Supplementary Material for: Prevalence and Risk Score for Hypertonic Dehydration Among Community-Dwelling Older Adults: an Analysis of the Bangkok Falls Study

Introduction: Dehydration is associated with morbidity, and many factors affect dehydration in older adults including age and medication use. This study determined the prevalence of hypertonic dehydration (HD) and factors affecting HD in older adults and developed a risk score (a set of consistent weights that assign a numerical value to each risk factor) which are potentially useful in predicting HD among community-dwelling Thai older adults.
Methods: Data were obtained from a cohort study of community-dwelling older adults aged ≥60 years in Bangkok, Thailand between October 1, 2019, and September 30, 2021. Current HD was defined as a serum osmolality >300 mOsm/kg. Univariate and multivariate logistic regression analyses were used to identify factors associated with current and impending HD. The risk score for current HD was developed based on the final multiple logistic regression model.
Results: A total of 704 participants were included in the final analysis. In this study, 59 (8.4%) participants had current HD and 152 (21.6%) had impending HD. We identified three risk factors for HD in older adults; age ≥ 75 years (adjusted odds ratio (aORs) 2.0, 95% confidence interval [CI]: 1.16-3.46), underlying diabetes mellitus (aORs 3.07, 95%CI: 1.77-5.31) and use of ß-blocker medication (aORs 1.98, 95%CI: 1.04-3.78). The increasing risks of current HD with increasing risk scores were 7.4% for a score of 1, 13.8 % for a score of 2, 19.8% for a score of 3, and 32.8% for a score of 4.
Conclusion: One-third of the older adults in this study had current or impending HD. We identified risk factors for HD and created a risk score for HD in one group of community-dwelling older adults. Older adults with risk scores of 1-4 were at 7.4%-32.8% risk for current HD. The clinical utility of this risk score requires further study and external validation.

引言：脱水与发病风险密切相关，老年人群的脱水受多种因素影响，其中包括年龄与药物使用情况。本研究明确了泰国社区居住老年人群高渗性脱水（hypertonic dehydration, HD）的患病率及其影响因素，并构建了一套风险评分模型——即通过为每项风险因子赋予固定权重以生成量化评分，该模型有望用于泰国社区居住老年人群HD的发病预测。
研究方法：本研究数据来源于2019年10月1日至2021年9月30日期间，在泰国曼谷开展的针对60岁及以上社区居住老年人群的队列研究。当前HD定义为血清渗透压＞300 mOsm/kg。本研究采用单因素及多因素logistic回归分析，明确与当前HD及前驱性HD相关的影响因素。基于最终构建的多因素logistic回归模型，生成当前HD的风险评分模型。
研究结果：最终共有704名受试者纳入分析。本研究中，59名（8.4%）受试者存在当前HD，152名（21.6%）存在前驱性HD。本研究明确了老年人群HD的三项危险因素：年龄≥75岁[调整后优势比（adjusted odds ratio, aOR）=2.0，95%置信区间（confidence interval, CI）：1.16~3.46]、合并糖尿病[调整后优势比=3.07，95%CI：1.77~5.31]以及使用β受体阻滞剂[调整后优势比=1.98，95%CI：1.04~3.78]。随着风险评分升高，当前HD的发病风险逐渐升高：评分为1分时风险为7.4%，2分时为13.8%，3分时为19.8%，4分时为32.8%。
结论：本研究中约三分之一的老年受试者存在当前HD或前驱性HD。本研究明确了HD的危险因素，并针对某一社区居住老年人群构建了HD风险评分模型。风险评分为1~4分的老年人群，当前HD的发病风险为7.4%~32.8%。该风险评分的临床应用价值仍需进一步研究及外部验证。