Risk factors and prognosis for COVID-19-induced acute kidney injury: a meta-analysis

Abstract

Objective: To analyse the incidence, risk factors and impact of acute kidney injury (AKI) on the prognosis of patients with COVID-19.

Design: Meta-analysis.

Data sources: PubMed, Embase, CNKI and MedRxiv of Systematic Reviews from 1 January 2020 to 15 May 2020.

Study selection: Studies examining the following demographics and outcomes were included: patients' age; sex; incidence of and risk factors for AKI and their impact on prognosis; COVID-19 disease type and incidence of continuous renal replacement therapy (CRRT) administration during COVID-19 infection.

Results: A total of 79 research articles, including 49 692 patients with COVID-19, met the systemic evaluation criteria. The mortality rate and incidence of AKI in patients with COVID-19 in China were significantly lower than those in patients with COVID-19 outside China. A significantly higher proportion of patients with COVID-19 from North America were aged ≥65 years and also developed AKI. European patients with COVID-19 had significantly higher mortality and a higher CRRT rate than patients from other regions. Further analysis of the risk factors for COVID-19 combined with AKI showed that age ≥60 years and severe COVID-19 were independent risk factors for AKI, with an OR of 3.53, 95% CI (2.92-4.25) and an OR of 6.07, 95% CI (2.53-14.58), respectively. The CRRT rate in patients with severe COVID-19 was significantly higher than in patients with non-severe COVID-19, with an OR of 6.60, 95% CI (2.83-15.39). The risk of death in patients with COVID-19 and AKI was significantly increased, with an OR of 11.05, 95% CI (9.13-13.36).

Conclusion: AKI was a common and serious complication of COVID-19. Older age and having severe COVID-19 were independent risk factors for AKI. The risk of in-hospital death was significantly increased in patients with COVID-19 complicated by AKI.

Keywords: acute renal failure; kidney & urinary tract disorders; nephrology.

Figure 1

Flow diagram for selection of studies.

Figure 2

Forest plot showing the subgroup analysis of AKI risk factors. (A) The Q test showed p>0.1, indicating no heterogeneity existed between studies. The fixed-effects model was used to combine the data, with an OR of 3.53 (95% CI (2.92–4.25), p<0.001), suggesting that age was a risk factor for AKI; the older the patient, the higher the risk of AKI. (B) The Q test showed p<0.1, indicating heterogeneity existed between studies. The random-effects model was used to combine the data, with an OR of 1.36 (95% CI (0.84–2.20), p=0.21) and no statistical significance, suggesting that being man had no significant correlation with the incidence of AKI in patients with COVID-19, but the probability of AKI in male patients with COVID-19 was higher than that of female patients with COVID-19. (C) The Q test showed p>0.1, indicating no heterogeneity existed between studies. The fixed-effects model was used to combine the data, with an OR of 6.07 (95% CI (2.53–14.58), p<0.001), suggesting that severe COVID-19 was a risk factor for AKI. Patients with severe COVID-19 had a higher risk of developing AKI than patients with non-severe COVID-19. AKI, acute kidney injury.

Figure 3

Forest plot showing the subgroup analysis of patients requiring CRRT during COVID-19 infection. The Q test showed p>0.1, indicating no heterogeneity existed between studies. The fixed-effects model was used to combine the data, with an OR of 6.60 (95% CI (2.83–15.39), p<0.001), suggesting that the rate of CRRT required by patients with severe COVID-19 was significantly higher than that of patients with non-severe COVID-19. CRRT, continuous renal replacement therapy.

Figure 4

Forest plot showing the subgroup analysis of risk of death. The Q test showed p>0.1, indicating no heterogeneity existed between studies. The fixed-effects model was used to combine the data, with an OR of 11.05 (95% CI (9.13–13.36), p<0.001), suggesting that AKI incidence was a risk factor for death. The risk of death in patients with COVID-19 complicated by AKI was higher than that in patients with COVID-19 not complicated by AKI. AKI, acute kidney injury.