Akaike's information criterion in generalized estimating equations

Health-care resource use and current treatment of adult atopic dermatitis patients in Japan: A retrospective claims database analysis

The real-world evidence on the profiles of patients suffering from atopic dermatitis (AD) in Japan is sparse. A retrospective claim database analysis was conducted to estimate the health-care resource use (HCRU) and current AD treatment. Data from October 2013 to September 2016 were extracted from the JMDC (Tokyo, Japan) claims database. HCRU was assessed by a comparison of AD patients and matched non-AD controls. A multivariate analysis was performed to estimate HCRU attributable to AD. AD patients (n = 39 893) have more claims of certain diagnoses such as rhinitis, viral and fungal infections, sleep disorders and conjunctivitis as well as higher HCRU (outpatient visits, prescriptions of AD-related and non-AD-related medications, phototherapy, laboratory tests) than matched non-AD controls (n = 39 893). Treatment pattern analysis included treatment-naive patients (n = 8478) and previously treated AD patients (n = 30 109). Approximately 20% of previously treated patients were on the continuous systemic treatment during 18-month follow up. Systemic corticosteroids were the most frequently used systemic treatments. Oral cyclosporin was less frequently used in both groups, but for the longest duration. Almost half of previously treated patients with oral cyclosporin continued treatment for more than 3 months. In conclusion, HCRU was higher in AD patients than non-AD controls, indicating a high burden of the disease imposed on AD patients. Continuous administration of systemic treatment, such as oral cyclosporin, systemic corticosteroids and phototherapy, observed in AD patients sheds light on the difficulties of managing AD in Japanese clinical practise.

The Effect of Violence and Intersecting Structural Inequities on High Rates of Food Insecurity among Marginalized Sex Workers in a Canadian Setting

Food security is both a basic human right and a public health necessity. Despite known gendered contexts of food insecurity, there is a dearth of research on prevalence and factors driving increased food insecurity for sex workers in a criminalized setting. The current study longitudinally examines the prevalence and structural and individual factors associated with increased odds of food insecurity among street and off-street sex workers in a Canadian urban setting. Prospective analyses drew on data from a community-based longitudinal cohort of cis and trans women in street and off-street sex work in An Evaluation of Sex Workers Health Access (2010-2014). The primary outcome was a time-updated measure of food insecurity, using the Radimer-Cornell scale. We used bivariable and multivariable logistic regression using generalized estimating equations to prospectively model correlates of food insecurity over a five-year period. Of 761 cis and trans women sex workers, 72.4% (n = 551) were food insecure over the study period. Over a third (35.2%, n = 268) identified as Indigenous and a quarter, 25.6% (n = 195) were of a gender/sexual minority. Within the 11.0% (n = 84) of women living with HIV, 96.4% (n = 81) were food insecure over the follow-up period. In multivariable analysis, Indigenous ancestry (AOR = 1.58 [95% CI 1.18, 2.10]), unstable housing (AOR = 1.27 [95% CI 1.03, 1.57]), stimulant use (AOR = 1.97 [95% CI 1.57, 2.45]), heroin use (AOR = 1.72 [95% CI 1.36, 2.19]), mental health diagnosis (AOR = 2.38 [95% CI 1.85, 3.05]), recent violence (AOR = 1.54 [95% CI 1.24, 1.91]), means of food access: reliant on food services only vs. self-sufficient (AOR = 1.78 [95% CI 1.38, 2.29]), and means of food access: both vs. self-sufficient (AOR = 2.29 [95% CI 1.84, 2.86]) were associated with food insecurity. In separate multivariable models, both recent and lifetime physical and/or sexual violence remained independently associated with food insecurity (AOR 1.54 [95% CI 1.24, 1.91]; AOR 4.62 [95% CI 2.99, 7.14], respectively). Almost all study participants living with HIV reported being food insecure. These intersecting risks demonstrate the negative impacts associated with living with HIV, experiencing food insecurity and/or physical or sexual violence. This study also highlights the potential for interventions that address structural inequities (e.g., decriminalizing sex work) to have crosscutting impacts to reduce barriers to accessing necessities (including food) or health and social services (e.g., methadone; primary care).

Mass Gatherings and Diarrheal Disease Transmission Among Rural Communities in Coastal Ecuador

Mass gatherings exacerbate infectious disease risks by creating crowded, high-contact conditions and straining the capacity of local infrastructure. While mass gatherings have been extensively studied in the context of epidemic disease transmission, the role of gatherings in incidence of high-burden, endemic infections has not been previously studied. Here, we examine diarrheal incidence among 17 communities in Esmeraldas, Ecuador, in relation to recurrent gatherings characterized using ethnographic data collected during and after the epidemiologic surveillance period (2004-2007). Using distributed-lag generalized estimating equations, adjusted for seasonality, trend, and heavy rainfall events, we found significant increases in diarrhea risk in host villages, peaking 2 weeks after an event's conclusion (incidence rate ratio, 1.21; confidence interval, adjusted for false coverage rate of ≤0.05: 1.02, 1.43). Stratified analysis revealed heightened risks associated with events where crowding and travel were most likely (2-week-lag incidence rate ratio, 1.51; confidence interval, adjusted for false coverage rate of ≤0.05: 1.09, 2.10). Our findings suggest that community-scale mass gatherings might play an important role in endemic diarrheal disease transmission and could be an important focus for interventions to improve community health in low-resource settings.

The relationship between health-related variables and increases in smoking among recently diagnosed HIV+ people who inject drugs in Vietnam

BACKGROUND

In Vietnam tobacco smoking is prevalent among people living with HIV (PLHIV) and causes excess mortality in this population. Injection drug use is a driver of HIV infections in Vietnam. Changes in HIV disease state may correlate to changes in smoking among PLHIV. This study investigates the relationship between increases in smoking and health-related variables among recently diagnosed HIV+ people who inject drugs (PWID) in Vietnam.

METHODS

We analyzed longitudinal data from 323 recently diagnosed HIV+ PWID in a randomized controlled trial from 2009 to 2013 in Thai Nguyen province, Vietnam. The outcome was an increase of >one cigarette/day from baseline visit cigarette smoking. A generalized estimating equation for repeated measures was used to estimate bivariable and multivariable associations between participant characteristics and smoking increases. We collected qualitative data to enhance our understanding of quantitative results, from 16 HIV+ PWID who smoke.

RESULTS

Ninety three point 5% of participants reported some smoking at baseline. Smoking fewer cigarettes, higher health related quality of life (QOL), and higher CD4 counts were predictive of increases in smoking at future visits in a multivariable model. Qualitative data showed smoking increases were tied to improved perceived health, and counseling during respiratory illnesses may increase intention to quit.

CONCLUSION

HIV+ PWID in Vietnam smoke at a very high rate. Increases in their smoking are correlated to increases in heath-related QOL, and increases in perceptions of health. Any tobacco-use intervention should account for internal tobacco use triggers faced by HIV+ PWID.

A predictive risk model for nonfatal opioid overdose in a statewide population of buprenorphine patients

BACKGROUND

Predicting which individuals who are prescribed buprenorphine for opioid use disorder are most likely to experience an overdose can help target interventions to prevent relapse and subsequent consequences.

METHODS

We used Maryland prescription drug monitoring data from 2015 to identify risk factors for nonfatal opioid overdoses that were identified in hospital discharge records in 2016. We developed a predictive risk model for prospective nonfatal opioid overdoses among buprenorphine patients (N = 25,487). We estimated a series of models that included demographics plus opioid, buprenorphine and benzodiazepine prescription variables. We applied logistic regression to generate performance measures.

