Computerized administration of health-related quality of life instruments compared to interviewer administration may reduce sample size requirements in clinical research: a pilot randomized controlled trial among rheumatology patients.
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OBJECTIVES: Computerized health-related quality of life (HRQoL) administration may facilitate clinical trials incorporating HRQoL assessment in rheumatology patients by reducing sample size requirements. We tested this hypothesis in a pilot randomized controlled trial. METHODS: Chinese-speaking adult rheumatology outpatients were randomized to computerized (PC) or interviewer (IA) administration of the EQ-5D (utility & VAS), Health Utilities Index (HUI2 & HUI3) and Family Functioning Measure (FFM). We compared measurement variability (i.e., variance) between PC and IA for each instrument before (Levene's test) and after adjusting for the effects of age, gender and education (multivariable modeling) and computed the variance ratio (VR) for PC over IA. RESULTS: In 138 patients (mean age: 48), the mean (SD) time for administration was similar for PC (n = 67) and IA (n = 71) at 17.7 (7.94) versus 17.3 minutes (7.49), respectively. More subjects expressed a preference for PC (n = 21) over IA (n = 13). Mean HRQoL scores were not significantly different for PC versus IA except for higher VAS scores with IA (difference -7.7, 95% CI -14.0 to 1.3, p = 0.018). Variances and adjusted VR were smaller with PC for the EQ-5D (adjusted VR 0.34, 95% CI 0.18 to 0.65), HUI3 (0.49, 0.27 to 0.89) and FFM (0.95, 0.61 to 1.46), but larger for the HUI2 (1.30, 0.67 to 2.55) and VAS (1.05, 0.55 to 2.00). CONCLUSION: The reduced variability in 3 of 5 instruments and good acceptance of computerized HRQoL assessment, if confirmed in larger studies, may lead to smaller sample size requirements, with potential reductions in cost and recruitment time for clinical trials and cohort studies.
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