Using EQ-5D-3L and OAB-5D to assess changes in the health-related quality of life of men with lower urinary tract symptoms associated with benign prostatic hyperplasia

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.

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).

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.

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.