The viral hepatitis B care cascade: A population-based comparison of immigrant groups.

BACKGROUND AND AIMS: The global burden of viral hepatitis B is substantial, and monitoring infections across the care cascade is important for elimination efforts. There is little information on care disparities by immigration status, and we aimed to quantify disease burden among immigrant subgroups. APPROACH AND RESULTS: In this population-based, retrospective cohort study, we used linked laboratory and health administrative records to describe the HBV care cascade in five distinct stages: (1) lifetime prevalence; (2) diagnosis; (3) engagement with care; (4) treatment initiation; and (5) treatment continuation. Infections were identified based on at least one reactive antigen or nucleic acid test, and lifetime prevalence was estimated as the sum of diagnosed and estimated undiagnosed cases. Care cascades were compared between long-term residents and immigrant groups, including subgroups born in hepatitis B endemic countries. Stratified analyses and multivariable Poisson regression were used to identify drivers for cascade progression. Between January 1997 and December 2014, 2,014,470 persons were included, 50,475 with infections, of whom 30,118 were engaged with care, 11,450 initiated treatment, and 6554 continued treatment >1 year. Lifetime prevalence was estimated as 163,309 (1.34%) overall, 115,722 (3.42%) among all immigrants, and 50,876 (9.37%) among those from highly endemic countries. Compared to long-term residents, immigrants were more likely to be diagnosed (adjusted rate ratio [aRR], 4.55; 95% CI, 4.46, 4.63), engaged with care (aRR, 1.07; 95% CI, 1.04, 1.09), and initiate treatment (aRR, 1.09; 95% CI, 1.03, 1.16). CONCLUSIONS: In conclusion, immigrants fared well compared to long-term residents along the care cascade, having higher rates of diagnosis and slightly better measures in subsequent cascade stages, although intensified screening efforts and better strategies to facilitate linkage to care are still needed.

Viral hepatitis C cascade of care: A population-level comparison of immigrant and long-term residents.

BACKGROUND & AIMS: Viral hepatitis C represents a major global burden, particularly among immigrant-receiving countries such as Canada, where knowledge of disparities in hepatitis C virus among immigrant groups for micro-elimination efforts is lacking. We quantify the hepatitis C cascades of care among immigrants and long-term residents prior to the introduction of direct-acting antiviral medications. METHODS: Using laboratory and health administrative records, we described the hepatitis C virus cascades of care in terms of diagnosis, engagement with care, treatment initiation, and clearance in Ontario, Canada (1997-2014). We stratified the cascade by immigrant and long-term resident groups and identify drivers at each stage using multivariable Poisson regression. RESULTS: We included 940 245 individuals in the study with an estimated hepatitis C prevalence of 167 923 (1.4%) overall, 23 759 (0.7%) among all immigrants, and 6019 (1.1%) among immigrants from hepatitis C endemic countries. Overall there were 104 616 individuals with reactive antibody results, 73 861 tested for viral RNA, 52 388 with viral RNA detected, 50 805 genotyped, 13 159 on treatment and 3919 with evidence of viral clearance. Compared to long-term residents, immigrants showed increased nucleic-acid testing (aRR: 1.09 [95%CI: 1.08, 1.10]), treatment initiation (aRR: 1.46 [95%CI: 1.38, 1.54]), and higher clearance rates (aRR: 1.07 [95%CI: 1.03, 1.11]). CONCLUSIONS: Hepatitis C virus is more prevalent among long-term residents compared to immigrants overall, however, immigrants from endemic countries are an important subgroup to consider for future screening and linkage to care initiatives. These findings are prior to the introduction of newer medications and provide a population-based benchmark for follow-up studies and evaluation of treatment programs and surveillance activities.

Validating viral hepatitis B and C diagnosis codes: a retrospective analysis using Ontario's health administrative data.

