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The risk of kidney stone presentations increases after hot days, likely due to greater insensible water losses resulting in more concentrated urine and altered urinary flow. It is thus expected that higher temperatures from climate change will increase the global prevalence of kidney stones if no adaptation measures are put in place. This study aims to quantify the impact of heat on kidney stone presentations through 2089, using South Carolina as a model state. We used a time series analysis of historical kidney stone presentations (1997–2014) and distributed lag non-linear models to estimate the temperature dependence of kidney stone presentations, and then quantified the projected impact of climate change on future heat-related kidney stone presentations using daily projections of wet-bulb temperatures to 2089, assuming no adaptation or demographic changes. Two climate change models were considered—one assuming aggressive reduction in greenhouse gas emissions (RCP 4.5) and one representing uninibited greenhouse gas emissions (RCP 8.5). The estimated total statewide kidney stone presentations attributable to heat are projected to increase by 2.2% in RCP 4.5 and 3.9% in RCP 8.5 by 2085–89 (vs. 2010–2014), with an associated total excess cost of ~ $57 million and ~ $99 million, respectively.

BACKGROUND: Previous studies assumed a uniform relationship between heat and kidney stone presentations. Determining whether sex and other characteristics modify the temperature-dependence of kidney stone presentations has implications for explaining differences in nephrolithiasis prevalence and improving projections of the effect of climate change on nephrolithiasis. METHODS: We performed an aggregated case-crossover study among 132,597 children and adults who presented with nephrolithiasis to 68 emergency departments throughout South Carolina from 1997-2015. We used quasi-Poisson regression with distributed lag non-linear models to estimate sex differences in the cumulative exposure- and lagged-response between maximum daily wet-bulb temperatures and emergent kidney stone presentations, aggregated at the ZIP-code level. We also explored interactions by age, race, payer, and climate. RESULTS: Compared to 10°C, daily wet-bulb temperatures at the 99(th) percentile were associated with a greater increased relative risk (RR) of kidney stone presentations over 10 days for males (RR 1.73; 95% CI: 1.56, 1.91) than for females (RR 1.15; 95% CI: 1.01, 1.32; interaction P

Birth certificates are potentially a valuable source of information for studying gestational weight gain (GWG) during pregnancy, particularly important given new Institute of Medicine (IOM) guidelines. We examined factors associated with the accuracy of maternal GWG self-report by linking the gold standard obstetric electronic medical record (EMR) of women from a large urban practice to state birth certificates. Primary outcomes included maternal under-reporting of GWG (10 lbs below the EMR), accurate reporting (within 10 lbs), and over-reporting (10 lbs above EMR). Data were stratified across categories of pre-pregnancy body mass index (BMI) and the actual GWG IOM categories (inadequate, adequate, and excessive) acquired in the clinical setting and recorded in the EMR. Among 1,223 women, mean (SD) age was 27.4 (6.2) years, mean (SD) BMI was 28.2 (8.1) kg/m(2), and mean GWG was 26.0 (20.2) pounds. The majority of women with normal BMI (25 kg/m(2)) and adequate GWG reported GWG accurately (78.8%), more so than any other group. After adjusting for age, race, insurance status, and number of prenatal visits, among women with actual adequate GWG, women with high BMI (≥25 kg/m(2)) were more likely to over-report GWG than women with normal BMI (RR 4.7, 95% CI 2.6-8.4). In patients with normal BMI, women with excessive GWG were more likely to under-report than women with adequate GWG (RR 6.0, 95% CI 3.0-12.1). Such findings raise concern for systematic bias that would limit the use of birth certificate data for studying population trends in GWG.