Alan Kinlaw

Risk factors associated with the presence and severity of food insecurity in rural Honduras.

OBJECTIVE To identify factors associated with the presence and severity of food insecurity among a sample of Honduran caregivers of young children. DESIGN Cross-sectional study in which the dependent variable, household food insecurity, was measured using a fourteen-item questionnaire developed and validated in a population of similar cultural context. A predictive modelling strategy used backwards elimination in logistic regression and multinomial logit regression models to compute odds ratios and 95% confidence intervals for food insecurity. SETTING Rural Honduras in the department of Intibucá, between March and April 2009. SUBJECTS Two-hundred and ninety-eight Honduran caregivers of children aged 6-18 months. RESULTS Ninety-three per cent of households were classified as having some degree of food insecurity (mild, moderate or severe). After controlling for caregiver age and marital status, compared with caregivers with more than primary-school education, those with less than primary-school education had 3·47 (95% CI 1·34, 8·99) times the odds of severe food insecurity and 2·29 (95% CI 1·00, 5·25) times the odds of moderate food insecurity. Our results also found that child anthropometric status was not associated with the presence or severity of food insecurity. CONCLUSIONS These results show that among the sociodemographic factors assessed, food insecurity in rural Honduras is associated with maternal education. Understanding key factors associated with food insecurity that are unique to Honduras can inform the design of interventions to effectively mitigate the negative impact of food insecurity on children.

New Findings from the Feeding Infants and Toddlers Study 2008

The purpose of this chapter is to describe the infant feeding practices among infants and toddlers (aged 0-24 months) and to describe food group consumption patterns of these infants and young children (0-48 months) participating in the 2008 Feeding Infants and Toddlers Study (FITS). The FITS 2008 is a cross-sectional survey of a national sample of US children (n = 3,273). Results indicate a longer duration of breastfeeding; however, 17% of infants received cows milk before the recommended age of one year. Introduction of complementary foods also appears to be delayed until about 4-6 months. There was a decline in consumption of infant cereal after 8 months that may be contributing to iron deficiencies in the 9-11 months age group. Consumption of 100% juice (particularly among infants) and the daily consumption of desserts or candy, sweetened beverages (particularly among 12-to 20-month-olds), and salty snacks is lower than in the 2002 survey. Overall, 10-20 and 30% of children were not consuming any fruit or vegetable, respectively, in a given day. More preschoolers were drinking 2% milk than whole milk, but about one third were still drinking whole milk. Despite some of these positive changes, improvements in young childrens diet still are needed.

Standardized binomial models for risk or prevalence ratios and differences

BACKGROUND Epidemiologists often analyse binary outcomes in cohort and cross-sectional studies using multivariable logistic regression models, yielding estimates of adjusted odds ratios. It is widely known that the odds ratio closely approximates the risk or prevalence ratio when the outcome is rare, and it does not do so when the outcome is common. Consequently, investigators may decide to directly estimate the risk or prevalence ratio using a log binomial regression model. METHODS We describe the use of a marginal structural binomial regression model to estimate standardized risk or prevalence ratios and differences. We illustrate the proposed approach using data from a cohort study of coronary heart disease status in Evans County, Georgia, USA. RESULTS The approach reduces problems with model convergence typical of log binomial regression by shifting all explanatory variables except the exposures of primary interest from the linear predictor of the outcome regression model to a model for the standardization weights. The approach also facilitates evaluation of departures from additivity in the joint effects of two exposures. CONCLUSIONS Epidemiologists should consider reporting standardized risk or prevalence ratios and differences in cohort and cross-sectional studies. These are readily-obtained using the SAS, Stata and R statistical software packages. The proposed approach estimates the exposure effect in the total population.

The use of one- versus two-tailed tests to evaluate prevention programs.

Investigators have used both one- and two-tailed tests to determine the significance of findings yielded by program evaluations. While the literature that addresses the appropriate use of each type of significance test should be used is historically inconsistent, almost all authorities now agree that one-tailed tests are rarely (if ever) appropriate. A review of 85 published evaluations of school-based drug prevention curricula specified on the National Registry of Effective Programs and Practices revealed that 20% employed one-tailed tests and, within this subgroup, an additional 4% also employed two-tailed tests. The majority of publications either did not specify the type of statistical test employed or used some other criterion such as effect sizes or confidence intervals. Evaluators reported that they used one-tailed tests either because they stipulated the direction of expected findings in advance, or because prior evaluations of similar programs had yielded no negative results. The authors conclude that one-tailed tests should never be used because they introduce greater potential for Type I errors and create an uneven playing field when outcomes are compared across programs. The authors also conclude that the traditional threshold of significance that places α at .05 is arbitrary and obsolete, and that evaluators should consistently report the exact p values they find.

Incidence of opioid-managed pelvic pain after hysteroscopic sterilization versus laparoscopic sterilization, US 2005-2012.

Compare incidence of opioid‐managed pelvic pain within 12 months after hysteroscopic and laparoscopic sterilization.

Left Truncation Bias to Explain the Protective Effect of Smoking on Preeclampsia: Potential, but How Plausible?

