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Background: Children's movement behaviors have been affected by the COVID-19 pandemic; however, little is known regarding movement behavior patterns over time by government-issued lockdowns. Our primary objective was to evaluate how children's movement behaviors changed by stages of lockdown/reopening in Ontario, Canada, from 2020 to 2021. Methods: A longitudinal cohort study with repeated measures of exposure and outcomes was conducted. The exposure variables were dates from before and during COVID-19 when child movement behavior questionnaires were completed. Lockdown/reopening dates were included as knot locations in the spline model. The outcomes were daily screen, physical activity, outdoor, and sleep time. Results: A total of 589 children with 4805 observations were included (53.1% boys, 5.9 [2.6] y). On average, screen time increased during the first and second lockdowns and decreased during the second reopening. Physical activity and outdoor time increased during the first lockdown, decreased during the first reopening, and increased during the second reopening. Younger children (<5 y) had greater increases in screen time and lower increases in physical activity and outdoor time than older children (≥5 y). Conclusions: Policy makers should consider the impact of lockdowns on child movement behaviors, especially in younger children. [ABSTRACT FROM AUTHOR]

Birthweight has been associated with diabetes in a reverse J-shape (highest risk at low birthweight and moderately high risk at high birthweight) and inversely associated with hypertension in adulthood with inconsistent evidence for cardiovascular disease. There is a lack of population-based studies examining the incidence of cardiometabolic outcomes in young adults born with low and high birthweights. To evaluate the association between birthweight and diabetes, hypertension, and ischemic heart disease (IHD) in young adulthood, we conducted a retrospective cohort study of 874,904 singletons born in Ontario, Canada, from 1994 to 2002, identified from population-based health administrative data. Separate Cox regression models examined birthweight in association with diabetes, hypertension, and IHD adjusting for confounders. Among adults 18–26 years, the diabetes incidence rate was 18.15 per 100,000 person-years, hypertension was 15.80 per 100,000 person-years, and IHD was 1.85 per 100,000 person-years. Adjusted hazard ratios (AHR) for the hazard of diabetes with low (<2500g) and high (>4000g), compared with normal (2500–4000g) birthweight, were 1.46 (95% CI 1.28, 1.68) and 1.09 (0.99, 1.21), respectively. AHR for hypertension with low and high birthweight were 1.34 (1.15, 1.56) and 0.86 (0.77, 0.97), respectively. AHR for IHD with low and high birthweight were 1.28 (0.80, 2.05) and 0.97 (0.71, 1.33), respectively. Overall, birthweight was associated with diabetes in young adults in a reverse J-shape and inversely with hypertension. There was insufficient evidence of an association with IHD. Further evidence is needed to understand the causal mechanisms between birthweight and cardiometabolic diseases in young adults. [ABSTRACT FROM AUTHOR]

Background: Evidence suggests that accelerated postnatal growth in children is detrimental for adult cardiovascular health. It is unclear whether children born late preterm (34–36 weeks) compared to full term (≥ 39 weeks), have different growth trajectories. Our objective was to evaluate the association between gestational age groups and growth trajectories of children born between 2006–2014 and followed to 2021 in Ontario, Canada. Methods: We conducted a retrospective cohort study of children from singleton births in TARGet Kids! primary care network with repeated measures of weight and height/length from birth to 14 years, who were linked to health administrative databases. Piecewise linear mixed models were used to model weight (kg/month) and height (cm/month) trajectories with knots at 3, 12, and 84 months. Analyses were conducted based on chronological age. Results: There were 4423 children included with a mean of 11 weight and height measures per child. The mean age at the last visit was 5.9 years (Standard Deviation: 3.1). Generally, the more preterm, the lower the mean value of weight and height until early adolescence. Differences in mean weight and height for very/moderate preterm and late preterm compared to full term were evident until 12 months of age. Weight trajectories were similar between children born late preterm and full term with small differences from 84–168 months (mean difference (MD) -0.04 kg/month, 95% CI -0.06, -0.03). Children born late preterm had faster height gain from 0–3 months (MD 0.70 cm/month, 95% CI 0.42, 0.97) and 3–12 months (MD 0.17 cm/month, 95% CI 0.11, 0.22). Conclusions: Compared to full term, children born late preterm had lower average weight and height from birth to 14 years, had a slightly slower rate of weight gain after 84 months and a faster rate of height gain from 0–12 months. Follow-up is needed to determine if growth differences are associated with long-term disease risk. [ABSTRACT FROM AUTHOR]

Background: Uptake of the SARS-CoV-2 vaccine for children aged 5–11 years has been lower than anticipated in Canada. Although research has explored parental intentions toward SARS-CoV-2 vaccination for children, parental decisions regarding vaccinations have not been studied in-depth. We sought to explore reasons why parents chose to vaccinate or not vaccinate their children against SARS-CoV-2 to better understand their decisions. Methods: We conducted a qualitative study involving in-depth individual interviews with a purposive sample of parents in the Greater Toronto Area, Ontario, Canada. We conducted interviews via telephone or video call from February to April 2022 and analyzed the data using reflexive thematic analysis. Results: We interviewed 20 parents. We found that parental attitudes toward SARS-CoV-2 vaccinations for their children represented a complex continuum of concern. We identified 4 cross-cutting themes: the newness of SARS-CoV-2 vaccines and the evidence supporting their use; the perceived politicization of guidance for SARS-CoV-2 vaccination; the social pressure surrounding SARS-CoV-2 vaccinations; and the weighing of individual versus collective benefits of vaccination. Parents found making a decision about vaccinating their child challenging and expressed difficulty sourcing and evaluating evidence, determining the trustworthiness of guidance, and balancing their own conceptions of health care decisions with societal expectations and political messaging. Interpretation: Parents' experiences making decisions regarding SARS-CoV-2 vaccination for their children were complex, even for those who were supportive of SARS-CoV-2 vaccinations. These findings provide some explanation for the current patterns of uptake of SARS-CoV-2 vaccination among children in Canada; health care providers and public health authorities can consider these insights when planning future vaccine rollouts. [ABSTRACT FROM AUTHOR]

