Impact of risk minimisation measures on the use of strontium ranelate in Europe: a multi-national cohort study in 5 EU countries by the EU-ADR Alliance.

INTRODUCTION: In May 2013 and March 2014, the European Medicines Agency (EMA) issued two decisions restricting the use of strontium ranelate (SR). These risk minimisation measures (RMM) introduced new contraindications and limited the indications of SR therapy. The EMA required an assessment of the impact of RMMs on the use of SR in Europe. Methods design: multi-national, multi-database cohort Setting: electronic medical record databases based on hospital (Denmark) and primary care provenance (Italy, Spain, the Netherlands, UK). PARTICIPANTS: the database source populations were included for population-based analyses, and SR users for patient-level analyses. INTERVENTION: New RMMs included contraindications (ischaemic heart disease, peripheral arterial disease, cerebrovascular disease, uncontrolled hypertension) and restricted SR indication to severe osteoporosis with initiation by experienced physician and not as first line anti-osteoporosis therapy. METHODS: Prevalence and incidence rates of SR use in the population; prevalence of contraindications and restricted indications in SR users, plus 1-year therapy persistence. Drug use measures were calculated in three periods for comparison: reference (2004 to May 2013), transition (June 2013 to March 2014) and assessment (from April 2014 to end 2016). RESULTS: The study population included 143 million person-years(PY) of follow-up and 76,141 incident episodes of SR treatment. Average monthly prevalence rates of SR use dropped by 86.4% from 62.6/10,000 PY (95 CI 62.4-62.9) in the reference to 8.5 (8.5-8.6) in the assessment period. Similarly, the incidence rate of SR use fell by 97.3% from 7.4/10,000 PY (7.4-7.4) to 0.2 (0.2-0.2) between the reference and assessment period. The prevalence of any contraindication decreased, whilst the prevalence of restricted indications increased in these periods. One-year persistence decreased in the assessment compared with reference period. CONCLUSIONS: Our study demonstrates a substantial impact of the regulatory action to restrict use of SR in Europe: SR utilisation overall decreased strongly. The proportion of patients fulfilling the restricted indications, without contraindications, increased after the proposed RMMs.