Marc Dorais1, Jacques LeLorier. 1. Research group in Pharmacoepidemiology and Pharmacoeconomics, Research Center, Centre Hospitalier de l'Université de Montréal - Hôtel-Dieu (CHUM), Montréal, Québec.
Abstract
BACKGROUND: In the province of Quebec, Canada, the reimbursement of thiazolidinediones (TZDs) is limited to patients who do not respond to doses of metformin and a sulfonylurea. OBJECTIVES: The objective of this research project was to study, in a real-life setting, the ârisk factorsâ for receiving these restricted drugs among patients who meet the reimbursement criteria. METHODS: Among patients eligible for drug coverage under the RAMQ between May 2000 and June 2005, we selected those who received six consecutive dispensations of high doses of both metformin and a sulfonylurea. The date of the sixth dispensation was set as the index date. The proportion of patients who received a TZD in the year following the index date was calculated and a logistic regression was used to estimate the impact of several factors on the probability of receiving a TZD. RESULTS: There were 4,836 patients in the cohort. A TZD was dispensed to 24.9% (95% CI: 23.7%;26.2%) of the patients. Compared to the oldest group of patients (65 years and more), the probability to receive a TZD was higher for patients aged 51 to 64 years (OR=1.33 95% CI: 1.11;1.59) and patients aged 19 to 50 years [OR=1.81 (95% CI: 1.40;2.33)]. Patients with the highest income were more likely to receive a TZD (OR=1.55 95% CI: 1.21;1.98) compared to patients with the lowest income. CONCLUSIONS: These findings suggest that the restricted access to TZDs probably results in social inequities, as individuals with lower incomes are less likely to receive these drugs. Key words: Restricted drugs, TZDs, diabetes.
BACKGROUND: In the province of Quebec, Canada, the reimbursement of thiazolidinediones (TZDs) is limited to patients who do not respond to doses of metformin and a sulfonylurea. OBJECTIVES: The objective of this research project was to study, in a real-life setting, the ârisk factorsâ for receiving these restricted drugs among patients who meet the reimbursement criteria. METHODS: Among patients eligible for drug coverage under the RAMQ between May 2000 and June 2005, we selected those who received six consecutive dispensations of high doses of both metformin and a sulfonylurea. The date of the sixth dispensation was set as the index date. The proportion of patients who received a TZD in the year following the index date was calculated and a logistic regression was used to estimate the impact of several factors on the probability of receiving a TZD. RESULTS: There were 4,836 patients in the cohort. A TZD was dispensed to 24.9% (95% CI: 23.7%;26.2%) of the patients. Compared to the oldest group of patients (65 years and more), the probability to receive a TZD was higher for patients aged 51 to 64 years (OR=1.33 95% CI: 1.11;1.59) and patients aged 19 to 50 years [OR=1.81 (95% CI: 1.40;2.33)]. Patients with the highest income were more likely to receive a TZD (OR=1.55 95% CI: 1.21;1.98) compared to patients with the lowest income. CONCLUSIONS: These findings suggest that the restricted access to TZDs probably results in social inequities, as individuals with lower incomes are less likely to receive these drugs. Key words: Restricted drugs, TZDs, diabetes.