Patricia C Parkin

University of Toronto, Toronto, Ontario, Canada

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Publications (129)485.76 Total impact

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    ABSTRACT: Three decades of research suggests that prevention of iron deficiency anemia (IDA) in the primary care setting may be an unrealized and unique opportunity to prevent poor developmental outcomes in children. A longitudinal study of infants with IDA showed that the developmental disadvantage persists long term despite iron therapy. Early stages of iron deficiency, termed non-anemic iron deficiency (NAID), provide an opportunity for early detection and treatment before progression to IDA. There is little research regarding NAID, which may be associated with delayed development in young children. The aim of this study is to compare the effectiveness of four months of oral iron treatment plus dietary advice, with placebo plus dietary advice, in improving developmental outcomes in children with NAID and to conduct an internal pilot study. From a screening cohort, those identified with NAID (hemoglobin ≥110 g/L and serum ferritin <14 μg/L) are invited to participate in a pragmatic, multi-site, placebo controlled, blinded, parallel group, superiority randomized trial. Participating physicians are part of a primary healthcare research network called TARGet Kids! Children between 12 and 40 months of age and identified with NAID are randomized to receive four months of oral iron treatment at 6 mg/kg/day plus dietary advice, or placebo plus dietary advice (75 per group). The primary outcome, child developmental score, is assessed using the Mullen Scales of Early Learning at baseline and at four months after randomization. Secondary outcomes include an age appropriate behavior measure (Children's Behavior Questionnaire) and two laboratory measures (hemoglobin and serum ferritin levels). Change in developmental and laboratory measures from baseline to the end of the four-month follow-up period will be analyzed using linear regression (analysis of covariance method). This trial will provide evidence regarding the association between child development and NAID, and the effectiveness of oral iron to improve developmental outcomes in children with NAID. The sample size of the trial will be recalculated using estimates taken from an internal pilot study. This trial was registered with (identifier: NCT01481766 ) on 22 November 2011.
    Trials 01/2015; 16(1):132. DOI:10.1186/s13063-015-0635-z · 2.12 Impact Factor
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    ABSTRACT: Identifying modifiers of glioma risk in patients with type 1 neurofibromatosis (NF1) could help support personalized tumor surveillance, advance understanding of gliomagenesis and potentially identify novel therapeutic targets. Here we report genetic polymorphisms in the human adenylate cyclase gene ADCY8 which correlate with glioma risk in NF1 in a sex-specific manner, elevating risk in females while reducing risk in males. This finding extends earlier evidence of a role for cAMP in gliomagenesis based on results in a genetically engineered mouse model (Nf1 GEM). Thus, sexually dimorphic cAMP signaling might render males and females differentially sensitive to variation in cAMP levels. Using male and female Nf1 GEM, we found significant sex differences exist in cAMP regulation and in the growth promoting effects of cAMP suppression. Overall, our results establish a sex-specific role for cAMP regulation in human gliomagenesis, specifically identifying ADCY8 as a modifier of glioma risk in NF1.
    Cancer Research 11/2014; 75(1). DOI:10.1158/0008-5472.CAN-14-1891 · 9.28 Impact Factor
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    ABSTRACT: Vitamin D fortification of non-cow's milk beverages is voluntary in North America. The effect of consuming non-cow's milk beverages on serum 25-hydroxyvitamin D levels in children is unclear. We studied the association between non-cow's milk consumption and 25-hydroxyvitamin D levels in healthy preschool-aged children. We also explored whether cow's milk consumption modified this association and analyzed the association between daily non-cow's milk and cow's milk consumption.
    Canadian Medical Association Journal 10/2014; 186(17). DOI:10.1503/cmaj.140555 · 5.81 Impact Factor
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    ABSTRACT: Urinary tract infection (UTI) is the most common serious bacterial infection in infants. To use resources optimally, factors contributing to costs through length of stay (LOS) must be identified. This study sought to identify clinical and health system factors associated with long LOS in infants with UTI.
    09/2014; 4(5):291-297. DOI:10.1542/hpeds.2014-0020
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    ABSTRACT: Routine use of pulse oximetry has been associated with changes in bronchiolitis management and may have lowered the hospitalization threshold for patients with bronchiolitis.
