Firstly, we described general characteristics of the retrospective cohort (Tables 1 and 2). They were mild type (1 case) or common type (219 cases) COVID-19 patients according to the updated guidance [2]. Among them, male patients had a higher risk of fever than females (odds ratio (OR) = 2.47, 95% confidence interval (CI):1.25–4.89, p = 0.01). They also tended to get more onset symptoms (≥ 3) than women (OR = 1.88, 95% CI:1.08–3.27, p = 0.03). (Table S1)
Afterwards, we found that fever resolved more slowly in patients without Arbidol administration (hazard ratio (HR) = 0.69, 95% CI: 0.48, 0.99, p = 0.02). In comparison with other antiviral drugs (91.2% Oseltamivir), we also discovered significant improvement in Arbidol group (HR = 0.58, 95% CI:0.37–0.92, p = 0.02). Besides, in males and patients with lower-grade fever (≤ 38.5℃), Arbidol showed superior efficacy in fever recovery (HR = 0.59, 95% CI:0.37–0.95, p = 0.03; HR = 0.57, 95% CI:0.34–0.95, p = 0.03). (Figs. 1 and 2)
Subsequently, we observed that negative-converting rate of nucleic acid within 14 days in non-Arbidol group was lower than that of Arbidol group (OR = 0.47, 95% CI:0.24–0.91, p = 0.028). The effect of Arbidol was more remarkable when compared to patients without any antiviral drugs (OR = 0.23, 95% CI:0.10–0.57, p = 0.002). At the last assay, a total number of 14 patients still got non-negative results. In patients without Arbidol application, we saw higher non-negative rate compared with others (OR = 3.13, 95% CI:1.00-9.83, p = 0.049). Consistent with the above data, Arbidol showed obvious efficacy on viral clearance in males (OR = 0.27, 95% CI:0.11–0.66, p = 0.005 for negative-conversion within 2 weeks; OR = 8.40, 95% CI:1.70-41.42, p = 0.006 for not negative rate at last assay). In particular, we found that patients with not negative results in non Arbidol group were all males, which was improved noticeably in Arbidol group. (Tables 3 and 4)
The medium hospital day in patients without antiviral drugs and treated with Arbidol was 19 and 15.5, respectively (p = 0.02). Considering the influence factors, we further demonstrated that Arbidol might contribute to the reduced hospitalization times in younger patients (≤ 50 year). During our observation period, no obvious adverse reaction was noted in Arbidol treated patients. One case from Arbidol group presented with allergic skin rash due to Moxifloxacin and the medication had to be dis-continued. (Table 5)