Abstract: Objective  To assess and predict the trends of ischemic stroke (IS) incidence and disability-adjusted life years (DALYs) among middle-aged and older adults in China and the United Kingdom, and to provide evidence for formulating IS prevention policies in countries at different developmental stages.
Methods  Data were retrieved from the global burden of disease database 2021, including the number of IS cases, DALYs, and their crude rates among adults aged 40 years and above (middle-aged and older adults) in China and the United Kingdom. The estimated annual percentage change (EAPC) was used to analyze the temporal trends. The age-period-cohort model was applied to estimate the effects of age, period, and birth cohort. Additionally, the Bayesian age-period-cohort model was used to predict the number of IS cases, age-standardized incidence rate, DALYs, and age-standardized DALYs rate among middle-aged and older adults in the two countries from 2022 to 2035.
Results  Between 1990 and 2021, the EAPC of IS age-standardized incidence rate among middle-aged and older adults in China was 0.99% (P<0.001), while the EAPC of IS age-standardized DALYs rate was -0.49% (P<0.001). In the United Kingdom, the EAPCs of IS age-standardized incidence rate and age-standardized DALYs rate in this population were -2.42% and -4.41%, respectively (both P<0.001). Age effect analysis indicated that the RR of IS age-standardized incidence rate increased most rapidly between the 55-59 and 60-64 year age groups in Chinese middle-aged and older adults, whereas the RR of IS age-standardized DALYs rate increased most rapidly between the 45-49 and 50-54 year age groups. The RRs of both IS age-standardized incidence rate and age-standardized DALYs rate in middle-aged and older adults in the United Kingdom continued to rise with increasing age. Period effect analysis indicated that the RRs of age-standardized incidence rate and age-standardized DALYs rate of IS in Chinese middle-aged and older adults both presented an upward trend between 1990 and 2021, whereas those in the United Kingdom showed a trend of initial decrease followed by a slight increase. Projections indicated that by 2035, the EAPCs of IS age-standardized incidence rate and age-standardized DALYs rate among Chinese middle-aged and older adults would be 2.71% and 1.62%, respectively (both P<0.001). Meanwhile, the EAPC of IS age-standardized incidence rate among middle-aged and older adults in the United Kingdom would be 0.92% (P<0.001), the EAPC of age-standardized DALYs rate was -0.28%, with no statistical significance. 
Conclusions  Strengthening health management for IS among middle-aged and older adults remains a common public health priority for countries at different developmental stages.

Key words: Ischemic stroke; Disease burden; Middle-aged and older adult; Trend analysis

摘要： 目的 评估并预测中国和英国中老年人群缺血性卒中（ischemic stroke，IS）的发病及伤残调整生命年（disability-adjusted life years，DALYs）趋势，为处于不同发展阶段的国家制订IS预防政策提供证据参考。
方法 数据来源于2021年全球疾病负担数据库，提取中国和英国40岁及以上中老年人群IS的发病人数、DALYs及其粗率。采用年估计变化百分比（estimated annual percentage change，EAPC）分析时间变化趋势，运用年龄-时期-队列模型估计年龄、时期与出生队列效应，并采用贝叶斯年龄-时期-队列模型预测2022—2035年中国和英国中老年人群IS的发病人数、年龄标准化发病率、DALYs及年龄标准化DALYs率。 
结果 1990—2021年，中国中老年人群IS的年龄标准化发病率EAPC为0.99%（P<0.001），年龄标准化DALYs率EAPC为-0.49%（P<0.001）；英国中老年人群IS的年龄标准化发病率EAPC为-2.42%（P<0.001），年龄标准化DALYs率EAPC为-4.41%（P<0.001）。年龄效应分析显示，中国中老年人群在55～59岁至60～64岁组间的年龄标准化发病率RR增速最快，在45～49岁至50～54岁组间的年龄标准化DALYs率RR增速最快；英国中老年人群年龄标准化发病率RR和年龄标准化DALYs率RR均随年龄增长持续上升。时期效应分析显示，1990—2021年中国中老年人群IS的年龄标准化发病率RR和年龄标准化DALYs率RR均呈上升趋势；英国中老年人群IS的年龄标准化发病率RR和年龄标准化DALYs率RR均呈先下降后略有上升趋势。预测至2035年，中国中老年人群IS的年龄标准化发病率和年龄标准化DALYs率的EAPC分别为2.71%和1.62%（均P<0.001）；英国中老年人群IS的年龄标准化发病率EAPC为0.92%（P<0.001），年龄标准化DALYs率的EAPC为-0.28%，无统计学意义。
结论 加强中老年人群IS的健康管理，仍是处于不同发展阶段国家共同面临的公共卫生任务。

关键词: 缺血性卒中; 疾病负担; 中老年人群; 趋势分析