Comparison of anti-infective drug use in elderly persons in Manitoba, Nova Scotia, and Saskatchewan, Canada: Relationship to drug insurance reimbursement policies

Background: Antimicrobial drug resistance continues to be a concern. Inappropriate use of antimicrobial agents is a well-documented contributory factor in the development of resistance. Canadian publicly funded drug insurance (pharmacare) programs have various approaches to reimbursement for antimicrobial drugs and promoting the appropriate prescribing of these agents. Objective: The objective of this study was to examine changes in antimicrobial use over a 3-year period in relation to the reimbursement policies of the public drug insurance programs for elderly persons in Manitoba, Nova Scotia, and Saskatchewan. Methods: The pharmacare databases of the 3 provincial drug insurance programs were accessed for fiscal years 1995/96, 1996/97, and 1997/98. Antimicrobial drug use was reported as mean age- and sex-standardized defined daily doses (DDDs) dispensed per 1000 beneficiaries per year. Provincial antimicrobial drug use was compared and related to provincial reimbursement policies. Results: The rates and types of antimicrobial drugs dispensed to elderly beneficiaries of the Manitoba, Nova Scotia, and Saskatchewan pharmacare programs varied. Between fiscal years 1995/96 and 1997/98, DDDs of antimicrobials per 1000 beneficiaries per year decreased by 11.5% in Saskatchewan and increased by 1.2% in Manitoba and 6.2% in Nova Scotia. Rates of use of broad-spectrum agents such as amoxicillin/clavulanate, azithromycin, clarithromycin, and fluoroquinolones were lower in the provinces that had reimbursement guidelines. Even when reimbursement policies were similar, as for fluoroquinolones in Manitoba and Saskatchewan, rates of use varied markedly, possibly as a result of the method of implementing the reimbursement guidelines. Use of fluoroquinolones, macrolides, penicillins, beta-lactamase-resistant penicillins, and tetracyclines was lower and use of sulfonamides and trimethoprim was greater in Saskatchewan than in Nova Scotia and Manitoba. Conclusions: The reimbursement guidelines of provincial drug insurance programs are among the factors affecting the use of antimicrobial agents. Both the type of reimbursement policy and the policy implementation mechanism affected the rate of utilization. Further research is needed to link drug-use information with data such as antimicrobial resistance patterns, diagnoses, physician visits, and hospitalizations.