Test-Retest Reliability of an Interactive Voice Response Version of the EQ-5D in a Sample of Cancer Survivors

    loading  Checking for direct PDF access through Ovid



Electronic data capture technologies, such as interactive voice response (IVR) systems, are emerging as important alternatives for collecting patient-reported outcome data.


The objective of this study was to assess the test-retest reliability of an IVR version of the EQ-5D.


Outpatient cancer clinic patients (n = 127) were asked to complete the IVR-based EQ-5D twice, 2 days apart. The analyses tested for mean differences (paired t-test) and test-retest reliability (intraclass correlation coefficient [ICC]) to assess measurement stability over time. Equivalence of the means was established if the 95% confidence interval (CI) was within the minimally important difference (MID) interval; namely −0.035 to 0.035 for the EQ-5D index and −3.0 to 3.0 for the visual analog scale (i.e. EQ VAS). Adequacy of the ICC was established by testing whether it differed from a value of 0.70.


Both administrations were completed per protocol by 114 subjects (EQ-5D index) and 110 subjects (EQ VAS). For the EQ-5D index, the means (SD) of the first and second administrations were 0.871 (0.14) and 0.871 (0.15), respectively. The 95% CI of the mean difference was −0.013, 0.013, within the equivalence interval. The ICC was 0.876 (95% lower bound of 0.826) and was significantly different from 0.70. The EQ VAS means (SD) were 81.3 (17.5) and 80.8 (17.5), respectively. The 95% CI of the mean difference was −0.598, 1.617, within the equivalence interval. The EQ VAS ICC was 0.944 (95% lower bound of 0.919) and was significantly greater than 0.70.


This analysis provides substantial evidence that the scores obtained from the IVR version of the EQ-5D are reliable upon repeated administrations.

Related Topics

    loading  Loading Related Articles