A time-series analysis of the effect of increased copayments on the prescription of antidepressants, anxiolytics, and sedatives in Sweden from 1990 to 1999

Abstract

Background: Outpatient prescription medication spending in Sweden has increased sharply since 1974. The Swedish government has raised copayments to reduce medication consumption and limit the growth of medication spending.

Objective: The aim of this study was to examine the effect of the 1995 and 1997 copayment increases on Swedish consumption of antidepressants, anxiolytics, sedatives.

Methods: Monthly drug-use data for July 1990 through December 1999 for these 3 pharmaceutical classes were obtained from Apoteket AB (Stockholm, Sweden). Data were provided for both sexes in units of defined daily doses per 1000 inhabitants. These series were analyzed with the use of Box-Jenkins autoregressive, integrated, moving-average time-series modeling methods.

Results: Dispensing of all 3 drugs classes increased immediately before copayment changes, with the exception of male sedative use at the time of the 1997 reform. Permanent increases in male antidepressant and sedative use occurred before the 1995 copayment reform. Only female antidepressant use was permanently reduced following the 1997 copayment reform.

Conclusions: Our findings suggest that Swedish patients' valuation of mental health medications exceeds the enacted price increases. The permanent increases in male antidepressant and sedative use, beginning in 1995, may have been the result of previous undertreatment. The permanent reduction in female antidepressant use, beginning in 1997, suggests that the price levels reached a threshold that matched or exceeded Swedish women's valuation of these modific