Cow's milk is consumed by most North American children, yet the relationships between the volume and fat content of cow's milk consumed and childhood fracture risk are unclear. Our primary objectives in this study were to evaluate whether the volume or fat content of cow's milk consumed at 1–3 years of age was associated with the risk of fracture between 3 and 10 years of age. This was a prospective cohort study of 2,466 children enrolled in Toronto, Ontario, Canada, between 2008 and 2016. The primary exposure was volume of cow's milk consumed between the ages of 1 and 3 years, and the secondary exposure was average percentage of milk fat consumed by each child during the same period. The primary outcome was a parental report of child fracture at ages 3–10 years. In the primary and secondary adjusted analyses, no association between milk volume and fracture risk (adjusted relative risk = 1.04, 95% confidence interval: 0.87, 1.26) or between milk-fat content and fracture risk (adjusted relative risk = 1.05, 95% confidence interval: 0.84, 1.31) was observed. In this study, we did not identify a protective association of early childhood cow's milk volume or fat consumption with fracture risk in later childhood. Future prospective research is needed to understand whether cow's milk is beneficial for fracture prevention through the life course. [ABSTRACT FROM AUTHOR]

Background: Little is known about nutrition outcomes in preschoolers associated with breastfeeding duration beyond 12 mo of age. Objective: The aim was to examine the association between total breastfeeding duration and nutrition outcomes at 3 to 5 y of age. Design: A cross-sectional study in healthy children, ages 3-5 y, recruited from 9 primary care practices in Toronto was conducted through the TARGet Kids! (The Applied Research Group for Kids) research network. Parents completed standardized surveys, including the Nutrition Screening for Every Preschooler (NutriSTEP) used to assess nutrition risk. Results: A total of 2987 children were included. Ninety-two percent of children were breastfed, and the mean ± SD breastfeeding duration was 11.4 ± 8.4 mo. The prevalence of nutrition risk (score >20) was 17.0%. We examined breastfeeding duration as a continuous variable.With the use of restricted cubic spline modeling, we confirmed a nonlinear relation between breastfeeding duration and NutriSTEP score, dietary intake and eating behavior subscores, and sugar-sweetened beverage and sweet-savory snack consumption. Segmented linear regression was used to examine this nonlinear relation in a piecewise approach. We found a decreasing trend in NutriSTEP score for children who were breastfed for 0-6 mo (β = -0.14; 95% CI: -0.29, 0.004), a significant decrease in NutriSTEP score for children breastfed for 6-12 mo (β = -0.20; 95% CI: -0.33, -0.07), and no significant change after 12 mo (β = 0.09; 95% CI: -0.07, 0.24) and beyond. The mean ± SD NutriSTEP scores were 17.1 ± 7.4 for no breastfeeding, 15.9 ± 6.5 for breastfeeding >0-6 mo, 13.9 ± 6.2 for >6-12 mo, 13.7 ± 6.3 for >12-18 mo, 14.6 ± 6.7 for >18-24 mo, and 14.3 ± 6.8 for >24-36 mo. Conclusions: Breastfeeding for ≤12 mo was associated with decreased nutrition risk and healthier eating behaviors and dietary intake at 3-5 y of age. We found insufficient evidence of additional benefit for breastfeeding beyond 12 mo of age. [ABSTRACT FROM AUTHOR]

Objectives: To identify the unanswered research questions in paediatric preventive care that are most important to parents and clinicians, and to explore how questions from parents and clinicians may differ.Design: Iterative mixed methods research priority setting process.Setting: Toronto, Ontario, Canada.Participants: Parents of children aged 0-5 years enrolled in a research network in Toronto, and clinicians practising in Toronto, Ontario, Canada.Interventions: Informed by the James Lind Alliance's methodology, an online questionnaire collected unanswered research questions in paediatric preventive care from study participants. Similar submissions were combined and ranked. A consensus workshop attended by 28 parents and clinicians considered the most highly ranked submissions and used the nominal group technique to select the 10 most important unanswered research questions.Results: Forty-two clinicians and 115 parents submitted 255 and 791 research questions, respectively, which were combined into 79 indicative questions. Most submissions were about nutrition, illness prevention, parenting and behaviour management. Parents were more likely to ask questions about screen time (49 parents vs 8 clinicians, p<0.05) and environmental toxins (18 parents vs 0 clinicians, p<0.05). The top 10 unanswered questions identified at the workshop related to mental health, parental stress, physical activity, obesity, childhood development, behaviour management and screen time.Conclusion: The top 10 most important unanswered research questions in paediatric preventive care from the perspective of parents and clinicians were identified. These research priorities may be important in advancing preventive healthcare for children. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the association of vitamin D intake and serum levels with fracture risk in children under 6 years of age. A case-control study was conducted in Toronto, Ontario, Canada. Cases were recruited from the fracture clinic at the Hospital for Sick Children, and matched controls were obtained from the TARGet Kids! primary-care research network. Controls were matched to cases on age, sex, height, and season. Fracture risk was estimated from conditional logistic regression, with adjustment for skin type, fracture history, waist circumference, outdoor free play, neighborhood income, soda consumption, and child's birth weight. A total of 206 cases were recruited during May 2009--April 2013 and matched to 343 controls. Serum 25-hydroxyvitamin D concentration (per 10-nmol/L increment: adjusted odds ratio (aOR) = 0.95, 95% confidence interval (CI): 0.88, 1.03) and intake of cow's milk (<2 cups/day vs. 2 cups/day: aOR = 0.95 (95% CI: 0.60, 1.52); >2 cups/day vs. 2 cups/day: aOR = 1.39 (95% CI: 0.85, 2.23)) were not significantly associated with reduced odds of fracture. A statistically significant association was observed between child use of vitamin D supplements and decreased odds of fracture (yes vs. no: aOR = 0.42, 95% CI: 0.25,0.69). Vitamin D supplementation, but not serum 25-hydroxyvitamin D level or milk intake, was associated with reduced fracture risk among these healthy young children. [ABSTRACT FROM AUTHOR]

