Wu I-Chen, Hsieh Hui-Min, Wu Ming-Tsang
Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan Faculty of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
Department of Public Health, Kaohsiung Medical University, Kaohsiung, Taiwan.
BMJ Open. 2015 Jan 9;5(1):e006694. doi: 10.1136/bmjopen-2014-006694.
To calculate the short-term risk-benefit effect of occasional and regular use of low-dose aspirin (≤100 mg/day) in primary prevention.
Two retrospective cohort studies.
Taiwan.
63 788 and 24 910 patients of two nationwide population-based studies were examined.
Two databases of 1 000 000 patients were randomly sampled from data of Taiwan's National Health Insurance (NHI) for years 1997-2000 (NHI 2000) and 2005 (NHI 2005). In NHI 2000, 63 788 patients 30-95 years of age were found not to have previously been prescribed aspirin before 1 January 2000, but to have first been prescribed low-dose aspirin after that date. They were also found to be at risk of first hospitalisation for any major vascular diseases including haemorrhage (major gastrointestinal haemorrhage or cerebral haemorrhage) and ischaemia (acute myocardial infarction or ischaemic stroke) after their first prescription. We also applied it to NHI 2005, and the number of eligible patients was 24 910. Patients prescribed low-dose aspirin for <20% of the days of a 60-day follow-up period were considered to be occasional users, and those prescribed low-dose aspirin for ≥80% of the days were considered to be regular users. Differences in rate of haemorrhage and ischaemia between these users were used to calculate their net clinical risk.
Vascular diseases.
In NHI 2000, the overall unadjusted rates of haemorrhage and ischaemia were 0.09% and 0.21%, respectively, for occasional users and 0.32% and 2.30%, respectively, for regular users. Adjusted net clinical risk of low-dose aspirin use between the two groups was 2.24% (95% CI 2.03% to 2.48%; p<0.001). Similar results were also found in NHI 2005.
Short-term regular use of low-dose aspirin might not be better than occasional use for preventing major vascular diseases in primary prevention. Prescribing regular low-dose aspirin for primary prevention should be done with caution. Future studies should explore the risk-benefit effect of long-term low-dose aspirin use in primary prevention.
计算偶尔和定期使用低剂量阿司匹林（≤100毫克/天）进行一级预防的短期风险效益效应。
两项回顾性队列研究。
台湾。
对两项全国性基于人群的研究中的63788名和24910名患者进行了检查。
从台湾国民健康保险（NHI）1997 - 2000年（NHI 2000）和2005年（NHI 2005）的数据中随机抽取两个包含100万患者的数据库。在NHI 2000中，发现63788名年龄在30 - 95岁之间的患者在2000年1月1日前未被开过阿司匹林，但在该日期之后首次被开了低剂量阿司匹林。还发现他们在首次开处方后有因任何重大血管疾病首次住院的风险，包括出血（重大胃肠道出血或脑出血）和缺血（急性心肌梗死或缺血性中风）。我们也将其应用于NHI 2005，符合条件的患者有24910名。在60天随访期内，服用低剂量阿司匹林天数<20%的患者被视为偶尔使用者，服用天数≥80%的患者被视为定期使用者。利用这些使用者之间出血和缺血发生率的差异来计算他们的净临床风险。
血管疾病。
在NHI 2000中，偶尔使用者出血和缺血的总体未调整发生率分别为0.09%和0.21%，定期使用者分别为0.32%和2.30%。两组之间低剂量阿司匹林使用的调整后净临床风险为2.24%（95%CI 2.03%至2.48%；p<0.001）。在NHI 2005中也发现了类似结果。
在一级预防中，短期定期使用低剂量阿司匹林预防重大血管疾病可能并不比偶尔使用更好。在一级预防中开具定期低剂量阿司匹林应谨慎。未来的研究应探索长期低剂量阿司匹林在一级预防中的风险效益效应。
