Mixed-effects Poisson Models Research Articles

Multisectoral community development in Nepal has greater effects on child growth and diet than nutrition education alone.

To compare the impact on child diet and growth of a multisectoral community intervention v. nutrition education and livestock management training alone. Longitudinal community-based randomized trial involving three groups of villages assigned to receive: (i) Full Package community development activities, delivered via women's groups; (ii) livestock training and nutrition education alone (Partial Package); or (iii) no intervention (Control). Household surveys, child growth monitoring, child and household diet quality measures (diet diversity (DD), animal-source food (ASF) consumption) were collected at five visits over 36 months. Mixed-effect linear regression and Poisson models used survey round, treatment group and group-by-round interaction to predict outcomes of interest, adjusted for household- and child-specific characteristics. Banke, Nepal. Households (n 974) with children aged 1-60 months (n 1333). Children in Full Package households had better endline anthropometry (weight-for-age, weight-for-height, mid-upper-arm-circumference Z-scores), DD, and more consumption of ASF, after adjusting for household- and child-specific characteristics. By endline, compared with Partial Package or Control groups, Full Package households demonstrated preferential child feeding practices and had significantly more improvement in household wealth and hygiene habits. In this longitudinal study, a comprehensive multisectoral intervention was more successful in improving key growth indicators as well as diet quality in young children. Provision of training in livestock management and nutrition education alone had limited effect on these outcomes. Although more time-consuming and costly to administer, incorporating nutrition training with community social capital development was associated with better child growth and nutrition outcomes than isolated training programmes alone.

Modeling Culicoides abundance in mainland France: implications for surveillance

BackgroundBiting midges of the genus Culicoides Latreille (Diptera: Ceratopogonidae) are involved in the transmission of several viruses affecting humans and livestock, particularly bluetongue (BTV). Over the last decade, Culicoides surveillance has been conducted discontinuously and at various temporal and spatial scales in mainland France following the BTV epizootics in 2008–2009 and its reemergence and continuous circulation since 2015. The ability to predict seasonal dynamics and spatial abundance of Culicoides spp. is a key element in identifying periods and areas at high risk of transmission in order to strengthen surveillance for early detection and to establish seasonally disease-free zones. The objective of this study was to model the abundance of Culicoides spp. using surveillance data.MethodsA mixed-effect Poisson model, adjusted for overdispersion and taking into account temperature data at each trap location, was used to model the weekly relative abundance of Culicoides spp. over a year in 24 vector zones, based on surveillance data collected during 2009–2012. Vector zones are the spatial units used for Culicoides surveillance since 2016 in mainland France.ResultsThe curves of the predicted annual abundance of Culicoides spp. in vector zones showed three different shapes: unimodal, bimodal or plateau, reflecting the temporal variability of the observed counts between zones. For each vector zone, the model enabled to identify periods of vector activity ranging from 25 to 51 weeks.ConclusionsAlthough the data were collected for surveillance purposes, our modeling approach integrating vector data with daily temperatures, which are known to be major drivers of Culicoides spp. activity, provided areas-specific predictions of Culicoides spp. abundance. Our findings provide decisions makers with essential information to identify risk periods in each vector zone and guide the allocation of resources for surveillance and control. Knowledge of Culicoides spp. dynamics is also of primary importance for modeling the risk of establishment and spread of midge-borne diseases in mainland France.

Impact of IgG Monitoring and IVIG Supplementation on the Frequency of Febrile Illnesses in Pediatric Acute Lymphoblastic Leukemia Patients Undergoing Maintenance Chemotherapy.

