Objective: To develop and test the first specific instrument for assessing caregiver health-related quality of life (HRQOL) in multiple sclerosis (MS) (CAREQOL-MS).
Study design and setting: Questionnaire items were derived from a literature review and the views of patients, caregivers, and experts. Instrument was reduced after the analyses of caregivers' interviews and experts' opinions. CAREQOL-MS psychometric properties were assessed in 276 MS caregivers.
Results: The final version consisted of 24 items (five subscales) and was free of floor or ceiling effects. For subscales, the Cronbach's alpha coefficient ranged from 0.75 to 0.90. The item-total correlation was 0.62-0.74 for subscale I (physical burden/global health); 0.56-0.74 for subscale II (social impact); 0.52-0.62 for subscale III (emotional impact), and 0.58-0.65 for subscale IV (need of help); subscale V (emotional reactions) had only two items. The intraclass correlation coefficient (0.96 for the total score; 0.75-0.95 for subscales) suggested satisfactory reproducibility. Association was close between CAREQOL-MS subscales and the Zarit burden interview and moderate with short form 36 mental/physical components. CAREQOL-MS subscales scores significantly increased (worse HRQOL) with increasing caregivers' age and Expanded Disability Status Scale. The standard error of the measurement ranged from 0.91 to 2.43 for subscales.
Conclusions: Our results provided initial evidence of the usefulness and satisfactory psychometric properties of the CAREQOL-MS.
Copyright © 2011 Elsevier Inc. All rights reserved.