OBJECTIVE: We aimed to determine the criterion validity of using diagnosis codes for hepatitis B virus (HBV) and hepatitis C virus (HCV) to identify infections. METHODS: Using linked laboratory and administrative data in Ontario, Canada, from January 2004 to December 2014, we validated HBV/HCV diagnosis codes against laboratory-confirmed infections. Performance measures (sensitivity, specificity, and positive predictive value) were estimated via cross-validated logistic regression and we explored variations by varying time windows from 1 to 5 years before (i.e., prognostic prediction) and after (i.e., diagnostic prediction) the date of laboratory confirmation. Subgroup analyses were performed among immigrants, males, baby boomers, and females to examine the robustness of these measures. RESULTS: A total of 1,599,023 individuals were tested for HBV and 840,924 for HCV, with a resulting 41,714 (2.7%) and 58,563 (7.0%) infections identified, respectively. HBV/HCV diagnosis codes ± 3 years of laboratory confirmation showed high specificity (99.9% HBV; 99.8% HCV), moderate positive predictive value (70.3% HBV; 85.8% HCV), and low sensitivity (12.8% HBV; 30.8% HCV). Varying the time window resulted in limited changes to performance measures. Diagnostic models consistently outperformed prognostic models. No major differences were observed among subgroups. CONCLUSION: HBV/HCV codes should not be the only source used for monitoring the population burden of these infections, due to low sensitivity and moderate positive predictive values. These results underscore the importance of ongoing laboratory and reportable disease surveillance systems for monitoring viral hepatitis in Ontario.

RéSUMé: OBJECTIF: Nous avons cherché à déterminer le critère de validité de l'utilisation des codes de diagnostic du virus de l'hépatite B (VHB) et du virus de l'hépatite C (VHC) pour identifier les infections. MéTHODES: En utilisant des données de laboratoire et administratives couplées en Ontario, au Canada, de janvier 2004 à décembre 2014, nous avons validé les codes de diagnostic du VHB/VHC contre les infections confirmées en laboratoire. Les mesures du rendement (sensibilité, spécificité et valeur prédictive positive) ont été estimées par régression logistique croisée et nous avons exploré les variations en variant les fenêtres temporelles de 1 à 5 ans avant (c.-à-d. prédiction pronostique) et après (c.-à-d. prédiction diagnostique) la date de confirmation en laboratoire. Des analyses de sous-groupes ont été effectuées auprès d'immigrants, d'hommes, de baby-boomers et de femmes pour examiner la robustesse de ces mesures. RéSULTATS: 1 599 023 individus ont été testés pour le VHB et 840 924 pour le VHC, dont 41 714 (2,7 %) et 58 563 (7,0 %) infections ont été identifiées, respectivement. Les codes de diagnostic VHB/VHC ± 3 ans de confirmation en laboratoire ont montré une spécificité élevée (99,9 % VHB; 99,8 % VHC), une valeur prédictive positive modérée (70,3 % VHB; 85,8 % VHC) et une faible sensibilité (12,8 % VHB; 30,8 % VHC). La variation de la fenêtre temporelle a entraîné des changements limités aux mesures du rendement. Les modèles diagnostiques ont constamment surpassé les modèles pronostiques. Aucune différence majeure n'a été observée entre les sous-groupes. CONCLUSION: Les codes VHB/VHC ne devraient pas être la seule source utilisée pour surveiller la charge de population de ces infections, en raison de la faible sensibilité et des valeurs prédictives positives modérées. Ces résultats soulignent l'importance des systèmes continus de surveillance des maladies à déclaration obligatoire en laboratoire pour surveiller l'hépatite virale en Ontario.

Spatial variations in ambient ultrafine particle concentrations and risk of congenital heart defects.

BACKGROUND: Cardiovascular malformations account for nearly one-third of all congenital anomalies, making these the most common type of birth defects. Little is known regarding the influence of ambient ultrafine particles (<0.1 µm) (UFPs) on their occurrence. OBJECTIVE: This population-based study examined the association between prenatal exposure to UFPs and congenital heart defects (CHDs). METHODS: A total of 158,743 singleton live births occurring in the City of Toronto, Canada between April 1st 2006 and March 31st 2012 were identified from a birth registry. Associations between exposure to ambient UFPs between the 2nd and 8th week post conception when the foetal heart begins to form and CHDs identified at birth were estimated using random-effects logistic regression models, adjusting for personal- and neighbourhood-level covariates. We also investigated multi-pollutant models accounting for co-exposures to PM2.5, NO2 and O3. RESULTS: A total of 1468 CHDs were identified. In fully adjusted models, UFP exposures during weeks 2 to 8 of pregnancy were not associated with overall CHDs (Odds Ratio (OR) per interquartile (IQR) increase = 1.02, 95% CI: 0.96-1.08). When investigating subtypes of CHDs, UFP exposures were associated with ventricular septal defects (Odds Ratio (OR) per interquartile (IQR) increase = 1.13, 95% CI: 1.03-1.33), but not with atrial septal defect (Odds Ratio (OR) per interquartile (IQR) increase = 0.89, 95% CI: 0.74-1.06). CONCLUSION: This is the first study to evaluate the association between prenatal exposure to UFPs and the risk of CHDs. UFP exposures during a critical period of embryogenesis were associated with an increased risk of ventricular septal defect.

