RESUMEN
Research linking characteristics of the neighborhood environment to health has relied on traditional regression methods where prespecified distances from participant's locations or areas are used to operationalize neighborhood-level measures. Because the relevant spatial scale of neighborhood environment measures may differ across places or individuals, using prespecified distances could result in biased association estimates or efficiency losses. We use novel hierarchical distributed lag models and data from the Multi-Ethnic Study of Atherosclerosis (MESA) to (1) examine whether and how the association between the availability of favorable food stores and body mass index (BMI) depends on continuous distance from participant locations (instead of traditional buffers), thus allowing us to indirectly infer the spatial scale at which this association operates; (2) examine if the spatial scale and magnitude of the association differs across six MESA sites, and (3) across individuals. As expected, we found that the association between higher availability of favorable food stores within closer distances from participant's residential location was stronger than at farther distances, and that the magnitude of the adjusted association declined quickly from zero to two miles. Furthermore, between-individual heterogeneity in the scale and magnitude of the association was present; the extent of this heterogeneity was different across the MESA sites. Individual heterogeneity was partially explained by sex. This study illustrated novel methods to examine how neighborhood environmental factors may be differentially associated with health at different scales, providing nuance to previous research that ignored the heterogeneity found across individuals and contexts.
Asunto(s)
Índice de Masa Corporal , Abastecimiento de Alimentos/estadística & datos numéricos , Características de la Residencia/estadística & datos numéricos , Estadística como Asunto , Anciano , Ambiente , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis de Regresión , Estados UnidosRESUMEN
OBJECTIVE: To determine the comparative effectiveness of ß-lactam monotherapy and ß-lactam and macrolide combination therapy on clinical outcomes in the treatment of children hospitalized with community-acquired pneumonia (CAP). STUDY DESIGN: This multicenter retrospective cohort study included children aged 1-18 years who were hospitalized with CAP and received ß-lactam antibiotic therapy either alone or in combination with a macrolide. Data were obtained from the Pediatric Health Information System. Associations between empiric antibiotic therapy and hospital readmission for the same episode of pneumonia were estimated using exact logistic regression. Associations between empiric antibiotic therapy and length of hospital stay were estimated using a generalized estimating equation with negative binomial distribution. RESULTS: There were 20â743 patients hospitalized with CAP. Of these, 24% received ß-lactam and macrolide combination therapy on admission. Compared with children who received ß-lactam monotherapy, children who received ß-lactam plus macrolide combination therapy were 20% less likely to stay in the hospital an additional day (adjusted relative risk 0.80; 95% CI, 0.75-0.86) but did not have a different readmission rate (relative risk 0.69; 95% CI, 0.41-1.12). An effect of combination treatment on reduced length of stay was not evident in children <6 years of age but increased with increasing age groups thereafter. CONCLUSION: School-aged patients hospitalized with CAP who received ß-lactam plus macrolide combination therapy have a shorter length of stay and similar rates of readmission compared with school-aged patients who receive ß-lactam monotherapy.