The unintended (and costly) effects due to the introduction of an unrestricted reimbursement policy for atypical antipsychotic medications in a Canadian public prescription drug program: 1996/97 to 2005/06.

BACKGROUND: Due to the increasing costs of pharmaceuticals, drug benefit programs often implement various policies that limit availability of drugs. These policies can have unforeseen consequences. OBJECTIVES: To examine the utilization and expenditures for antipsychotic medications in a provincial government community-based drug program over a 10-year period when atypical antipsychotics were introduced and multiple reimbursement policy changes with respect to these agents were employed. METHODS: Retrospective analysis of the Newfoundland and Labrador Prescription Drug Program (NLPDP) claims database from 1996/97 to 2005/06. Antipsychotic medication utilization and expenditure were measured and effects of changes in reimbursement policies examined. Excess expenditure was measured by subtracting the actual from modelled expenditure under different policies. RESULTS: Between 1996/97 and 2005/06, the number of prescriptions for antipsychotic medications increased by 75% and expenditures by more than 720% to $7.2 million (peaking at $7.9 million in 2003/04), with atypical agents making up 96% of the total. Expenditure for antipsychotic medications grew by an annual average rate of 26.3%. At the same time, the number of people enrolled in the drug program declined by an annual average rate of 1.13%. The total excess amount of money spent was $266,195 per 1,000 beneficiaries during unlimited access to atypical agents. CONCLUSION: There has been a substantial, unintentional, increase in the prescribing of atypical antipsychotics each year in Newfoundland and Labrador over the 10 years, likely due to off-label use following the unrestricted and partial restrictive access policies for these medications. Perhaps restricted access for recognized usage should be enforced.