Syndemic Factors Associated with Safer Sex Efficacy Among Northern and Indigenous Adolescents in Arctic Canada.

BACKGROUND: Syndemic approaches explore the synergistic relationships between social and health inequities. Such approaches are particularly salient for the Northwest Territories, Canada, that experiences national social (food insecurity, intimate partner violence [IPV]) and health (sexually transmitted infections [STI]) disparities. Safer sex efficacy (SSE) includes knowledge, intention, and relationship dynamics that facilitate safer sex negotiation. We examined factors associated with SSE among NWT adolescents. METHODS: We conducted a cross-sectional survey with a venue-based sample of adolescents aged 13-17 in 17 NWT communities from 2016 to 2017. Summary statistics and statistical comparisons were conducted, followed by crude and adjusted multivariable regression models to assess factors associated with SSE. RESULTS: Among participants (n = 610; mean age 14.2 years [SD 1.5]; 49.5% cisgender women, 48.9% cisgender men, 1.6% transgender persons; 73.3% Indigenous), one-quarter (n = 144; 23.6%) reported food insecurity and nearly one-fifth (n = 111; 18.2%) IPV. In adjusted analyses, among young women, food insecurity (ß - 1.89[CI - 2.98, - 0.80], p = 0.001) and IPV (ß - 1.31[CI - 2.53, - 0.09], p = 0.036) were associated with lower SSE, and currently dating was associated with increased SSE (ß 1.17[CI 0.15, 2.19], p = 0.024). Among young men, food insecurity (ß - 2.27[CI - 3.39, - 1.15], p = 0.014) was associated with reduced SSE. Among sexually active participants (n = 115), increased SSE was associated with consistent condom use among young women (ß 1.40[0.19, 2.61], p = 0.024) and men (ß 2.14[0.14, 4.14], p = 0.036). CONCLUSIONS: Food insecurity and IPV were associated with lower SSE-a protective factor associated with consistent condom use-underscoring the need to address poverty and violence to advance adolescent sexual health in the NWT.

A population-based comparison of preterm neonatal deaths (22-34 gestational weeks) in France and Ontario: a cohort study.

BACKGROUND: The management and outcomes of preterm births can vary greatly even among developed nations with the same access to medicine, technology and expertise. We aimed to compare aspects of obstetrical management and mortality for preterm infants in France and Ontario, Canada. METHODS: The Better Outcomes Registry & Network (BORN) Information System in Ontario and Épidémiologique sur les petits âges gestationnels (EPIPAGE-2) in France collected information on maternal demographics, obstetrical characteristics, obstetrical interventions and neonatal outcomes for infants born between 22 and 34 weeks gestation. We used standardized covariate definitions and extracted data from 2011 (for EPIPAGE-2) and from 2012 and 2013 (for BORN) to conduct a cohort study comparing the 2 data sets (stratified into gestational age groups of 22-26, 27-31 and 32-34 wk) using multivariable logistic regression models. RESULTS: Mothers in the BORN cohort were older (30.7 yr v. 29.6 yr) but less likely to have gestational hypertension (13.4% v. 17.9%) than those in the EPIPAGE-2 cohort. Infants from EPIPAGE-2 had lower birth weights (1.3 kg v. 1.5 kg) and were more likely to be born in an institution with level 3 care (71.9% v. 55.8%). After adjustment for these differences, there was significantly higher neonatal mortality among infants from EPIPAGE-2 in the 22-26 week gestation age group (adjusted odds ratio 2.81; 95% confidence interval 1.17 to 6.74). INTERPRETATION: Even after we adjusted for both intrinsic population differences and differences in management between Ontario and France, we found a higher rate of neonatal mortality at earlier gestational ages in France. This may be related to differences in ethical approaches and/or postnatal management and should be explored further.

Spatiotemporal Variations in Ambient Ultrafine Particles and the Incidence of Childhood Asthma.

