Development and psychometric evaluation of the loneliness inventory for older adults (Lonely): A mixed‐methods study

AIM: To develop and initially validate the Loneliness Inventory for Older Adults. DESIGN: Scale development and evaluation. METHODS: This was a two‐phase study. In phase 1, the initial items pool (126 items) was generated based on the concept analysis and literature review. Moreover, content validity was established by geriatric and psychometric experts. Phase 2 evaluated structural validity by performing item analysis, exploratory factor analysis and convergent validity. Reliability was evaluated by examining internal consistency, stability (ICC) and absolute reliability. RESULTS: Following the development process, 94 items were removed and a provisional version of the questionnaire with 32 items was subjected to psychometric evaluation. Three hundred and seventy older adults completed the questionnaire. After performing factor analysis, overall 3 items were removed due to low loading, and the questionnaire was reduced to 29 items tapping into five factors. The Cronbach's alpha for the instrument was 0.94, and the ICC value was 0.97.