RESUMO
BACKGROUND: The risk/benefit ratio of using statins for primary prevention of cardiovascular (CV) events in elderly people has not been established. The main objectives of the present study are to assess the cost-effectiveness of statin cessation and to examine the non-inferiority of statin cessation in terms of mortality in patients aged 75 years and over, treated with statins for primary prevention of CV events. METHODS: The "Statins in the elderly" (SITE) study is an ongoing 3-year follow-up, open-label comparative multi-centre, randomized clinical trial that is being conducted in two parallel groups in outpatient primary care offices. Participants meeting the following criteria are included: people aged 75 years and older being treated with statins as primary prevention for CV events, who provide informed consent. After randomization, patients in the statin-cessation strategy are instructed to withdraw their treatment. In the comparison strategy, patients continue their statin treatment at the usual dosage. The cost-effectiveness of the statin-cessation strategy compared to continuing statins will be estimated through the incremental cost per quality-adjusted life years (QALYs) gained at 36 months, from the perspective of the French healthcare system. Overall mortality will be the primary clinical endpoint. We assumed that the mortality rate at 3 years will be 15%. The sample size was computed to achieve 90% power in showing the non-inferiority of statin cessation, assuming a non-inferiority margin of 5% of the between-group difference in overall mortality. In total, the SITE study will include 2430 individuals. DISCUSSION: There is some debate on the value of statins in people over 75 years old, especially for primary prevention of CV events, due to a lack of evidence of their efficacy in this population, potential compliance-related events, drug-drug interactions and side effects that could impair quality of life. Data from clinical trials guide the initiation of medication therapy for primary or secondary prevention of CV disease but do not define the timing, safety, or risks of discontinuing the agents. The SITE study is one of the first to examine whether treatment cessation is a cost-effective and a safe strategy in people of 75 years and over, formerly treated with statins. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02547883. Registered on 11 September 2015.