Socioeconomic Inequalities Worsen the Risk of Death in CKD: A Population-Based Cohort Study in Italy

Key Points Socioeconomic position is associated with mortality in patients with CKD. Socioeconomic inequalities are stronger in men then in women. There was no evidence of association between deprivation and ESKD. Background Few studies have explored the effect of socioeconomic position on CKD. This study aims to fill this gap using a large Italian cohort of patients with CKD. Methods We analyzed a cohort of incident CKD cases from the Lazio Regional Health Information System from January 1, 2012, to December 31, 2021. We used the deprivation index (DI), a five-category census-block indicator that integrates several dimensions of disadvantage. The outcomes were mortality and ESKD. We characterized the health status of patients in the 2 years before CKD identification and followed each participant from the index date to the end of follow-up ( i.e ., the date of the outcome, of emigration, or December 31, 2022, whichever came first). We used Cox proportional hazard models to investigate the association between DI and outcomes (hazard ratio, 95% confidence interval [CI]). Results From 2012 to 2021, 127,457 new cases (55.9% men) were diagnosed. The average age was 72.2 (±13.7) for men and 74.4 (±14.8) for women. During an average follow-up of 4.3 years (±3.2), 57,158 patients died (45%), and 5994 developed ESKD (5%). The age-adjusted association between DI and mortality was higher in men than in women ( P value interaction = 0.02), hazard ratios for the extreme categories of DI (very high versus very low) were 1.16, 95% CI, 1.12 to 1.21 for men, and 1.08, 95% CI, 1.04 to 1.13, for women. There was no evidence of association between DI and ESKD. Conclusions In this population, socioeconomic disadvantage is associated with a higher risk of death, but not of ESKD, in patients with CKD.