Nail changes associated with mortality in end-stage renal disease: A national retrospective cohort study.

End-stage renal disease (ESRD) is characterized by irreversible loss of kidney function requiring dialysis or a kidney transplant to maintain fluid homeostasis. The integumentary system is known to be affected, and nail changes, such as Terry's nails and half-and-half nails, are frequently observed. However, the prognostic significance of nail manifestations in this population remains poorly defined. This study sought to determine whether a diagnosis of changes in nails was associated with an increased risk of all-cause mortality. A retrospective cohort analysis was performed using the United States Renal Data System (USRDS), which contains medical claims of all ESRD patients in the United States. Patients in the USRDS database with no missing data and enrolled between 2005 and 2018, allowing for at least a 1-year follow-up, were included. A nail change diagnosis and several clinical covariates were determined using International Classification of Disease (ICD)-9 and ICD-10 codes. Mortality risk was evaluated using Cox Proportional Hazards (CPH) models controlling for various demographic and clinical parameters. Of the 1,028,817 ESRD subjects included in this analysis, 66,704 (6.5%) subjects had a nail change diagnosis. In the final CPH model, a nail change diagnosis was independently associated with an increased risk of all-cause mortality (hazard ratio = 1.22; 95% confidence interval = 1.20-1.23) after controlling for demographic and clinical risk factors. Despite this association, nail changes are likely underdiagnosed in the ESRD population. Our findings underscore the importance of a comprehensive dermatological evaluation of ESRD patients and recognition of nail changes as a possible prognostic indicator.