Supplementary Material for: Outcomes of Infected Cardiovascular Implantable Devices in Dialysis Patients

<b><i>Background/Aims:</i></b> Dialysis patients are at a higher risk for cardiovascular implantable electronic device (CIED) infection-related hospitalizations. We compared the outcomes and cost for dialysis and non-dialysis patients hospitalized with CIED infections. <b><i>Methods:</i></b> We conducted a retrospective analysis of the Nationwide Inpatient Sample (NIS) discharge records from 2005 to 2010. Patients with CIED infections were identified using ICD-9 codes for device-related infections or device procedure along with bacteremia, endocarditis or systemic infection. Dialysis patients were identified using ICD-9 codes. Multivariable logistic and linear regressions were performed to examine in-hospital mortality, length of stay and cost. <b><i>Results:</i></b> Of the 87,798 estimated hospitalizations with CIED infections, 6,665 (7.6%) were dialysis patients. CIED-infection-related hospitalization has increased over time among dialysis patients. In-hospital mortality was higher among dialysis patients (13.6% vs. 5.9%, p < 0.001). In the multivariable model, dialysis patients had higher odds of in-hospital mortality (odds ratio 1.98; 95% CI: 1.6, 2.4) compared to the non-dialysis group. Dialysis patients had a longer median length of stay (12 days vs. 7 days, p < 0.001) and majority required extended care facility upon discharge (51.2% vs. 35.0%, p < 0.001) compared to the non-dialysis group. Dialysis status was associated with 50.3% increased cost of hospitalization (p < 0.001). <b><i>Conclusion:</i></b> CIED-infection related hospitalization is increasing among patients undergoing dialysis and is associated with higher in-hospital mortality, longer hospital stay and higher costs of hospitalization. Future studies should examine the reasons for such a high risk and find means to improve outcomes in dialysis population

Supplementary Material for: Serum Potassium, End-Stage Renal Disease and Mortality in Chronic Kidney Disease

<b><i>Background/Aims:</i></b> Hypokalemia and hyperkalemia are often noted in chronic kidney disease (CKD) patients, but their impact on mortality and end-stage renal disease (ESRD) is less well understood. We aimed at studying the associations between potassium disorders, and mortality and progression to ESRD in a CKD population. <b><i>Methods:</i></b> Using our electronic health record-based CKD registry, 36,359 patients with eGFR <60 ml/min/1.73 m² and potassium levels measured from January 1, 2005 to September 15, 2009 were identified. We examined factors associated with hypokalemia (<3.5 mmol/l) and hyperkalemia (>5.0 mmol/l) using logistic regression models and associations between serum potassium levels (both as continuous and categorical variables) and all-cause mortality or ESRD using Cox-proportional hazards models. <b><i>Results:</i></b> Serum potassium <3.5 mmol/l was noted among 3% and >5.0 mmol/l among 11% of the study population. In the multivariable logistic regression analysis, lower eGFR, diabetes and use of ACE inhibitors or Angiotensin-Receptor Blockers were associated with higher odds of having hyperkalemia. Heart failure and African American race were factors associated with higher odds of hypokalemia. After adjustment for covariates including kidney function, serum potassium <4.0 and >5.0 mmol/l were significantly associated with increased mortality risk, but there was no increased risk for progression to ESRD. Time-dependent repeated measures analysis confirmed these findings. When potassium was examined as a continuous variable, there was a U-shaped association between serum potassium levels and mortality. <b><i>Conclusion:</i></b> In patients with stage 3-4 CKD, serum potassium levels <4.0 and >5.0 mmol/l are associated with higher mortality but not with ESRD