Background: Fortified cow milk is a material contributor of vitamin D and dietary fat in children. Recommendations for children >2 y of age advise reduced milk-fat consumption to reduce childhood obesity, yet the relation between lower milk fat, vitamin D stores, and body mass index (BMI) is unclear. Objectives: The primary objective was to explore the association between milk-fat percentage and both BMI z score (zBMI) and venous 25-hydroxyvitamin D [25(OH)D]; the secondary objective was to assess whether milk volume consumed modified this relation. Design: This was a cross-sectional analysis. Healthy urban children aged 12-72 mo were recruited from 9 primary health care practices within The Applied Research Group for Kids (TARGet Kids!) research group in Toronto, Canada. We used adjusted bivariate linear regression to examine the relation between milk-fat percentage and child 25(OH)D and zBMI concurrently. Effect modification by milk volume consumed on the evaluated relations was explored with the use of an interaction term in the statistical model. Results: Among the 2745 included children there was a positive association between milk-fat percentage and 25(OH)D (P = 0.006) and a negative association between milk-fat percentage and zBMI (P < 0.0001). Participants who drank whole milk had a 5.4-nmol/L (95% CI: 4.32, 6.54) higher median 25(OH)D concentration and a 0.72 lower (95% CI: 0.68, 0.76) zBMI score than children who drank 1% milk. Milk volume consumed modified the effect of milk-fat percentage on 25(OH)D (P = 0.003) but not on zBMI (P = 0.77). Conclusions: Whole milk consumption among healthy young children was associated with higher vitamin D stores and lower BMI. Longitudinal and interventional studies are needed to confirm these findings. TARGet Kids! was registered at clinicaltrials.gov as NCT01869530. [ABSTRACT FROM AUTHOR]

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Background: The OptEC trial aims to evaluate the effectiveness of oral iron in young children with non-anemic iron deficiency (NAID). The initial sample size calculated for the OptEC trial ranged from 112-198 subjects. Given the uncertainty regarding the parameters used to calculate the sample, an internal pilot study was conducted. The objectives of this internal pilot study were to obtain reliable estimate of parameters (standard deviation and design factor) to recalculate the sample size and to assess the adherence rate and reasons for non-adherence in children enrolled in the pilot study.Methods: The first 30 subjects enrolled into the OptEC trial constituted the internal pilot study. The primary outcome of the OptEC trial is the Early Learning Composite (ELC). For estimation of the SD of the ELC, descriptive statistics of the 4 month follow-up ELC scores were assessed within each intervention group. The observed SD within each group was then pooled to obtain an estimated SD (S2) of the ELC. Correlation (ρ) between the ELC measured at baseline and follow-up was assessed. Recalculation of the sample size was performed using analysis of covariance (ANCOVA) method which uses the design factor (1- ρ(2)). Adherence rate was calculated using a parent reported rate of missed doses of the study intervention.Conclusion: The new estimate of the SD of the ELC was found to be 17.40 (S2). The design factor was (1- ρ2) = 0.21. Using a significance level of 5%, power of 80%, S2 = 17.40 and effect estimate (Δ) ranging from 6-8 points, the new sample size based on ANCOVA method ranged from 32-56 subjects (16-28 per group). Adherence ranged between 14% and 100% with 44% of the children having an adherence rate ≥ 86%. Information generated from our internal pilot study was used to update the design of the full and definitive trial, including recalculation of sample size, determination of the adequacy of adherence, and application of strategies to improve adherence.Trial Registration: ClinicalTrials.gov Identifier: NCT01481766 (date of registration: November 22, 2011). [ABSTRACT FROM AUTHOR]

Abstract: Objective: To determine whether safety warnings issued by health regulatory agencies regarding desmopressin treatment influenced treatment rates among children. Patient population and methods: We conducted a time-series analysis using health administrative data from Ontario, Canada, between January 1, 2003 and March 31, 2010. We examined desmopressin prescribing rates among children (<13 years) and investigated the impact of a United States Food and Drug Administration warning (December 2007) and a subsequent Health Canada warning (July 2008) on these rates. A secondary analysis stratified rates according to route of administration. Results: On average, quarterly desmopressin treatment rates were 29.8% lower following the two warnings (4.7 per 1000 population) compared with the period prior to warnings being issued (6.7 per 1000 population). Structural break analyses identified a significant decrease in overall desmopressin prescribing rates in Q3 2008, with the 95% confidence interval (CI) spanning both safety warnings (Q4 2007 to Q1 2009). A secondary analysis of prescribing rates for oral formulations found consistent results (structural break Q4 2008, 95% CI Q2 2007 to Q2 2009). The average quarterly prescribing rate of intranasal formulations declined by 73.1% following the warnings compared with the period preceding the warnings. Conclusion: Safety warnings issued by regulatory agencies dramatically influenced desmopressin use among Ontario’s children. [Copyright &y& Elsevier]

OBJECTIVES: To determine the agreement between weight-for-length and BMI-for-age in children 0 to <2 years by using research-collected data, examine factors that may affect agreement, and determine if agreement differs between research- and routinely collected data. METHODS: Cross-sectional data on healthy, term-born children (n = 1632) aged 0 to <2 years attending the TARGet Kids! practice-based research network in Toronto, Canada (December 2008-October 2014) were collected. Multiple visits for each child were included. Length (cm) and weight (kg) measurements were obtained by trained research assistants during research visits, and by nonresearch staff during all other visits. BMI-for-age z-scores were compared with weight-for-length z-scores (the criterion measure). RESULTS: The correlation between weight-for-length and BMI-for-age was strong (r = 0.986, P < .0001) and Bland-Altman plots revealed good agreement (difference = -0.08, SD = 0.20, P = .91). A small proportion (6.3%) of observations were misclassified and most misclassifications occurred near the percentile cutoffs. There were no differences by age and sex. Agreement was similar between research- and routinely collected data (r = 0.99, P < .001; mean difference -0.84, SD = 0.20, P = .67). CONCLUSIONS: Weight-for-length and BMI-for-age demonstrated high agreement with low misclassification. BMI-for-age may be an appropriate indicator of growth in the first 2 years of life and has the potential to be used from birth to adulthood. Additional investigation is needed to determine if BMI-for-age in children <2 years is associated with future health outcomes. [ABSTRACT FROM AUTHOR]

