Comorbidity and in-hospital mortality in peritoneal dialysis patients: data of the Emilia Romagna region of Italy.

Kidney failure increases in-hospital mortality (IHM); however, comorbidity is crucial for predicting mortality in dialysis patients. Our aim was to evaluate the impact of comorbidity, assessed by modified Elixhauser index (mEI), Charlson Comorbidity Index (CCI), and age-adjusted CCI, on IHM in a cohort of peritoneal dialysis patients admitted to hospitals of the Emilia Romagna region (ERR) of Italy.All hospital admissions of peritoneal dialysis patients recorded between 2007 and 2021 in the ERR database were analyzed. The International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) was used for detecting diagnoses and procedures, and the inclusion criterion was code 5498. Comorbidity burden was evaluated by three different scores, and hemodialysis (HD) treatment need was considered. IHM was our outcome.During the 15 years of the study, 3,242 hospitalized peritoneal dialysis patients (62.7% males) were evaluated. Mean age was 62.8±20.6 years, 9.6% underwent HD, and IHM was 5.9% (n=192). IHM mortality was stable throughout the study period. Deceased subjects were older, were hospitalized longer, had a higher comorbidity burden, and had a higher percentage of HD treatment needs than survivors. Age, male sex, comorbidity burden, and HD treatment were predictors of IHM. Receiver operating characteristics (ROC) analysis confirmed the impact of comorbidity burden on IHM, especially when age was considered.We conclude that in male, elderly hospitalized peritoneal dialysis patients with failing dialysis technique, comorbidity burden should be considered being a predictor of IHM.