Rationale: Little is known regarding the impact of ambient ultrafine particles (UFPs; <0.1 µm) on childhood asthma development. Objectives: To examine the association between prenatal and early postnatal life exposure to UFPs and development of childhood asthma. Methods: A total of 160,641 singleton live births occurring in the City of Toronto, Canada between April 1, 2006, and March 31, 2012, were identified from a birth registry. Associations between exposure to ambient air pollutants and childhood asthma incidence (up to age 6) were estimated using random effects Cox proportional hazards models, adjusting for personal- and neighborhood-level covariates. We investigated both single-pollutant and multipollutant models accounting for coexposures to particulate matter ≤2.5 µm in aerodynamic diameter (PM2.5) and NO2. Measurements and Main Results: We identified 27,062 children with incident asthma diagnosis during the follow-up. In adjusted models, second-trimester exposure to UFPs (hazard ratio per interquartile range increase, 1.09; 95% confidence interval, 1.06-1.12) was associated with asthma incidence. In models additionally adjusted for PM2.5 and nitrogen dioxide, UFPs exposure during the second trimester of pregnancy remained positively associated with childhood asthma incidence (hazard ratio per interquartile range increase, 1.05; 95% confidence interval, 1.01-1.09). Conclusions: This is the first study to evaluate the association between perinatal exposure to UFPs and the incidence of childhood asthma. Exposure to UFPs during a critical period of lung development was linked to the onset of asthma in children, independent of PM2.5 and NO2.

Examining the effects of an obstetrics interprofessional programme on reductions to reportable events and their related costs.

There are many ways to account for the return on investment (ROI) in healthcare: improved communication, teamwork, culture, patient satisfaction, staff satisfaction, and clinical outcomes are but a few. Some of these are easier to quantify and associate to an intervention than others. What if the outcomes listed were not just independent results, but beget one another? In 2001, the Society of Obstetricians and Gynaecologists of Canada created the Managing Obstetrical Risk Efficiently (MOREOB) programme, to improve healthcare culture and patient outcomes in obstetrics by leveraging front-line ownership. Our study provides evidence that MOREOB lowers the frequency and cost of reportable events in maternity units. We sought to review the impact of this intervention on the frequency and cost of reportable events at the insurer level of a clinically focused, three-year interprofessional culture change intervention applied to the maternity unit. We compared the impact of reportable events both in the obstetrical and in the non-obstetrical areas of the same hospitals during the same time periods. We analysed these data using an interrupted time series (ITS) design, among 34 Ontario Canada hospitals. The ITS design assessed changes in the frequency and cost of reportable events before and after the implementation of the intervention. The method was ideally suited as the various maternity units had differing programme commencement and completion dates. The frequency of reportable events showed little change during the three-year intervention. As culture change grew, the changes in behaviour and processes that impact patient outcomes took longer to accrue. A large reduction in the frequency of reportable events occurred in the following three-year (14% reduction) and six-year (25% reduction) tranches. Our results show statistically significant reductions in the frequency and costs associated with reportable events at the level of an insurer. The results also give insight as to the investment of time required to achieve a level of sustainability.

Prevalence of tuberculosis infection and disease in children referred for tuberculosis medical surveillance in Ontario: a single-cohort study.

BACKGROUND: There are few data about the utility of the Canadian tuberculosis medical surveillance system for detecting tuberculosis in children and adolescents. We sought to assess the prevalence of tuberculosis infection and disease in children and adolescents referred by the tuberculosis medical surveillance program who were evaluated at The Hospital for Sick Children (SickKids) tuberculosis program. METHODS: We retrospectively studied clinical records, radiographic findings and results of interferon-γ release assays (IGRAs) of all children less than 18 years of age referred by the tuberculosis medical surveillance program and evaluated at SickKids between November 2012 and June 2016. RESULTS: The median age of the 216 children was 10.0 years. Most were born in the Philippines (157 [72.7%]) or India (39 [18.0%]). Of the 216, 166 (76.8%) had a history of prior treatment for tuberculosis, and 34 (15.7%) were federal-sponsored refugees from settings with a high tuberculosis burden. Negative IGRA results were found in 110/130 (84.6%) of those with prior tuberculosis treatment. Thirty-one children (14.4%) had any chest radiographic abnormality, of whom 4 had changes thought to be due to tuberculosis. No child received a diagnosis of active tuberculosis at assessment or during follow-up; 3 (1.4%) were treated for latent tuberculosis infection following IGRA testing at SickKids. A positive IGRA result was associated with contact with infectious tuberculosis (odds ratio [OR] 5.97, 95% confidence interval [CI] 2.06-17.52) and older age at first clinic visit (OR 2.98, 95% CI 1.24-8.30) but not with radiographic abnormalities or history of prior tuberculosis treatment. INTERPRETATION: Most children were referred because of a history of prior treatment for tuberculosis; few had clinical or laboratory evidence of infection or prior disease. The tuberculosis medical surveillance process did not identify any children who required treatment for active disease and requires improvement.