RESULTS

About 3.24% of the study cohort had ≥1 nonfatal opioid overdoses. In the model with all predictors, odds of nonfatal overdoses among buprenorphine patients were higher among males (OR = 1.39, 95% CI:1.21-1.62) and those with more buprenorphine pharmacies (OR = 1.19, 95% CI:1.11-1.28), 1+ buprenorphine prescription paid by Medicaid (OR = 1.21, 95% CI:1.02-1.48), Medicare (OR = 1.93, 95% CI:1.63-2.43), or a commercial plan (OR = 1.98, 95% CI:1.30-2.89), 1+ opioid prescription paid by Medicare (OR = 1.30, 95% CI:1.03-1.68), and more benzodiazepine prescriptions (OR = 1.04, 95% CI:1.02-1.05). The odds were lower among those with longer days of buprenorphine (OR = 0.64, 95% CI:0.60-0.69) or opioid (OR = 0.79, 95% CI:0.65-0.95) supply. The model had moderate predictive ability (c-statistic = 0.69).

CONCLUSIONS

Several modifiable risk factors, such as length of buprenorphine treatment, may be targets for interventions to improve clinical care and reduce harms. This model could be practically implemented with common prescription-related information and allow payers and clinical systems to better target overdose risk reduction interventions, such as naloxone distribution.

Clinical and pathological stage discordance among 433,514 breast cancer patients

BACKGROUND

We aim to determine clinical and pathological stage discordance rates and to evaluate factors associated with discordance.

METHODS

Adults with clinical stages I-III breast cancer were identified from the National Cancer Data Base. Concordance was defined as cTN = pTN (discordance: cTN≠pTN). Multivariate logistic regression was used to identify factors associated with discordance.

RESULTS

Comparing clinical and pathological stage, 23.1% were downstaged and 8.7% were upstaged. After adjustment, factors associated with downstaging (vs concordance) included grade 3 (OR 10.56, vs grade 1) and HER2-negative (OR 3.79). Factors associated with upstaging (vs concordance) were grade 3 (OR 10.56, vs grade 1), HER2-negative (OR 1.25), and lobular histology (OR 2.47, vs ductal). ER-negative status was associated with stage concordance (vs downstaged or upstaged, OR 0.52 and 0.87).

CONCLUSIONS

Among breast cancer patients, nearly one-third exhibit clinical-pathological stage discordance. This high likelihood of discordance is important to consider for counseling and treatment planning.

Vocal behaviour of allied male dolphins during cooperative mate guarding

Coercive mate guarding, where males use aggression to control female movements, is a form of sexual coercion which functions to constrain female mate choice. Non-human primates, for example, herd females to keep them away from competing males, but male bottlenose dolphins (Tursiops aduncus) also herd females to keep them close to their alliance partners. Indeed, pairs and trios of male dolphins work together to sequester single estrus females and defend them from competing alliances. Yet how males facilitate such coordination remains unknown. Here, we investigate the vocal behaviour of allied male bottlenose dolphins during the herding of individual females, examining how the production of whistles and ‘pops’ (a threat vocalisation) varied with behavioural state and inter-animal distances. Allied males produced both whistles and pops significantly more often and at higher rates during social interactions, though they differed in function. Whistle rates increased significantly when new individuals joined the consorting group, consistent with previous work showing that whistles are part of a greeting sequence for this species. Whistle matching also appeared to play a role in within-alliance coordination. Pop vocalisations increased significantly when the nearest male to the female changed, likely inducing the female to remain close as the males coordinate a guard switch. Building upon prior research examining female movements in response to pops, we show that males approach the female and current guard whilst popping, leading to a guard switch. Our results provide new insights into the use of vocal signals during cooperative mate guarding between allied male dolphins.

Resilience of ecosystem processes: a new approach shows that functional redundancy of biological control services is reduced by landscape simplification

Functional redundancy can increase the resilience of ecosystem processes by providing insurance against species loss and the effects of abundance fluctuations. However, due to the difficulty of assessing individual species' contributions and the lack of a metric allowing for a quantification of redundancy within communities, few attempts have been made to estimate redundancy for individual ecosystem processes. We present a new method linking interaction metrics with metabolic theory that allows for a quantification of redundancy at the level of ecosystem processes. Using this approach, redundancy in the predation on aphids and other prey by natural enemies across a landscape heterogeneity gradient was estimated. Functional redundancy of predators was high in heterogeneous landscapes, low in homogeneous landscapes and scaled with predator specialisation. Our approach allows quantifying functional redundancy within communities and can be used to assess the role of functional redundancy across a wide variety of ecosystem processes and environmental factors.

Analysis of the European baseline survey of norovirus in oysters

The European Commission requested scientific technical assistance for the analysis of a European Union coordinated monitoring programme on the prevalence of norovirus in raw oysters. A total of 2,180 valid samples were taken from production areas and 2,129 from dispatch centres, taken over two consecutive years, ensuring the precision and the confidence desired in the estimation. The prevalence at production areas was estimated to be 34.5% (CI: 30.1-39.1%), while for batches from dispatch centres it was 10.8% (CI: 8.2-14.4%). The analyses show a strong seasonal effect, with higher contamination in the period November to April, as well as lower contamination for Class A areas than other classes. These associations were observed in both production areas and batches from dispatch centres. The results for both genogroups were above the respective limit of quantification (LOQ) in less than 10% of the samples taken. The simple substitution of not-detected and positive samples below the LOQ, by half of the limit of detection and half of the LOQ, respectively, produced estimates of the proportion of samples above or equal to 300 copies per gram (cpg) comparable to the statistical model. The current bacteriological microbiological criteria applicable to live bivalve molluscs might be complemented by a norovirus criterion. The analyses of the substitution approach show that selection of a potential limit within a microbiological criterion close to or lower than the LOQ (for example, less than 300 cpg, given the current test used in this survey) would be difficult to apply. This survey only assessed thresholds from the perspective of the analytical capability and not that of human health risk.

Azacytidine Failure Revisited: an Appraisal Based on Real-Life Data from the MDS Registry of the Hellenic Myelodysplastic Syndrome Study Group (HMDS)

N/A

Visual and auditory temporal integration in healthy younger and older adults

As people age, they tend to integrate successive visual stimuli over longer intervals than younger adults. It may be expected that temporal integration is affected similarly in other modalities, possibly due to general, age-related cognitive slowing of the brain. However, the previous literature does not provide convincing evidence that this is the case in audition. One hypothesis is that the primacy of time in audition attenuates the degree to which temporal integration in that modality extends over time as a function of age. We sought to settle this issue by comparing visual and auditory temporal integration in younger and older adults directly, achieved by minimizing task differences between modalities. Participants were presented with a visual or an auditory rapid serial presentation task, at 40-100 ms/item. In both tasks, two subsequent targets were to be identified. Critically, these could be perceptually integrated and reported by the participants as such, providing a direct measure of temporal integration. In both tasks, older participants integrated more than younger adults, especially when stimuli were presented across longer time intervals. This difference was more pronounced in vision and only marginally significant in audition. We conclude that temporal integration increases with age in both modalities, but that this change might be slightly less pronounced in audition.

Modeling change trajectories with count and zero-inflated outcomes: Challenges and recommendations

The goal of this article is to describe models to examine change over time with an outcome that represents a count, such as the number of alcoholic drinks per day. Common challenges encountered with this type of data are: (1) the outcome is discrete, may have a large number of zeroes, and may be overdispersed, (2) the data are clustered (multiple observations within each individual), (3) the researchers needs to carefully consider and choose an appropriate time metric, and (4) the researcher needs to identify both a proper individual (potentially nonlinear) change model and an appropriate distributional form that captures the properties of the data. In this article, we provide an overview of generalized linear models, generalized estimating equation models, and generalized latent variable (mixed-effects) models for longitudinal count outcomes focusing on the Poisson, negative binomial, zero-inflated, and hurdle distributions. We review common challenges and provide recommendations for identifying an appropriate change trajectory while determining an appropriate distributional form for the outcome (e.g., determining zero-inflation and overdispersion). We demonstrate the process of fitting and choosing a model with empirical longitudinal data on alcohol intake across adolescence collected as part of the National Longitudinal Survey of Youth 1997.

