Supplementary Material for: Impact of first wave of COVID-19 pandemic on mortality at emergency department in elderly patients with covid and non-covid diagnoses

Introduction: Mortality in emergency departments (ED) is not well known. This study aimed to assess the impact of the first-wave pandemic on deaths accounted in the ED of older patients with COVID and non-covid diseases.
Methods: We used data from the EDEN (Emergency Department and Elderly Needs) cohort (preCOVID period) and from the EDEN-Covid cohort (COVID period) that included all patients ≥65 years seen in 52 Spanish EDs from April 1 to 7, 2019, and March 30 to April 5, 2020, respectively. We recorded patient characteristics and final destination at ED. We compared older patients in the pre-COVID period, with older patients with non-covid and with covid-19. ED-Mortality (before discharge or hospitalization) is the prior outcome and was expressed as an adjusted Odds Ratio (aOR) with 95% interval confidence (IC).
Results: We included 23,338 older patients from the preCOVID period (aged 78.3 (8.1) years), 6,715 patients with non-covid conditions (aged 78.9 (8.2) years) and 3,055 with covid (aged 78.3 (8.3) years) from the COVID period. Compared to the older patients preCOVID period, patients with non-covid and with COVID-19 were more often male, referred by a doctor and by ambulance, with more comorbidity and disability, dementia, nursing-home and more risk according to qSOFA, respectively (p<0.001). Compared to the preCOVID period, patients with non-covid and with covid-19 were more often to be hospitalized from ED (24.8% vs 44.3% vs 79.1%) and were more often to die in ED (0.6% vs 1.2% vs 2.2%), respectively (p<0.001). Compared to the pre-covid period, aOR for age, sex, comorbidity and disability, ED mortality in elderly patients cared in ED during the COVID period was 2.31 (95% CI 1,76-3,06), and 3.75 (95% CI 2.77-5.07) for patients with COVID. By adding the variable qSOFA to the model, such OR were 1.59 (95% CI 1,11-2.30) and 2.16 (95% CI 1,47-3,17), respectively.
Conclusions: During the early first pandemic wave of COVID-19, more complex and life-threatening older with COVID and non-covid diseases were seen compared to the pre-covid period. In addition, the need for hospitalization and the ED-mortality doubled in non-covid and tripled in COVID diagnosis. This increase in ED mortality is not only explained by the complexity or severity of the elderly patients but also because of the system's overload.

**引言**：急诊室(ED, Emergency Department)的老年患者病死率尚未得到充分研究与认知。本研究旨在评估新冠疫情第一波大流行对合并新冠及非新冠疾病的老年患者在急诊室内死亡事件的影响。
**方法**：本研究使用了EDEN(EDEN, Emergency Department and Elderly Needs)队列（新冠疫情前时期）与EDEN-新冠队列（新冠疫情时期）的数据，前者纳入2019年4月1日至7日西班牙52家急诊室接诊的所有≥65岁患者，后者则纳入2020年3月30日至4月5日的同类患者。研究记录了患者的临床特征及急诊室最终转归情况，并将新冠疫情前时期的老年患者、非新冠疾病老年患者与新冠病毒感染老年患者进行分组比较。本研究的主要结局为急诊室病死率(ED-Mortality，即出院或住院前发生的死亡)，以校正比值比(aOR, adjusted Odds Ratio)及95%置信区间(CI, confidence interval)进行表达。
**结果**：本研究共纳入新冠疫情前时期的23338例老年患者（平均年龄78.3±8.1岁），新冠疫情时期的非新冠疾病患者6715例（平均年龄78.9±8.2岁）以及新冠病毒感染患者3055例（平均年龄78.3±8.3岁）。与新冠疫情前时期的老年患者相比，非新冠疾病患者与新冠病毒感染患者的男性占比更高，经医师转诊及救护车转运的比例更高，合并症与残疾发生率、痴呆发生率、疗养院入住率及快速序贯器官衰竭评分(qSOFA, quick Sequential Organ Failure Assessment)提示的风险均更高（均p<0.001）。与新冠疫情前时期相比，非新冠疾病患者与新冠病毒感染患者的急诊室住院率更高，分别为44.3%与79.1%（新冠疫情前时期为24.8%）；急诊室病死率亦更高，分别为1.2%与2.2%（新冠疫情前时期为0.6%）（均p<0.001）。校正年龄、性别、合并症及残疾情况后，与新冠疫情前时期相比，新冠疫情时期急诊接诊的老年患者的急诊室病死率校正比值比(aOR)为2.31（95%CI:1.76-3.06），新冠病毒感染患者的该aOR为3.75（95%CI:2.77-5.07）。在模型中加入快速序贯器官衰竭评分(qSOFA)变量后，上述校正比值比分别变为1.59（95%CI:1.11-2.30）与2.16（95%CI:1.47-3.17）。
**结论**：在新冠疫情第一波早期大流行阶段，与新冠疫情前时期相比，急诊室接诊的新冠及非新冠疾病老年患者病情更为复杂且危及生命。此外，非新冠疾病患者的急诊住院需求与急诊室病死率均翻倍，新冠病毒感染患者的该两项指标则增至原来的三倍。急诊室病死率的升高不仅与老年患者的病情复杂程度及严重程度相关，亦与医疗系统的过载状态有关。