Effect modification of perinatal exposure to air pollution and childhood asthma incidence.

Perinatal exposure to ambient air pollution has been associated with childhood asthma incidence, however, less is known regarding the potential effect modifiers in this association. We examined whether maternal and infant characteristics modified the association between perinatal exposure to air pollution and development of childhood asthma.761 172 births occurring between 2006 and 2012 were identified in the province of Ontario, Canada. Associations between exposure to ambient air pollutants and childhood asthma incidence (up to age 6) were estimated using Cox regression models.110,981 children with asthma were identified. In models adjusted for postnatal exposures, second trimester exposures to particulate matter with a diameter ≤2.5 µm (PM2.5) (Hazard Ratio (HR) per interquartile (IQR) increase=1.07, 95% CI: 1.06-1.09) and nitrogen dioxide (NO2) (HR per IQR increase=1.06, 95% CI: 1.03-1.08) were associated with childhood asthma development. Enhanced impacts were found among children born to mothers with asthma, those who smoked during pregnancy, boys, those born preterm, of low birth weight and among those born to mothers living in urban areas during pregnancy.Prenatal exposure to air pollution may have a differential impact on the risk of asthma development according to maternal and infant characteristics.

Examining Community Stability in the Face of Mass Extinction in Communities of Digital Organisms.

Digital evolution is a computer-based instantiation of Darwinian evolution in which short self-replicating computer programs compete, mutate, and evolve. It is an excellent platform for addressing topics in long-term evolution and paleobiology, such as mass extinction and recovery, with experimental evolutionary approaches. We evolved model communities with ecological interdependence among community members, which were subjected to two principal types of mass extinction: a pulse extinction that killed randomly, and a selective press extinction involving an alteration of the abiotic environment to which the communities had to adapt. These treatments were applied at two different strengths, along with unperturbed control experiments. We examined how stability in the digital communities was affected from the perspectives of division of labor, relative shift in rank abundance, and genealogical connectedness of the community's component ecotypes. Mass extinction that was due to a Strong Press treatment was most effective in producing reshaped communities that differed from the pre-treatment ones in all of the measured perspectives; weaker versions of the treatments did not generally produce significant departures from a Control treatment; and results for the Strong Pulse treatment generally fell between those extremes. The Strong Pulse treatment differed from others in that it produced a slight but detectable shift towards more generalized communities. Compared to Press treatments, Pulse treatments also showed a greater contribution from re-evolved ecological doppelgangers rather than new ecotypes. However, relatively few Control communities showed stability in any of these metrics over the whole course of the experiment, and most did not represent stable states (by some measure of stability) that were disrupted by the extinction treatments. Our results have interesting, broad qualitative parallels with findings from the paleontological record, and show the potential of digital evolution studies to illuminate many aspects of mass extinction and recovery by addressing them in a truly experimental manner.

Maternal exposure to ambient air pollution and risk of early childhood cancers: A population-based study in Ontario, Canada.

BACKGROUND: There are increasing concerns regarding the role of exposure to ambient air pollution during pregnancy in the development of early childhood cancers. OBJECTIVE: This population based study examined whether prenatal and early life (<1year of age) exposures to ambient air pollutants, including nitrogen dioxide (NO2) and particulate matter with aerodynamic diameters ≤2.5µm (PM2.5), were associated with selected common early childhood cancers in Canada. METHODS: 2,350,898 singleton live births occurring between 1988 and 2012 were identified in the province of Ontario, Canada. We assigned temporally varying satellite-derived estimates of PM2.5 and land-use regression model estimates of NO2 to maternal residences during pregnancy. Incident cases of 13 subtypes of pediatric cancers among children up to age 6 until 2013 were ascertained through administrative health data linkages. Associations of trimester-specific, overall pregnancy and first year of life exposures were evaluated using Cox proportional hazards models, adjusting for potential confounders. RESULTS: A total of 2044 childhood cancers were identified. Exposure to PM2.5, per interquartile range increase, over the entire pregnancy, and during the first trimester was associated with an increased risk of astrocytoma (hazard ratio (HR) per 3.9µg/m3=1.38 (95% CI: 1.01, 1.88) and, HR per 4.0µg/m3=1.40 (95% CI: 1.05-1.86), respectively). We also found a positive association between first trimester NO2 and acute lymphoblastic leukemia (ALL) (HR=1.20 (95% CI: 1.02-1.41) per IQR (13.3ppb)). CONCLUSIONS: In this population-based study in the largest province of Canada, results suggest an association between exposure to ambient air pollution during pregnancy, especially in the first trimester and an increased risk of astrocytoma and ALL. Further studies are required to replicate the findings of this study with adjustment for important individual-level confounders.