Objectives: Parents' decisions to vaccinate their children against COVID-19 are complex and often informed by discussions with primary care physicians. However, little is known about physicians' perspectives on COVID-19 vaccinations for children or their experiences counselling parents in their decision-making. We explored physicians' experiences providing COVID-19 vaccination recommendations to parents and their reflections on the contextual factors that shaped these experiences., Design: We conducted an interpretive qualitative study using in-depth interviews. We analyzed the data using reflexive thematic analysis and a socioecological framework., Setting: This study involved primary care practices associated with The Applied Research Group for Kids (TARGet Kids!) primary care research network in the Greater Toronto Area, Ontario, Canada., Participants: Participants were 10 primary care physicians, including family physicians, paediatricians and paediatric subspecialists., Results: Participants discussed elements at the individual level (their identity, role, and knowledge), the interpersonal level (their relationships with families, responsiveness to parents' concerns, and efforts to build trust) and structural level (contextual factors related to the evolving COVID-19 climate, health system pandemic response, and constraints on care delivery) that influenced their experiences providing recommendations to parents. Our findings illustrated that physicians' interactions with families were shaped by a confluence of their own perspectives, their responses to parents' perspectives, and the evolving landscape of the broader pandemic., Conclusions: Our study underscores the social and relational nature of vaccination decision-making and highlights the multiple influences on primary care physicians' experiences providing COVID-19 vaccination recommendations to parents. Our findings offer suggestions for future COVID-19 vaccination programmes for children. Delivery of new COVID-19 vaccinations for children may be well suited within primary care offices, where trusting relationships are established, but physicians need support in staying knowledgeable about emerging information, communicating available evidence to parents to inform their decision-making and dedicating time for vaccination counselling., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To investigate the regular use of xylitol, compared with sorbitol, to prevent acute otitis media (AOM), upper respiratory tract infections (URTIs) and dental caries., Design: Blinded randomised controlled trial with a 6-month study period., Setting: Enrolment took place at 11 primary care practices in Ontario, Canada., Patients: Children aged 1-5 years who did not use xylitol or sorbitol at enrolment., Interventions: Children were randomly assigned to use a placebo syrup with sorbitol or xylitol syrup two times per day for 6 months., Main Outcome Measures: Primary outcome was the number of clinician-diagnosed AOM episodes over 6 months. Secondary outcomes were caregiver-reported URTIs and dental caries., Results: Among the 250 randomised children, the mean (SD) age was 38±14 months and there were 124 girls (50%). There were three clinician-diagnosed AOM episodes in the 125 placebo group participants and six in the 125 xylitol group participants (OR 2.04; 95% CI 0.43, 12.92; p=0.50). There was no difference in number of caregiver-reported URTI episodes (rate ratio (RR) 0.88; 95% CI 0.70, 1.11) between the placebo (4.2 per participant over 6 months; 95% CI 3.6, 5.0) and xylitol (3.7; 95% CI 3.2, 4.4) groups. Dental caries were reported for four participants in the placebo group and two in the xylitol group (OR 0.42; 95% CI 0.04, 3.05; p=0.42). In a post-hoc analysis of URTIs during the COVID-19 pandemic, the rate among the 59 participants receiving placebo was 2.3 per participant over 6 months (95% CI 1.8, 3.0) and for the 55 receiving xylitol, 1.3 over 6 months (95% CI 0.92, 1.82; RR 0.56; 95% CI 0.36, 0.87). The most common adverse event was diarrhoea (28% with placebo; 34% with xylitol)., Conclusions: Regular use of xylitol did not prevent AOM, URTIs or dental caries in a trial with limited statistical power. A post-hoc analysis indicated that URTIs were less common with xylitol exposure during the COVID-19 pandemic, but this finding could be spurious., Trial Registration Number: NCT03055091., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The Developmental Origins of Health and Disease (DOHaD) paradigm emphasizes the significance of early life factors for the prevention of chronic health conditions, like type 2 diabetes (T2DM) and obesity, which disproportionately affect First Nations communities in Canada. Despite increasing DOHaD research related to maternal health during pregnancy, early childhood growth patterns, and infant feeding practices with many populations, data from First Nations communities in Canada are limited. In partnership with Sandy Lake First Nation, the aims of this project were to characterize birthweights and growth patterns of First Nations infants/children over the first 6 years of life and to study the impact of maternal and infant social and behavioral factors on birthweight and growth trajectories., Methods: We recruited 194 families through community announcements and clinic visits. Infant/child length/height and weight were measured at 1 and 2 weeks; 1, 2, 6, 12, and 18 months; and 2, 3, 4, 5 and 6 years. Maternal and infant/child questionnaires captured data about health, nutrition, and social support. Weight-for-Age z-score (WAZ), Height-for-Age z-score (HAZ), and BMI-for-Age z-score (BAZ) were calculated using WHO reference standards and trajectories were analyzed using generalized additive models. Generalized estimating equations and logistic regression were used to determine associations between exposures and outcomes., Results: WAZ and BAZ were above the WHO mean and increased with age until age 6 years. Generalized estimating equations indicated that WAZ was positively associated with age (0.152; 95% CI 0.014, 0.29), HAZ was positively associated with birthweight (0.155; 95% CI 0.035, 0.275), and BAZ was positively associated with caregiver's BMI (0.049; 95% CI 0.004, 0.090). There was an increased odds of rapid weight gain (RWG) with exposure to gestational diabetes (OR: 7.47, 95% CI 1.68, 46.22). Almost 70% of parents initiated breastfeeding, and breastfeeding initiation was modestly associated with lower WAZ (-0.18; 95% CI -0.64, 0.28) and BAZ (-0.23; 95% CI -0.79, 0.34)., Conclusions: This work highlights early life factors that may contribute to T2DM etiology and can be used to support community and Indigenous-led prevention strategies., (© 2023. The Author(s).)

