OBJECTIVES: The Hypoparathyroidism Daily Diary of Symptom Experience (HPT-DD-SE) and Hypoparathyroidism Life Impact Questionnaire (HPT-LIQ) are new disease-specific, patient-reported outcome (PRO) measures to assess the effect of investigational treatment on symptoms and health-related quality of life (HRQOL) in patients with Hypoparathyroidism (HPT). Originally developed in US English, the measures were adapted into 16 additional languages.

METHODS: The adaptation of the HPT-DD-SE and HPT-LIQ adhered to published International Society for Pharmacoeconomics and Outcomes Research and Food and Drug Administration guidelines requirements for PRO measures to support labelling claims. The adaptation procedure involved two independent forward translations, back translation, and a conceptual equivalence review. Each language adaptation underwent in-country cognitive debriefing (CD) to evaluate content validity with HPT patients who were native speakers of the target language.

RESULTS: The HPT-DD-SE and HPT-LIQ were adapted into 16 languages for 14 countries in Europe, North America, and Australia. The CD sample (N=80; 5 per language) was 71% female, and had an age range of 21-78. The mean age per target language CD sample ranged from 36.5 to 62.5 years. Mean years in education ranged from 10.4 to 16.6 years. The adaptation of the HPT-DD-SE and HPT-LIQ into the new languages was successful; minor changes were made to the harmonised translations prior to the CD interviews to ensure conceptual equivalence with the US-English HPT-DD-SE and HPT-LIQ. Following the CD interviews, minor changes were made to the translations to improve grammar or localise wording for greater conceptual clarity. The CD results demonstrate that patients in the target countries found the HPT-DD-SE and HPT-LIQ to be clear, comprehensive, and understandable.

CONCLUSIONS: The HPT-DD-SE and HPT-LIQ were successfully adapted into 16 new languages according to regulatory and industry standards. The new language adaptations of the measures significantly improve their suitability for use in multinational clinical trials.