Table 2.

Hazard ratios for mortality in untreated and treated patients by group

Type	HR (95% CI)
Patients aged <70 y
Treated (n=2,523)	1
Untreated (n=4,524)	0.46 (0.34−0.62)
Patients aged ≥70 y
Treated (n=2,345)	1
Untreated (n=1,544)	1.59 (1.40−1.80)
Mild casea)
Treated (n=3,358)	1
Untreated (n=5,501)	0.98 (0.80−1.21)
Severe caseb)
Treated (n=1,510)	1
Untreated (n=567)	2.32 (2.00−2.69)
Severe cases and aged ≥70 y
Treated (n=874)	1
Untreated (n=387)	2.09 (1.77−2.46)

HR, hazard ratio; CI, confidence interval.

^a)Mild case: patient requiring oxygen therapy (nasal cannula or mask).

^b)Severe case: patient requiring high-flow oxygen therapy, mechanical ventilator, or extracorporeal membrane oxygenation/continuous renal replacement therapy.