A comparative analysis of black spot identification methods and road accident segmentation methods

Indicating road safety-related aspects in the phase of planning and operating is always a challenging task for experts. The success of any method applied in identifying a high-risk location or black spot (BS) on the road should depend fundamentally on how data is organized into specific homogeneous segments. The appropriate combination of black spot identification (BSID) method and segmentation method contributes significantly to the reduction in false positive (a site involved in safety investigation while it is not needed) and false negative (not involving a site in safety investigation while it is needed) cases in identifying BS segments. The purpose of this research is to study and compare the effect of methodological diversity of road network segmentation on the performance of different BSID methods. To do this, four commonly applied BS methods (empirical Bayesian (EB), excess EB, accident frequency, and accident ratio) have been evaluated against four different segmentation methods (spatial clustering, constant length, constant traffic volume, and the standard Highway Safety Manual segmentation method). Two evaluations have been used to compare the performance of the methods. The approach first evaluates the segmentation methods based on the accuracy of the developed safety performance function (SPF). The second evaluation applies consistency tests to compare the joint performances of the BS methods and segmentation methods. In conclusion, BSID methods showed a significant change in their performance depending on the different segmentation method applied. In general, the EB method has surpassed the other BSID methods in case of all segmentation approaches.

Public health application of predictive modeling: an example from farm vehicle crashes

Background

The goal of predictive modelling is to identify the likelihood of future events, such as the predictive modelling used in climate science to forecast weather patterns and significant weather occurrences. In public health, increasingly sophisticated predictive models are used to predict health events in patients and to screen high risk individuals, such as for cardiovascular disease and breast cancer. Although causal modelling is frequently used in epidemiology to identify risk factors, predictive modelling provides highly useful information for individual risk prediction and for informing courses of treatment. Such predictive knowledge is often of great utility to physicians, counsellors, health education specialists, policymakers or other professionals, who may then advice course correction or interventions to prevent adverse health outcomes from occurring. In this manuscript, we use an example dataset that documents farm vehicle crashes and conventional statistical methods to forecast the risk of an injury or death in a farm vehicle crash for a specific individual or a scenario.

Results

Using data from 7094 farm crashes that occurred between 2005 and 2010 in nine mid-western states, we demonstrate and discuss predictive model fitting approaches, model validation techniques using external datasets, and the calculation and interpretation of predicted probabilities. We then developed two automated risk prediction tools using readily available software packages. We discuss best practices and common limitations associated with predictive models built from observational datasets.

Conclusions

Predictive analysis offers tools that could aid the decision making of policymakers, physicians, and environmental health practitioners to improve public health.

Comparison of PREDICTS atherosclerosis biomarker changes after initiation of new treatments in patients with SLE

Objective

Patients with SLE have an increased risk of atherosclerosis (ATH) that is not adequately explained by traditional risk factors. We previously described the Predictors of Risk for Elevated Flares, Damage Progression, and Increased Cardiovascular disease in PaTients with SLE (PREDICTS) atherosclerosis-risk panel, which includes proinflammatory HDL (piHDL), leptin, soluble tumour necrosis factor-like weak inducer of apoptosis (sTWEAK) and homocysteine, as well as age and diabetes. A high PREDICTS score confers 28-fold increased odds for future atherosclerosis in SLE. The aim of this study is to determine whether PREDICTS biomarkers are modifiable by common lupus therapies.

Methods

This prospective observational study included SLE subjects started on new lupus treatments. Leptin, sTWEAK, homocysteine and antioxidant function of HDL were measured at baseline (prior to drug initiation), 6 weeks and 12 weeks.

Results

16 subjects started mycophenolate (MMF), 18 azathioprine (AZA) and 25 hydroxychloroquine (HCQ). In MMF-treated subjects, HDL function progressively improved from 2.23 ± 1.32 at baseline to 1.37±0.81 at 6 weeks (p=0.02) and 0.93±0.54 at 12 weeks (p=0.009). sTWEAK levels also improved in MMF-treated subjects from 477.5±447.1 to 290.3±204.6 pg/mL after 12 weeks (p=0.04), but leptin and homocysteine levels were not significantly changed. In HCQ-treated subjects, only HDL function improved from 1.80±1.29 at baseline to 1.03±0.74 after 12 weeks (p=0.05). There were no changes in the AZA group. MMF treatment was still associated with significant improvements in HDL function after accounting for potential confounders such as total prednisone dose and changes in disease activity. Overall, the mean number of high-risk PREDICTS biomarkers at week 12 significantly decreased in the entire group of patients started on a new lupus therapy (2.1±0.9 to 1.8±0.9, p=0.02) and in the MMF-treated group (2.4±0.8 vs 1.8±0.9, p=0.003), but not in the AZA or HCQ groups. In multivariate analysis, the odds of having a high PREDICTS atherosclerosis risk score at 12 weeks were lower with MMF treatment (OR 0.002, 95% CI 0.000 to 0.55, p=0.03).

Conclusions

12 weeks of MMF therapy improves the overall PREDICTS atherosclerosis biomarker profile. Further studies will determine whether biomarker changes reflect decreases in future cardiovascular events.

Orbitofrontal Circuits Control Multiple Reinforcement-Learning Processes

Adaptive decision making in dynamic environments requires multiple reinforcement-learning steps that may be implemented by dissociable neural circuits. Here, we used a novel directionally specific viral ablation approach to investigate the function of several anatomically defined orbitofrontal cortex (OFC) circuits during adaptive, flexible decision making in rats trained on a probabilistic reversal learning task. Ablation of OFC neurons projecting to the nucleus accumbens selectively disrupted performance following a reversal, by disrupting the use of negative outcomes to guide subsequent choices. Ablation of amygdala neurons projecting to the OFC also impaired reversal performance, but due to disruptions in the use of positive outcomes to guide subsequent choices. Ablation of OFC neurons projecting to the amygdala, by contrast, enhanced reversal performance by destabilizing action values. Our data are inconsistent with a unitary function of the OFC in decision making. Rather, distinct OFC-amygdala-striatal circuits mediate distinct components of the action-value updating and maintenance necessary for decision making.

Do changes in health reveal the possibility of undiagnosed pancreatic cancer? Development of a risk-prediction model based on healthcare claims data

BACKGROUND AND OBJECTIVE

Early detection methods for pancreatic cancer are lacking. We aimed to develop a prediction model for pancreatic cancer based on changes in health captured by healthcare claims data.

METHODS

We conducted a case-control study on 29,646 Medicare-enrolled patients aged 68 years and above with pancreatic ductal adenocarcinoma (PDAC) reported to the Surveillance Epidemiology an End Results (SEER) tumor registries program in 2004-2011 and 88,938 age and sex-matched controls. We developed a prediction model using multivariable logistic regression on Medicare claims for 16 risk factors and pre-diagnostic symptoms of PDAC present within 15 months prior to PDAC diagnosis. Claims within 3 months of PDAC diagnosis were excluded in sensitivity analyses. We evaluated the discriminatory power of the model with the area under the receiver operating curve (AUC) and performed cross-validation by bootstrapping.

RESULTS

The prediction model on all cases and controls reached AUC of 0.68. Excluding the final 3 months of claims lowered the AUC to 0.58. Among new-onset diabetes patients, the prediction model reached AUC of 0.73, which decreased to 0.63 when claims from the final 3 months were excluded. Performance measures of the prediction models was confirmed by internal validation using the bootstrap method.

CONCLUSION

Models based on healthcare claims for clinical risk factors, symptoms and signs of pancreatic cancer are limited in classifying those who go on to diagnosis of pancreatic cancer and those who do not, especially when excluding claims that immediately precede the diagnosis of PDAC.

A Multisite Health System Survey to Assess Organizational Context to Support Evidence-Based Practice

BACKGROUND

Implementation and sustainability of a culture of evidence-based practice (EBP) require a systematic approach. A baseline assessment of the organizational context can inform implementation efforts.

AIMS

To examine organizational hospital context and provider characteristics associated with EBP readiness and to describe EBP context across hospitals.