Maternal Exposure to Aeroallergens and the Risk of Early Delivery.

BACKGROUND: Daily changes in aeroallergens during pregnancy could trigger early labor, but few investigations have evaluated this issue. This study aimed to investigate the association between exposure to aeroallergens during the week preceding birth and the risk of early delivery among preterm and term pregnancies. METHODS: We identified data on 225,234 singleton births that occurred in six large cities in the province of Ontario, Canada, from 2004 to 2011 (April to October) from a birth registry. We obtained daily counts of pollen grains and fungal spores from fixed-site monitoring stations in each city and assigned them to pregnancy period of each birth. Associations between exposure to aeroallergens in the preceding week and risk of delivery among preterm (<37 gestational weeks), early-term (37-38 weeks), and full-term (≥39 weeks) pregnancies were evaluated with Cox regression models, adjusting for maternal characteristics, meteorologic parameters, and air pollution concentrations, and pooled across the six cities. RESULTS: The risk of delivery increased by 3% per interquartile range width (IQRw = 22.1 grains/m) increase in weed pollen the day before birth among early-term (hazard ratio [HR] = 1.03; 95% confidence interval [CI]: 1.01, 1.05) and full-term pregnancies (HR = 1.03; 95% CI: 1.01, 1.04). Exposure to fungal spores cumulated over 0 to 2 lagged days was associated with increased risk of delivery among full-term pregnancies only (HR = 1.07; 95% CI: 1.01, 1.12). We observed no associations among preterm deliveries. CONCLUSIONS: Increasing concentrations of ambient weed pollen and fungal spores may be associated with earlier delivery among term births.

Ambient air pollution and adverse birth outcomes: Differences by maternal comorbidities.

BACKGROUND: Prenatal exposure to ambient air pollution has been associated with adverse birth outcomes, but the potential modifying effect of maternal comorbidities remains understudied. Our objective was to investigate whether associations between prenatal air pollution exposures and birth outcomes differ by maternal comorbidities. METHODS: A total of 818,400 singleton live births were identified in the province of Ontario, Canada from 2005 to 2012. We assigned exposures to fine particulate matter (PM2.5), nitrogen dioxide (NO2) and ozone (O3) to maternal residences during pregnancy. We evaluated potential effect modification by maternal comorbidities (i.e. asthma, hypertension, pre-existing diabetes mellitus, heart disease, gestational diabetes and preeclampsia) on the associations between prenatal air pollution and preterm birth, term low birth weight and small for gestational age. RESULTS: Interquartile range (IQR) increases in PM2.5 (2µg/m(3)), NO2 (9ppb) and O3 (5ppb) over the entire pregnancy were associated with a 4% (95% CI: 2.4-5.6%), 8.4% (95% CI: 5.5-10.3%) and 2% (95% CI: 0.5-4.1%) increase in the odds of preterm birth, respectively. Increases of 10.6% (95% CI: 0.2-2.1%) and 23.8% (95% CI: 5.5-44.8%) in the odds of preterm birth were observed among women with pre-existing diabetes while the increases were of 3.8% (95% CI: 2.2-5.4%) and 6.5% (95% CI: 3.7-8.4%) among women without this condition for pregnancy exposure to PM2.5 and NO2, respectively (Pint<0.01). The increase in the odds of preterm birth for exposure to PM2.5 during pregnancy was higher among women with preeclampsia (8.3%, 95% CI: 0.8-16.4%) than among women without (3.6%, 95% CI: 1.8-5.3%) (Pint=0.04). A stronger increase in the odds of preterm birth was found for exposure to O3 during pregnancy among asthmatic women (12.0%, 95% CI: 3.5-21.1%) compared to non-asthmatic women (2.0%, 95% CI: 0.1-3.5%) (Pint<0.01). We did not find statistically significant effect modification for the other outcomes investigated. CONCLUSIONS: Findings of this study suggest that associations of ambient air pollution with preterm birth are stronger among women with pre-existing diabetes, asthma, and preeclampsia.

Incidence of Hospitalization for Respiratory Syncytial Virus Infection amongst Children in Ontario, Canada: A Population-Based Study Using Validated Health Administrative Data.

