In-hospital outcomes by peritoneal versus hemodialysis inpatient procedure coding in adults with end-stage kidney disease: a 2021 National Inpatient sample study

Purpose To compare discharge-level inpatient outcomes among adults with end-stage kidney disease (ESKD) whose hospitalizations contained exclusive inpatient procedure coding for peritoneal dialysis (PD) versus hemodialysis (HD). Methods We analyzed the 2021 National Inpatient Sample using survey-weighted regression. The primary outcome was in-hospital mortality; secondary outcomes were length of stay (LOS), total hospital charges, and routine-home discharge among survivors. Sensitivity analyses added APR-DRG severity, restricted mortality analysis to non-elective admissions, and used stabilized inverse-probability-of-treatment weighting (IPTW). Results The cohort included 152,055 discharges, representing 760,274 hospitalizations nationally. In the primary adjusted model, PD coding was associated with lower mortality odds (aOR 0.672, 95% CI 0.591–0.765). The association attenuated substantially after APR-DRG severity adjustment (aOR 0.850, 95% CI 0.740–0.977; P = 026) and remained present with IPTW (OR 0.662, 95% CI 0.574–0.764). PD coding was also associated with shorter LOS (ratio 0.797), lower billed charges (ratio 0.780), and more frequent routine-home discharge (aOR 1.314). Conclusion PD-coded hospitalizations had more favorable measured short-term outcomes, but the mortality association attenuated substantially after APR-DRG severity adjustment (aOR 0.850, 95% CI 0.740–0.977; P = 026), indicating important case-mix differences. Because inpatient procedure codes do not establish chronic outpatient modality and acute crossover may be differential, these associations should not be interpreted as causal evidence favoring chronic PD over HD.