Table 4.

Factors predicting the development of hypoxia requiring oxygen support

Oxygen support during the hospital stay
	OR (95% CI), P
	Model-1	Model-2
Age (Reference: 18-45 years)
<18 years	0.4 (0.2-0.9), 0.023	0.2 (0.1-0.8), 0.023
45-60 years	2.9 (2.1-3.8), <0.001	2.0 (1.3-2.9), 0.001
>60 years	2.9 (2.1-4), <0.001	1.6 (1.0-2.6), 0.037
Male (Reference: Female)	1.2 (1.0-1.6), 0.077	1.1 (0.8-1.5), 0.730
Vaccinated	0.6 (0.5-0.8), <0.001	0.7 (0.5-1.0), 0.050
Symptom onset to hospitalization (Reference: 1 week)
2 weeks	1.2 (0.9-1.5), 0.254	1.0 (0.7-1.4), 0.961
3 or more weeks	1.2 (0.6-2.3), 0.614	0.7 (0.2-1.9), 0.451
Asymptomatic	0.3 (0.2-0.6), <0.001	0.1 (0.04-0.3), <0.001
Symptoms reported (Reference: No)
Breathlessness	6.3 (5-8.1), <0.001	3.7 (2.7-5.2), <0.001
Dry cough	1.3 (1-1.7), 0.024
Rhinitis	0.5 (0.3-0.9), 0.012
Sore throat	0.7 (0.5-0.9), 0.026
Fatigue	0.7 (0.5-0.9), 0.036
Comorbidities (Reference: No)
1	1.3 (1-1.8), 0.032	1.3 (0.9-1.9), 0.171
2 or more	1.6 (1·2-2.3), 0.006	1.5 (0.9-2.4), 0.092
Lab parameters (Reference: No)
Leucocyte count (Reference: Normal)
Leukopenia		0.4 (0.2-0.6), <0.001
Leukocytosis		2.6 (1.7-4.0), <0.001
D-Dimer >500 (Reference:=<500)		2.5 (1.7-3.9), <0.001
CRP high (Reference: Normal)		5.9 (3.4-9.9), <0.001
Creatinine >1.0 mg/dl		1.8 (1.1-2.9), 0.018

Model-1: Adjusting for baseline clinical parameters, Model-2: Model-1 plus baseline lab parameters Age, gender and comorbidities are included in all models Only symptoms and lab parameters with significant P value are included in these final models. OR: Odds ratio, CI: Confidence interval, CRP: C-reactive protein