Current evidence is inconclusive on cognitive benefits or harms of statins among stroke patients, who have high risk of dementia. This observational cohort study investigated the association between statin use and post-stroke dementia using data from the Clinical Practice Research Datalink. Patients without prior dementia who had an incident stroke but received no statins in the preceding year were followed for up to 10 years. We used inverse probability weighted marginal structural models to estimate observational analogues of intention-to-treat (ITT, statin initiation vs. no initiation) and per-protocol (PP, sustained statin use vs. no use) effects on the risk of dementia. To explore potential impact of unmeasured confounding, we examined the risks of coronary heart disease (CHD, positive control outcome), fracture and peptic ulcer (negative control outcomes). In 18,577 statin initiators and 14,613 non-initiators (mean follow-up of 4.2 years), the adjusted hazard ratio (aHR) for dementia was 0.70 (95% confidence interval [CI] 0.64–0.75) in ITT analysis and 0.55 (95% CI 0.50–0.62) in PP analysis. The corresponding aHR_ITT and aHR_PP were 0.87 (95% CI 0.79–0.95) and 0.70 (95% CI 0.62–0.80) for CHD, 1.03 (95% CI 0.82–1.29) and 1.09 (95% CI 0.77–1.54) for peptic ulcer, and 0.88 (95% CI 0.80–0.96) and 0.86 (95% CI 0.75–0.98) for fracture. Statin initiation after stroke was associated with lower risk of dementia, with a potentially greater benefit in patients who persisted with statins over time. The observed association of statin use with post-stroke dementia may in part be overestimated due to unmeasured confounding shared with the association between statin use and fracture.

目前的证据尚无关于他汀类药物对中风患者的认知益处或危害的结论，这些患者有很高的痴呆风险。这项观察性队列研究使用来自临床实践研究数据链的数据调查了他汀类药物使用与中风后痴呆之间的关联。既往无痴呆症且发生过中风但在前一年未接受他汀类药物治疗的患者被随访长达 10 年。我们使用逆概率加权边际结构模型来估计意向治疗（ITT，他汀类药物启动与未启动）和符合方案（PP，持续使用他汀类药物与不使用）对痴呆症风险影响的观察性类似物。为了探索未测量混杂的潜在影响，我们检查了冠心病（冠心病，阳性对照结果）的风险，骨折和消化性溃疡（阴性对照结果）。在 18,577 名他汀类药物启动者和 14,613 名非启动者（平均随访 4.2 年）中，ITT 分析中痴呆的调整后风险比 (aHR) 为 0.70（95% 置信区间 [CI] 0.64–0.75）和 ​​0.55（95% PP 分析中的 CI 0.50–0.62）。对应的aHR_{CHD 的ITT}和 aHR _PP分别为 0.87 (95% CI 0.79-0.95) 和 0.70 (95% CI 0.62-0.80)，消化性溃疡的 1.03 (95% CI 0.82-1.29) 和 1.09 (95% CI 0.77-1.54)，骨折为 0.88（95% CI 0.80-0.96）和 0.86（95% CI 0.75-0.98）。中风后开始服用他汀类药物与痴呆症风险降低相关，随着时间的推移坚持使用他汀类药物的患者可能获益更大。观察到的他汀类药物使用与卒中后痴呆的相关性可能部分被高估，原因是未测量的混杂因素与他汀类药物使用与骨折之间的相关性有关。