S1 Data set -

Background
Perceived social support is a complex construct that includes tangible and supportive feedback in addition to emotional, instrumental, appraisal, and informational support. Social support shields older adults from the negative effects of aging, such as illness and death, as well as the negative outcomes of stressful life events. The purpose of this study was to assess the perceived social support and associated factors among older people residing in metropolitan cities in northwest Ethiopia, as there is a dearth of evidence regarding this topic, particularly in the study area.
Methods
A community-based cross-sectional study was carried out between December 19, 2020, and February 21, 2021. The systematic random sampling technique was used to select 830 study participants. Data collected using an interviewer administered questionnaire was entered using Epi-data version 4.6 and analyzed using Stata version 14. Both bivariate and multivariate logistic regression analyses were done. In the multivariate analysis, variables with P-value <0.05 were considered statistically significant. Adjusted odds ratio (AOR) with a 95% confidence interval was used to determine the strength and direction of the association.
Results
A total of 816 participants were included with a 98.3% response rate. The mean age of participants was 68.2 (SD±7.2) years. In the current study, 339 (41.54%) of participants had low perceived social support. Having four and above children (AOR = 1.71, 95% CI = 1.10, 2.66), likely to have a severe mental illness (AOR = 0.33, 95% CI = 0.16, 0.68), medium and high sense of coherence (AOR = 1.79, 95%CI = 1.05, 3.06) and 2.86 (AOR = 2.86, 95%CI = 1.44, 5.67), respectively, middle, fourth, and highest quantiles of wealth index (AOR = 1.97, 95%CI = 1.07, 3.60), 3.64 (AOR = 3.60, 95%CI = 1.91, 6.94), and 5.82 (AOR = 5.82, 95%CI = 2.90, 11.71),. Having no social service participation (AOR = 2.12, 95%CI = 1.06, 9.50) were significantly associated with low perceived social support.
Conclusion and recommendations
In this study more than two-fifth of older people have low perceived social support. Number of children, mental health, sense of coherence, wealth index, and participation in social services were had a significant association with the perceived social support of older people. In order for these vulnerable populations to age healthily, alternative forms of support should be provided as the societal culture supporting the elderly has declined. Particularly, emphasis should be given for older people with mental health problems and those having no social service participation. Besides, further research is crucial targeting the actual social support of the elderly people including those living in the street, temporal residents, and religious places.

## 研究背景
感知社会支持（Perceived Social Support）是一类复杂的构念，除情感支持、工具性支持、评价性支持与信息性支持外，还涵盖有形支持与支持性反馈。社会支持可帮助老年人抵御衰老带来的负面影响（如疾病与死亡）以及应激性生活事件引发的不良结局。鉴于当前该领域相关研究证据匮乏，尤其是在本研究区域内，本研究旨在评估埃塞俄比亚西北部大都市地区老年人的感知社会支持状况及其影响因素。

## 研究方法
本研究于2020年12月19日至2021年2月21日期间开展，为基于社区的横断面研究。采用系统随机抽样方法选取830名研究对象。通过访谈式问卷收集数据，使用EpiData 4.6软件录入数据，并用Stata 14软件进行统计分析。同时开展双变量及多变量logistic回归分析。多变量分析中，P值<0.05的变量被认定为具有统计学意义。采用校正比值比（Adjusted Odds Ratio, AOR）及95%置信区间（Confidence Interval, CI）来分析关联的强度与方向。

## 研究结果
最终共纳入816名研究对象，应答率为98.3%。研究对象的平均年龄为68.2岁（标准差SD±7.2）。本研究中，339名（41.54%）研究对象存在感知社会支持水平低下的情况。拥有4个及以上子女（AOR=1.71，95%CI=1.10~2.66）、疑似罹患重度精神疾病（AOR=0.33，95%CI=0.16~0.68）、中等及高度的心理一致感（Sense of Coherence，对应AOR分别为1.79，95%CI=1.05~3.06与2.86，95%CI=1.44~5.67）、财富指数处于中等、第四分位及最高分位（AOR分别为1.97，95%CI=1.07~3.60；3.64，95%CI=1.91~6.94；5.82，95%CI=2.90~11.71），以及未参与社会服务活动（AOR=2.12，95%CI=1.06~9.50）均与感知社会支持水平低下存在显著关联。

## 结论与建议
本研究显示，超过五分之二的老年人存在感知社会支持水平低下的问题。子女数量、心理健康状况、心理一致感、财富指数及社会服务参与情况均与老年人的感知社会支持水平存在显著关联。鉴于当前社会尊老养老的文化氛围有所弱化，为使这一弱势群体实现健康老龄化，应为其提供替代性支持方式。尤其应重点关注存在心理健康问题及未参与社会服务活动的老年人。此外，后续研究应聚焦于各类老年群体的实际社会支持状况，包括流浪老人、暂住人口及宗教场所居住的老年人。