Development and Psychometric Properties of a Tuberculosis-Specific Multidimensional Health-Related Quality-of-Life Measure for Patients with Pulmonary Tuberculosis

Abstract

Background: Various generic instruments exist to assess health-related quality of life (HRQOL) in patients with tuberculosis (TB), but a psychometrically sound disease-specific instrument is lacking. Objectives: The present study aimed to develop and psychometrically validate a multidimensional TB-specific HRQOL instrument relevant to the value of patients with pulmonary TB in Iraq with an eye toward cross-cultural application. Methods: The core general HRQOL questionnaire is composed of the Functional Assessment of Cancer Therapy-General items. A modular approach was followed for the development of the Functional Assessment of Chronic Illness Therapy-Tuberculosis (FACIT-TB) questionnaire in which a set of items assessing quality-of-life (QOL) issues not sufficiently covered by the core Functional Assessment of Cancer Therapy-General items, but considered to be relevant to the target population, was added. Moreover, principal-component analysis was used to determine the new subscale structure of the questionnaire. Results: In addition to the 27 items of the core questionnaire, a set of 20 items referring to disease symptoms related to the site of infection, adverse effects, and additional QOL dimensions such as fatigue, social stigma, and economic burden of the illness was included. Factor analysis demonstrated that the FACIT-TB construct comprised five domains. Conclusions: A rigorous method was applied in the development of the FACIT-TB measure to fully understand the impact of TB on patients' QOL. The instrument is psychometrically sound and portrays multiple important dimensions of HRQOL. FACIT-TB is relatively brief, is easy to administer and score, and is appropriate for use in clinical trials and practice. 2015 International Society for Pharmacoeconomics and Outcomes Research (ISPOR).