Background: Preterm birth is an important outcome or exposure in epidemiologic research. When administrative data on measured gestational age is not available, parent-reported gestational age can be obtained from questionnaires, which is subject to potential bias. To our knowledge, few studies have assessed the validity of parent-reported gestational age categories, including commonly defined categories of preterm birth., Methods: We used linked data from primarily healthy children <6 years of age in TARGet Kids! in Toronto, Canada, and ICES administrative healthcare data from April 2011 to March 2020. We assessed the criterion validity of questionnaire-based parent-reported gestational age by calculating sensitivity and specificity for term (≥37 weeks), late preterm (34-36 weeks), and moderately preterm (32-33 weeks) gestational age categories, using administrative healthcare records of gestational age as the criterion standard. We conducted subgroup analyses for various parent and socioeconomic factors that may influence recall., Results: Of the 4684 participants, 97.3% correctly classified the gestational age category according to administrative healthcare data. Parent-reported gestational age sensitivity ranged from 83.7% to 98.5% and specificity ranged from 88.3% to 99.8%, depending on category. For each subgroup characteristic, sensitivity and specificity were all ≥70%. Lower educational attainment, lower family income, father reporting, ≥1 year since birth, ≥2 children, lower parent age, and reported gestational diabetes and/or hypertension were associated with slightly lower sensitivity and/or specificity., Conclusions: In this linked cohort, parent-reported gestational age categories had high accuracy. Criterion validity varied minimally among some parent and socioeconomic factors. Our findings can inform future quantitative bias analyses., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Uptake of the SARS-CoV-2 vaccine for children aged 5-11 years has been lower than anticipated in Canada. Although research has explored parental intentions toward SARS-CoV-2 vaccination for children, parental decisions regarding vaccinations have not been studied in-depth. We sought to explore reasons why parents chose to vaccinate or not vaccinate their children against SARS-CoV-2 to better understand their decisions., Methods: We conducted a qualitative study involving in-depth individual interviews with a purposive sample of parents in the Greater Toronto Area, Ontario, Canada. We conducted interviews via telephone or video call from February to April 2022 and analyzed the data using reflexive thematic analysis., Results: We interviewed 20 parents. We found that parental attitudes toward SARS-CoV-2 vaccinations for their children represented a complex continuum of concern. We identified 4 cross-cutting themes: the newness of SARS-CoV-2 vaccines and the evidence supporting their use; the perceived politicization of guidance for SARS-CoV-2 vaccination; the social pressure surrounding SARS-CoV-2 vaccinations; and the weighing of individual versus collective benefits of vaccination. Parents found making a decision about vaccinating their child challenging and expressed difficulty sourcing and evaluating evidence, determining the trustworthiness of guidance, and balancing their own conceptions of health care decisions with societal expectations and political messaging., Interpretation: Parents' experiences making decisions regarding SARS-CoV-2 vaccination for their children were complex, even for those who were supportive of SARS-CoV-2 vaccinations. These findings provide some explanation for the current patterns of uptake of SARS-CoV-2 vaccination among children in Canada; health care providers and public health authorities can consider these insights when planning future vaccine rollouts., Competing Interests: Competing interests: Clara Juando-Prats reports funding from the Social Sciences and Humanities Research Council, Audentes Therapeutics and Astellas Gene Therapies. Janet Parsons reports funding from the Canadian Institutes of Health Research, Canadian Immunization Research Network and the New Frontiers in Research Fund. No other competing interests were declared., (© 2023 CMA Impact Inc. or its licensors.)

Importance: The long-term cardiometabolic consequences of late preterm birth (34-36 weeks' gestation) are not well understood., Objective: To assess whether late preterm birth and size for gestational age are associated with cardiometabolic risk (CMR) in childhood., Design, Setting, and Participants: This retrospective cohort study included 1742 children born in Ontario, Canada, between April 1, 2006, and September 30, 2014, and followed up until September 30, 2019. Data from children enrolled in The Applied Research Group for Kids (TARGet Kids!) primary care practice-based research network were linked to administrative health care data at ICES (formerly known as the Institute for Clinical Evaluative Sciences). Participants were excluded if they had conditions affecting growth (eg, failure to thrive or cystic fibrosis), any acute or chronic conditions (other than asthma and high-functioning autism), severe developmental delay, or families who were unable to communicate in English., Exposures: Late preterm birth, gestational age as a continuous measure, and size for gestational age., Main Outcomes and Measures: The primary outcome was composite CMR score (overall age- and sex-standardized z score of CMR components, including waist circumference, log triglyceride level, glucose level, systolic blood pressure, and high-density lipoprotein cholesterol level). Secondary outcomes were the individual CMR components. Multivariable linear regression analysis was used to separately evaluate the associations of late preterm birth, continuous gestational age, and size for gestational age with CMR at ages 3 to 12 years., Results: Among 2440 eligible children, 1742 (mean [SD] age, 5.6 [2.2] years; 951 boys [54.6%]) were included in the final cohort. Overall, 87 children (5.0%) were born moderately preterm (<34 weeks' gestation), 145 (8.3%) were born late preterm (34-36 weeks' gestation), 455 (26.1%) were born early term (37-38 weeks' gestation), and 1055 (60.6%) were born full term (≥39 weeks' gestation). Compared with children born full term, those born moderately preterm (adjusted β = 0.50; 95% CI, 0.24-0.75) and late preterm (adjusted β = 0.27; 95% CI, 0.06-0.47) had higher CMR scores. Each additional gestational week was associated with a 0.06 U (adjusted β; 95% CI, -0.08 to -0.03 U) decrease in CMR., Conclusions and Relevance: In this study, children born late preterm and moderately preterm had higher CMR. These results suggest that screening and early-life interventions for these children may prevent cardiometabolic outcomes.

Objectives: In many jurisdictions, routine medical care was reduced in response to the COVID-19 pandemic. The objective of this study was to determine whether the frequency of on-time routine childhood vaccinations among children age 0-2 years was lower following the COVID-19 declaration of emergency in Ontario, Canada, on March 17, 2020, compared to prior to the pandemic., Methods: We conducted a longitudinal cohort study of healthy children aged 0-2 years participating in the TARGet Kids! primary care research network in Toronto, Canada. A logistic mixed effects regression model was used to determine odds ratios (ORs) for delayed vaccination (> 30 days vs. ≤ 30 days from the recommended date) before and after the COVID-19 declaration of emergency, adjusted for confounding variables. A Cox proportional hazards model was used to explore the relationship between the declaration of emergency and time to vaccination., Results: Among 1277 children, the proportion of on-time vaccinations was 81.8% prior to the COVID-19 declaration of emergency and 62.1% after (p < 0.001). The odds of delayed vaccination increased (odds ratio = 3.77, 95% CI: 2.86-4.96), and the hazard of administration of recommended vaccinations decreased after the declaration of emergency (hazard ratio = 0.75, 95% CI: 0.60-0.92). The median vaccination delay time was 5 days (95% CI: 4-5 days) prior to the declaration of emergency and 17 days (95% CI: 12-22 days) after., Conclusion: The frequency of on-time routine childhood vaccinations was lower during the first wave of the COVID-19 pandemic. Sustained delays in routine vaccinations may lead to an increase in rates of vaccine-preventable diseases., (© 2022. The Author(s) under exclusive license to The Canadian Public Health Association.)

