Reliability, validity, and responsiveness of general and disease-specific quality of life measures in a clinical trial for cytomegalovirus retinitis

The objective of this study was to evaluate a questionnaire for assessing g eneral and disease-specific quality of life among people with cytomegalovir us (CMV) retinitis. Cross-sectional and longitudinal analyses of data from 279 people enrolled in the CMV Retinitis Retreatment Trial were used. At ba seline, Cronbach's alpha and multitrait analysis were used to assess intern al consistency and discriminant construct validity for scales of general he alth, vision, and treatment impact. Associations of scales with clinical me asures of health and vision were assessed at baseline with Pearson correlat ions and t tests, and over time with generalized estimating equations regre ssion. Internal consistency coefficients ranged from .68 to .88. Criteria f or discriminant validity were fulfilled for most scales; however, the gener al health perceptions and energy scales were highly correlated. Scales were moderately correlated with clinical measures at baseline. Over time, scale scores were associated with Karnofsky scores and clinical measures of CMV retinitis and vision. General and CMV retinitis-specific quality of life me asures appear reliable, valid, and responsive, (C) 2001 Elsevier Science In c. All rights reserved.