Background: An inverse association between maternal smoking and preeclampsia has been frequently observed in epidemiologic studies for several decades. In the May 2015 issue of this journal, Lisonkova and Joseph described a simulation study suggesting that bias from left truncation might explain the inverse association. The simulations were based on strong assumptions regarding the underlying mechanisms through which bias might occur. Methods: To examine the sensitivity of the previous authors’ conclusions to these assumptions, we constructed a new Monte Carlo simulation using published estimates to frame our data-generating parameters. We estimated the association between smoking and preeclampsia across a range of scenarios that incorporated abnormal placentation and early pregnancy loss. Results: Our results confirmed that the previous authors’ findings are highly dependent on assumptions regarding the strength of association between abnormal placentation and preeclampsia. Thus, the bias they described may be less pronounced than was suggested. Conclusions: Under empirically derived constraints of these critical assumptions, left truncation does not appear to fully explain the inverse association between smoking and preeclampsia. Furthermore, when considering processes in which left truncation may result from the exposure, it is important to precisely describe the target population and parameter of interest before assessing potential bias. We comment on the specification of a meaningful target population when assessing maternal smoking and preeclampsia as a public health issue. We describe considerations for defining a target population in studies of perinatal exposures when those exposures cause competing events (e.g., early pregnancy loss) for primary outcomes of interest.

Trends and Patterns of Urodynamic Studies in U.S. Women, 2000–2012

OBJECTIVE: To estimate utilization rates for cystometrograms and describe trends in urodynamic procedures among U.S. women from 2000 to 2012. METHODS: We analyzed outpatient administrative health care claims for women aged 18 years or older from 2000 to 2012. The database contains deidentified and adjudicated claims from approximately 150 U.S. payers for employees, spouses, and retirees. We identified cystometrograms, which occur during bladder filling and represent a major component of complex urodynamics, and concurrent procedures; we also assessed age, year, region, health care provider specialty, and associated diagnosis codes. We estimated standardized cystometrogram utilization rates per 10,000 person-years and 95% confidence intervals (CIs) and used stratified Poisson models to estimate the independent (adjusted) effects of year and region. RESULTS: During 142,928,847 person-years of observation among 57,629,961 eligible women, we identified 561,823 cystometrograms for an overall utilization rate of 39.3 per 10,000 person-years (95% CI 39.2–39.4). Cystometrogram utilization increased with age with a peak at age 76 years (86.6/10,000 person-years, 95% CI 84.5–88.7). Standardized rates were relatively constant from 2000 to 2004 and then increased and peaked in 2009 (43.3/10,000 person-years, 95% CI 43.0–43.7). In 2012, they were substantially lower (27.6/10,000 person-years, 95% CI 27.4–27.9). CONCLUSION: Urodynamic procedures were more commonly performed in women aged 65 years or older. Utilization peaked in 2009 and declined sharply in 2012. Clinically, we need to assess the underlying reasons for these trends (ie, whether they reflect a decrease in urodynamics before stress urinary incontinence surgery) and whether these trends reflect appropriate use of this diagnostic study. LEVEL OF EVIDENCE: II

Hydrogen sulfide concentrations at three middle schools near industrial livestock facilities.

Safe school environments are essential for healthy development, yet some schools are near large-scale livestock facilities that emit air pollution. Hydrogen sulfide (H2S) from decomposing manure is an indicator of livestock-related air pollution. We measured outdoor concentrations of H2S at three public middle schools near livestock facilities in North Carolina. We used circular graphs to relate H2S detection and wind direction to geospatial distributions of nearby livestock barns. We also used logistic and linear regression to model H2S in relation to upwind, distance-weighted livestock barn area. Circular graphs suggested an association between upwind livestock barns and H2S detection. The log-odds of H2S detection per 1000 m2 increased with upwind weighted swine barn area (School A: β-coefficient (β)=0.43, SE=0.06; School B: β=0.64, SE=0.24) and upwind weighted poultry barn area (School A: β=0.05, SE=0.01), with stronger associations during periods of atmospheric stability than atmospheric instability (School A stable: β=0.69, SE=0.11; School A unstable: β=0.32, SE=0.09). H2S concentration also increased linearly with upwind swine barn area, with greater increases during stable atmospheric conditions (stable: β=0.16 parts per billion (p.p.b.), SE=0.01; unstable: β=0.05 p.p.b., SE=0.01). Off-site migration of pollutants from industrial livestock operations can decrease air quality at nearby schools.

Trends in Pharmacotherapy for Bladder Dysfunction Among Children in the United States, 2000 to 2013

Bladder-related issues such as nocturnal enuresis and incontinence have long been a part of general pediatric practice. Increasingly, clinicians are prescribing medications directed at a variety of types of bladder dysfunction, but no prior population-based data exist. We used MarketScan health care claims data on 32 074 638 insured children to estimate utilization patterns by age, sex, year, and geographic region in the United States from 2000 to 2013, and to assess related diagnosis codes. Approximately 1 in 500 children filled an antimuscarinic prescription. The most common prescriptions were for oxybutynin (78%) and tolterodine (17%). Rates were highest at ages 6 to 10 years (65/100 000 person-months), 31% higher for girls versus boys, peaked in 2011 (44/100 000 person-months), and were highest in the Midwest (59/100 000 person-months). Seventy-three percent of children with prescriptions had diagnosis codes for genitourinary symptoms, and 13% had codes for congenital anomalies. Research is needed regarding the comparative effectiveness and safety of these drugs in children.

Impact of New Medications and

Background: Despite several new medications being Food and Drug Administration-approved for overactive bladder (OAB) and new prescription drug payment programs, there are limited population-based data regarding OAB medication use among older adults. Objectives: To examine: (1) impacts of new medications and