IMPORTANCE: RSV is a common illness among young children that causes significant morbidity and health care costs. OBJECTIVE: Routinely collected health administrative data can be used to track disease incidence, explore risk factors and conduct health services research. Due to potential for misclassification bias, the accuracy of data-elements should be validated prior to use. The objectives of this study were to validate an algorithm to accurately identify pediatric cases of hospitalized respiratory syncytial virus (RSV) from within Ontario's health administrative data, estimate annual incidence of hospitalization due to RSV and report the prevalence of major risk factors within hospitalized patients. STUDY DESIGN AND SETTING: A retrospective chart review was performed to establish a reference-standard cohort of children from the Ottawa region admitted to the Children's Hospital of Eastern Ontario (CHEO) for RSV-related disease in 2010 and 2011. Chart review data was linked to Ontario's administrative data and used to evaluate the diagnostic accuracy of algorithms of RSV-related ICD-10 codes within provincial hospitalization and emergency department databases. Age- and sex-standardized incidence was calculated over time, with trends in incidence assessed using Poisson regression. RESULTS: From a total of 1411 admissions, chart review identified 327 children hospitalized for laboratory confirmed RSV-related disease. Following linkage to administrative data and restriction to first admissions, there were 289 RSV patients in the reference-standard cohort. The best algorithm, based on hospitalization data, resulted in sensitivity 97.9% (95%CI: 95.5-99.2%), specificity 99.6% (95%CI: 98.2-99.8%), PPV 96.9% (95%CI: 94.2-98.6%), NPV 99.4% (95%CI: 99.4-99.9%). Incidence of hospitalized RSV in Ontario from 2005-2012 was 10.2 per 1000 children under 1 year and 4.8 per 1000 children aged 1 to 3 years. During the surveillance period, there was no identifiable increasing or decreasing linear trend in the incidence of hospitalized RSV, hospital length of stay and PICU admission rates. Among the Ontario RSV cohort, 16.3% had one or more major risk factors, with a decreasing trend observed over time. CONCLUSION: Children hospitalized for RSV-related disease can be accurately identified within population-based health administrative data. RSV is a major public health concern and incidence has not changed over time, suggesting a lack of progress in prevention.

Association Between Chronic Aspiration and Chronic Airway Infection with Pseudomonas aeruginosa and Other Gram-Negative Bacteria in Children with Cerebral Palsy.

PURPOSE: Children with cerebral palsy (CP) are at an increased risk for aspiration, and subsequent pneumonia or pneumonitis. Pneumonia is a common cause of hospital admission, intensive care unit (ICU) admission, and death in patients with CP, and may disproportionately contribute to mortality. The role of respiratory microflora is unknown. This study examined the relationship between respiratory infections with Gram-negative bacteria (GNB), particularly Pseudomonas aeruginosa, and the frequency/severity of pneumonia hospitalization. METHODS: Retrospective chart review of 69 patients with CP and hospitalization for pneumonia. Eligible patients required hospitalization for bacterial pneumonia, at least one respiratory culture, and fulfillment of Bax definition of CP. Group assignment was based on respiratory culture. Charts were analyzed for comorbid illness, hospitalization demographics, and disease severity. RESULTS: Children with isolation of P. aeruginosa or other GNB had increased frequency of ICU admission (77.4, 65.1, vs. 26.9 %, respectively, p < 0.01), intubation (45.2, 39.5 vs. 11.5 %, p = 0.02, p = 0.03 respectively), and large pleural effusions (37.5, vs. 0 %) than children without GNB. Children with isolation of GNB had more prolonged hospitalizations and were more likely to have multiple hospitalizations than those without GNB. CONCLUSION: Colonization with P. aeruginosa and other Gram-negative organisms in children with CP is associated with increased morbidity, prolonged hospitalization, and severity of pneumonia including need for PICU admission and intervention. Further research is required to determine causality, the role of antimicrobials active against Gram negative in pneumonia treatment, and the role of GNB eradication therapy in children with CP.

A Randomized Controlled Trial of Innovative Postpartum Care Model for Mother-Baby Dyads.

