BACKGROUND AND OBJECTIVES Survivors of stroke are at high risk of dementia, but it is unclear whether this elevated risk is due to other confounding factors. We sought to determine the magnitude and time course of dementia risk after stroke with robust comparison with matched nonstroke populations in an entire province. METHODS We conducted a population-wide analysis of over 15 million people in Ontario, Canada, between 2002 and 2022. Using linked administrative databases, we identified adults hospitalized for ischemic stroke, intracerebral hemorrhage, or acute myocardial infarction (AMI). We performed 1:1 matching of people with stroke to all residents of Ontario (reference population) without stroke and separately to those with AMI, on age, sex, rural residence, neighborhood deprivation, and vascular comorbidities. We calculated the incident rate per 100 person-years and hazard ratios (HRs) for all-cause dementia between 90 days after stroke and 1 year, 5 years, 10 years, and total follow-up and evaluated time-varying HRs. In sensitivity analyses, we adjusted for new stroke in follow-up and the cumulative number of health care encounters. RESULTS Of 175,980 stroke survivors, 174,817 (99.3%) were successfully matched to people in the reference population and 151,673 (90%) were matched to those with AMI. Over a mean follow-up of 5.6 years (SD 4.71, maximum 20 years), a total of 32,621 (18.7%) were diagnosed with dementia after stroke compared with 21,929 (12.5%) in the Ontario reference population. The rate of dementia per 100 person-years over total follow-up time was higher after acute stroke compared with the reference population (3.34 vs 1.89) and the AMI cohort (3.19 vs 1.75). The HR of dementia was higher in those with stroke compared with the reference population (1.76, 95% CI 1.73-1.79) and the AMI cohort (1.82, 1.79-1.85). HRs varied across time, with over 2.5-fold increase in dementia risk within 1 year, decreasing to 1.5-fold at 5 years and 1.3-fold at 20 years after stroke. Estimates were similar in sensitivity analyses. Recurrent stroke was associated with 3-fold increased dementia risk. DISCUSSION In this population-wide study, almost one-fifth of stroke survivors were diagnosed with dementia, with an 80% higher risk of dementia after robust matching to those without stroke. Targeted dementia prevention efforts in acute and chronic survivors of stroke are needed.

中文翻译：

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中风幸存者痴呆风险的幅度和时间进程：一项全人群的匹配队列研究。


背景和目标 中风幸存者患痴呆的风险很高，但目前尚不清楚这种升高的风险是否是由于其他混杂因素造成的。我们试图通过与整个省份匹配的非中风人群进行强有力的比较，来确定中风后痴呆风险的幅度和时间进程。方法 我们在 2002 年至 2022 年期间对加拿大安大略省的 1500 多万人进行了全人口分析。使用链接的管理数据库，我们确定了因缺血性卒中、脑出血或急性心肌梗死 （AMI） 住院的成人。我们将卒中患者与安大略省所有无卒中的居民（参考人群）进行了 1：1 匹配，并分别与患有 AMI 的人进行了年龄、性别、农村居住、社区剥夺和血管合并症的匹配。我们计算了卒中后 90 天与 1 年、5 年、10 年之间全因痴呆的每 100 人年发生率和风险比 （HRs），以及总随访和评估时变 HRs。在敏感性分析中，我们调整了随访中的新卒中和医疗保健就诊的累积次数。结果 在 175,980 名卒中幸存者中，174,817 名 （99.3%） 与参考人群成功匹配，151,673 名 （90%） 与 AMI 患者匹配。在平均 5.6 年的随访中 （SD 4.71，最长 20 年），共有 32,621 例 （18.7%） 被诊断出患有中风后痴呆，而安大略省参考人群为 21,929 例 （12.5%）。与参考人群 （3.34 vs 1.89） 和 AMI 队列 （3.19 vs 1.75） 相比，急性卒中后每 100 人年痴呆的发生率高于总随访时间。 与参考人群 （1.76， 95% CI 1.73-1.79） 和 AMI 队列 （1.82， 1.79-1.85） 相比，卒中患者的痴呆 HR 更高。HR 随时间变化，中风后 1 年内痴呆风险增加 2.5 倍以上，5 年下降至 1.5 倍，20 年下降至 1.3 倍。敏感性分析的估计值相似。复发性卒中与痴呆风险增加 3 倍相关。讨论 在这项全人群的研究中，近五分之一的中风幸存者被诊断出患有痴呆，与没有中风的人强匹配后，患痴呆的风险高出 80%。需要对急性和慢性中风幸存者进行有针对性的痴呆预防工作。