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Fine particulate air pollution (PM2.5) has been associated with many adverse health outcomes including school absences. Specifically, a previous study in the Utah Valley area, conducted during a time with relatively high air pollution exposure, found significant positive correlations between school absences and air pollution.We examined the hypothesis that ambient PM2.5 exposures are associated with elementary school absences using a quasi-natural experiment to help control for observed and unobserved structural factors that influence school absences. The Alpine, Provo, and Salt Lake City school districts are located in valleys subject to daily mean PM2.5 concentrations almost twice as high as those in the Park City School District. We used seminonparametric generalized additive Poisson regression models to evaluate associations between absences and daily PM2.5 levels in the 3 districts that were exposed to the most pollution while using Park City absences as a quasi-control. The study covered 3 school years (2011/12-2013/14).School absences were most strongly associated with observed structural factors such as seasonal trends across school years, day-of-week effects, holiday effects, weather, etc. However, after controlling for these structural factors directly and using a control district, a 10 μg/m3 increase in PM2.5 was associated with an approximately 1.7% increase in daily elementary school absences.Exposure to ambient air pollution can contribute to elementary school absences, although this effect is difficult to disentangle from various other factors.  相似文献   
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Objective

Treatment of renal cell carcinoma has evolved with emphasis on nephron preservation for small renal masses. Our objective was to evaluate the proportions of treatment types for octogenarians with clinical stage 1 renal cell carcinoma.

Materials and Methods

The National Cancer Database was analyzed from 2004 to 2015. Patients with clinical stage 1, tumor size?≤?7?cm, and age 80–89?years old were compared to a younger control arm of patients?≤?70?years old. Treatment modality was categorized as radical nephrectomy (RN), partial nephrectomy (PN), percutaneous ablative therapy (PAT), and no treatment (NT). Primary outcome was treatment utilization over time using estimated annual percentage change (EAPC). Secondary outcomes included logistic regression for 30?day readmission after treatment and any definitive tumor treatment choice.

Results

18,903 octogenarians were identified and compared to a control of 142,179 patients?≤?70?years old. Overall, NT (36%) was the most common modality for octogenarians while PN (44.8%) was most common for the control arm. Using EAPC for octogenarians, we found increases for PAT (7.1%), PN (2.8%), and NT (1.6%) but a decrease for RN (?4.6%). EAPC for the younger cohort noted increases for PAT (6.8%), PN (5.4%), and NT (4.4%) but a decrease for RN (?5.5%).

Conclusion

For octogenarians with stage 1 renal cell carcinoma, minimally invasive treatments are increasingly utilized, while RN is decreasing. Compared to a younger cohort, a greater proportion of octogenarians are receiving NT. These findings remain encouraging for appropriate treatment of localized disease in patients with advanced age.  相似文献   
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