A demonstration of modeling count data with an application to physical activity

Counting outcomes such as days of physical activity or servings of fruits and vegetables often have distributions that are highly skewed toward the right with a preponderance of zeros, posing analytical challenges. This paper demonstrates how such outcomes may be analyzed with several modifications to Poisson regression. Five regression models 1) Poisson, 2) overdispersed Poisson, 3) negative binomial, 4) zero-inflated Poisson (ZIP), and 5) zero-inflated negative binomial (ZINB) are fitted to data assessing predictors of vigorous physical activity (VPA) among Latina women. The models are described, and analytical and graphical approaches are discussed to aid in model selection. Poisson regression provided a poor fit where 82% of the subjects reported no days of VPA. The fit improved considerably with the negative binomial and ZIP models. There was little difference in fit between the ZIP and ZINB models. Overall, the ZIP model fit best. No days of VPA were associated with poorer self-reported health and less assimilation to Anglo culture, and marginally associated with increasing BMI. The intensity portion of the model suggested that increasing days of VPA were associated with more education, and marginally associated with increasing age. These underutilized models provide useful approaches for handling counting outcomes

A Prospective Study of Lupus and Rheumatoid Arthritis in Relation to Deployment in Support of Iraq and Afghanistan: The Millennium Cohort Study

The objective of this study was to prospectively assess the association between deployment in support of the operations in Iraq and Afghanistan and newly reported lupus and rheumatoid arthritis while also considering the effects of demographic, behavioral, and occupational characteristics. A total of 77,047 (2001–2003) and 31,110 (2004–2006) participants completed the baseline Millennium Cohort questionnaire and were resurveyed approximately every 3 years. Longitudinal analyses were used to assess the adjusted association between deployment to Iraq and Afghanistan with and without combat exposures and newly reported disease. After adjusting, deployment was not significantly associated with newly reported lupus compared with nondeployers. However, compared with nondeployers, deployers with and without combat exposures were significantly less likely to newly report rheumatoid arthritis. Women, non-Hispanic black, and Hispanic participants had a significantly elevated risk for both diseases. Overall, deployment was not associated with an increased risk of newly reported lupus or rheumatoid arthritis

Contextual Predictors of Mental Health Service Use Among Children Opento Child Welfare

Children involved with child welfare systems are at high risk for emotional and behavioral problems. Many children with identified mental health problems do not receive care, especially ethnic/minority children

Latina mothers as agents of change in children’s eating habits: findings from the randomized controlled trial Entre Familia: Reflejos de Salud

Abstract Background Few children consume sufficient servings of fruits and vegetables. Interventions aiming to improve children’s dietary intake often target parent level factors, but limited research has examined the mediating role of parental factors on children’s dietary intake. This study examined 10-month follow up data from the Entre Familia: Reflejos de Salud (Within the Family: Reflections of Health) trial to investigate (1) intervention effects on children’s dietary intake, both sustained and new changes, and (2) whether changes in mothers’ dietary intake, her parenting strategies, and behavioral strategies to promoting healthy eating in the home mediated changes in children’s dietary intake. Methods Participants were 361 Mexican-origin families living in Imperial County, California. Families were randomly assigned to a 4-month dietary intervention or a delayed treatment control group. The intervention was delivered by promotoras (community health workers) via home visits and telephone calls. Assessments occurred at baseline, and 4- and 10-months post-baseline. Results At 10-months post-baseline, sustained intervention effects were observed on children’s reported intake of varieties of vegetables, with differences getting larger over time. However, differential intervention effects on fast food were not sustained due to significant reductions in the control group compared with smaller changes in the intervention group. New intervention effects were observed on servings of sugar-sweetened beverages. However, the intervention continued to have no effect on children’s reported fruit and vegetable servings, and varieties of fruits consumed. Mother-reported behavioral strategies to increase fiber and lower fat mediated the relationship between the intervention and children’s intake of varieties of vegetables. Mothers’ percent energy from fat and behavioral strategies to lower fat were mediators of children’s daily servings of sugar-sweetened beverages. Conclusions This study suggests that a promotora-led family based intervention can provide mothers with skills to promote modest changes in children’s diet. Examining the parent related mechanisms of change will inform future interventions on important targets for improving children’s diet. Trial registration https://clinicaltrials.gov/ . NCT02441049 . Retrospectively registered 05.06.2015

Prostate Cancer Postoperative Nomogram Scores and Obesity

Nomograms are tools used in clinical practice to predict cancer outcomes and to help make decisions regarding management of disease. Since its conception, utility of the prostate cancer nomogram has more than tripled. Limited information is available on the relation between the nomograms' predicted probabilities and obesity. The purpose of this study was to examine whether the predictions from a validated postoperative prostate cancer nomogram were associated with obesity.We carried out a cross-sectional analysis of 1220 patients who underwent radical prostatectomy (RP) in southern California from 2000 to 2008. Progression-free probabilities (PFPs) were ascertained from the 10-year Kattan postoperative nomogram. Multivariable logistic regression models estimated odds ratios (ORs) and 95% confidence intervals (CIs).In the present study, aggressive prostate cancer (Gleason ≥7), but not advanced stage, was associated with obesity (p = 0.01). After adjusting for age, black race, family history of prostate cancer and current smoking, an inverse association was observed for 10-year progression-free predictions (OR = 0.50; 95% CI = 0.28–0.90) and positive associations were observed for preoperative PSA levels (OR = 1.23; 95% CI = 1.01–1.50) and Gleason >7 (OR = 1.45; 95% CI = 1.11–1.90).Obese RP patients were more likely to have lower PFP values than non-obese patients, suggesting a higher risk of experiencing prostate cancer progression. Identifying men with potentially higher risks due to obesity may improve disease prognosis and treatment decision-making

A longitudinal study of children's enjoyment of physical education

Contains fulltext : 156479.pdf (publisher's version ) (Open Access)RU Radboud Universiteit, 1 april 2016Promotor : Jansen, J.A. Co-promotores : Beucken, J.J.J.P van den, Wolke, J.G.C.268 p

Interactions between individual and perceived environmental factors on Latinas' physical activity

Background Latinas have disproportionately low levels of physical activity (PA) and the ecological correlates of their PA remain unclear. This study aims to test interactions between individual and environmental factors on Latinas’ PA. Methods We analyzed baseline data from 436 Latinas participating in a PA randomized controlled trial in San Diego, CA [Fe en Acción/Faith in Action]. Measures included demographics, perceived environment, PA and anthropometrics. Mixed effects models examined interactions between individual and environmental factors on self-reported leisure-time and transportation, and accelerometer-assessed PA. Results Significant positive associations were found between neighborhood aesthetics and leisure-time moderate-to-vigorous PA (MVPA) and between having destinations within walking distance from home and transportation PA (P < 0.05). We found significant interactions of income with aesthetics and sidewalk maintenance as well as between weight status and safety from crime. Favorable aesthetics was related to more leisure-time MVPA only among lower income women (odds ratio (OR) = 1.57; 95% confidence interval (CI): 1.18, 2.08); however, higher income women reporting better sidewalk maintenance reported more leisure-time MVPA (OR = 1.51; 95% CI: 1.06, 2.15). Higher perceived safety from crime was positively related to transportation PA only among overweight/obese women. Conclusions Subgroup differences should be considered when developing interventions targeting the neighborhood environment to promote Latinas’ PA