Table_2_Antidepressant Use and Suicide Rates in Adults Aged 75 and Above: A Swedish Nationwide Cohort Study.DOCX

Background: The treatment of depression is a main strategy for suicide prevention in older adults. We aimed to calculate suicide rates by antidepressant prescription patterns in persons aged ≥ 75 years. A further aim was to estimate the contribution of antidepressants to the change in suicide rates over time.
Methods: Swedish residents aged ≥ 75 years (N = 1,401,349) were followed between 2007 and 2014 in a national register-based retrospective cohort study. Biannual suicide rates were calculated for those with selective serotonin reuptake inhibitor (SSRI) single use, mirtazapine single use, single use of other antidepressants and use of ≥ 2 antidepressants. The contribution of antidepressants to the change in biannual suicide rates was analyzed by decomposition analysis.
Results: There were 1,277 suicides. About one third of these were on an antidepressant during their last 3 months of life. In the total cohort, the average biannual suicide rate in non-users of antidepressants was 13 per 100,000 person-years. The corresponding figure in users of antidepressants was 34 per 100,000 person-years. These rates were 25, 42 and 65 per 100,000 person-years in users of SSRI, mirtazapine and ≥ 2 antidepressants, respectively. In the total cohort, antidepressant users contributed by 26% to the estimated increase of 7 per 100,000 in biannual suicide rates. In men, biannual suicide rates increased by 11 suicides per 100,000 over the study period; antidepressant users contributed by 25% of the change. In women, those on antidepressant therapy accounted for 29% of the estimated increase of 4.4 per 100,000.
Conclusion: Only one third of the oldest Swedish population who died by suicide filled an antidepressant prescription in their last 3 months of life. Higher suicide rates were observed in mirtazapine users compared to those on SSRIs. Users of antidepressants accounted for only one quarter of the increase in the suicide rate. The identification and treatment of suicidal older adults remains an area for prevention efforts.

背景：针对老年群体的抑郁治疗是老年自杀预防的核心策略之一。本研究旨在针对75岁及以上人群，根据抗抑郁药（antidepressant）处方模式计算自杀率；另一研究目标为估算抗抑郁药对自杀率随时间变化的贡献程度。

方法：本研究为基于全国登记系统的回顾性队列研究，纳入2007年至2014年间随访的1401349名75岁及以上瑞典常住居民。针对单纯使用选择性5-羟色胺再摄取抑制剂（selective serotonin reuptake inhibitor, SSRI）、单纯使用米氮平（mirtazapine）、单纯使用其他抗抑郁药以及同时使用≥2种抗抑郁药的人群，分别计算其每半年一次的自杀率；采用分解分析法分析抗抑郁药对每半年自杀率变化的贡献程度。

结果：本研究中共发生1277例自杀事件。其中约三分之一的自杀者在生命最后三个月内曾使用抗抑郁药。在全部队列人群中，未使用抗抑郁药者的平均每半年自杀率为13/10万人年；使用抗抑郁药者的对应自杀率为34/10万人年。其中，单纯使用SSRI、米氮平以及≥2种抗抑郁药的人群自杀率分别为25、42和65/10万人年。在全部队列中，抗抑郁药使用者对每半年自杀率7/10万人年的预估增幅贡献了26%。在男性群体中，研究期间每半年自杀率每10万人年增加11例，抗抑郁药使用者对该变化的贡献占比为25%；在女性群体中，每半年自杀率预估增幅为4.4/10万人年，抗抑郁药使用者的贡献占比为29%。

结论：在因自杀离世的瑞典高龄人群中，仅三分之一的个体在生命最后三个月内开具过抗抑郁药处方。与使用SSRI的人群相比，米氮平使用者的自杀率更高。抗抑郁药使用者仅占自杀率增幅的四分之一。针对存在自杀风险的老年群体的识别与干预，仍是自杀预防工作需重点投入的方向。