Table 5 Multivariable model for mortality in each study.

Bossini et al²⁴

Multicenter

Italy

Age > 60 vs < 60

1.12 (1.03–1.24)

0.01

Stepwise selection after including all statistically significant variables from univariate logistic regression

Shortness of breath

13.7 (2.7–68.9)

0.004

Cravedi et al²⁵

Multicenter

International

Age

1.07 (1.02–1.14)

0.022

Akaike information criterion and Nagelkerke pseudo R² after logistic regression

Respiratory rate ≥ 20 vs < 20

6.88 (1.63–41.98)

0.017

IL-6

1 (1–1.01)

0.04

eGFR

0.96 (0.93–0.99)

0.029

Caillard et al²⁶

Multicenter

France

Age > 60 vs < 60

3.81 (1.56–9.31)

0.003

Backward selection after including all statistically significant variables from univariate Cox regression

Cardiovascular disease

2.04 (1.07–3.90)

0.031

Dyspnea on admission

2.35 (1.23–4.49)

0.010

Hilbrands et al²⁹

Multicenter

Europe

Age

1.07 (1.04–1.10)

 < 0.001

Backward selection after included all statistically significant variables from univariate Cox regression

Respiratory rate

1.07 (1.03–1.11)

 < 0.001

 > 25% increased creatinine

1.89 (1.05–3.40)

0.03

Prednisolone use

2.88 (1.03–8.03)

0.04

Willicombe et al³¹

Imperial College, London

UK

Age

1.07 (1.00–1.13)

0.041

Backward selection after included all statistically significant variables from univariate logistic regression

No diabetes mellitus

0.27 (0.07–0.99)

0.047

Living donor transplantation

0.08 (0.01–0.72)

0.024

Prednisolone use

5.98 (1.65–21.60)

0.006

Oto et al³²

Multicenter

Turkey

Presence of ischemic heart disease

4.129 (1.104–15.442)

0.035

Variables with p-value < 0.05 from univariate logistic regression were adjusted in the multivariable model

Creatinine at presentation

1.681 (1.083–2.608)

0.021

Kute et al³³

Multicenter

India

Baseline creatinine before COVID-19

5.424 (1.294–2.273E7)

0.043

Not reported (Cox regression)

Villanego et al³⁴

Multicenter

Spain

Age

1.06 (1.05–1.08)

 < 0.001

Variables with p-value < 0.1 from univariate analysis were included in the multivariable Cox model

Time from transplantation ≤ 6 months

1.64 (1.07–2.50)

0.021

Gastrointestinal symptoms

0.66 (0.48–0.90)

0.011

Pneumonia

5.04 (2.81–9.05)

 < 0.001

Alshaqaq et al³⁵

Multicenter

Saudi Arabia

Age

1.06 (1.013–1.109)

0.012

Statistically significant variables and clinically important variables were included in a multivariate Cox regression model

Creatinine at presentation

1.002 (1.00–1.004)

0.016

Use of azathioprine

6.38 (1.374–29.630)

0.018

Acute kidney injury

18.11 (2.244–146.21)

0.007

Requiao-Moura et al³⁶

Multicenter

Brazil

Age

1.054 (1.040–1.067)

 < 0.001

Variables with p-value ≤ 0.1 from univariate analysis were included in the multivariable logistic regression model

Time after transplantation (years)

1.025 (1.002–1.047)

0.030

Hypertension

1.566 (1.070–2.293)

0.021

Cardiovascular disease

1.517 (1.047–2.198)

0.028

CNI-MPA combination

1.197 (1.022–1.401)

0.026

Recent high dose of steroids

1.534 (1.063–2.214)

0.022

Days of symptom before presentation

0.954 (0.928–0.981)

0.001

Dyspnea

3.437 (2.584–4.571)

 < 0.001

Headache

0.552 (0.371–0.821)

0.003

Anosmia

0.563 (0.387–0.821)

0.003