    JAMA The Journal of the American Medical Association 08/2014; 312(7):712-8. DOI:10.1001/jama.2014.8637 · 30.39 Impact Factor
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    ABSTRACT: The Applied Research Group for Kids (TARGet Kids!) is an ongoing open longitudinal cohort study enrolling healthy children (from birth to 5 years of age) and following them into adolescence. The aim of the TARGet Kids! cohort is to link early life exposures to health problems including obesity, micronutrient deficiencies and developmental problems. The overarching goal is to improve the health of Canadians by optimizing growth and developmental trajectories through preventive interventions in early childhood. TARGet Kids!, the only child health research network embedded in primary care practices in Canada, leverages the unique relationship between children and families and their trusted primary care practitioners, with whom they have at least seven health supervision visits in the first 5 years of life. Children are enrolled during regularly scheduled well-child visits. To date, we have enrolled 5062 children. In addition to demographic information, we collect physical measurements (e.g. height, weight), lifestyle factors (nutrition, screen time and physical activity), child behaviour and developmental screening and a blood sample (providing measures of cardiometabolic, iron and vitamin D status, and trace metals). All data are collected at each well-child visit: twice a year until age 2 and every year until age 10. Information can be found at:
    International Journal of Epidemiology 06/2014; DOI:10.1093/ije/dyu123 · 9.20 Impact Factor
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    ABSTRACT: To identify sociodemographic, dietary, and biological factors associated with families who do not receive dental care in early childhood and to identify risk factors associated with having cavities among children who receive early dental care. A cross-sectional study of healthy Canadian children seen for primary health care between September 2011 and January 2013 was conducted through the TARGet Kids! practice-based research network in Toronto, Canada. Adjusted logistic regression was used to determine factors associated with children who were not seen by a dentist in early childhood and to determine risk factors associated with having dental cavities among children who received early dental care. Of the 2505 children included in the analysis, <1% were seen by a dentist by 1 year of age. Older children were less likely to have never been to the dentist (odds ratio [OR], 0.88; 95% confidence interval [CI], 0.87-0.90). Low family income (OR, 2.73; 95% CI, 1.47-5.06), prolonged bottle use (OR, 1.43; 95% CI, 1.03-2.00), and higher intakes of sweetened drinks (OR, 1.20; 95% CI, 1.01-1.42) were associated with increased risk for never having been to the dentist. Among those who had been to the dentist, older children (OR, 1.04; 95% CI, 1.03-1.05), children of low income families (OR, 1.90; 95% CI, 1.17-3.10), and those of East Asian maternal ethnicity (OR, 1.91; 95% CI, 1.10-3.29) were more likely to have dental cavities. Among healthy urban children seen by a primary care provider, those most susceptible to cavities were least likely to receive early dental care. These findings support the need for publicly funded universal early preventive dental care and underscore the importance for primary care physicians to promote dental care in early childhood.
    PEDIATRICS 05/2014; 133(6). DOI:10.1542/peds.2013-3725 · 5.30 Impact Factor
  • Journal of clinical epidemiology 04/2014; 67(7). DOI:10.1016/j.jclinepi.2014.02.006 · 5.48 Impact Factor
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    ABSTRACT: 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 age 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 862 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% CI: 0.84-0.90) indicating good agreement. Overall accuracy of the measurement was 93%. Sensitivity and specificity ranged from 83-100% and 96-100% respectively. Conclusion 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.
    Annals of epidemiology 04/2014; 24(4). DOI:10.1016/j.annepidem.2013.12.015 · 2.15 Impact Factor
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    ABSTRACT: This study aimed to examine the treatment decision-making process for children hospitalized with newly diagnosed immune thrombocytopenia (ITP). Using focus groups, we studied children with ITP, parents of children with ITP, and health care professionals, inquiring about participants' experience with decision support and decision making in newly diagnosed ITP. Data were examined using thematic analysis. Themes that emerged from children were feelings of "anxiety, fear, and confusion"; the need to "understand information"; and "treatment choice," the experience of which was age dependent. For parents, "anxiety, fear, and confusion" was a dominant theme; "treatment choice" revealed that participants felt directed toward intravenous immune globulin (IVIG) for initial treatment. For health care professionals, "comfort level" highlighted factors contributing to professionals' comfort with offering options; "assumptions" were made about parental desire for participation in shared decision making (SDM) and parental acceptance of treatment options; "providing information" was informative regarding modes of facilitating SDM; and "treatment choice" revealed a discrepancy between current practice (directed toward IVIG) and the ideal of SDM. At our center, families of children with newly diagnosed ITP are not experiencing SDM. Our findings support the implementation of SDM to facilitate patient-centered care for the management of pediatric ITP.
