The effect of deinsuring chlorpropamide on the prescribing of oral antihyperglycemics for Nova Scotia Seniors' Pharmacare beneficiaries.

On behalf of the Nova Scotia Seniors' Pharmacare Program, the Drug Evaluation Alliance of Nova Scotia developed a multicomponent intervention plan to facilitate the removal of chlorpropamide as an insured benefit. Chlorpropamide has caused serious hypoglycemia in seniors to a greater extent than some other agents. Pharmacy administrative claims were used to compute monthly use rates for insulin and each oral antihyperglycemic drug from January 1, 2000-December 30, 2002, in an intervention cohort (patients receiving chlorpropamide) and a control cohort (patients receiving an antihyperglycemic agent other than chlorpropamide). Initially, 630 patients were receiving chlorpropamide therapy. By the time chlorpropamide was deinsured, only 10% of the treatment cohort continued receiving chlorpropamide; shortly after deinsurance, no beneficiaries continued receiving the drug. The antihyperglycemics with the greatest increase in prescription were glyburide and gliclazide. The deinsuring of chlorpropamide and the educational strategies that accompanied it resulted in the selection of more appropriate antihyperglycemics for Nova Scotia seniors.

Trends in oral antihyperglycemic and insulin use in the Nova Scotia senior population (1993-1999).

Trends in prescribing patterns of insulin and oral antihyperglycemic drugs for Nova Scotia seniors pharmacare beneficiaries were examined from April 1, 1993 to March 31, 2000 and evaluated relative to published guidelines. The number of patients, prescriptions, and drug costs for oral antihyperglycemic drugs and insulins were calculated. The source of insulin was examined subsequent to the marketing of human insulin in 1993. The percentage of patients using human insulin increased from 66% in 1993 to 96% in 1995, and beef and pork insulin use decreased from 38% in 1993 to 19% in 1995. First generation sulfonylureas decreased between 1993 and 1999; chlorpropamide decreased from 23% to 7% of antihyperglycemic users, and tolbutamide decreased from 4% to 1%. Among second-generation sulfonyl-ureas, glyburide remained frequently used with 59% of antihyperglycemic users in 1999, while gliclazide increased in use from 2% to 22% between 1993 and 1999. Metformin, a biguanide, increased in use from 29% to 37% of antihyperglycemic users. Acarabose having been introduced to the market later, increased in use from 1% to 5% between 1996 and 1999. Once human insulin became available, patients were rapidly transferred from animal to human insulin. Chlorpropamide remained widely used despite safety concerns for use in the elderly. Glyburide was the most frequently prescribed oral antihyperglycemic agent. Recently raised concerns about its safety in patients with renal disease require follow-up. Further work is needed to determine the reasons for slow uptake of recommendations related to chlorpropamide and the effect of switches to human insulin and newer oral antihyperglycemics on patient outcomes and health care costs.

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 broadspectrum 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.