Table 1. Characteristics of included studies.

AKI: acute kidney injury; COVID-19: coronavirus disease 2019

Author	Study year	Location	Study type	Total number of patients	Median age (years)	Male (%)	AKI in COVID-19 patients
Cai et al. [7]	2020	China	Retrospective, single-center	298	47	50	17
Cao et al. [8]	2020	China	Retrospective, single-center	198	50.1	51	10
Colaneri et al. [9]	2020	Italy	Retrospective, single-center	44	67.5	36.4	2
Feng et al. [10]	2020	China	Prospective, single-center	114	64	62.39	35
Hu et al. [11]	2020	China	Retrospective, single-center	323	61	51.5	17
Huang et al. [12]	2020	China	Prospective, single-center	41	49	73	3
Regina et al. [13]	2020	Switzerland	Observational, single center	200	70	60	30
Wan et al. [14]	2020	China	Retrospective, single-center	135	47	53.3	5
Yan et al. [1]	2020	China	Retrospective, multicenter	2,018	43	56	10
Zhang et al. [15]	2020	China	Retrospective, single-center	221	55	48.9	10
Zhao et al. [16]	2020	China	Retrospective, single-center	91	46	53.8	5
Cao et al. [17]	2020	China	Retrospective, single-center	102	54	52	17
Brill et al. [18]	2020	UK	Retrospective, single-center	450	72	60	80
Chan et al. [19]	2020	USA	Observational, single-center	3,235	64	57	1,406
Hirsch et al. [20]	2020	USA	Retrospective, single-center	5,549	64	60	1,993
Pei et al. [21]	2020	China	Retrospective, single-center	333	57.1	57.1	22
Rubin et al. [22]	2020	France	Retrospective, single-center	71	61.2	77	57
Wang et al. [23]	2020	China	Retrospective, multicenter	138	54.3	57	5
Zhang et al. [3]	2020	China	Retrospective, single-center	663	55.6	48.4	68
Zhou et al. [2]	2020	China	Retrospective, multicenter	191	56	62	28