Monitoring serum immunoglobulin G (IgG) levels in pediatric oncology patients and treating subtherapeutic levels with intravenous immunoglobulin (IVIG) may prevent infections; however, evidence is limited. This retrospective study assessed pediatric acute lymphoblastic leukemia patients diagnosed 2006 to 2011 to evaluate if monitoring/supplementing IgG would reduce febrile illnesses during maintenance chemotherapy. A subject was categorized as "ever IgG monitored" if they had ≥1 IgG levels checked and their risk days were stratified into not IgG monitored days and IgG monitored days. IgG monitored days were further stratified into IgG monitored with IVIG supplementation, monitored with no IVIG supplementation (IgG level >500 mg/dL) and monitored with no IVIG supplementation days (IgG level <500 mg/dL). Generalized linear mixed effects poisson models were used to compare events (febrile episode, positive blood culture, and febrile upper respiratory infection rates among these groups. In 136 patients, the febrile episode rate was higher in the ever IgG monitored cohort than the never monitored cohort (5.26 vs. 3.78 episodes/1000 d). Among monitored patients, IVIG monitoring and supplementation did not significantly impact the febrile episode, febrile upper respiratory infection, or the positive blood culture rates. These data suggest that monitoring/supplementing low IgG is not indicated for infection prophylaxis in acute lymphoblastic leukemia patients during maintenance chemotherapy.

Double Burden of Malnutrition in Rural Ecuador: Adult Overweight and Child Stunting Co-occur at the Community but Not the Household Level (P10-075-19)

ObjectivesNorthern coastal Ecuador has seen rapid market integration since the initiation of a road system in the late 1990 s connecting the region to the Andean mountains. We previously demonstrated that, between 2003 and 2013, living in a relatively remote (less accessible) community was protective against stunting in children under five. Our objectives were to characterize trends in BMI among rural adults over the same period, and to examine the co-occurrence of adult overweight or obesity (OB/OW) and child stunting. MethodsAdult anthropometry was collected through a series of case-control studies repeated over a decade across thirty communities (N = 2053). Anthropometry was measured for all children under five in every community (N = 4170). Logistic and mixed-effect Poisson models, weighted to account for the case-control sampling design, were used to estimate the prevalence of OW/OB over time, to examine individual- and household-level risk factors associated with adult OW/OB, and to examine the co-occurrence of adult OW/OB and under-five stunting within households. ResultsAmong men, OW/OB increased over time (35.0% in 2003 to 52.9% by 2013) and was most common in the least remote versus the most remote communities (46.2% versus 26.9% across the study period). Among women, OW/OB was more prevalent (65.4%), but was not associated with community remoteness and did not increase over time. At the community level, the prevalence of under-five stunting was correlated with the prevalence of OW/OB among men (Spearman’s ρ = 0.56, P = 0.002) but not women (Spearman’s ρ = 0.16, P = 0.404). However, the presence of a stunted child under five within the household was not associated with adult OW/OB (odds ratio 0.87, P = 0.151). ConclusionsChanges in food environments and livelihoods due to the presence of roads may have driven increasing OW/OB among men over the study period. The positive association between adult male OW/OB and child stunting at the community level, but not at the household level, suggests that strategies to address the double burden of malnutrition that target the community (e.g., the food environment) are more likely to be effective than interventions targeted to households alone. Funding SourcesThis project was supported by the National Institutes of Health [R01-AI050038].

Association of Pneumococcal Conjugate Vaccine Coverage With Pneumococcal Meningitis: An Analysis of French Administrative Areas, 2001-2016.

Geographic variations of invasive pneumococcal disease incidence and serotype distributions were observed after pneumococcal conjugate vaccine introduction at regional levels and among French administrative areas. The variations could be related to regional vaccine coverage (VC) variations that might have direct consequences for vaccination-policy impact on invasive pneumococcal disease, particularly pneumococcal meningitis (PM) incidence. We assessed vaccine impact from 2001 to 2016 in France by estimating the contribution of regional VC differences to variations of annual local PM incidence. Using a mixed-effect Poisson model, we showed that, despite some variations of VC among administrative areas, vaccine impact on vaccine-serotype PM was homogeneously confirmed among administrative areas. Compared with the prevaccine era, the cumulative VC impact on vaccine serotypes led, in 2016, to PM reductions ranging among regions from 87% (25th percentile) to 91% (75th percentile) for 7-valent pneumococcal conjugate vaccine serotypes and from 58% to 63% for the 6 additional 13-valent pneumococcal conjugate vaccine serotypes. Nonvaccine-serotype PM increases from the prevaccine era ranged among areas from 98% to 127%. By taking into account the cumulative impact of growing VC and VC differences, our analyses confirmed high vaccine impact on vaccine-serotype PM case rates and suggest that VC variations cannot explain PM administrative area differences.

