A Pharmacoeconomic Model Comparing Two Long-Acting Treatments for Overactive Bladder

Abstract

Authorshe cost of overactive bladder (OAB) is a significant financial burden on patients, families, and the health care system. In 2000, the total economic cost of OAB in the United States was estimated at $18.2 billion, which is more than either osteoporosis or Parkinson' s disease. OAB costs at the community level were approximately $13.8 billion, while costs at institutions were $4.4 billion.1 A study examining insurance claims showed that total annual claims among OAB patients was $5,018 versus $1,767 among non-OAB controls (1995 dollars). 2Drug Treatment for OAB Head-to-head studies comparing 2 immediate-release forms of antimuscarinic drug therapy, oxybutynin, and tolterodine, have shown that they have similar efficacy; however, tolterodine has an improved side-effect profile, most notably less dry mouth, and is associated with fewer treatment withdrawals as a result of drug-related adverse events. 3-7The side effects from OAB drug therapy have resulted in poor compliance and, subsequently, low persistence with therapy over time. 4,8,9 Persistence with drug therapy is important for achieving long-term treatment benefits. In a number of retrospective claims studies, patients receiving tolterodine have been shown to remain on therapy longer than those receiving oxybutynin. 6,[9][10][11][12][13][14][15] There is also evidence that suggests that OAB patients who are able to continue with medication have greater symptom improvement and use fewer resources. 16Phase III clinical trials of controlled-release oxybutynin have indicated better patient compliance, reduced side effects, and equivalent efficacy as compared to oxybutynin IR. [17][18][19] Both extended-release tolterodine and controlled-release oxybutynin have been shown to be more effective and better tolerated than immediate-release tolterodine. 20,21 These data further suggest that extended-release tolterodine has better tolerability and fewer side effects than controlled-release oxybutynin. Although there are no head-to-head studies to suggest that one of the extended-release drugs is more efficacious than the other, one recent study compared extended-release tolterodine to controlled-release oxybutynin using a 4-way crossover design in a small number of patients. 22 Using change in bladder capacity as a surrogate for efficacy, a 6 mg dose of extended-release tolterodine was found to be equivalent to a 20 mg dose of oxybutynin. However, the 6 mg dose of extended-release tolterodine produced a side-effect profile with respect to dry mouth similar to the 10 mg dose of controlled-release oxybutynin. This implies that extended-release tolterodine might be as efficacious as oxybutynin but has an improved tolerability profile. T A B S T R A C TOBJECTIVE: To compare the estimated first-line treatment costs of extended-release tolterodine versus controlled-release oxybutynin in patients with overactive bladder (OAB).METHODS: We developed a decision-analysis model to estimate the patterns of treatment, resource consumption, and cost impact of treating OAB with...

Persistence and adherence in the treatment of overactive bladder syndrome with anticholinergic therapy: a systematic review of the literature

“…Consistent with findings from Noe et al. (26), results also suggested that OAB induced‐comorbidities constitute a greater proportion of total treatment costs for OAB than drug costs.…”

“…Two studies also demonstrated that drug costs were a small percentage of the total costs incurred as a result of OAB (26,169). Noe et al.…”

“…Noe et al. (26) found that drug costs accounted for a fraction of the total costs for OAB over a 3‐month period. Ko et al.…”

“…Fourteen studies evaluating persistence and ⁄ or adherence with anticholinergic treatment for OAB using medical claims data were identified in this review, and results suggest markedly higher rates of discontinuation than what has been reported in clinical trials (25,26,31,32,(158)(159)(160)(162)(163)(164)(165)(166)(167)169). Several studies in the US examined persistence and ⁄ or adherence for multiple anticholinergic medications commonly used to treat OAB.…”

“…Although anticholinergic mediations have been shown to improve patients’ symptoms, they create a widespread blockade of cholinergic activity that often result in side effects such as dry mouth, urinary retention, constipation and blurred vision, as well as central nervous system effects such as somnolence and confusion (23). These adverse effects can be highly bothersome to patients and – along with other factors such as insurance limits and cost concerns, inconvenience and low efficacy (25) – may diminish patient persistence and adherence to treatment (26,27).…”