Table 2.
Assessment of outcome analysis of each studies
| Authors | Adjustment | NOS |
| Garcez 2020 | Age, sex, literacy, previous diagnoses, Charlson comorbidity index, polypharmacy, days of symptoms, oxygen support, temperature, mean arterial pressure, lymphocyte count, C-reactive protein, glomerular filtration rate, D-dimer, and albumin | 8 |
| Kennedy 2020 | Age older than 75 years, the presence of 4 or more comorbid conditions, living in nursing home or assisted living, and prior psychoactive medications. | 8 |
| Knopp 2020 | Unclear | 7 |
| Marengoni 2020 | N/A | 6 |
| Mcloughlin 2020 | Age, sex and Clinical Frailty Scale score | 7 |
| Mendes 2020 | N/A | 7 |
| Poloni 2020 | N/A | 7 |
| Ticinesi 2020 | Age, multimorbidity and baseline respiratory conditions | 8 |
| Zerah 2020 | N/A | 7 |
NOS: Newcastle-Ottawa Scale.