The association between obesity and outcomes in acute pancreatitis: an individual patient data meta-analysis.

There are data to suggest that obesity is associated with local and systemic complications as well as mortality in acute pancreatitis (AP). Cohort studies to date, however, have shown conflicting results from mostly unadjusted analyses. Therefore, we performed an individual patient data meta-analysis with the primary aim to investigate the association between obesity and mortality in AP. Our secondary aim was to investigate the association between obesity and necrosis, organ failure, multiple organ failure, and invasive intervention. We systematically searched four electronic databases for prospective studies on obesity and outcomes in AP. Researchers of eligible studies were invited to share individual patient data using a standardized data collection form. All end points were investigated with a one-stage mixed effects Poisson model with random intercepts and forced entry of relevant confounders. We included five databases with 1302 patients, of whom 418 (32%) were obese. In total, 466 (36%) patients had necrosis, 328 (25%) had organ failure, 188 (14%) had multiple organ failure, 210 (16%) had an intervention, and 84 (7%) patients died. We found no significant association between obesity and mortality [relative risk (RR) 1.40, 95% confidence interval (CI): 0.89-2.20], necrosis (RR: 1.08, 95% CI: 0.90-1.31) or invasive intervention (RR: 1.10, 95% CI: 0.83-1.47) after adjustment for confounders. However, obesity was independently associated with the development of organ failure (RR: 1.38, 95% CI: 1.11-1.73) and multiple organ failure (RR: 1.81, 95% CI: 1.35-2.42). Obesity is independently associated with the development of organ failure and multiple organ failure in AP. However, there is no association between obesity and mortality, necrosis, and an intervention.

The Effect of Hormonal Contraception and Menstrual Cycle Timing on Genital Herpes Simplex Virus-2 Shedding and Lesions.

The effect of female sex hormones on herpes simplex virus (HSV)-2 shedding and lesion frequency is poorly understood. Previous studies suggest that hormonal contraception may increase the frequency of HSV-2 shedding. We studied HSV-2 seropositive women who performed daily genital swabbing for HSV DNA and completed diaries for genital lesions and menses. We used Poisson mixed effects models to determine if HSV detection varied throughout the menstrual cycle, or in response to hormonal contraception. We used the Wilcoxon signed-rank test and rank-sum test to determine if lesion frequency differed by cycle phase or hormonal contraceptive use. In 189 women aged 19 to 46 years who collected swabs on 10,715 days and were not using hormonal contraception, HSV-2 DNA was detected on 20.9% of days in the follicular phase and 17.8% of days in the luteal phase (rate ratio, 1.19; 95% confidence interval, 1.03-1.37, P = 0.02). Genital lesions did not differ in the follicular versus luteal phase (12.8% vs. 10.7%, P = 0.07). In analyses of hormonal contraception, including 244 women, HSV-2 DNA was detected on 19.0% of days for women not using hormonal contraception and 18.3% of days for those using hormonal contraception (P = 0.50). Lesions were present on 11.1% of days for women not using hormonal contraception, and 8.7% of days for those using hormonal contraception (P = 0.66). In women with genital HSV-2 infection who are not using hormonal contraception, the follicular phase of the cycle may be associated with a higher frequency of HSV-2 shedding compared to the luteal phase. Lesion frequency is similar during the 2 menstrual phases. Hormonal contraception use was not observed to affect genital HSV-2 DNA detection or lesions.