OBJECTIVE: To evaluate the efficacy, safety, and maternal satisfaction of a newly established integrative postpartum community-based clinic providing comprehensive support for mothers during the first month after discharge from the hospital. Our primary interests were breastfeeding rates, readmission and patient satisfaction. METHODS: A randomized controlled trial was conducted in Ottawa, Canada, where 472 mothers were randomized via a 1:2 ratio to either receive standard of care (n = 157) or to attend the postpartum breastfeeding clinic (n = 315). Outcome data were captured through questionnaires completed by the participants at 2, 4, 12 and 24 weeks postpartum. Unadjusted and adjusted logistic regression models were conducted to determine the effect of the intervention on exclusive breastfeeding at 12 weeks (primary outcome). Secondary outcomes included breastfeeding rate at 2, 4 and 24 weeks, breastfeeding self-efficacy scale, readmission rate, and satisfaction score. RESULTS: More mothers in the intervention group (n = 195, 66.1%) were exclusively breastfeeding at 12 weeks compared to mothers in the control group (n = 81, 60.5%), however no statistically significant difference was observed (OR = 1.28; 95% CI:0.84-1.95)). The rate of emergency room visits at 2 weeks for the intervention group was 11.4% compared to the standard of care group (15.2%) (OR = 0.69; 95% CI: 0.39-1.23). The intervention group was significantly more satisfied with the overall care they received for breastfeeding compared to the control group (OR = 1.96; 95% CI: 3.50-6.88)). CONCLUSION: This new model of care did not significantly increase exclusive breastfeeding at 12 weeks. However, there were clinically meaningful improvements in the rate of postnatal problems and satisfaction that support this new service delivery model for postpartum care. A community-based multidisciplinary postpartum clinic is feasible to implement and can provide appropriate and highly satisfactory care to mother-baby dyads. This model of care may be more beneficial in a population that is not already predisposed to breastfeed. TRIAL REGISTRATION: ClinicalTrials.gov NCT02043119.

The Feasibility, Accuracy, and Impact of Xpert MTB/RIF Testing in a Remote Aboriginal Community in Canada.

BACKGROUND: Xpert MTB/RIF testing for Mycobacterium tuberculosis and rifampin resistance is being used extensively in countries with a high burden of TB. However, recent evidence suggests that it may not have the same accuracy or impact in high-income, low-burden TB countries. METHODS: A prospective, pragmatic study was done between March 2012 and March 2014 to determine the feasibility, accuracy, and impact on TB disease management provided by the Xpert test in a remote, medically underserved, predominantly Inuit population in Iqaluit, Nunavut, Canada. RESULTS: A total of 453 Xpert tests were run on sputum samples from 344 patients with suspected TB. Twenty-seven patients were identified as having active TB disease by culture. There were no cases of drug-resistant TB. Using culture as the gold standard, one Xpert test compared with one, two, or three sputum samples cultured per patient had a sensitivity of 85% (95% CI, 66%-95%) and a specificity of 99% (95% CI, 97%-100%) for detection of M tuberculosis. The indeterminate rate was 4.4% of all samples run. Treatment initiation was significantly shortened using Xpert vs the national standard of three smears (1.8 days vs 7.7 days, P < .007) and particularly shorter in smear-negative, culture-positive cases (1.8 days vs 37.1 days, P < .008). CONCLUSIONS: In a predominantly Inuit population in a remote region of Canada where the burden of TB is high and no TB testing facilities are available, onsite Xpert testing was feasible and accurate and shortened the time to TB treatment initiation.

Antimicrobial stewardship in pediatrics: focusing on the challenges clinicians face.

BACKGROUND: Antimicrobial use is very common in hospitalized children. An assessment of clinician's prevailing knowledge and clinical approach to prescribing antimicrobials is helpful in order to develop the best strategies for successful stewardship programs. The objectives of the study were to determine fundamental knowledge of principles, approach to antimicrobial use through the clinical vignettes and to identify perceived challenges in decreasing antimicrobial use. METHODS: A questionnaire was developed by subject matter experts and pretested to ensure validity. Using a cross-sectional prospective design, the questionnaire was completed anonymously by staff and trainee physicians at a single tertiary care pediatric hospital between late November 2011 and February 2012. RESULTS: Of 159 eligible physicians, 86 (54.1%) responded, of which 77 (46 staff and 31 trainees) reported regularly prescribing antimicrobials. The majority of physicians had modest knowledge of factors that would increase risk of resistance however, less than 20% had correct knowledge of local resistance patterns for common bacteria. Almost half of physicians correctly answered the clinical vignettes. Over half of trainees and one third of staff relied most on online manuals for information regarding antimicrobials to assist prescription decision-making. Overall, physicians perceived that discontinuing empiric antimicrobials was the most difficult to achieve to decrease antibiotic use. CONCLUSIONS: Our results highlight several challenges that pediatric practioners face with respect to knowledge and approach to antimicrobial prescribing. Pediatric stewardship programs could in this setting focus on discontinuing antimicrobials appropriately and promoting local antibiograms in the proper clinical setting to decrease overall use of antimicrobials.