Importance: Longitudinal research on specific forms of electronic screen use and mental health symptoms in children and youth during COVID-19 is minimal. Understanding the association may help develop policies and interventions targeting specific screen activities to promote healthful screen use and mental health in children and youth., Objective: To determine whether specific forms of screen use (television [TV] or digital media, video games, electronic learning, and video-chatting time) were associated with symptoms of depression, anxiety, conduct problems, irritability, hyperactivity, and inattention in children and youth during COVID-19., Design, Setting, and Participants: A longitudinal cohort study with repeated measures of exposures and outcomes was conducted in children and youth aged 2 to 18 years in Ontario, Canada, between May 2020 and April 2021 across 4 cohorts of children or youth: 2 community cohorts and 2 clinically referred cohorts. Parents were asked to complete repeated questionnaires about their children's health behaviors and mental health symptoms during COVID-19., Main Outcomes and Measures: The exposure variables were children's daily TV or digital media time, video game time, electronic-learning time, and video-chatting time. The mental health outcomes were parent-reported symptoms of child depression, anxiety, conduct problems and irritability, and hyperactivity/inattention using validated standardized tools., Results: This study included 2026 children with 6648 observations. In younger children (mean [SD] age, 5.9 [2.5] years; 275 male participants [51.7%]), higher TV or digital media time was associated with higher levels of conduct problems (age 2-4 years: β, 0.22 [95% CI, 0.10-0.35]; P < .001; age ≥4 years: β, 0.07 [95% CI, 0.02-0.11]; P = .007) and hyperactivity/inattention (β, 0.07 [95% CI, 0.006-0.14]; P = .04). In older children and youth (mean [SD] age, 11.3 [3.3] years; 844 male participants [56.5%]), higher levels of TV or digital media time were associated with higher levels of depression, anxiety, and inattention; higher levels of video game time were associated with higher levels of depression, irritability, inattention, and hyperactivity. Higher levels of electronic learning time were associated with higher levels of depression and anxiety., Conclusions and Relevance: In this cohort study, higher levels of screen use were associated poor mental health of children and youth during the COVID-19 pandemic. These findings suggest that policy intervention as well as evidence-informed social supports are needed to promote healthful screen use and mental health in children and youth during the pandemic and beyond.

Introduction: The 'Developmental Origins of Health and Disease' hypothesis suggests that a healthy trajectory of growth and development in pregnancy and early childhood is necessary for optimal health, development and lifetime well-being. The purpose of this paper is to present the protocol for a randomised controlled trial evaluating a preconception-early childhood telephone-based intervention with tailored e-health resources for women and their partners to optimise growth and development among children in Canada: a Healthy Life Trajectory Initiative (HeLTI Canada). The primary objective of HeLTI Canada is to determine whether a 4-phase 'preconception to early childhood' lifecourse intervention can reduce the rate of child overweight and obesity. Secondary objectives include improved child: (1) growth trajectories; (2) cardiometabolic risk factors; (3) health behaviours, including nutrition, physical activity, sedentary behaviour and sleep; and (4) development and school readiness at age 5 years., Method and Analysis: A randomised controlled multicentre trial will be conducted in two of Canada's highly populous provinces-Alberta and Ontario-with 786 nulliparous (15%) and 4444 primiparous (85%) women, their partners and, when possible, the first 'sibling child.' The intervention is telephone-based collaborative care delivered by experienced public health nurses trained in healthy conversation skills that includes detailed risk assessments, individualised structured management plans, scheduled follow-up calls, and access to a web-based app with individualised, evidence-based resources. An 'index child' conceived after randomisation will be followed until age 5 years and assessed for the primary and secondary outcomes. Pregnancy, infancy (age 2 years) and parental outcomes across time will also be assessed., Ethics and Dissemination: The study has received approval from Clinical Trials Ontario (CTO 1776). The findings will be published in peer-reviewed journals and disseminated to policymakers at local, national and international agencies. Findings will also be shared with study participants and their communities., Trial Registration Number: ISRCTN13308752; Pre-results., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Importance: Parents may use screen exposure or screen exposure combined with feeding for infants and toddlers to alleviate their own stress., Objective: To evaluate the association of individual and contextual stressors with child screen exposure (CSE) and CSE combined with feeding (CSE+F) in children aged 7 to 18 months as measured by parent-reported use and variation in quantity of CSE and CSE+F., Design, Setting, and Participants: This cross-sectional, population-based study drew parent-child participants from TARGet Kids, a network of primary health care research settings throughout Toronto, Ontario, Canada, between November 1, 2011, and July 31, 2018. The included children were aged 7 to 18 months. Exclusion criteria were health conditions affecting growth, acute conditions, chronic conditions, severe developmental delay, and families who were unable to communicate in the English language. Data were analyzed from April 1, 2019, to July 31, 2019., Exposures: Parenting stress, child age, child negative affectivity, family living arrangements, and family income were assessed with parent-completed questionnaires., Main Outcomes and Measures: The primary outcome was CSE and the variation in CSE, which represented the amount of background and engaged use of screens (television, videos or DVDs, video games, computers, and mobile devices) in a typical week. The secondary outcome was CSE+F, which represented the frequency of breakfast, lunch, dinner, and snack consumption during screen exposure in a typical week. Both CSE and CSE+F were assessed with the parent-completed Nutrition and Health Questionnaire; Infant Behavior Questionnaire, Revised Very Short; and Parenting Stress Index, Short Form., Results: The final sample size was 1085 children for the analysis of CSE and 1083 children for the analysis of CSE+F. Among 914 respondents, the children's mean (SD) age was 11.6 (2.3) months, and 478 (52.3%) were male. Among 910 respondents, 839 (92.2%) were mothers, with a mean (SD) age among 873 respondents of 34.4 (4.2) years. In a typical week, 581 of 779 children (74.6%) were reported to have any CSE, and 321 of 874 children (36.7%) had some CSE+F. Higher parenting stress levels (odds ratio [OR], 1.01; 95% CI, 1.00-1.02; P = .04) and older child age (OR, 1.43; 95% CI, 1.01-2.03; P = .04) were associated with CSE. Higher parenting stress levels (incidence rate [IR], 1.00; 95% CI, 1.00-1.01; P = .002) and lower household income (IR, 1.26; 95% CI, 1.10-1.45; P = .01) were associated with increased CSE. Older child age (OR, 1.79; 95% CI, 1.35-2.38; P < .001) and lower household income (OR, 2.54; 95% CI, 1.72-3.74; P < .001) were associated with CSE+F. Lower household income (IR, 1.21; 95% CI, 1.03-1.42; P = .02) was associated with increased CSE+F., Conclusions and Relevance: This study found that parenting stress, income, and child age were associated with CSE, and child age and household income were associated with CSE+F. Given these findings, interventions to improve parental coping mechanisms may decrease child screen exposure.

