To evaluate the cost effectiveness of onabotulinumtoxinA (BOTOX®, 200 units [200 U]) for the management of urinary incontinence (UI) in adults with neurogenic detrusor overactivity (NDO) due to subcervical spinal cord injury or multiple sclerosis that is not adequately managed with anticholinergic drugs (ACHDs).Perspective
UK National Health Service (NHS) perspective.Methods
A Markov state-transition model was developed, which compared onabotulinumtoxinA + best supportive care (BSC) with BSC alone (comprising behavioural therapy and pads, alone or in combination with clean intermittent catheterization and possibly with ACHDs). Non-responders were eligible for invasive procedures. Health states were defined according to the reduction in UI episodes. Efficacy data and estimates of resource utilization were pooled from 468 patients on onabotulinumtoxinA in two phase III clinical trials. Drug costs (2013) and administration costs (NHS Reference Costs 2011-2012) were obtained from published sources. The time horizon of the model was 5 years, and costs and benefits were discounted at 3.5 %. Scenario, one-way and probabilistic sensitivity analyses (PSAs) were conducted to explore uncertainties around the assumptions.Results
In the base case, treatment with onabotulinumtoxinA + BSC over 5 years was associated with an increase in costs of £1,689 and an increase in quality-adjusted life-years (QALYs) of 0.4, compared with BSC alone, resulting in an incremental cost-effectiveness ratio of £3,850 per QALY gained. Sensitivity analyses showed that utility values had the greatest influence on model results. PSA suggests that onabotulinumtoxinA + BSC had a 100 % probability of being cost effective at a willingness to pay of <£20,000.Conclusion
For adult patients with NDO who are not adequately managed with ACHDs, onabotulinumtoxinA + BSC appears to be a cost-effective use of resources in the UK NHS.