This retrospective cohort study investigated the long-term risk of end-stage kidney disease (ESKD) following COVID-19 using a nationwide database of Japanese medical claims.

Propensity score matching was utilised to form a cohort of individuals with COVID-19 and a non-infected control group using data from the National Claims Database encompassing six prefectures in Japan. The primary outcome measured was the initiation of renal replacement therapy (dialysis or kidney transplantation) after the index month of the study period. Cox proportional hazards models incorporating inverse probability of censoring weighting were employed to estimate HRs for the association between COVID-19 and ESKD.

A total of 3 073 150 pairs were matched in this study. During follow-up, COVID-19 was associated with a significantly increased instantaneous risk of the composite ESKD outcome (HR 2.79, 95% CI 2.56 to 3.04). The risk was increased for haemodialysis initiation (HR 2.77, 95% CI 2.54 to 3.02) and peritoneal dialysis (HR 5.16, 95% CI 1.93 to 13.75), whereas the estimate for kidney transplantation was imprecise (HR 5.20, 95% CI 0.62 to 43.27). Subgroup analyses showed broadly consistent associations across age, sex, hypertension, diabetes and COVID-19 severity.

These findings suggest that COVID-19 may have sustained adverse effects on kidney outcomes, supporting close post-acute renal monitoring and early risk stratification in high-risk patients.