S1 Data -

Background
Corticosteroids are commonly used to treat COVID-19 patients with hypoxemia, and clinicians have adjusted the corticosteroid intensity on the basis of clinical needs. However, neither the optimal dose nor the duration of treatment has been recommended.
Objective
To investigate whether cumulative doses of corticosteroids, measured as dexamethasone-equivalent doses over the first 14 days, impact outcomes in patients with COVID-19 pneumonia.
Methods
We conducted a retrospective cohort study of COVID-19 pneumonia patients admitted between April 1st, 2020, and September 30th, 2021. The study focused on the type and dose of corticosteroid administered during the initial 14 days, clinical outcomes, and complications. The primary outcome was in-hospital mortality.
Results
Among 271 patients, the mean cumulative dexamethasone-equivalent dose was 158 (119.9–197.25) mg in survivors and 185 (131.7–222.0) mg in nonsurvivors. Univariate analysis revealed that the cumulative dexamethasone-equivalent dose was a risk factor for in-hospital mortality. However, this association did not hold true in the multivariate analysis. After the cumulative dexamethasone-equivalent dose was categorized into quartiles, the moderate dosage (126.01–165.00 mg) in the second quartile was found to be associated with the lowest in-hospital mortality (16.2%). Higher cumulative dexamethasone-equivalent doses were associated with longer hospital and ICU stays and fewer ventilator-free days (p < 0.001). Doses exceeding 165 mg were associated with an increased risk of hospital-acquired infections (p < 0.001).
Conclusions
The cumulative dexamethasone-equivalent dose during the first 14 days is not associated with in-hospital mortality in hypoxemic COVID-19 patients. However, higher cumulative doses exceeding 165 mg are associated with an increased risk of in-hospital mortality and secondary hospital-acquired infections.

## 研究背景
糖皮质激素（Corticosteroids）目前被广泛用于治疗合并低氧血症的新型冠状病毒肺炎（COVID-19）患者，临床医师会根据临床需求调整糖皮质激素的使用强度。但目前尚未有公认的最佳给药剂量与疗程推荐方案。

## 研究目的
探讨以最初14天内的地塞米松等效剂量（dexamethasone-equivalent doses）计算的糖皮质激素累计给药剂量，是否会对新型冠状病毒肺炎（COVID-19）肺炎患者的临床结局产生影响。

## 研究方法
本研究为回顾性队列研究，纳入2020年4月1日至2021年9月30日期间收治的新型冠状病毒肺炎肺炎患者。研究重点关注患者最初14天内糖皮质激素的给药类型与剂量、临床结局及并发症情况，主要结局指标为住院死亡率（in-hospital mortality）。

## 研究结果
本研究共纳入271例患者，存活患者的糖皮质激素累计地塞米松等效剂量均值为158mg（四分位距119.9~197.25mg），非存活患者该均值为185mg（四分位距131.7~222.0mg）。单因素分析显示，累计地塞米松等效剂量是住院死亡率的危险因素；但该关联在多因素分析中并不成立。将累计地塞米松等效剂量按四分位数分组后，第二四分位数区间的中等剂量组（126.01~165.00mg）的住院死亡率最低，为16.2%。更高的累计地塞米松等效剂量与更长的住院时长、重症监护室（ICU）停留时间以及更少的无呼吸机使用天数显著相关（p < 0.001）；给药剂量超过165mg则与医院获得性感染（hospital-acquired infections）风险升高显著相关（p < 0.001）。

## 研究结论
对于合并低氧血症的新型冠状病毒肺炎患者，其最初14天内的糖皮质激素累计地塞米松等效剂量与住院死亡率无显著关联；但累计给药剂量超过165mg的高剂量组，其住院死亡率与继发医院获得性感染的风险均显著升高。