Table 6 Multivariable logistic regression model for in-hospital mortality in patients ≥ 80 years of age hospitalized with COVID-19

Wave

 First

Ref

Ref

-

Ref

 Successive

0.61 (0.53–0.70)

 < 0.001

0.58 (0.50–0.68)

 < 0.001

0.67 (0.57–0.79)

 < 0.001

Age group

 80–84 years

Ref

Ref

Ref

 85–90 years

1.25 (1.09–1.43)

0.001

1.26 (1.10–1.44)

0.001

1.31 (1.25–1.54)

0.001

 90–94 years

1.27 (1.08–1.50)

0.004

1.30 (1.10–1.53)

0.001

1.38 (1.13–1.67)

0.001

  ≥ 95 years

1.41 (1.11–1.87)

0.003

1.47 (1.14–1.90)

0.003

1.56 (1.17–2.09)

0.003

 Sex, male

1.44 (1.28–1.63)

 < 0.001

1.41 (1.25–1.59)

 < 0.001

1.33 (1.16–1.53)

 < 0.001

Acquisition

 Community

Ref

-

Ref

-

Ref

 Nosocomial

1.52 (1.21–1.90)

 < 0.001

1.54 (1.23–1.94)

 < 0.001

1.46 (1.11–1.92)

 < 0.001

 Nursing Home

0.71 (0.61–0.84)

 < 0.001

0.71 (0.61–0.84)

 < 0.001

0.72 (0.61–0.88)

 < 0.001

Degree of dependence

 Independent or mild

Ref

-

Ref

-

Ref

 Moderate

1.40 (1.21–1.64)

 < 0.001

1.42 (1.21–1.63)

 < 0.001

1.5 (1–29-1.81)

 < 0.001

 Severe

1.63 (1.37–1.94)

 < 0.001

1.67 (1.40–2.00)

 < 0.001

2.05 (1.67–2.53)

 < 0.001

Comorbidities

 CCI

1.07 (1.04–1.10)

 < 0.001

1.07 (1.04–1.10)

 < 0.001

1.07 (1.03–1.11)

 < 0.001

Physical examination

 Oxygen saturation < 94%

2.15 (1.91–2.41)

 < 0.001

2.09 (1.87–2.35)

 < 0.001

1.58 (1.38–1.81)

 < 0.001

 qSOFA score ≥ 2

2.79 (2.38–3.27)

 < 0.001

2.09 (1.86–2.25)

 < 0.001

2.31 1.92–2.78)

 < 0.001

Treatment

 Steroid

-

-

1.29 (1.13–1.45)

 < 0.001

1.29 (1.12–1.50)

 < 0.001

 Tocilizumab

1.35 (1.00–1.84)

0.049

1.23 (0.89–1.71)

0.68

 Remdesivir

0.52 (0.34–0.79)

0.002

0.51 (0.32–7.98)

0.509

Laboratory findings

 Lymphocytes (× 10³/μL)

1.00 (1.00–1.00)

 < 0.001

 Lactate dehydrogenase (U/L)

1.00 (1.00–1.00)

 < 0.001

 C-reactive protein (mg/L)

1.00 (1.00–1.00)

 < 0.001