Table 5. Early symptoms associated with severe cases requiring oxygen therapy.
| Variables | Univariate model | Multivariate model 1a | Multivariate model 2b | Multivariate model 3c | |
|---|---|---|---|---|---|
| OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | ||
| Sex | |||||
| Male vs. female | 1.3 (1.1–1.5) | 1.6 (1.3–1.9) | 1.5 (1.3–1.8) | 1.6 (1.4–2.0) | |
| Age (yr) | |||||
| 60–69 vs. 0–59 | 4.3 (3.4–5.3) | 2.9 (2.2–3.7) | 3.2 (2.5–4.0) | 3.2 (2.6–4.1) | |
| 70–79 vs. 0–59 | 9.5 (7.6–11.9) | 5.8 (4.4–7.6) | 6.6 (5.1–8.5) | 7.0 (5.4–9.1) | |
| ≥ 80 vs. 0–59 | 22.5 (17.3–29.4) | 15.8 (11.2–22.2) | 16.0 (11.7–21.8) | 20.6 (14.9–28.4) | |
| No. of comorbidities | |||||
| 1–2 vs. 0 | 4.6 (3.9–5.5) | 2.0 (1.6–2.5) | 2.1 (1.7–2.6) | 2.1 (1.7–2.6) | |
| ≥ 3 vs. 0 | 13.5 (9.9–18.4) | 3.6 (2.4–5.3) | 3.4 (2.3–4.9) | 3.6 (2.5–5.3) | |
| No. of symptoms on admission | |||||
| 1 vs. 0 | 1.6 (1.2–2.0) | 1.7 (1.3–2.3) | |||
| 2 vs. 0 | 1.5 (1.2–2.0) | 1.8 (1.3–2.4) | |||
| ≥ 3 vs. 0 | 2.9 (2.3–3.6) | 3.6 (2.7–4.8) | |||
| Fever | |||||
| Yes vs. No | 2.8 (2.4–3.3) | 2.5 (1.8–3.4) | |||
| Cough | |||||
| Yes vs. No | 1.3 (1.2–1.6) | 1.2 (1.0–1.5) | |||
| Sputum | |||||
| Yes vs. No | 1.5 (1.2–1.7) | 1.2 (0.9–1.5) | |||
| Sore throat | |||||
| Yes vs. No | 0.5 (0.4–0.7) | 0.7 (0.5–1.0) | |||
| Rhinorrhea | |||||
| Yes vs. No | 0.6 (0.4–0.8) | 0.6 (0.4–0.9) | 0.8 (0.5–1.1) | ||
| Myalgia | |||||
| Yes vs. No | 1.1 (0.9–1.4) | 1.2 (0.9–1.5) | |||
| Fatigue | |||||
| Yes vs. No | 2.0 (1.5–2.7) | 1.3 (0.9–1.9) | |||
| Dyspnea | |||||
| Yes vs. No | 8.9 (7.4–10.7) | 6.9 (5.5–8.7) | |||
| Headache | |||||
| Yes vs. No | 0.8 (0.6–1.0) | 0.7 (0.6–1.0) | 1.0 (0.8–1.3) | ||
| Altered mental status | |||||
| Yes vs. No | 15.4 (6.8–34.7) | 4.2 (1.5–11.7) | |||
| Nausea or vomiting | |||||
| Yes vs. No | 2.0 (1.5–2.7) | 1.1 (0.8–1.7) | |||
| Diarrhea | |||||
| Yes vs. No | 1.3 (1.1–1.7) | 1.2 (0.9–1.7) | |||
| Systolic BP (mmHg) | |||||
| ≥ 120 vs. < 120 | 1.2 (1.0–1.5) | 0.9 (0.7–1.2) | 0.9 (0.7–1.2) | 0.9 (0.7–1.1) | |
| Diastolic BP (mmHg) | |||||
| ≥ 80 vs. < 80 | 0.8 (0.7–0.9) | 0.9 (0.7–1.1) | 0.8 (0.7–1.0) | 0.8 (0.7–1.0) | |
| Heart rate (bpm) | |||||
| ≥ 120 vs. < 120 | 2.7 (1.8–4.0) | 1.8 (1.1–3.0) | 2.3 (1.5–3.6) | 2.3 (1.5–3.7) | |
| Body temperature (°C) | |||||
| ≥ 37.5 vs. < 37.5 | 2.9 (2.4–3.4) | 1.4 (1.0–2.1) | 3.6 (2.9–4.4) | 2.5 (2.0–3.2) | |
OR = odds ratio, CI = confidence interval, BP = blood pressure, COVID-19 = coronavirus disease 2019.
aLogistic regression model for severe COVID-19 requiring supplemental oxygen therapy as the dependent variable and the presence of each symptom on admission as the main predictor variable (C-statistics = 0.87, P value for the Hosmer-Lemeshow test = 0.914); bLogistic regression model for severe COVID-19 requiring supplemental oxygen therapy as the dependent variable and the presence of rhinorrhea and headache on admission as the main predictor variables (C-statistics = 0.83, P value for the Hosmer-Lemeshow test = 0.080); cLogistic regression model for severe COVID-19 requiring supplemental oxygen therapy as the dependent variable and the number of symptoms prevalent on admission as the main predictor variable (C-statistics = 0.84, P value for the Hosmer-Lemeshow test = 0.143).