to assess its psychometric properties.