IMPACT OF RACE ON LONG-TERM ASTHMA CONTROL IN CHILDREN

SESSION TITLE: Pediatric Asthma SESSION TYPE: Original Investigations PRESENTED ON: 10/08/2018 01:30 PM - 02:30 PM PURPOSE: Asthma control in minorities such as African American and Hispanic children is considered more difficult. The aim of this study was to document racial disparities (if any) in asthma control among children whose asthma is managed per NAEPP (EPR-3) guidelines. METHODS: This was a three-year prospective cohort study. After IRB approval, children referred by primary care physicians with the diagnosis of uncontrolled asthma were enrolled in our pediatric asthma center since 2011, and were provided asthma care as per NAEPP guidelines. At each visit (3-6 months), families completed asthma questionnaires including acute care need, symptom control, and Asthma Control Test (ACT). Results were compared between ethnic groups (Caucasians and African Americans/Hispanics) over time. The distribution of scores was measured by mean, standard deviation, median, and interquartile range depending upon the normality of the data. Poisson Mixed Effects Model was used to evaluate change in asthma indicators over 6 month increments. Alpha level of significance was ≤ 0.05. RESULTS: The sample included 395 children, ages 2-17 years [median 6 (3, 9)], and were 61% male. Caucasians 262 (69%), African American 91(24%) and Hispanic children 27 (7%) were including in this study. Acute care need (hospital admissions, emergency department visits, urgent care visits, school days missed and number of days/month requiring albuterol and days/month with wheezing improved significantly (p<0.0001 for all) when data from baseline (initial visit) were compared to data at 6 month follow up respectively and improvement persisted for three year follow-up period ACT scores improved significantly between the baseline (first visit) and 3 month follow-up visit (16.9 ±5.7 and 20 ±5.2 respectively, p<0.05) and improvement persisted throughout three-year follow up. Data was compared using race (Caucasians vs. African Americans/Hispanics) as covariate. Compared to Caucasians, minority children had slightly more acute care need, number of days/month with wheezing and low ACT at baseline, but differences were not statistically significant. Both groups improved significantly from baseline and improvements persisted throughout three year follow up. Race was not a significant covariate (p=0.90) in overall asthma improvement over time. There was significantly better rate of improvement in minority children compared to Caucasians over time in hospital admissions (p=0.01), missed school days (p=0.009), and number of days/month with wheezing (p=0.02). CONCLUSIONS: Better asthma control can be achieved in children by managing their asthma as per NAEPP (EPR-3) guidelines. Once asthma guidelines are followed, race was not a significant factor in overall asthma improvement over time. CLINICAL IMPLICATIONS: Following guidelines improves asthma care and once guidelines are followed, race is not a significant factor in asthma control. DISCLOSURES: No relevant relationships by Anne May, source=Web Response no disclosure on file for Karen McCoy; No relevant relationships by Christopher Nemastil, source=Web Response No relevant relationships by Judy Pitts, source=Web Response No relevant relationships by Ann Salvator, source=Web Response No relevant relationships by Shahid Sheikh, source=Web Response No relevant relationships by Lisa Ulrich, source=Web Response

Zero-Inflated Models for RNA-Seq Count Data

One of the main objectives of many biological studies is to explore differential gene expression profiles between samples. Genes are referred to as differentially expressed (DE) if the read counts change across treatments or conditions systematically. Poisson and negative binomial (NB) regressions are widely used methods for non-over-dispersed (NOD) and over-dispersed (OD) count data respectively. However, in the presence of excessive number of zeros, these methods need adjustments. In this paper, we consider a zero-inflated Poisson mixed effects model (ZIPMM) and zero-inflated negative binomial mixed effects model (ZINBMM) to address excessive zero counts in the NOD and OD RNA-seq data respectively in the presence of random effects. We apply these methods to both simulated and real RNA-seq datasets. The ZIPMM and ZINBMM perform better on both simulated and real datasets.

