The impact of Regional co-payment and National reimbursement criteria on statins use in Italy: an interrupted time-series analysis

BACKGROUND Statins are among the most commonly prescribed drugs worldwide in the prevention of cardiovascular diseases and their effectiveness is largely acknowledged. The consumption of statins increased four-fold during the 2000-2010 decade in Italy and national and regional control policies were developed. Restrictions to reimbursement were fixed at the national level, whereas co-payment was introduced in some, but not all, regions. The aim of the present study is to assess the impact of such policies on the consumption of statins in Italy between 2001-2007 among outpatients. METHODS The statin use was measured in terms of defined daily doses per 1,000 inhabitants per day (DDD/1000 inh. day) from May 2001 to December 2007. The study was conducted in 17 out of 21 regions, nine of which had implemented a co-payment policy. Time trends in consumption before and after the introduction of co-payment policies and reimbursement criteria were examined using segmented regression analysis of interrupted time-series, adjusting for seasonal components. RESULTS The consumption of statins increased by 22.9 DDD/1000 inh. day in May 2001 to 54.7 DDD/1000 inh. day in December 2007. On average, there was a 1.7% increase in statin use each month before the national guideline changed while the increase was about 0.5% afterwards. The revision of the reimbursement criteria was associated with a significant decrease in level (coefficient = -2.80, 95% CI -3.70 to -1.90 p-value <0.001) and trend (coefficient = -0.33, 95% CI -0.37 to -0.29 p-value <0.001). The introduction of co-payment was associated with a significant change in trend of consumption so that the overall use of the drug increased by 0.04 (95% CI 0.02 to 0.07, p-value < 0.001) DDD/1000 inh. day per month in the post-intervention period, but there was no evidence of a change in level of consumption (p-value = 0.163). CONCLUSIONS Consumption of statins in Italy increased almost three-fold during the study period. The restriction to reimbursement Interventions was associated with an immediate drop and a decrease in trend of statin use, while the regional copayment was associated with a small increase in trend of statin use.