Omicron variant infection worsen the prognosis of haemodialysis (HD) patients.

Background: Haemodialysis (HD) patients are predisposed to physical ailments, and their occurrence of coronavirus disease 2019 (COVID-19) could potentially lead to a more unfavourable prognosis. However, the impact of SARS-CoV-2 (Omicron variant) infection on the prognosis of HD patients remains unclear. This study aimed to explore the impact of Omicron variant infection on the prognosis of HD patients.

Methods: Eligible participants were patients undergoing maintenance HD treatment during a large-scale outbreak of COVID-19 (Omicron variant) in Shanghai, China, from April 7 to May 30, 2022. According to SARS-CoV-2 infection status of participants, the HD patients were divided into two groups: a COVID-19 group and a non-COVID-19 group. The primary outcome assessed was in-hospital mortality, and secondary outcomes encompassed the incidence of severe cases, admission to intensive care, length of hospital stay, and blood indices. Statistical analysis was conducted by comparative analysis and multiple logistic regression.

Results: This study recruited 588 HD patients, including 199 cases in the COVID-19 group and 389 in the non-COVID-19 group. In the COVID-19 group, the mortality rate was 8.45% (17/199), whereas in the non-COVID-19 group, the rate was 3.34% (13/389) (p < 0.05). Compared with the non-COVID-19 group, the COVID-19 group had a risk ratio (RR) with 95% confidence interval (CI) of 2.56 (1.27-5.15) for mortality, and the absolute risk difference (ARD) with 95% CI of 5.20% (1.34%-9.06%). Multiple logistic regression confirmed Omicron variant as a risk factor for mortality among HD patients. Additionally, the COVID-19 group had a higher proportion of severe cases, intensive care admission, hypocalcaemia and hyperphosphatemia and longer hospitalization duration, compared to the non-COVID-19 group (p < 0.05).

Conclusions: Omicron variant infection was associated with increased mortality risk in HD patients, and Omicron infection worsen the prognosis of HD patients. Enhancing immune protection against SARS-CoV-2 is crucial for HD patients during the ongoing COVID-19 pandemic.