Alcohol retail sales licenses and sexually transmitted infections in Texas counties, 2008-2015

ABSTRACTBackground: Research suggests that reduced retail alcohol outlet density may be associated with lower prevalence of HIV and other sexually transmitted infections (STIs). On-premise sale of alcohol for immediate consumption is theorized as increasing social interactions that can lead to sexual encounters. Objective: We examined associations between on- and off-premise retail alcohol sales licenses and number of newly diagnosed HIV and STI cases in Texas counties. Methods: Retail alcohol sales license data were obtained from the Texas Alcoholic Beverage Commission. HIV and bacterial STI data were obtained from the Texas Department of State Health Services. Associations between retail alcohol sales licenses and STIs were estimated using spatial linear models and Poisson mixed effects models for over-dispersed count data. Results: Adjusting for county-specific confounders, there was no evidence of residual spatial correlation. In Poisson models, each additional on-premise (e.g., bar and restaurant) alcohol license per 10,000 population in a county was associated with a 1.5% increase (95% CI: 0.4%, 2.6%) in the rate of HIV and a 2.4% increase (95% CI: 1.9%, 3.0%) in the rate of bacterial STIs, adjusting for potential confounders. In contrast, number of off-premise licenses (e.g., take-out stores) was inversely associated with the incidence of STI and HIV, although the association with HIV was not statistically significant. Conclusions: This study adds to the limited literature on the association between retail alcohol availability and STIs. Additional research is needed on the role of alcohol availability (and policies affecting availability) in the spread of HIV and other STIs.

A relational perspective on pure project performance

PurposeThe understanding of leaders’ network centrality in social networks has been acknowledged as a major topic that can advance the social network field; most studies in this area have either taken firms as the subject by which the network centrality of firms was measured or/and have been conducted for the functional project context. Very little research has been done in the pure project context. This paper aims to revisit the centrality–performance link in the singular specialized project context.Design/methodology/approachThe proposed relationships using panel data on 48 movie directors who lead pure projects has been studied. Freeman’s (1979) and Wasserman and Faust’s (1994) procedures have been adopted to compute our three centrality measures and their effects have been examined on box-office and artistic performance. A random effect and a mixed-effects Poisson model have been fit to examine the significance of the centrality–performance relationship.FindingsThe findings provide empirical evidence to support three out of the six hypotheses. The findings suggested that degree and closeness centrality are positively related to commercial performance and betweenness centrality is negatively related to commercial performance. However, it was found that only the degree centrality is related to artistic performance.Originality/valueThis study has two features that distinguish it from prior studies that link centrality to performance. First, the focus is on centrality attached to the leaders instead of the centrality attached to functional project teams or firms, as previously investigated. Second, this study is the first attempt of its kind to analyse the proposed relationship for an Asian market.

The impact of Brexit on the UK inwards FDI

Considering the impact of Brexit on the foreign direct investment (FDI) in the United Kingdom, contrary to previous studies from economic literature, this research focused on two proxies for FDI: FDI projects with the associated new and safeguarded jobs and FDI inflows as percent of GDP. Moreover, other methods were used to measure the Brexit impact on the FDI: a gravity model approach based on mixed-effects Poisson models and a counterfactual analysis based on differences-to-differences estimators. The main results indicated that the number of FDI projects might decrease after Brexit by 65% till 90% in 2019. A higher increase by 97% is expected to the number of new and safeguarded jobs. Even if FDI inflows in the UK significantly increased compared to the rest of OECD countries because of the EU membership, Great Britain should follow the model of Norway and Iceland after Brexit in order to avoid significant losses in the FDI inflows.

