Supplementary Material for: Factors Leading to Institutionalization among the Oldest Old: Longitudinal Findings from the AgeCoDe-AgeQualiDe Study

<b><i>Introduction:</i></b> Due to the strong association between old age and the need for long-term care, the number of individuals in need for care is projected to increase noticeably. The aim of this study was to examine the determinants of institutionalization among the <i>oldest old</i> longitudinally. <b><i>Methods:</i></b> Longitudinal data (follow-up [FU] wave 7–9) were gathered from a multicenter prospective cohort study (“Study on needs, health service use, costs and health-related quality of life in a large sample of oldest old primary care patients [85+],” AgeQualiDe). At FU wave 7, in 2014, complete measures were available for 763 individuals. The average age was 88.9 (standard deviation 2.9) years (range 85–100), and 68% were female. Sociodemographic and health-related independent variables (e.g., depressive symptoms or functioning) were included in the regression model. Institutionalization (admission to assisted living home or nursing home) was used as an outcome measure. Logistic random-effects models were used. <b><i>Results:</i></b> Regressions revealed that among oldest old, the odds of being institutionalized were lower for men (odds ratio [OR] = 0.03; 95% confidence interval [CI] 0.00–0.16). Institutionalization was associated with an increased age (OR = 1.27; 95% CI 1.04–1.55). Additionally, widowed individuals (ref. non-widowed) had higher odds of being institutionalized (OR = 8.95; 95% CI 1.61–49.81). Institutionalization was also associated with functional decline (OR = 0.16; 95% CI 0.11–0.23), whereas it was not significantly associated with cognitive decline, depressive symptoms, and social support. <b><i>Conclusion:</i></b> Our findings stress the importance of gender, age, widowhood, and functional decline for institutionalization among the oldest old. Preventing or at least postponing functional decline might help to delay institutionalization as far as possible.

**引言：** 鉴于老年与长期照护需求间存在紧密关联，有照护需求的人群规模预计将显著增长。本研究旨在纵向探究高龄老人（oldest old）的机构养老影响因素。

**方法：** 本研究的纵向数据（随访（follow-up [FU]）第7-9波）来自一项多中心前瞻性队列研究——《高龄基层医疗患者（85岁及以上）的照护需求、卫生服务利用、成本与健康相关生命质量研究》（AgeQualiDe）。2014年的第7波随访中，共纳入763名完成全部测评的受试者，其平均年龄为88.9岁（标准差2.9岁，年龄范围85~100岁），女性占比68%。本研究将社会人口学及健康相关自变量（如抑郁症状、躯体功能）纳入回归模型，以机构养老（入住养老辅助公寓或养老院）作为结局指标，采用logistic随机效应模型进行分析。

**结果：** 回归分析显示，在高龄老人中，男性的机构养老风险更低（优势比（odds ratio [OR]）=0.03；95%置信区间（confidence interval [CI]）0.00~0.16）。机构养老风险随年龄增长而升高（OR=1.27；95%CI 1.04~1.55）。此外，丧偶受试者（以非丧偶者为参照组）的机构养老风险更高（OR=8.95；95%CI 1.61~49.81）。机构养老亦与功能下降相关（OR=0.16；95%CI 0.11~0.23），而与认知下降、抑郁症状及社会支持均无显著关联。

**结论：** 本研究结果凸显了性别、年龄、丧偶状态及功能下降对高龄老人机构养老的影响作用。预防或至少延缓功能下降，或可尽可能推迟高龄老人的机构养老进程。