Table 2 Crude and adjusted odds ratios of influenza and URI (previous 1–14, 1–30, and 1–90 days) for COVID-19 infection in all participants.

From: The associations of previous influenza/upper respiratory infection with COVID-19 susceptibility/morbidity/mortality: a nationwide cohort study in South Korea

Characteristics

COVID-19 (exposure/total, %)

Control (exposure/total, %)

ORs (95% confidence interval) for COVID-19

E-value (95% CI)

Crude

P-value

Model 1†‡

P-value

Model 2§

P-value

Previous 1–14 days

Influenza

27/8,070 (0.3%)

20/32,280 (0.1%)

5.62 (3.16–9.98)

 < 0.001*

5.37 (3.01–9.60)

 < 0.001*

3.07 (1.61–5.85)

0.001*

5.59 (2.60–11.18)

URI

1,441/8,070 (17.9%)

1,003/32,280 (3.1%)

6.82 (6.26–7.43)

 < 0.001*

7.00 (6.42–7.62)

 < 0.001*

6.95 (6.38–7.58)

 < 0.001*

13.38 (12.24–14.64)

Previous 1–30 days

Influenza

32/8,070 (0.4%)

48/32,280 (0.1%)

2.68 (1.71–4.19)

 < 0.001*

2.46 (1.56–3.87)

 < 0.001*

1.18 (0.72–1.91)

0.510

1.00 (1.00–1.67)

URI

1,741/8,070 (21.6%)

1,741/32,280 (5.4%)

4.87 (4.53–5.23)

 < 0.001*

5.00 (4.65–5.38)

 < 0.001*

4.99 (4.64–5.37)

 < 0.001*

9.45 (8.75–10.21)

Previous 1–90 days

Influenza

146/8,070 (1.8%)

229/32,280 (0.7%)

2.60 (2.10–3.20)

 < 0.001*

2.52 (2.04–3.12)

 < 0.001*

1.91 (1.54–2.37)

 < 0.001*

3.23 (2.45–4.17)

URI

2,694/8,070 (33.4%)

5,130/32,280 (15.9%)

2.68 (2.54–2.84)

 < 0.001*

2.73 (2.58–2.89)

 < 0.001*

2.70 (2.55–2.86)

 < 0.001*

4.84 (4.54–5.17)

  1. *Conditional logistic regression model, Significance at P < 0.05.
  2. Stratified model for age, sex and income.
  3. Model 1 was adjusted for CCI scores, asthma, COPD, and hypertension.
  4. §Model 2 was adjusted for model 1 plus influenza and URI.