Abstract MP04: Sex Hormones and 10 Year Progression of Coronary Artery Calcium Among Post-Menopausal Women in the Multi-Ethnic Study of Atherosclerosis

Background: Cardiovascular disease (CVD) is the leading cause of death in women. Sex differences in risk factors, prevalence and mortality suggest the involvement of sex hormones in disease processes. Coronary artery calcium (CAC) is a marker of subclinical atherosclerosis and its progression. CAC is prognostic of CVD risk, independent of traditional risk factors, even among low-risk women. We hypothesized that a more androgenic hormone pattern will predict CAC progression over 10 years in post-menopausal women. Methods: We studied 2759 post-menopausal women, aged 45-84 years, participating in MESA who underwent serum sex hormone measurement and a cardiac CT scan for CAC at baseline (2000-2002). Among these, 2427 women had up to 3 follow-up cardiac CT scans at subsequent visits spanning 10 years. CAC was assessed by Agatson units. CAC and sex hormones were log-transformed for analysis. Using multivariable-adjusted Poisson and linear mixed effects models, we tested the longitudinal associations of testosterone (T), free T, dehydroepiandrosterone (DHEA), estradiol (E2), and sex hormone binding globulin (SHBG) with prevalent CAC and progression of CAC over 10 years. Results: At baseline, average age was 65 years, 46% had prevalent CAC and 32% were using hormone therapy (HT). Cross-sectionally, there were no associations between sex hormones and prevalent CAC. After adjustment for demographics, lifestyle factors and use of HT, higher levels of free T and lower levels of SHBG were associated with an increase in CAC progression over 10 years ( Table, Model 2). These associations remained statistically significant after adjusting for potential mediating cardiovascular risk factors (Model 3) and in sensitivity analyses excluding women on HT. Conclusion: A more androgenic hormone profile of higher free T and lower SHBG is associated with a greater CAC progression over 10 years in post-menopausal women. Sex hormone levels may help identify women at increased CVD risk who may benefit from other risk reduction strategies.

Examination of Cross-Sectional Associations of Neighborhood Deprivation and Alcohol Outlet Density With Hazardous Drinking Using a Twin Design.

The purpose of this study was to examine whether neighborhood socioeconomic deprivation and alcohol outlet density are associated with hazardous drinking using a co-twin design to control for confounding because of genetic and shared environmental factors. The study sample included cross-sectional data from 1,996 same-sex adult twin pairs (mean age = 36.6; 65.9% female) from the Washington State Twin Registry. The Singh Index was used to characterize neighborhood social deprivation for participants' census tract of residence. Geocoded alcohol outlet data were used to create a measure of census tract alcohol outlet density. The three-item Alcohol Use Disorders Identification Test-Consumption scale (AUDIT-C) was used to measure the level of hazardous drinking. Poisson mixed-effects models were used to examine associations between neighborhood factors and AUDIT-C score. Covariates included household income, level of education completed, non-White race, sex, and rurality of residence. Accounting for covariates, there was a statistically significant within-pair association between neighborhood socioeconomic deprivation and a higher level of hazardous drinking. There was no within-pair association between the density of alcohol outlets and hazardous drinking. Associations did not differ by zygosity. The socioeconomic conditions of the neighborhood may play an important role in the development of alcohol misuse even after accounting for genetic and shared environmental influences. Twin designs may be a promising complementary approach to investigating the role of neighborhood characteristics on alcohol and substance use. Further research is needed to better understand the ways through which and for whom neighborhood characteristics may influence hazardous drinking.

