Is EQ-5D-5L sensitive enough to detect treatment-related changes in health status of prostate cancer patients? A nationwide Norwegian longitudinal study from the prostate cancer registry

To examine the generic European Quality of Life 5-Dimensions questionnaire (EQ-5D-5L) responsiveness to change in health status of patients with invasive prostate cancer (PCa) from pre- to post-treatment and compare these results with the responsiveness of disease-specific instruments assumed to be particularly sensitive to change in a large sample of PCa patients. In this nationwide registry study (2017–2019), PCa patients in Norway (n = 620) and a matched reference group from the general population without previous cancer history (n = 1776) were invited. All participants completed the EQ-5D-5L, the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC-QLQ-C30) and the Expanded Prostate Cancer Index Composite short form (EPIC-26) pre- and post-treatment. Paired t-tests were performed with latent change scores in a structural equation model framework. EQ-5D-5L showed minor changes from pre- to post-treatment for four dimensions and sum score (Cohen’s d ≤ 0.20). EORTC-QLQ-C30 revealed a moderate decline in social function (-9.85, p < 0.001, Cohen’s d -0.52). EPIC-26 showed a large decline in sexual function (-38.1, p < 0.001, Cohen’s d -1.42), and urine incontinency (-24.3, p < 0.001, Cohen’s d -1.86). Correlations between change in EQ-5D-5L and change in domains found to be important for participants with PCa (sexual function, urine incontinence and social function) revealed small to medium correlations for the PCa group. The low responsiveness indicates that the EQ-5D-5L is not sensitive enough in detecting health status changes due to significant problem areas in PCa patients. Adding disease-specific measures is pivotal to measuring these changes in health status.