METHODS

A nonexperimental descriptive correlational design was used to conduct a web-based survey of direct-care registered nurses (N = 701) and nurse managers (N = 94) across a large Midwestern multisite healthcare system using the Alberta Context Tool (ACT).

RESULTS

Many significant relationships existed among nurse characteristics and ACT domains, including age (lower age had higher Leadership, Evaluation, and Formal Interactions), education (graduate education had lower Social Capital than a bachelor's or associate degree), role (direct-care nurses had lower Culture than managers and lower Social Capital), and work status (full-time employees had lower Evaluation and Social Capital). EBP context across type of hospitals is similar, with marginal differences in Social Capital and Organizational Slack (higher in critical access hospitals).

LINKING EVIDENCE TO ACTION

Assessing organizational context to support EBP is the first step in developing and enhancing a sustainable culture of inquiry. The ACT has been tested across countries, settings, and healthcare disciplines to measure perception of readiness of the practice environment toward EBP. Optimal organizational context is essential to support EBP and sustain the use of evidence in professional nursing practice. Nursing leaders can use baseline assessment information to identify strengths and opportunities to enhance EBP implementation. Enhancing organizational context across nurse characteristics (e.g., age, role, and work status) to acknowledge nurses' contributions, balance nurses' personal and work life, enhance connectedness, and support work culture is beneficial. Fostering development of Social Capital in nurses is needed to influence EBP readiness. A systematic and standardized approach to foster EBP across health systems is key to successful implementation.

Which healthcare workers work with acute respiratory illness? Evidence from Canadian acute-care hospitals during 4 influenza seasons: 2010-2011 to 2013-2014

BACKGROUND

Healthcare workers (HCWs) are at risk of acquiring and transmitting respiratory viruses while working in healthcare settings.

OBJECTIVES

To investigate the incidence of and factors associated with HCWs working during an acute respiratory illness (ARI).

METHODS

HCWs from 9 Canadian hospitals were prospectively enrolled in active surveillance for ARI during the 2010-2011 to 2013-2014 influenza seasons. Daily illness diaries during ARI episodes collected information on symptoms and work attendance.

RESULTS

At least 1 ARI episode was reported by 50.4% of participants each study season. Overall, 94.6% of ill individuals reported working at least 1 day while symptomatic, resulting in an estimated 1.9 days of working while symptomatic and 0.5 days of absence during an ARI per participant season. In multivariable analysis, the adjusted relative risk of working while symptomatic was higher for physicians and lower for nurses relative to other HCWs. Participants were more likely to work if symptoms were less severe and on the illness onset date compared to subsequent days. The most cited reason for working while symptomatic was that symptoms were mild and the HCW felt well enough to work (67%). Participants were more likely to state that they could not afford to stay home if they did not have paid sick leave and were younger.

CONCLUSIONS

HCWs worked during most episodes of ARI, most often because their symptoms were mild. Further data are needed to understand how best to balance the costs and risks of absenteeism versus those associated with working while ill.

Sex workers' experiences and occupational conditions post-implementation of end-demand criminalization in Metro Vancouver, Canada

OBJECTIVES

In 2014, Canada introduced end-demand criminalization (the Protection of Communities and Exploited Persons Act (PCEPA)), criminalizing purchase of sexual services while leaving the sale of sex legal. We assessed factors correlated with self-reported changes in working conditions post-PCEPA among sex workers (SWs) in Metro Vancouver.

METHODS

Post-PCEPA data for one year were drawn from a community-based cohort of SWs. We analyzed self-reported changes in working conditions among 299 participants who worked prior to PCEPA and were asked about working conditions post-PCEPA. Multivariate GEE analysis evaluated factors correlated with negative changes post-PCEPA, including reduced capacity to screen clients and reduced access to workspaces/clients.

RESULTS

Most (72.2%) experienced no change in working conditions, and 26.4% reported negative changes (e.g., reduced ability to screen clients or reduced access to workspaces/clients). Reporting negative changes was correlated with being an im/migrant to Canada (adjusted odds ratio (AOR) 2.79, 95% CI 1.59-4.92) and recent physical workplace violence (AOR 4.01, 95% CI 1.12-14.40). In sub-analysis, physical/sexual workplace violence (AOR 3.77, 95% CI 1.17-12.16) and living in the suburbs of Richmond/Burnaby (AOR 2.81, 95% CI 1.15-6.84) correlated with reduced screening capacity; incarceration (AOR 2.98, 95% CI 1.04-8.57) and being an im/migrant (AOR 2.39, 95% CI 1.14-4.99) correlated with reduced access to workspaces/clients.

CONCLUSIONS

Most SWs reported no change in working conditions and one quarter reported negative changes, suggesting that PCEPA may be failing to advance sex workers' safety. Im/migrants, women experiencing workplace violence, and those facing criminalization were most likely to report negative impacts. Decriminalization of all aspects of sex work is needed to support well-being, health, and safety.

A Multilevel Analysis of Regressors of Access to Improved Drinking Water and Sanitation Facilities in Ghana

People's access to quality water and sanitation resources significantly improves their health. Using the 2014 Ghana DHS dataset, multilevel robust Poisson regression modelling was performed to investigate the factors that enhance Ghanaian households' access to improved sources of drinking water and toilet facilities. The results indicated that household head and household socioeconomic factors have significant effects on access to improved sources of drinking water and toilet facilities, and this varies from one community of residence to another. The following households had a higher probability of having access to improved sources of drinking water: female-headed households, households with heads who had at least attained middle-school-level education, urban households, and nonpoorest households. Correspondingly, the following households were more likely to have access to improved toilet facilities: female-headed households had a higher chance of access, as well as those whose heads had at least middle-school-level education, were at least 35 years old, or were currently married, rural households, households with a minimum of seven members, and households who attained at least middle wealth status. In their efforts to increase citizens' access to improved water and sanitation facilities, the government and other development organizations should develop citizens' wealth-creation capacities and enable their attainment of formal education.

Association between solar insolation and a history of suicide attempts in bipolar I disorder

In many international studies, rates of completed suicide and suicide attempts have a seasonal pattern that peaks in spring or summer. This exploratory study investigated the association between solar insolation and a history of suicide attempt in patients with bipolar I disorder. Solar insolation is the amount of electromagnetic energy from the Sun striking a surface area on Earth. Data were collected previously from 5536 patients with bipolar I disorder at 50 collection sites in 32 countries at a wide range of latitudes in both hemispheres. Suicide related data were available for 3365 patients from 310 onset locations in 51 countries. 1047 (31.1%) had a history of suicide attempt. There was a significant inverse association between a history of suicide attempt and the ratio of mean winter solar insolation/mean summer solar insolation. This ratio is smallest near the poles where the winter insolation is very small compared to the summer insolation. This ratio is largest near the equator where there is relatively little variation in the insolation over the year. Other variables in the model that were positively associated with suicide attempt were being female, a history of alcohol or substance abuse, and being in a younger birth cohort. Living in a country with a state-sponsored religion decreased the association. (All estimated coefficients p < 0.01). In summary, living in locations with large changes in solar insolation between winter and summer may be associated with increased suicide attempts in patients with bipolar disorder. Further investigation of the impacts of solar insolation on the course of bipolar disorder is needed.

Explaining the association between anxiety disorders and alcohol use disorder: A twin study

BACKGROUND

It is unknown whether social anxiety disorder (SAD) has a unique association with alcohol use disorder (AUD) over and beyond that of other anxiety disorders, how the associations develop over time, and whether the associations are likely to be causal.

METHODS

Diagnoses of AUD, SAD, generalized anxiety disorder, panic disorder, agoraphobia, and specific phobias were assessed twice using the Composite International Diagnostic Interview among 2,801 adult Norwegian twins. The data were analyzed using logistic regression analyses and multivariate biometric structural equation modeling.

