DEVELOPMENT OF THE MULTIDIMENSIONAL INDEX OF LIFE QUALITY - A QUALITY-OF-LIFE MEASURE FOR CARDIOVASCULAR-DISEASE

OBJECTIVES. The purpose of this study was to design a multidimensional measure of health-related quality of life appropriate for patients wi th cardiovascular disease that was psychometrically sound, brief, and easy to administer. METHODS. Qualitative interviews conducted with hea lthy subjects and patients with cardiovascular diseases identified nin e major quality of life domains. Based on the responses of 129 cardiov ascular disease patients recruited from hospitals and clinics, a crite rion-based approach was used to select 35 questionnaire items that bes t tapped these domains. Psychometric properties of the Multidimensiona l Index of Life Quality (MILQ) were tested with a sample of 348 patien ts with various cardiovascular diseases. RESULTS. Cronbach's alpha was 0.76 or higher for eight of the nine MILQ domains. Test-retest reliab ility coefficients were 0.73 or greater in all but two domains. Indivi dual domain scores as well as a weighted overall quality of life index were correlated highly with self-assessed health and the number of he art-related symptoms. CONCLUSIONS. The Multidimensional Index of Life Quality is a psychometrically reliable and valid instrument for measur ing quality of life in patients with cardiovascular diseases. The MILQ also may be a suitable measure for other types of chronic diseases.