Objective: Health care policy positions breastfeeding as an important part of the solution to household food insecurity; however, there are critical gaps in our knowledge of the relationship between breastfeeding duration (exposure variable) and household food insecurity (outcome variable). Our objective was to examine this relationship., Methods: A cross-sectional study was conducted from 2008 to 2016 of healthy urban children (N = 3838) who were 0 to 3 years old and recruited from The Applied Research Group for Kids (TARGet Kids!), a practice-based research network in Toronto, Canada. Total breastfeeding duration was collected from parent-reported questionnaires. Household food insecurity was measured using 1-item and 2-item food insecurity screens. Multivariable regression analysis was performed adjusting for prespecified covariates., Results: The median total breastfeeding duration was 10.5 months (interquartile range, 6.0-14.0), and 14.7% of households were food insecure. After adjusting for child characteristics (age, sex), maternal characteristics (age, ethnicity, education, employment), and family characteristics (number of children, single parent family, neighborhood equity score), there was no significant association between total breastfeeding duration and household food insecurity (odds ratio, 0.99; 95% confidence interval, 0.98-1.01). Although low-income families had an increased odds of being household food insecure (P ≤ .001), we found no significant association between total breastfeeding duration and household food insecurity at varying income levels., Conclusions: We found no association between breastfeeding duration and household food insecurity, regardless of family income. Although breastfeeding is associated with improved child health outcomes and considered to be part of the solution to household food insecurity, interventions focused on social determinants may provide more promising targets for the prevention of household food insecurity., (Copyright © 2019 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.)

Introduction: Asthma prevalence is commonly measured in national surveys by questionnaire. The Ontario Asthma Surveillance Information System (OASIS) developed a validated health claims diagnosis algorithm to estimate asthma prevalence. The primary objective was to assess the agreement between two approaches of measuring asthma in young children. Secondary objectives were to identify concordant and discordant pairs, and to identify factors associated with disagreement., Study Design and Setting: A measurement study to evaluate the agreement between the OASIS algorithm and parent-reported asthma (criterion standard). Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated. Multivariable logistic regression was used to determine factors associated with disagreement., Results: Healthy children aged 1 to 5 years (n =3642) participating in the TARGet Kids! practice based research network 2008-2013 in Toronto, Canada were included. Prevalence of asthma was 14% and 6% by the OASIS algorithm and parent-reported asthma, respectively. The Kappa statistic was 0.43, sensitivity 81%, specificity 90%, PPV 34%, and NPV 99%. There were 3249 concordant and 393 discordant pairs. Statistically significant factors associated with asthma identified by OASIS but not parent report included: male sex, higher zBMI, and parent history of asthma. Males were less likely to have asthma identified by parent report but not OASIS., Conclusion: The OASIS algorithm identified more asthma cases in young children than parent-reported asthma. The OASIS algorithm had high sensitivity, specificity, and NPV but low PPV relative to parent-reported asthma. These findings need replication in other populations., (© 2019 Wiley Periodicals, Inc.)

Objectives: The American Academy of Pediatrics recommends universal screening for anemia using hemoglobin at 12 months. However, hemoglobin lacks diagnostic accuracy for iron deficiency, and the optimal age for screening has not been determined. Our objective was to assess a screening strategy for iron deficiency using serum ferritin., Methods: We conducted a cross-sectional study of children 1 to 3 years old attending a health supervision visit. We examined the relationship between child age and serum ferritin, age and hemoglobin, hemoglobin and serum ferritin, and the prevalence of elevated C-reactive protein (CRP)., Results: Restricted cubic spline analysis ( n = 1735) revealed a nonlinear relationship between age and serum ferritin ( P < .0001). A linear spline model revealed that from 12 to 15 months, for each 1-month increase in age, serum ferritin levels decreased by 9% (95% confidence interval [CI]: 5 to 13). From 15 to 24 months, the rate of change was nonsignificant. From 24 to 38 months, for each month increase in age, serum ferritin increased by 2% (95% CI: 1 to 2). For hemoglobin, from 12 to 24 months, the rate of change was nonsignificant. From 24 to 38 months, for each 1-month increase in age, hemoglobin increased by 20% (95% CI: 9 to 32). Compared with the serum ferritin cutoff of <12 μg/L, the hemoglobin cutoff of <110 g/L had a sensitivity of 25% (95% CI: 19 to 32) and a specificity of 89% (95% CI: 87 to 91). Elevated CRP ≥10 mg/L occurred in 3.3% (95% CI: 2.5 to 4.2)., Conclusions: Screening for iron deficiency using serum ferritin at 15 or 18 months may be a promising strategy. For children at low risk for acute inflammation, concurrent measurement of CRP may not be necessary., Competing Interests: POTENTIAL CONFLICT OF INTEREST: Dr Parkin has received nonfinancial support from Mead Johnson Nutrition (Fer-In-Sol liquid iron supplement; 2011–2017) for an ongoing investigator-initiated trial of iron deficiency in young children; the other authors have indicated they have no potential conflicts of interest to disclose., (Copyright © 2018 by the American Academy of Pediatrics.)

Background: Iron deficiency in early childhood has been associated with poor developmental outcomes. Little is known about the nutritional health of young children receiving care at Canadian Community Health Centres (CHCs). Our objectives were to describe iron deficiency among toddlers at an Ontario CHC, to compare young children attending CHCs and non-CHCs, and assess the feasibility of conducting research on children in CHC settings., Methods: One CHC, Kingston Community Health Centres (CHC) with two clinical sites and one community programming site was added to the nine non-CHC pediatric and primary care clinics in the existing TARGet Kids! research network. A cross-sectional feasibilitystudy was conducted.and. Healthy children, ages 12-36 months were Enrolled. iron deficiency without inflammation (ferritin< 14 μg/L and CRP < 10 mg/L) and serum ferritin were assessed. Adjusted multivariable regression analyses were used to evaluate an association between CHC enrolment and iron status., Results: The CHC cohort (n = 31) was older, had lower household income, lower maternal education, higher nutrition risk scores, higher cow's milk intake, shorter breastfeeding duration and higher prevalence of unhealthy weights compared with the non-CHC cohort (n = 875). There was no association between CHC status and serum ferritin (difference in median serum ferritin 4.78 μg/L, 95% confidence interval [CI] -2.5, 14.3, p = 0.22) or iron deficiency (OR 0.55, 95% CI 0.11, - 2.73, p = 0.46) using multivariable linear and logistic regression, respectively., Conclusion: Despite differences in sociodemographic variables, we did not detect a difference in iron status between toddlers enrolled at CHCs compared to non-CHC settings. Further research is needed to understand the health effects of poverty generally, and iron deficiency specifically among children receiving care at CHCs.