RESULTS

SAD had the strongest association with AUD, and SAD predicted AUD over and above the effect of other anxiety disorders. In addition, SAD was prospectively associated with AUD, whereas other anxiety disorders were not. AUD was associated with a slightly elevated risk of later anxiety disorders other than SAD. Biometric modeling favored a model where SAD influenced AUD compared to models where the relationship was reversed or due to correlated risk factors. Positive associations between AUD and other anxiety disorders were fully explained by shared genetic risk factors.

CONCLUSIONS

Unlike other anxiety disorders, SAD plausibly has a direct effect on AUD. Interventions aimed at prevention or treatment of SAD may have an additional beneficial effect of preventing AUD, whereas interventions aimed at other anxiety disorders are unlikely to have a similar sequential effect on AUD.

Factors associated with adverse outcomes from cardiovascular events in the kidney transplant population: an analysis of national discharge data, hospital characteristics, and process measures

Background

Kidney transplant (KT) patients presenting with cardiovascular (CVD) events are being managed increasingly in non-transplant facilities. We aimed to identify drivers of mortality and costs, including transplant hospital status.

Methods

Data from the 2009–2011 Nationwide Inpatient Sample, the American Hospital Association, and Hospital Compare were used to evaluate post-KT patients hospitalized for MI, CHF, stroke, cardiac arrest, dysrhythmia, and malignant hypertension. We used generalized estimating equations to identify clinical, structural, and process factors associated with risk-adjusted mortality and high cost hospitalization (HCH).

Results

Data on 7803 admissions were abstracted from 275 hospitals. Transplant hospitals had lower crude mortality (3.0% vs. 3.8%, p = 0.06), and higher un-adjusted total episodic costs (Median $33,271 vs. $28,022, p < 0.0001). After risk-adjusting for clinical, structural, and process factors, mortality predictors included: age, CVD burden, CV destination hospital, diagnostic cardiac catheterization without intervention (all, p < 0.001). Female sex, race, documented co-morbidities, and hospital teaching status were protective (all, p < 0.05). Transplant and non-transplant hospitals had similar risk-adjusted mortality. HCH was associated with: age, CVD burden, CV procedures, and staffing patterns. Hospitalizations at transplant facilities had 37% lower risk-adjusted odds of HCH. Cardiovascular process measures were not associated with adverse outcomes.

Conclusion

KT patients presenting with CVD events had similar risk-adjusted mortality at transplant and non-transplant hospitals, but high cost care was less likely in transplant hospitals. Transplant hospitals may provide better value in cardiovascular care for transplant patients. These data have significant implications for patients, transplant and non-transplant providers, and payers.

The relationship between hospital adoption and use of high technology medical imaging and in-patient mortality and length of stay

PURPOSE

The purpose of this paper is to investigate the relationship between hospital adoption and use of computed tomography (CT) scanners, and magnetic resonance imaging (MRI) machines and in-patient mortality and length of stay.

DESIGN/METHODOLOGY/APPROACH

This study used panel data (2007-2010) from 124 hospital corporations operating in Ontario, Canada. Imaging use focused on medical patients accounting for 25 percent of hospital discharges. Main outcomes were in-hospital mortality rates and average length of stay. A model for each outcome-technology combination was built, and controlled for hospital structural characteristics, market factors and patient characteristics.

FINDINGS

In 2010, 36 and 59 percent of hospitals had adopted MRI machines and CT scanners, respectively. Approximately 23.5 percent of patients received CT scans and 3.5 percent received MRI scans during the study period. Adoption of these technologies was associated with reductions of up to 1.1 percent in mortality rates and up to 4.5 percent in length of stay. The imaging use-mortality relationship was non-linear and varied by technology penetration within hospitals. For CT, imaging use reduced mortality until use reached 19 percent in hospitals with one scanner and 28 percent in hospitals with 2+ scanners. For MRI, imaging use was largely associated with decreased mortality. The use of CT scanners also increased length of stay linearly regardless of technology penetration (4.6 percent for every 10 percent increase in use). Adoption and use of MRI was not associated with length of stay.

RESEARCH LIMITATIONS/IMPLICATIONS

These results suggest that there may be some unnecessary use of imaging, particularly in small hospitals where imaging is contracted out. In larger hospitals, the results highlight the need to further investigate the use of imaging beyond certain thresholds. Independent of the rate of imaging use, the results also indicate that the presence of CT and MRI devices within a hospital benefits quality and efficiency.

ORIGINALITY/VALUE

To the authors' knowledge, this study is the first to investigate the combined effect of adoption and use of medical imaging on outcomes specific to CT scanners and MRI machines in the context of hospital in-patient care.

The effects of multiyear and seasonal weather factors on incidence of Lyme disease and its vector in New York State

BACKGROUND

More frequent extreme weather and warmer weather due to climate change might change the spatiotemporal distributions of vector-borne diseases, including Lyme disease. However, limited studies have examined the associations of Lyme disease and its vectors with weather factors, especially multi-year and multi-weather factors related to vector life cycle.

OBJECTIVES

We investigated the associations between multi-year, unique weather indicators (relevant to tick and host activities) and Lyme disease incidence or documented I. scapularis encounters in New York State (NYS).

METHODS

Using a generalized estimating equation model, we linked Lyme disease and tick (I. scapularis) data, obtained from the NYS Department of Health (NYSDOH) Communicable Disease Surveillance and Tick Identification Service, with weather data. We used a season-specific exposure index by considering days in different seasons with certain temperature and precipitation ranges, summer Palmer Hydrological Drought Index, and fitted linear regression models using generalized estimating equations.

RESULTS

Lyme disease and I. scapularis encounters were modestly correlated (Spearman correlation = 0.60, p-value <0.001). The results indicate that summer Lyme disease cases and tick encounters may increase by 4-10%, per one day in spring with a minimum temperature range between 40 and 50 °F in the year of diagnosis and previous year. A day increase in summer with maximum temperature > 75 °F in the previous year was associated with 2% increase in summer disease counts. Mild winter days were associated with an increase in summer tick encounters.

CONCLUSIONS

Extended spring and summer days and mild winter temperatures appear to increase Lyme disease cases and tick exposure risk in NYS.

"Sickenin' in the rain" - increased risk of gastrointestinal and respiratory infections after urban pluvial flooding in a population-based cross-sectional study in the Netherlands

Background

Climate change is expected to increase the chance of extreme rainfall events in the Northern Hemisphere and herewith, there is an increased chance of urban pluvial flooding. Urban pluvial flooding often consists of street flooding and/or flooding of combined sewerage systems, leading to contamination of the floodwater with several gastrointestinal and/or respiratory pathogens. An increase in flooding events therefore pose a health risk to those exposed to urban floodwater. We studied the association between exposure to pluvial floodwater and acute gastroenteritis (AGE) and acute respiratory infection (ARI).

Methods

We performed a retrospective, cross-sectional survey during the summer of 2015 in 60 locations in the Netherlands with reported flooding. Two weeks after the flooding, questionnaires were sent to households in these locations, collecting data on self-reported AGE and ARI and information on floodwater exposure in the previous 2 weeks. Multivariable generalized estimating equations (GEE) regression models, accounting for the clustered data structure, were used to identify risk factors for AGE and ARI.

Results

In total, 699 households with 1,656 participants (response rate 21%) returned the questionnaire. Contact with floodwater was significantly associated with AGE (aOR 4.2, 95%CI 2.1–8.4) and ARI (aOR 3.3, 95%CI 2.0–5.4). Risk factors for AGE were skin contact with floodwater (aOR 4.0, 95%CI 1.8-9.0), performing post-flooding cleaning operations (aOR 8.6, 95%CI 3.5-20.9) and cycling through floodwater (aOR 2.3, 95%CI 1.0-5.0). Skin contact with floodwater (aOR 3.6, 95%CI 1.9-6.9) and performing post-flooding cleaning operations (aOR 5.5, 95%CI 3.0-10.3) were identified as risk factors for ARI.

Conclusions

Results suggest an association between direct exposure to pluvial floodwater and AGE and ARI. As it is predicted that the frequency of pluvial flooding events will increase in the future, there is a need for flood-proof solutions in urban development and increased awareness among stakeholders and the public about the potential health risks. Future prospective studies are recommended to confirm our results.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-3984-5) contains supplementary material, which is available to authorized users.

