Results
Survival rate was 79% (401/508) among patients hospitalized for COVID-19 during the study period. Overall, median age of COVID-19 survivors was 64 years; majority (73%) were admitted from home with 25% from a skilled nursing facility (SNF). The overall median TTS was 4 days (IQR: 2-10) for survivors, with 43% (n=174) within 3 days, 34% (n=135) between 4-10 days, and 23% (n=92) after a prolonged period exceeding 10 days. More females achieved prompt vs. prolonged time to recovery (51% vs. 37%) (Table 1 ).
At time of admission, significantly less patients in the short TTS group experienced fevers (47% vs. 58% vs. 63%, p = 0.0214), required supplemental oxygen (55% vs. 73% vs. 77%, p < 0.0001), while none had septic shock (vs. 4% vs. 16%, p<0.0001), required direct ICU admission (vs. 7% vs. 25%,p < 0.0001) or mechanical ventilation (vs. 2% vs. 16%, p < 0.0001) compared to the intermediate and prolonged groups, respectively (Table 1 ). Therapy directed against COVID-19 was less frequently prescribed to patients with short compared to intermediate and prolonged TTS: hydroxychloroquine ± azithromycin (13% vs. 32% vs. 37%, p < 0.0001), remdesivir (14% vs.29% vs. 48%, p < 0.0001), tocilizumab (0.6% vs. 0.7% vs. 12%, p < 0.0001), corticosteroids (34% vs. 31% vs. 58%, p < 0.0001), and convalescent plasma (10% vs. 24% vs. 40%, p < 0.0001).
Patients with prompt recovery were less likely to have secondary bacterial infections at time of admission (presumed 13% vs. 24% vs. 39%, p = 0.0001; culture-positive 11% vs. vs. 21% vs. 28%,p = 0.0013), especially in the respiratory site (0% [0/19] vs. 10% [3/29] vs. 46% [12/26], p = 0.0002) compared to intermediate and prolonged TTS groups, respectively. Nonetheless, 83% of the patients in the short TTS group who did not have secondary bacterial infections were prescribed broad-spectrum antibacterial therapy for a median duration of 4 days. A notable proportion of the prolonged TTS cohort were co-infected with multidrug-resistant pathogens such as Pseudomonas aeruginosa (15%) and carbapenem-resistant organisms (4%) compared to none in the short TTS group; patients who resided in a SNF prior to admission accounted for 56% (5/9) of those with Pseudomonas aeruginosa and all three cases involving carbapenem-resistant organisms. Interestingly, co-infection with ESBL-producing isolates (mostly urine) occurred in 4% of patients overall, irrespective of TTS. Compared to the intermediate and prolonged TTS cohorts, less patients with a short TTS developed AKI (10% vs. 17% vs. 34%, p < 0.0001) and none developed ARDS (vs. 1% vs. 17%, p < 0.0001) (Table 1 ). Ultimately, those who recovered fastest experienced a shorter hospital stay (median 5 vs. 9 vs. 22 days, p < 0.0001) (Table 1 ).
By multivariable logistic regression analysis, independent predictors for prompt recovery from COVID-19 were female sex, absence of fever, longer time from symptom onset to hospitalization, no direct ICU admission, not requiring supplemental oxygen upon presentation and absence of presumed or documented co/secondary bacterial infections (Table 2 ).