Association Between Temperature and Inpatient Stone Admission in a Pediatric Population

Background: Higher temperatures have been associated with increased stone formation and subsequent utilization of hospital resources, including inpatient admission. However, these observations have been derived from the adult population. We sought to examine if this purported association extends to the pediatric population. Methods: We used the 2016 Kids' Inpatient Database to identify nationwide pediatric inpatient admissions related to nephrolithiasis. Temperature data from the National Oceanic and Atmospheric Administration was linked to each admission. Comparative statistics analyzed patient and admission characteristics. Multivariable logistic regression analyzed associations between stone-related admissions and temperature. As a frame of reference, this analysis was replicated using the National Inpatient Sample from 2016 to evaluate associations in the adult population. Results: Of the 2,496,257 pediatric admissions, 8453 (0.33%) were related to nephrolithiasis. Temperatures at the time of stone admission were higher than those during nonstone admission (55.9°F vs 54.8°F, p < 0.001). The stone admission group had a higher proportion of females than the nonstone admission group (64.8% vs 55.4%, p < 0.001). Stone admission was significantly associated with temperature (odds ratio [OR] 1.025 per 10°F, confidence interval [95% CI] 1.003-1.049, p = 0.03) and female gender (OR 1.097, 95% CI 1.027-1.171, p = 0.006). In the adult population, 380,520 out of 30,000,941 patients (1.3%) were admitted with a stone. The effect of temperature on stone admissions was similar to that in the pediatric population (OR 1.020, 95% CI 1.014-1.026, p < 0.001), but women were >20% less likely to be admitted for stones than men (OR 0.770, 95% CI 0.757-0.784, p < 0.001). Conclusions: Increased temperatures were associated with an increased risk of stone-related admission in both the pediatric and adult populations. Females were at increased risk for stone-related admissions during childhood, but this trend reverses in adulthood.