Empirical-likelihood-based criteria for model selection on marginal analysis of longitudinal data with dropout missingness

Longitudinal data are common in clinical trials and observational studies, where missing outcomes due to dropouts are always encountered. Under such context with the assumption of missing at random, the weighted generalized estimating equation (WGEE) approach is widely adopted for marginal analysis. Model selection on marginal mean regression is a crucial aspect of data analysis, and identifying an appropriate correlation structure for model fitting may also be of interest and importance. However, the existing information criteria for model selection in WGEE have limitations, such as separate criteria for the selection of marginal mean and correlation structures, unsatisfactory selection performance in small-sample setups, and so forth. In particular, there are few studies to develop joint information criteria for selection of both marginal mean and correlation structures. In this work, by embedding empirical likelihood into the WGEE framework, we propose two innovative information criteria named a joint empirical Akaike information criterion and a joint empirical Bayesian information criterion, which can simultaneously select the variables for marginal mean regression and also correlation structure. Through extensive simulation studies, these empirical-likelihood-based criteria exhibit robustness, flexibility, and outperformance compared to the other criteria including the weighted quasi-likelihood under the independence model criterion, the missing longitudinal information criterion, and the joint longitudinal information criterion. In addition, we provide a theoretical justification of our proposed criteria, and present two real data examples in practice for further illustration.

Prevalence and correlates of selling illicit cannabis among people who use drugs in Vancouver, Canada: A ten-year prospective cohort study

BACKGROUND

The illicit selling and use of cannabis is prevalent among marginalized people who use illicit drugs (PWUD). Given that participation in illicit drug markets has been previously associated with a range of health and social harms, we sought to examine the predictors of selling cannabis among PWUD in Vancouver, Canada, a setting with a de facto legalized cannabis market, on the eve of the planned implementation of legalized non-medical cannabis including measures to regulate the existing illicit market.

METHODS

Multivariable generalized estimating equations (GEE) logistic regression was used to analyze longitudinal factors associated with selling illicit cannabis among three prospective cohorts of PWUD between September 2005 and May 2015.

RESULTS

Among the 3258 participants included in this study, 328 (10.1%) reported selling illicit cannabis at baseline, and 46 (5.1%) initiated cannabis selling over the study period. In the multivariable analysis of the whole sample, factors significantly associated with selling cannabis included cannabis use (Adjusted Odds Ratio [AOR] = 4.05), dealing other drugs (AOR = 3.87), being male (AOR = 1.83), experiencing violence (AOR = 1.40), non-medical prescription opioid use (AOR = 1.32), non-custodial involvement in the criminal justice system (AOR = 1.31), being stopped by police (AOR = 1.30), crack use (AOR = 1.25), homelessness (AOR = 1.23), age (AOR = 0.96 per year) and participation in sex work (AOR = 0.67) (all p < 0.05). The subanalyses indicated that dealing drugs other than cannabis, cannabis use, and non-custodial involvement in the criminal justice system were the only factors significantly associated with selling cannabis in all four subgroups.

CONCLUSION

These findings support existing evidence indicating that selling illicit cannabis is often a survival-driven strategy to support the basic needs and substance use of some PWUD. Our findings suggest jurisdictions with planned or impending cannabis legalization and regulation should consider the vulnerability of PWUD when seeking to eradicate illicit cannabis markets, for example, in setting criminal penalties for selling cannabis outside of regulatory frameworks.

Association of Baseline Peptidylarginine Deiminase 4 Autoantibodies With Favorable Response to Treatment Escalation in Rheumatoid Arthritis

OBJECTIVE

To determine if the baseline presence of autoantibodies to peptidylarginine deiminase 4 (PAD4) predicts therapeutic response to biologic and conventional disease-modifying antirheumatic drugs (DMARDs) in patients with rheumatoid arthritis (RA) in whom methotrexate (MTX) monotherapy was unsuccessful.

METHODS

Baseline serum from 282 RA patients in whom MTX monotherapy was unsuccessful was screened for the presence of anti-PAD4 antibodies by immunoprecipitation. Clinical response to either triple DMARD (MTX, sulfasalazine, and hydroxychloroquine) or MTX/etanercept combination therapy was determined at 24 and 48 weeks post-treatment initiation. Disease activity was measured using the Disease Activity Score 28-joint assessment (DAS28), and erosive disease was quantified using the Sharp/van der Heijde scoring method. Generalized estimating equations (GEEs) were used to model the clinical responses to treatment in patients with and those without baseline anti-PAD4 antibodies.

RESULTS

Anti-PAD4 antibody positivity was associated with male sex, a history of never smoking, and anti-citrullinated protein antibodies. At baseline, patients with anti-PAD4 antibodies had longer disease duration and significantly more radiographic joint damage than anti-PAD4-negative patients, but did not differ in disease activity according to the DAS28. In unadjusted analyses and multivariable GEE models, patients with anti-PAD4 antibodies exhibited greater improvements in DAS28 (adjusted P = 0.02 and P = 0.008, respectively) and less radiographic progression (adjusted P = 0.01 and P = 0.002, respectively) compared to anti-PAD antibody-negative patients, independent of treatment received.

CONCLUSION

Although anti-PAD4 antibodies were associated with worse baseline radiographic joint damage, suggesting a history of active or undiagnosed disease, treatment escalation therapy was more effective in reducing disease activity and slowing the progression of joint damage in this patient subset.

Impact of academic detailing on benzodiazepine use among veterans with posttraumatic stress disorder

Background: Benzodiazepine use in the US Veterans Administration (VA) has been decreasing; however, a small number of veterans with posttraumatic stress disorder (PTSD) continue to receive benzodiazepine. Academic detailing, a targeted-educational outreach intervention, was implemented at VA to help reduce the disparity between existing and evidence-based practices, including the reduction in benzodiazepine use in veterans with PTSD. Since evidence to support the national implementation of academic detailing in this clinical scenario was scarce, we performed a quality improvement evaluation on academic detailing's impact on benzodiazepine use in veterans with PTSD. Methods: A retrospective cohort design was used to evaluate the impact of academic detailing on benzodiazepine prescribing in veterans with PTSD from January 1, 2016, to December 31, 2016. Providers exposed to academic detailing (AD-exposed) were compared with providers unexposed to academic detailing (AD-unexposed) using generalized estimating equations (GEEs) controlling for baseline covariates. Secondary aims evaluated academic detailing's impact on average lorazepam equivalent daily dose (LEDD), total LEDD, and benzodiazepine day supply. Results: Overall, there was a decrease in the prevalence in benzodiazepine use in veterans with PTSD from 115.5 to 103.3 per 1000 population (P < .001). However, the decrease was greater in AD-exposed providers (18.37%; P < .001) compared with AD-unexposed providers (8.74%; P < .001). In the GEE models, AD-exposed providers had greater reduction in the monthly prevalence of veterans with PTSD and a benzodiazepine prescription compared with AD-unexposed providers, by -1.30 veterans per 1000 population (95% confidence interval [CI]: -2.14, -0.46). Similar findings were reported for the benzodiazepine day supply; however, no significant differences were reported for total and average LEDD. Conclusions: Although benzodiazepine use has been decreasing in veterans with PTSD, opportunities to improve prescribing continue to exist at the VA. In this quality improvement evaluation, AD-exposed providers were associated with a greater reduction in the prevalence of veterans with PTSD and a benzodiazepine prescription compared with AD-unexposed providers.

