Average duration of treatment with antidepressants among concession card holders in Australia.

Abstract

To analyse the average treatment duration with antidepressants that are reimbursed for concession card holders under the Pharmaceutical Benefits Scheme in Australia. This pharmacoepidemiological study was based on a representative 10% sample of patients receiving Pharmaceutical Benefits Scheme prescriptions. Antidepressants redeemed by concession card holders in the period from 2010 to 2013 were analysed. A 5-year baseline period was used to exclude prevalent users from incident users. Estimation of treatment duration was based on the epidemiological equation: prevalence/incidence = average duration. The mean value for prevalence and incidence over the studied period was used in the equation. The number of prevalent and incident users increased from 90,475 to 103,305 and from 25,006 to 26,289, respectively. The epidemiological average treatment duration in the period was about 4 years. When considered by age-bands, average treatment duration was 2 years in patients under 24 years, 3 years in patients 35 to 44 years and up to 5 years in the 55 to 64 year age group. Of new users of antidepressants reimbursed under the Pharmaceutical Benefits Scheme, 86% received their first prescription from general practitioners, 4.3% from psychiatrists and 9.7% from other physicians. While recommendations have underlined the importance of giving antidepressants for a sufficient period of time, the results from this study show that it is as important to remind general practitioners to review patients on antidepressant treatment regularly, and try to cease drug treatment when timely.