Objectives: International data suggest the prevalence of severe obesity in young children may be increasing, yet no Canadian data are available. The objectives of this study were to examine definitions of severe obesity and to evaluate associated risk factors among young children in Ontario., Methods: A cross-sectional study was conducted in children 17 to 24 months of age using two Ontario data sources: TARGet Kids! (n = 3713) and BORN Ontario (n = 768). Body mass index z score (zBMI) definitions were adapted from the World Health Organization (WHO) (z score > 3) and the US Centers for Disease Control (CDC) (> 120% of the 95th percentile) and applied to define severe obesity in young children. Multinomial logistic regression was used to evaluate associations between demographic and pregnancy risk factors and zBMI categories., Results: A total of 1.1% (95% CI, 0.8-1.4) of children met the adapted WHO definition of severe obesity compared to 0.3% (95% CI, 0.2-0.6) using the CDC definition. Median neighbourhood household income (OR = 0.80, 95% CI, 0.69-0.93) and maternal pre-pregnancy BMI (OR = 1.08, 95% CI, 1.01-1.15) were associated with severe obesity in unadjusted analyses. After adjustment for potential confounders, the OR for the association between maternal pre-pregnancy BMI and severe obesity was 1.04 (95% CI, 0.94-1.15)., Conclusion: More than 1% of Ontario children met the adapted WHO definition of severe obesity in very early childhood. Modifiable risk factors were identified. Future studies are needed to understand the terminology, prevalence, and risk factors for severe obesity in young children across Canada.

Objectives: To determine whether parent report of difficulty buying food was associated with child body mass index (BMI) z-score or with eating habits in young children., Methods: This was a cross-sectional study in primary care offices in Toronto, Ontario. Subjects were children aged 1-5 years and their caregivers, recruited through the TARGet Kids! Research Network from July 2008 to August 2011. Regression models were developed to test the association between parent report of difficulty buying food because of cost and the following outcomes: child BMI z-score, parent's report of child's intake of fruit and vegetables, fruit juice and sweetened beverages, and fast food. Confounders included child's age, sex, birth weight, maternal BMI, education, ethnicity, immigration status, and neighbourhood income., Results: The study sample consisted of 3333 children. Data on difficulty buying food were available for 3099 children, and 431 of these (13.9%) were from households reporting difficulty buying food. There was no association with child BMI z-score (p = 0.86). Children from households reporting difficulty buying food (compared with never having difficulty buying food) had increased odds of consuming three or fewer servings of fruits and vegetables per day (odds ratio [OR]: 1.31, 95% confidence interval [CI]: 1.03-1.69), more than one serving of fruit juice/sweetened beverage per day (OR: 1.60, 95% CI: 1.28-2.00), and, among children 1-2 years old, one or more servings of fast food per week (OR: 2.91, 95% CI: 1.67-5.08)., Conclusion: Parental report of difficulty buying food is associated with less optimal eating habits in children but not with BMI z-score.

Objectives: Children from immigrant families may be at risk for iron deficiency (ID) due to differences in pre-migration and post-migration exposures. Our objectives were to determine whether there is an association between family immigrant status and iron stores and to evaluate whether known dietary, environmental or biological determinants of low iron status influence this relationship., Design: This was a cross-sectional study of healthy urban preschool children (12-72 months) recruited from seven primary care practices in Toronto. Laboratory assessment of serum ferritin and haemoglobin and standardised parent-completed surveys were completed between 2008 and 2013 during routine health maintenance visits. Multiple regression analyses were used to evaluate the association between family immigrant status and serum ferritin, ID (ferritin <14 μg/L) and iron deficiency anaemia (IDA) (ferritin <14 μg/L and haemoglobin ≤110 g/L)., Results: Of 2614 children included in the analysis, 47.6% had immigrant family status. The median serum ferritin was 30 μg/L and 10.4% of all children had ID and 1.9% had IDA. After adjusting for maternal ethnicity and education, age, sex, income quintile, cow's milk intake, breastfeeding duration and bottle use, there were no significant associations between immigrant status and ferritin, ID or IDA. Significant predictors of low iron status included age, sex, cow's milk intake and breastfeeding duration., Conclusions: We found no association between family immigrant status and iron status after including clinically important covariates in the models. These data suggest immigrant children may not need enhanced screening for iron status or targeted interventions for iron supplementation., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Purpose: Measuring ethnicity accurately is important for identifying ethnicity variations in disease risk. We evaluated the degree of agreement and accuracy of maternal ethnicity measured using the new standardized closed-ended geographically based ethnicity question and geographic reclassification of open-ended ethnicity questions from the Canadian census., Methods: A prospectively designed study of respondent agreement of mothers of healthy children aged 1-5 years recruited through the TARGet Kids! practice-based research network. For the primary analysis, the degree of agreement between geographic reclassification of the Canadian census maternal ethnicity variables and the new geographically based closed-ended maternal ethnicity variable completed by the same respondent was evaluated using a kappa analysis., Results: Eight hundred sixty-two mothers who completed both measures of ethnicity were included in the analysis. The kappa agreement statistic for the two definitions of maternal ethnicity was 0.87 (95% confidence interval, 0.84-0.90) indicating good agreement. Overall accuracy of the measurement was 93%. Sensitivity and specificity ranged from 83% to 100% and 96% to 100%, respectively., Conclusions: The new standardized closed-ended geographically based ethnicity question represents a practical alternative to widely used open-ended ethnicity questions. It may reduce risk of misinterpretation of ethnicity by respondents, simplify analysis, and improve the accuracy of ethnicity measurement., (Copyright © 2014 Elsevier Inc. All rights reserved.)