The effect of hormonal contraception and menstrual cycle timing on genital herpes simplex virus-2 shedding and lesions

Background The effect of female sex hormones on herpes simplex virus (HSV)-2 shedding and lesion frequency is poorly understood. Previous studies suggest that hormonal contraception may increase the frequency of HSV-2 shedding. Methods We studied HSV-2 seropositive women who performed daily genital swabbing for HSV DNA and completed diaries for genital lesions and menses. We used Poisson mixed effects models to determine if HSV detection varied throughout the menstrual cycle, or in response to hormonal contraception. We used the Wilcoxon signed-rank test and rank-sum test to determine if lesion frequency differed by cycle phase or hormonal contraceptive use. Results In 189 women aged 19 to 46 years who collected swabs on 10,715 days and were not using hormonal contraception, HSV-2 DNA was detected on 20.9% of days in the follicular phase and 17.8% of days in the luteal phase (rate ratio, 1.19; 95% confidence interval, 1.03-1.37, P = 0.02). Genital lesions did not differ in the follicular versus luteal phase (12.8% vs. 10.7%, P = 0.07). In analyses of hormonal contraception, including 244 women, HSV-2 DNA was detected on 19.0% of days for women not using hormonal contraception and 18.3% of days for those using hormonal contraception (P = 0.50). Lesions were present on 11.1% of days for women not using hormonal contraception, and 8.7% of days for those using hormonal contraception (P = 0.66). Conclusions In women with genital HSV-2 infection who are not using hormonal contraception, the follicular phase of the cycle may be associated with a higher frequency of HSV-2 shedding compared to the luteal phase. Lesion frequency is similar during the 2 menstrual phases. Hormonal contraception use was not observed to affect genital HSV-2 DNA detection or lesions.

Risk factors associated with the A2C resistance pattern among E. coli isolates from broiler flocks in Canada

The extra-label use of ceftiofur in Canadian hatcheries was cause for concern due to an increased prevalence of ceftiofur resistant Salmonella Heidelberg in chickens and humans in Québec. Due to on-going concerns related to human health the use of ceftiofur was eventually phased out of the poultry production industry in 2014–2015. Simultaneous resistance to amoxicillin-clavulanic acid, ceftiofur and cefoxitin, a pattern known as A2C, caused by the presence of blaCMY-2 has become increasingly prevalent in broiler flocks worldwide. This study used data from the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) broiler farm surveillance program to examine the risk factors for A2C resistant Escherichia coli isolates (A2C-REI) from 1482 samples taken from 371 broiler flocks in Canada, between 2013 and 2015. Results of a mixed effects Poisson model with fixed effects at the flock level and random effects at the hatchery level indicated that the in ovo use of ceftiofur (Prevalence Ratio (PR): 1.91, 95% CI: 1.43–2.57), and the use of hydrogen peroxide to disinfect water lines during the growing period (PR: 1.52, 95% CI: 1.11–2.07), were risk factors for increased expected prevalence of A2C-REI, compared to farms not using these strategies. Controlling for wild birds (PR: 0.64, 95% CI: 0.48–0.84), use of avilamycin in feed (PR: 0.63, 95% CI: 0.41–0.98), and storage of manure on the farm (PR: 0.67, 95% CI: 0.51–0.89) were associated with a lower expected prevalence of A2C-REI, than farms that did not use these strategies. This study identified important management factors that were associated with the prevalence of A2C-REI on Canadian broiler farms. The findings of this study can be used as a baseline for the monitoring of the effects of the removal of ceftiofur from poultry production in Canada.

Cancer incidence in the Western Australian mining industry (1996–2013)

BackgroundMiners are frequently exposed to established and potential carcinogens. We aimed to assess cancer incidence in miners relative to the general population and identify high-risk subgroups. MethodsIncident cancers in Western Australian miners (n=153,922; 86% male) during 1996–2013 were identified. Indirectly standardised incidence ratios (SIRs) were calculated and mixed-effects Poisson models were used to calculate Incidence Rate Ratios (IRRs) to identify high-risk within-cohort subgroups. ResultsCompared with the general population, the overall cancer incidence in miners (n=4194 cases) was lower for both females (SIR:0.83, 95%CI:0.74–0.92) and males (SIR:0.96, 95%CI:0.93–0.99). Overall, cancer incidence did not differ by employment duration or employment commencement time. Ever-underground work was associated with lung cancer (IRR:1.81, 95%CI:1.11–2.93). Relative to multi-ore miners, IRRs for specific cancers were significantly different when exclusively mining: iron (prostate:0.73, 95%CI:0.56–0.94); gold (lung:1.77, 95%CI:1.04–3.01 and colorectum:1.70, 95%CI:1.16–2.51); and other metals (urinary tract:1.85, 95%CI:1.03–3.31 and leukaemia:0.36, 95%CI:0.14–0.96). ConclusionWorking underground emerged as a significant determinant of lung cancer risk in our contemporary mining cohort. Increased risks of lung, prostate, colorectal and urinary tract cancers and leukaemia were identified in miners of specific ores. These findings underline the importance of continued surveillance of the health and exposures of this relatively young cohort of miners.

