A 12-week clinical trial (TIMES) demonstrated that therapy with tolterodine extended release (TOL) + tamsulosin (TAM) provides clinical benefits vs TOL or TAM monotherapy or placebo (PBO) in men with lower urinary tract symptoms (LUTS) including overactive bladder (OAB). The present analysis estimated the costs and quality-adjusted life-years (QALYs) associated with these therapies from the perspective of the UK healthcare system.
TIMES cohorts receiving TOL, TAM, TOL + TAM, or PBO were followed from therapy initiation to 12 weeks. A decision-tree model was used to extrapolate the 12-week results to 1 year (including need for surgery owing to treatment failure at 12 weeks) and to track patients’ outcomes (symptoms, utility, and costs). Because TIMES did not include costs and QALYs, data from the EpiLUTS epidemiologic survey (12,796 males) were used to model a mathematical relationship between LUTS (daytime and nocturnal frequency, urgency episodes, urgency urinary incontinence episodes, and International Prostate Symptom Score [IPSS]), quality-of-life, and utility. This was used to convert improvements in TIMES patients’ LUTS into utility scores and QALYs. The model included drug and surgery procedure costs and hospital length of stay.
Incremental QALYs of TOL + TAM vs PBO, TAM, and TOL were 0.042, 0.021, and 0.013, and corresponding incremental costs were £189, £223, and -£70, respectively, resulting in cost-utility ratios for TOL + TAM of £4508/QALY gained compared with PBO and £10,381/QALY gained compared with TAM. TOL + TAM combination therapy was both more effective and cost-saving compared with TOL. Univariate sensitivity analyses showed that patient utility was most responsive to changes in drug efficacy on IPSS and urgency episodes. Changing the percentage of patients undergoing surgery did not substantially affect model outcomes. The main limitation of the study was that the relation between LUTS and patient utility was based on an indirect association.
TOL + TAM combination therapy appears to be cost-effective compared with TOL or TAM monotherapy or PBO in male patients with LUTS.