Purpose: Overactive bladder is a common disease for which current pharmaceutical treatment is often unsatisfactory.� Antimuscarinic medications have been the mainstay of treatment, but 1 year discontinuation rates are often >75% due to side effects.� Newer modalities, including Botox� and Interstim�, can be used when antimuscarinics are unsuccessful.� Our objective was to compare Interstim� and Botox� therapies for urge incontinence refractory to antimuscarinics.
Methods: A decision analysis model was constructed using values for efficacy and complications from the literature.� Markov state transition modelling was used with health states and transitions between states designed to fully account for the complex interplay of therapeutic efficacy and multiple possible complications.� Overall utility for the two operations was compared monthly for a period of 54 months, the average Interstim� battery life.� Multiple one-way sensitivity analyses for all utilities and outcome probabilities were performed.
Results: For every month during the simulation the overall utility value was higher for Botox� than Interstim�.� After 54 months cumulative utility was 3.86 vs. 3.74 favoring Botox� for an average yearly quality adjusted life year (QALY) value of 0.86 vs. 0.83.� All differences between the two surgeries were less than published minimally important differences (MID) for utilities.� Few meaningful threshold values were established supporting the robustness of our model results.
Conclusions: While Botox� has higher average QALYs at all time points, the differences are less than the MID.� Therefore, the two operations are highly comparable with similar overall utility.� Until appropriately powered randomized controlled trials are available, both operations are reasonable and effective strategies for the treatment of urge incontinence refractory to antimuscarinic therapy.� They have similar QALY outcomes when considering efficacy and complications. 
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