Benefits and Harms of Statins in People with Dementia: A Systematic Review and Meta-Analysis.

OBJECTIVES: More people with dementia also fall into the category of high vascular risk, for which a statin is usually prescribed. However, these recommendations are based on studies in people without dementia. We aimed to evaluate the evidence for the long-term effectiveness and harm of statin therapy in patients with dementia. DESIGN: Systematic review of randomized controlled trials and observational research. SETTING: Publications from developed countries indexed in the PubMed, Web of Science, and Cochrane trial database between 2007 and 2019. PARTICIPANTS: Trials including people with all types of dementia with a mean age older than 65 years. INTERVENTION: Treatment with a statin for 6 months or longer. MEASUREMENTS: Major adverse cardiovascular events, dementia progression, and general health at 2 years, or medication adverse events (AEs) at any time. Each article was assessed for bias using the Newcastle-Ottawa or Cochrane Collaboration tools. A narrative synthesis and pooled analyses are reported. RESULTS: Five articles met the inclusion criteria. They reported only on dementia of the Alzheimer's type. There was no evidence regarding cardiovascular events or general health. We made a very low confidence finding that statins reduce dementia progression based on three cohort studies of heterogeneous design. We made a very low confidence finding of no significant difference in AEs based on two randomized controlled trials of 18 months: odds ratios of any AE = 1.21 (95% confidence interval [CI] = .83-1.77), serious AE = 1.03 (95% CI = .76-1.87), and death = 1.69 (95% CI = .79-3.62). CONCLUSION: Evidence was insufficient to fully evaluate the efficacy of statins in people with dementia. We found that statins may have a small benefit delaying progression in Alzheimer's dementia, although this conflicted with previous findings from shorter randomized trials. For safety, the trial data lacked power to show clinically important differences between the groups. We recommend that clinical data be leveraged for further observational studies to inform prescribing decisions. J Am Geriatr Soc 68:650-658, 2020.