Association Between Daily Water Intake and 24-hour Urine Volume Among Adolescents With Kidney Stones.

OBJECTIVE: To determine the association between daily water intake and 24-hour urine volume among adolescents with nephrolithiasis in order to estimate a "fluid prescription," the additional water intake needed to increase urine volume to a target goal. METHODS: We conducted a secondary analysis of an ecological momentary assessment study that prospectively measured daily water intake of 25 adolescents with nephrolithiasis over 7 days. We identified 24-hour urine volumes obtained for clinical care within 12 months of water intake assessment. A linear regression model was fit to estimate the magnitude of the association between daily water intake and 24-hour urine volume, adjusting for age, sex, race, and daily temperature. RESULTS: Twenty-two participants completed fifty-seven 24-hour urine collections within 12 months of the study period. Median daily water intake was 1.4 L (IQR 0.67-1.94). Median 24-hour urine volume was 2.01 L (IQR 1.20-2.73). A 1 L increase in daily water intake was associated with a 710 mL increase in 24-hour urine output (95%CI 0.55-0.87). Using the model output, the equation was generated to estimate the additional fluid intake needed fluid prescription (FP) to produce the desired increase in urine output (dUOP): FP = dUOP/0.71. CONCLUSION: The FP equation (FP = dUOP)/0.71), which reflects the relationship between water intake and urine volume, could be used to help adolescents with nephrolithiasis achieve urine output goals to decrease stone recurrence.

Characteristics and Outcomes of Pediatric Heart Failure-Related Emergency Department Visits in the United States: A Population-Based Study.

OBJECTIVES: To describe the frequency, characteristics, and outcomes of heart failure-related emergency department (ED) visits in pediatric patients. We aimed to test the hypothesis that these visits are associated with higher admission rates, mortality, and resource utilization. STUDY DESIGN: A retrospective analysis of the Nationwide Emergency Department Sample for 2010 of patients ≤18 years of age was performed to describe ED visits with and without heart failure. Cases were identified using International Classification of Disease, Ninth Revision, Clinical Modification codes and assessed for factors associated with admission, mortality, and resource utilization. RESULTS: Among 28.6 million pediatric visits to the ED, there were 5971 (0.02%) heart failure-related cases. Heart failure-related ED patients were significantly more likely to be admitted (59.8% vs 4.01%; OR 35.3, 95% CI 31.5-39.7). Among heart failure-related visits, admission was more common in patients with congenital heart disease (OR 5.0, 95% CI 3.3-7.4) and in those with comorbidities including respiratory failure (OR 78.3, 95% CI 10.4-591) and renal failure (OR 7.9, 95% CI 1.7-36.3). Heart failure-related cases admitted to the hospital had a higher likelihood of death than nonheart failure-related cases (5.9% vs 0.32%, P < .001). Factors associated with mortality included respiratory failure (OR 4.5, 95% CI 2.2-9.2) and renal failure (OR 7.8, 95% CI 2.9-20.7). Heart failure-related ED visits were more expensive than nonheart failure-related ED visits ($1460 [IQR $861-2038] vs $778 [IQR $442-1375] [P < .01].) CONCLUSIONS: Heart failure-related visits represent a minority of pediatric ED visits but are associated with increased hospital admission and resource utilization.

Imputing Missing Race/Ethnicity in Pediatric Electronic Health Records: Reducing Bias with Use of U.S. Census Location and Surname Data.

OBJECTIVE: To assess the utility of imputing race/ethnicity using U.S. Census race/ethnicity, residential address, and surname information compared to standard missing data methods in a pediatric cohort. DATA SOURCES/STUDY SETTING: Electronic health record data from 30 pediatric practices with known race/ethnicity. STUDY DESIGN: In a simulation experiment, we constructed dichotomous and continuous outcomes with pre-specified associations with known race/ethnicity. Bias was introduced by nonrandomly setting race/ethnicity to missing. We compared typical methods for handling missing race/ethnicity (multiple imputation alone with clinical factors, complete case analysis, indicator variables) to multiple imputation incorporating surname and address information. PRINCIPAL FINDINGS: Imputation using U.S. Census information reduced bias for both continuous and dichotomous outcomes. CONCLUSIONS: The new method reduces bias when race/ethnicity is partially, nonrandomly missing.