OBJECTIVES: In Ontario a variety of drug therapies for overactive bladder (OAB) are reimbursed by the public drug program.  However, all agents other than oxybutynin IR are available through limited access, which requires a trial of oxybutynin IR.  The objective of this study was to assess the cost effectiveness of alternative strategies for reimbursing OAB treatments. METHODS: A Markov model was developed to assess the cost and QALYs from OAB drugs and no therapy. The model incorporated the impact of treatment on the frequency of micturitions and incontinence episodes. Outcomes for each potential reimbursement strategy were assessed by a three step approach.  First, long term prescribing rates for each product were forecasted based on previous data. Prescribing rates under alternate strategies were estimated. Costs and QALYs for each strategy were estimated by weighting the costs and QALYs for each therapy by their prescribing rates under each strategy. Alternative strategies including expanding the list of reimbursed products, increasing access to products and enforcing step therapy (more restricted access). RESULTS: A strategy of enforcing step therapy whereby solifenacin (increased access) and oxybutynin IR were considered as first line therapies with enforcement of step therapy for certain other therapies (more restricted access) was the most cost effective scenario. CONCLUSIONS: Analysis supports the enforcement of step therapy whereby oxybutynin IR or solifenacin are considered first line therapy. Analysis suggests that suitable second line therapies may be mirabegron, fesoterodine and trospium. Darifenacin, oxybutynin ER, transdermal oxybutynin, oxybutynin gel, tolterodine ER and tolterodine IR are not cost effective.