Objectives: To assess changes in the health status of men with lower urinary tract symptoms associated with benign prostatic hyperplasia (LUTS/BPH) using the EQ-5D-3L and OAB-5D instruments and to evaluate the sensitivity of the instruments.
Methods: Data were available from a large randomised phase III trial of men with moderate-to-severe storage and voiding LUTS/BPH (NEPTUNE). Men received a fixed-dose combination of solifenacin 6 mg plus oral controlled absorption system (OCAS™) formulation of tamsulosin (TOCAS, 0.4 mg), TOCAS monotherapy or placebo and completed the EQ-5D-3L and OAB-5D at baseline and weeks 4, 8 and 12. Analysis of covariance was used to estimate changes in EQ-5D-3L Index, EQ-VAS and OAB-5D. Changes in dimension level were summarised using the Paretian Classification of Health Change (PCHC).
Results: Improved health-related quality of life from baseline was seen in all treatment arms on EQ-5D-3L and OAB-5D at week 12, although only OAB-5D showed statistically significant differences between active treatment and placebo, both on the index score and using the PCHC approach. Effect sizes in the active treatment groups were large (>0.8) on OAB-5D but small (≈0.2) on EQ-5D-3L. EQ-5D-3L showed a very high ceiling effect (45% of men reported full health at baseline) and a substantial proportion of these men reported improvements at week 12 in several dimensions of OAB-5D.
Conclusions: A large ceiling effect on EQ-5D-3L substantially limited its sensitivity in this population. OAB-5D proved more sensitive to changes in health status and could be considered a complement to ED-5D-3L as a source of utilities for health economic modelling.
Keywords: Health-related quality of life; LUTS/BPH; Solifenacin; Tamsulosin.