Dazed, confused, and then hungry: pesticides alter predator-prey interactions of estuarine organisms

Like predators, contaminant stressors such as pesticides may have large and interacting effects on natural communities by removing species or altering behaviors and species interactions. Yet, few studies in estuarine systems have evaluated the effects of a single, low-dose exposure to pesticides on key predators. Here, we investigated the effects of a common pyrethroid (resmethrin) + synergist (piperonyl butoxide; PBO) mixture used for mosquito abatement on two life stages (adult and juvenile) of an important invertebrate estuarine predator, prey, and fishery species: the blue crab (Callinectes sapidus). The effects of resmethrin with PBO (Res-PBO) were assessed using behavioral and mesocosm experiments to link effects on individuals with changes in predator-prey interactions: (1) In static non-renewal exposures, crabs exposed to 1:3, 10:30, or 100:300 µg l^-1 Res-PBO or PBO-alone had increased mortality and reduced locomotor ability within 1-12 h, with higher effects in adults than juveniles. (2) In mesocosms, sublethal exposure to 1:3 µg l^-1 Res-PBO altered abult and juvnile foraging ability by  lowering the ability of adult crabs to cannibalize juvenile crabs but increasing juvenile crab foraging rates. Juvenile crabs were also more vulnerable to predation following pesticide exposure. Thus, a single, sublethal exposure to low, environmentally occurring pesticide concentrations reduced blue crab survivorship and locomotor functioning, and altered predator-prey interactions by changing foraging rates and increasing vulnerability to predators. Pesticide stressors may therefore play an important but underestimated role in shaping coastal ecosystems in which invertebrate predators are important and may contribute to U.S. blue crab population declines.

Do Symptoms of Depression Interact with Substance Use to Affect HIV Continuum of Care Outcomes?

Few studies examine how depression and substance use interact to affect HIV control. In 14,380 persons with HIV (PWH), we used logistic regression and generalized estimating equations to evaluate how symptoms of depression interact with alcohol, cocaine, opioid, and methamphetamine use to affect subsequent retention in care, maintaining an active prescription for ART, and consistent virologic suppression. Among PWH with no or mild depressive symptoms, heavy alcohol use had no association with virologic suppression (OR 1.00 [0.95-1.06]); among those with moderate or severe symptoms, it was associated with reduced viral suppression (OR 0.80 [0.74-0.87]). We found no interactions with heavy alcohol use on retention in care or maintaining ART prescription or with other substances for any outcome. These results highlight the importance of treating moderate or severe depression in PWH, especially with comorbid heavy alcohol use, and support multifaceted interventions targeting alcohol use and depression.

Validity of a two-component imaging-derived disease activity score for improved assessment of synovitis in early rheumatoid arthritis

OBJECTIVES

Imaging of joint inflammation provides a standard against which to derive an updated DAS for RA. Our objectives were to develop and validate a DAS based on reweighting the DAS28 components to maximize association with US-assessed synovitis.

METHODS

Early RA patients from two observational cohorts (n = 434 and n = 117) and a clinical trial (n = 59) were assessed at intervals up to 104 weeks from baseline; all US scans were within 1 week of clinical exam. There were 899, 163 and 183 visits in each cohort. Associations of combined US grey scale and power Doppler scores (GSPD) with 28 tender joint count and 28 swollen joint count (SJC28), CRP, ESR and general health visual analogue scale were examined in linear mixed model regressions. Cross-validation evaluated model predictive ability. Coefficients learned from training data defined a re-weighted DAS28 that was validated against radiographic progression in independent data (3037 observations; 717 patients).

RESULTS

Of the conventional DAS28 components only SJC28 and CRP were associated with GSPD in all three development cohorts. A two-component model including SJC28 and CRP outperformed a four-component model (R2 = 0.235, 0.392, 0.380 vs 0.232, 0.380, 0.375, respectively). The re-weighted two-component DAS28CRP outperformed conventional DAS28 definitions in predicting GSPD (Δtest log-likelihood <-2.6, P < 0.01), Larsen score and presence of erosions.

CONCLUSION

A score based on SJC28 and CRP alone demonstrated stronger associations with synovitis and radiographic progression than the original DAS28 and should be considered in research on pathophysiological manifestations of early RA. Implications for clinical management of RA remain to be established.

Birth mode, breastfeeding and childhood infectious morbidity in the Yucatec Maya

OBJECTIVES

Cesarean delivery is linked to breastfeeding complications and child morbidity. These outcomes may disproportionately affect Latin American indigenous populations that are experiencing rising cesarean delivery rates, but often inhabit environments that exacerbate postnatal morbidity risks. We therefore assess relationships between birth mode, infant feeding practices, and childhood infectious morbidity in a modernizing Yucatec Maya community, where prolonged breastfeeding is the norm. We predicted that under these conditions, cesarean delivery would increase risk of childhood infectious morbidity, but prolonged breastfeeding postcesarean would mitigate morbidity risk.

METHODS

Using a longitudinal child health dataset (n = 88 children aged 0-60 months, 24% cesarean-delivered, 2290 observations total), we compare gastrointestinal infectious (GI) and respiratory infectious (RI) morbidity rates by birth mode. We model associations between cesarean delivery and breastfeeding duration, formula feeding and child nutritional status, then model GI and RI as a function of birth mode, child age, and feeding practices.

RESULTS

Cesarean delivery was associated with longer breastfeeding durations and higher child weight-for-age, but not with formula feeding, GI, or RI. Adolescent motherhood and RI were risk factors for GI; formula feeding and GI were risk factors for RI. Regional housing materials protected against GI; breastfeeding protected against RI and mitigated the effect of formula feeding.

CONCLUSIONS

We find no direct link between birth mode and child infectious morbidity. Yucatec Maya mothers practice prolonged breastfeeding, especially postcesarean, and in conjunction with formula feeding. This practice protects against childhood RI, but not GI, perhaps because GI is more susceptible to maternal and household factors.

Temporal Patterns in Chlamydia Repeat Testing in Massachusetts

INTRODUCTION

National guidelines recommend test-of-cure for pregnant women and test-of-reinfection for all patients with chlamydia infections in order to interrupt transmission and prevent adverse sequelae for patients, partners, and newborns. Little is known about retesting and positivity rates, and whether they are changing over time, particularly in private sector practices.

METHODS

Electronic health record data on patients with chlamydia tests were extracted from three independent clinical practice groups serving ≅20% of the Massachusetts population. Records were extracted using the Electronic medical record Support for Public Health platform (esphealth.org). These data were analyzed for temporal trends in annual repeat testing rates by using generalized estimating equations after index positive chlamydia tests between 2010 and 2015 and for differences in intervals to first repeat tests among pregnant females, non-pregnant females, and males. Data extraction and analysis were performed during calendar years 2017 and 2018.

RESULTS

An index positive C. trachomatis result was identified for 972 pregnant female cases, 10,309 non-pregnant female cases, and 4,973 male cases. Test-of-cure 3-5 weeks after an index positive test occurred in 37% of pregnant females. Test-of-reinfection 8-16 weeks after an index positive test occurred in 39% of pregnant females, 18% of non-pregnant females, and 9% of males. There were no significant increases in test-of-cure or test-of-reinfection rates from 2010 to 2015. Among cases with repeat tests, 16% of pregnant females, 15% of non-pregnant females, and 16% of males had positive results.

CONCLUSIONS

Chlamydia test-of-cure and test-of-reinfection rates are low, with no evidence of improvement over time. There are substantial opportunities to improve adherence to chlamydia repeat testing recommendations.

Socioeconomic and environmental factors associated with malaria hotspots in the Nanoro demographic surveillance area, Burkina Faso

BACKGROUND

With limited resources and spatio-temporal heterogeneity of malaria in developing countries, it is still difficult to assess the real impact of socioeconomic and environmental factors in order to set up targeted campaigns against malaria at an accurate scale. Our goal was to detect malaria hotspots in rural area and assess the extent to which household socioeconomic status and meteorological recordings may explain the occurrence and evolution of these hotspots.

METHODS

Data on malaria cases from 2010 to 2014 and on socioeconomic and meteorological factors were acquired from four health facilities within the Nanoro demographic surveillance area. Statistical cross correlation was used to quantify the temporal association between weekly malaria incidence and meteorological factors. Local spatial autocorrelation analysis was performed and restricted to each transmission period using Kulldorff's elliptic spatial scan statistic. Univariate and multivariable analysis were used to assess the principal socioeconomic and meteorological determinants of malaria hotspots using a Generalized Estimating Equation (GEE) approach.

