Time Series Analysis on the Impact of Generic Substitution and Reference Pricing on Antipsychotic Costs in Finland
Abstract
Objectives
To analyze the medium- to long-term impact of generic substitution and the reference price system on the daily cost of antipsychotics in Finland. The additional impact of reference pricing over and above previously implemented generic substitution was also assessed.
Methods
An interrupted time series design with a control group and segmented regression analysis was used to estimate the effect of the implementation of generic substitution and the reference price system on the daily cost of antipsychotics. The data have 69 monthly values of the average daily cost for each of the studied antipsychotics: 39 months before and 30 months after the introduction of reference pricing. For one of the studied antipsychotic, the time before the introduction of reference pricing could be further divided into time before and after the introduction of generic substitution.
Results
According to the model, 2.5 years after the implementation of reference pricing, the daily cost of the studied antipsychotics was 24.6% to 50.6% lower than it would have been if reference pricing had not been implemented. Two and a half years after the implementation of the reference price system, however, the additional impact of reference pricing over and above previously implemented generic substitution was modest, less than 1 percentage point.
Conclusions
Although the price competition induced by reference pricing decreased the prices of antipsychotics in Finland in the short-term, the prices had a tendency to stagnate or even to turn in an upward direction in the medium- to long-term. Furthermore, the additional impact of reference pricing over and above previously implemented generic substitution remained quite modest.
Authors
Hanna Koskinen, Hennamari Mikkola, Leena K Saastamoinen, Elina Ahola, Jaana E Martikainen
Additional Information
- Peer-Reviewed: yes.
- Open Access: yes.
- Cite as: Koskinen, H., Mikkola, H., Saastamoinen, L. K., Ahola, E., & Martikainen, J. E. (2015). Time Series Analysis on the Impact of Generic Substitution and Reference Pricing on Antipsychotic Costs in Finland. Value in health : the journal of the International Society for Pharmacoeconomics and Outcomes Research, 18(8), 1105–1112. https://doi.org/10.1016/j.jval.2015.08.014