Attributes of primary care in relation to polypharmacy: a multicenter cross-sectional study in Japan.

To investigate the association between attributes of primary care and polypharmacy. Cross-sectional study. A primary care practice-based research network in Japan (28 primary care clinics). Adult outpatients filled out a standardized questionnaire. Polypharmacy defined as the use of five or more concurrent prescription or over-the-counter medications. Attributes of primary care were assessed via patient experience using the Japanese version of Primary Care Assessment Tool (JPCAT). Poisson mixed effects model was used to adjust for clustering within clinics and covariates. Data were analyzed for 544 primary care outpatients. After adjusting for patients' sociodemographic and health characteristics, the JPCAT community orientation score was found to be inversely associated with polypharmacy at the clinic level [risk ratio per 1 standard deviation increase=0.83; 95% confidence interval (CI), 0.73-0.96; P=0.008]. Sensitivity analyses using a different definition of polypharmacy showed results similar to those of the primary analyses. We found that a higher level of community-oriented primary care is associated with a lower prevalence of polypharmacy in outpatients at the clinic level. These findings may be useful in developing community-based interventions to minimize polypharmacy.

The effects of european economic integration and the impact of Brexit on the uk immigrants from the CEE countries

Considering the debates regarding lower increase in the economic growth after Brexit, the main objective of this paper is to measure the positive impact of economic integration of Central and Eastern European (CEE) countries on the UK economy and the effect of Brexit on the immigration from these countries to the UK. The European Union membership of some CEE countries increased, in average, the number of the UK immigrants by 12 times in the period 2004-2014 compared to the group of countries formed by Russia and Ukraine. The empirical fi ndings show positive economic effects of immigration on the UK’s economy, even if the pro Brexit group claimed that a control of immigration is necessary. CEE countries emigrants stimulated the UK economic growth, price stability and reduced the homicide rate. The effects of immigration on the unemployment rate, health and education spending were positive, but very low. According to mixed-effects Poisson models estimations, after Brexit the number of the UK immigrants from the CEE countries that are member of the EU might decrease by 2 times. This signifi cant decline in immigration might impose austerity measures, because of the fall in the economic growth trend with negative impact on the UK economy. Therefore, we recommend policies that focus more on high-skilled labour force than on the reduction of the number of immigrants. The UK should propose measures to slow the expected immigration decline in order to alleviate economic issues like decline in economic growth, decrease in labour productivity, cutting backs on public services.

Robust Poisson likelihood estimation for frailty Cox models: A simulation study

ABSTRACTFrailty models can be fit as mixed-effects Poisson models after transforming time-to-event data to the Poisson model framework. We assess, through simulations, the robustness of Poisson likelihood estimation for Cox proportional hazards models with log-normal frailties under misspecified frailty distribution. The log-gamma and Laplace distributions were used as true distributions for frailties on a natural log scale. Factors such as the magnitude of heterogeneity, censoring rate, number and sizes of groups were explored. In the simulations, the Poisson modeling approach that assumes log-normally distributed frailties provided accurate estimates of within- and between-group fixed effects even under a misspecified frailty distribution. Non-robust estimation of variance components was observed in the situations of substantial heterogeneity, large event rates, or high data dimensions.