RESULTS

Rainfall and temperature were positively and significantly associated with malaria incidence, with a lag time of 9 and 14 weeks, respectively. Spatial analysis showed a spatial autocorrelation of malaria incidence and significant hotspots which was relatively stable throughout the study period. Furthermore, low socioeconomic status households were strongly associated with malaria hotspots (aOR = 1.21, 95% confidence interval: 1.03-1.40).

CONCLUSION

These fine-scale findings highlight a relatively stable spatio-temporal pattern of malaria risk and indicate that social and environmental factors play an important role in malaria incidence. Integrating data on these factors into existing malaria struggle tools would help in the development of sustainable bottleneck strategies adapted to the local context for malaria control.

Enteral iron supplementation, red blood cell transfusion, and risk of bronchopulmonary dysplasia in very-low-birth-weight infants

BACKGROUND

Enteral iron supplementation and RBC transfusions are routinely administered to very-low-birth-weight (VLBW) infants, although the potential risks of these exposures have not been adequately quantified. This study evaluated the association between the cumulative dose of enteral iron supplementation, total volume of RBCs transfused, and risk of bronchopulmonary dysplasia (BPD) in VLBW infants.

STUDY DESIGN AND METHODS

Retrospective, multicenter observational cohort study in Atlanta, Georgia. Cumulative supplemental enteral iron exposure and total volume of RBCs transfused were measured until the age at assessment of BPD. Multivariable generalized linear models were used to control for confounding, and the reliability of the factors was assessed in 1000 bootstrap models.

RESULTS

A total of 598 VLBW infants were studied. In multivariable analyses, a greater cumulative dose of supplemental enteral iron exposure was associated with an increased risk of BPD (adjusted relative risk per 50-mg increase, 1.07; 95% confidence interval [CI], 1.02-1.11; p = 0.002). Similarly, a greater volume of RBCs transfused was associated with a higher risk of BPD (adjusted relative risk per 20-mL increase, 1.05; 95% CI, 1.02-1.07; p < 0.001). Both factors were reliably associated with BPD (>50%). Volume of RBCs transfused was similar to gestational age in reliability as a risk factor for BPD (present in 100% of models) and was more reliable than mechanical ventilation at 1 week of age.

CONCLUSION

The cumulative dose of supplemental enteral iron exposure and total volume of RBC transfusion are both independently associated with an increased risk of BPD in VLBW infants.

Is policy 'liberalization' associated with higher odds of adolescent cannabis use? A re-analysis of data from 38 countries

BACKGROUND

Policy makers worldwide face the choice of whether to reform cannabis policy from the 'full prohibition' model. A paper by Shi et al. (2015) suggested that such 'liberalization' is significantly associated with higher odds of adolescent cannabis use.

AIM

To test the validity and reliability of Shi et al's conclusion that the HBSC data show an association between policy 'liberalization' and increased likelihood of adolescent cannabis use.

METHODS

Replication and re-analysis of the same pooled data from three waves of the Health Behaviour in School-aged Children (HBSC) survey (2001/2, 2005/6 and 2009/10). This replicates - as far as possible - the coding and analytical strategy of the Shi et al article. The re-analysis makes some improvements by: excluding a variable ('number of siblings') for which many cases have missing data; including available data from the theoretically relevant case of Sweden for the latter two waves of the HBSC survey, which Shi et al omit; and including random slopes for gender between countries as well as random intercepts for countries in the mixed effects model, as the predictive effect of gender on cannabis use varies across countries.

RESULTS

Shi et al's verbal summary of their findings is not supported by detailed interpretation of their own numerical results. Without making the suggested amendments, it is possible to find a statistically significant association between policy 'liberalization' and higher odds of some measures of adolescent cannabis use. But when these improvements are made, this association becomes statistically non-significant.

CONCLUSION

Using a larger and more theoretically relevant sample of the HBSC respondents and an improved statistical model shows that the HBSC data do not reveal a statistically significant association between policy 'liberalization' and higher odds of adolescent cannabis use.

Income-related inequality and inequity in children's health care: A longitudinal analysis using data from Brazil

The Brazilian Unified Health System was created in the late 1980s to ensure free universal access to health care and was funded by taxes and social contributions. The persistent inequity in access to health services in favour of richer individuals in Brazil has been observed in the literature. However, to the best of our knowledge, no measurement of inequality in medicine use or private health insurance (PHI) among children has been performed with longitudinal data. This paper uses inequality indices and their decompositions to analyse the income-related inequalities/inequities in children's health care in the city of Pelotas, Brazil, using longitudinal data following children from 12 to 72 months of age. Our sample with data in all waves has between 1877 and 2638 children (varying according to outcome). We seek to answer three questions: i) How does the inequality/inequity in health care evolve as children grow up? ii) What are the main factors associated with inequality in children's health care? iii) How much of the change in inequality/inequity is explained by mobility in children's health care and income mobility? We found that inequities in health care have their beginnings in early childhood but that there was a reduction in inequity at 72 months of age. Ownership of children's PHI was associated with greater pro-rich inequity in health care. The reduction in inequality/inequity was linked to mobility in the sense that initially poorer children had greater gains in health care (a greater increase in PHI ownership and a lower reduction in medicine use). Despite this improvement among the poorest, apparently, the Brazilian public health service seems to fail to ensure equity in health care use among children, with possible long-term consequences on inequalities in health.

•

The inequities in health care have their beginnings even in early childhood.

•

Income and mother's education have a strong contribution in the inequalities.

•

Private health insurance has strong contribution in inequalities of medicine use.

•

There was reduction in inequity for children's health care in Pelotas/Brazil.

•

This improvement for poorest children occurred when they reached 72 months.

Impact of preexisting mental illness on breast cancer endocrine therapy adherence

PURPOSE

Patients with estrogen receptor positive (ER+) breast cancer are often non-adherent to endocrine therapies, despite clear survival benefits. We utilized a nationally representative cancer cohort to examine the role of specific mental illnesses on endocrine therapy adherence.

METHODS

Using the SEER-Medicare database, we included 21,894 women aged 68+ at their first surgically treated stage I-IV ER+ breast cancer during 2007-2013. All had continuous fee-for-service Medicare Parts A and B for 36+ months before, 18+ months after diagnosis, and continuous Part D for 4+ months before, 18+ after diagnosis. Mental illness was defined as occurring in the 36 months prior to cancer onset. We analyzed endocrine therapy adherence, initiation, and discontinuation using longitudinal linear and Cox regression models.

RESULTS

Unipolar depression (11.0%), anxiety (9.5%), non-schizophrenia psychosis (4.6%), and dementias (4.6%) were the most prevalent diagnoses. Endocrine therapies were initiated by 80.0% of women. Among those with at least one year of use, 28.0% were non-adherent (< 0.80 adherence, mean = 0.84) and 25.7% discontinued. Patients with dementia or bipolar depression/psychotic/schizophrenia disorders had lower adjusted initiation probabilities by year one of follow-up, versus those without these diagnoses [0.74 95% CI (0.73-0.74) and 0.73 (0.72-0.73), respectively, reference 0.76 (0.76-0.77)]. Patients with substance use or anxiety disorders less frequently continued endocrine therapy for at least one year, after adjustment, [0.85 95% CI (0.85-0.86) and 0.88 (0.87-0.88), respectively, reference 0.90 (0.89-0.90)]. Patients with substance use disorders had 2.3% lower adherence rates (p < 0.001).

CONCLUSIONS

Nearly one-quarter of female Medicare beneficiaries have diagnosed mental illness preceding invasive breast cancer. Those with certain mental illnesses have modestly reduced rates of initiation, adherence, and discontinuation and this may help define patients at higher risk of treatment abandonment. Overall, endocrine therapy adherence remains suboptimal, unnecessarily worsening recurrence and mortality risk.