Serum Potassium and Short-term Clinical Outcomes Among Hemodialysis Patients: Impact of the Long Interdialytic Interval  Steven M. Brunelli, MD, MSCE, Charles Du Mond, PhD, Nina Oestreicher, PhD, Viatcheslav Rakov, MD, David M. Spiegel, MD  American Journal of Kidney Diseases  Volume 70, Issue 1, Pages 21-29 (July 2017) DOI: 10.1053/j.ajkd.2016.10.024 Copyright © 2016 The Authors Terms and Conditions

Figure 1 Study schematic. Routine serum potassium measurements (arrows) occurring on Monday, Wednesday, or Friday were considered for analysis. Outcomes were assessed over a 4-day period (grey bars) consisting of the day of the potassium measurement (index date) and the subsequent 3 days. American Journal of Kidney Diseases 2017 70, 21-29DOI: (10.1053/j.ajkd.2016.10.024) Copyright © 2016 The Authors Terms and Conditions

Figure 2 Adjusted probability of hospitalization by serum potassium (K+) category and day of the week. The probability of hospitalization for each serum potassium category on each day of the week (Monday, light grey symbols; Wednesday, dark grey symbols; Friday, black symbols) is presented. ∗Significantly different from the referent category (4.0-<4.5 mEq/L) on the same day of the week (P<0.05). Analyses were adjusted for covariates as listed in the Methods section. American Journal of Kidney Diseases 2017 70, 21-29DOI: (10.1053/j.ajkd.2016.10.024) Copyright © 2016 The Authors Terms and Conditions

Figure 3 Adjusted mean hospitalization costs by serum potassium (K+) category and day of the week. Costs are presented for each serum potassium category and day of the week (white, Monday; light grey, Wednesday; dark grey, Friday). Analyses were adjusted for covariates as listed in the Methods section. American Journal of Kidney Diseases 2017 70, 21-29DOI: (10.1053/j.ajkd.2016.10.024) Copyright © 2016 The Authors Terms and Conditions

Figure 4 Adjusted risk of hospitalization by cause and serum potassium (K+) category. Causes of hospitalization within outcome windows were ascribed based on International Classification of Diseases, Ninth Revision diagnosis codes, which were categorized based on CCS level 1 classifiers. All-cause includes all classifiers; other includes all Clinical Classifications Software level 1 classifiers not specifically named. ∗Significantly different from the referent category (4.0-<4.5 mEq/L; P<0.05). Analyses were adjusted for covariates as listed in the Methods section. American Journal of Kidney Diseases 2017 70, 21-29DOI: (10.1053/j.ajkd.2016.10.024) Copyright © 2016 The Authors Terms and Conditions

Figure 5 Adjusted risk of death or emergency department (ED) visit by serum potassium (K+) category. Odds ratios (95% confidence intervals [CIs]) for (A) death or (B) ED visit are presented. Serum potassium of 4.0-<4.5 mEq/L served as the referent category for both analyses. Analyses were adjusted for covariates as listed in the Methods section. American Journal of Kidney Diseases 2017 70, 21-29DOI: (10.1053/j.ajkd.2016.10.024) Copyright © 2016 The Authors Terms and Conditions