GSTM1 and COVID-19: Comparison of dialysis adequacy and dialysis outcomes related to blood tests results were similar in the pre-COVID-19 and peri-COVID-19 groups for Kt/V (≥ 1.2%), iPTH (16.3 to 33 pmol/L), corrected Ca (8.4 to 9.5 mg/dL), PO4 (3.5 to 5.5 mg/dL) and Hb (≥ 10 g/dL). ALP levels were 7.28% (95% CI: 1.17 to 13.02%) lower in the peri-COVID-19 group compared to the pre-COVID-19 group (P = 0.020). The peri-COVID-19 group had albumin levels 2.13% higher (95% CI: 0.88 to 3.39%) than that of the pre-COVID-19 group (P ≤ 0.001).