    Journal of Pediatric Hematology/Oncology 02/2014; DOI:10.1097/MPH.0000000000000120 · 0.96 Impact Factor
  • 02/2014; 168(4). DOI:10.1001/jamapediatrics.2013.5379
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    ABSTRACT: Vitamin D levels are alarmingly low (<75 nmol/L) in 65-70% of North American children older than 1 year. An increased risk of viral upper respiratory tract infections (URTI), asthma-related hospitalizations and use of anti-inflammatory medication have all been linked with low vitamin D. No study has determined whether wintertime vitamin D supplementation can reduce the risk of URTI and asthma exacerbations, two of the most common and costly illnesses of early childhood. The objectives of this study are: 1) to compare the effect of 'high dose' (2000 IU/day) vs. 'standard dose' (400 IU/day) vitamin D supplementation in achieving reductions in laboratory confirmed URTI and asthma exacerbations during the winter in preschool-aged Canadian children; and 2) to assess the effect of 'high dose' vitamin D supplementation on vitamin D serum levels and specific viruses that cause URTI.Methods/design: This study is a pragmatic randomized controlled trial. Over 3 successive winters we will recruit 750 healthy children 1-5 years of age. Participating physicians are part of a primary healthcare research network called TARGet Kids! Children will be randomized to the 'standard dose' or 'high dose' oral supplemental vitamin D for a minimum of 4 months (200 children per group). Parents will obtain a nasal swab from their child with each URTI, report the number of asthma exacerbations and complete symptom checklists. Unscheduled physician visits for URTIs and asthma exacerbations will be recorded. By May, a blood sample will be drawn to determine vitamin D serum levels. The primary analysis will be a comparison of URTI rate between study groups using a Poisson regression model. Secondary analyses will compare vitamin D serum levels, asthma exacerbations and the frequency of specific viral agents between groups. Identifying whether vitamin D supplementation of preschoolers can reduce wintertime viral URTIs and asthma exacerbations and what dose is optimal may reduce population wide morbidity and associated health care and societal costs. This information will assist in determining practice and health policy recommendations related to vitamin D supplementation in healthy Canadian preschoolers and place Canada at the forefront of pediatric vitamin D health outcomes research.
    BMC Pediatrics 02/2014; 14(1):37. DOI:10.1186/1471-2431-14-37 · 1.92 Impact Factor
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    ABSTRACT: IMPORTANCE Alopecia areata is an idiopathic cause of hair loss with limited therapeutic repertoire. OBJECTIVE To compare the efficacy and safety of a high- vs low-potency topical corticosteroid in pediatric patients. DESIGN, SETTING, AND PARTICIPANTS This single-center, randomized, blind, 2-arm, parallel-group, superiority trial was carried out over a 24-week period at a tertiary referral academic dermatology clinic at The Hospital for Sick Children in Toronto, Ontario, Canada. Forty-two children attending the outpatients clinic, 2 to 16 years of age with alopecia areata affecting at least 10% of scalp surface area, were eligible; 1 declined to participate. There were no withdrawals from the study. INTERVENTIONS FOR CLINICAL TRIALS Patients were randomly assigned to receive clobetasol propionate, 0.05% cream, or hydrocortisone, 1%, cream. Patients applied a thin layer of the assigned cream twice daily to the areas of hair loss for 2 cycles of 6 weeks on, 6 weeks off, for a total of 24 weeks. MAIN OUTCOMES AND MEASURES The primary outcome was the change in scalp surface area with hair loss over 24 weeks following enrollment. RESULTS All participants were assessed at 6, 12, 18, and 24 weeks (except 1 participant who missed the 6-week visit). After adjusting for baseline hair loss, the clobetasol group had a statistically significant (P < .001) greater decrease in the surface area with hair loss, compared with the hydrocortisone group at all time points except at 6 weeks. One patient with extensive alopecia areata experienced skin atrophy that resolved spontaneously in 6 weeks. There was no difference observed in the number of patients with abnormal urinary cortisol at the beginning and the end of the study. CONCLUSIONS AND RELEVANCE Topical clobetasol propionate, 0.05%, cream is efficacious and safe as a first-line agent for limited patchy childhood alopecia areata. TRIAL REGISTRATION Identifier: NCT01453686.
    11/2013; 150(1). DOI:10.1001/jamadermatol.2013.5764
  • Stephen B Freedman, Julie M Degroot, Patricia C Parkin
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    ABSTRACT: Emergency Department (ED) revisits are very common in children with gastroenteritis administered intravenous rehydration. To determine if bicarbonate values are associated with ED revisits in children with gastroenteritis. We conducted a secondary analysis of prospectively collected data, which included children >3 months of age with gastroenteritis treated with intravenous rehydration. Regression analysis was employed to determine whether, among discharged children, bicarbonate independently predicts revisits within 7 days (primary outcome) and successful discharge (secondary outcome). The latter composite outcome measure was defined as discharge at the index visit and the absence of a revisit requiring intravenous rehydration. Of 226 potentially eligible children, 174 were discharged and were included in the primary outcome analysis. Of the eligible children, 18% (30/174) had a revisit that was predicted by a higher baseline bicarbonate (odds ratio [OR] 1.1; 95% confidence interval [CI] 1.0-1.3; p = 0.03), absence of a primary care provider (OR 7.8; 95% CI 1.2-51.0; p = 0.03), and ondansetron administration (OR 2.4; 95% CI 1.0-5.5; p = 0.05). Bicarbonate was not associated with successful discharge. Negatively associated independent predictors of successful discharge were volume of intravenous fluids administered (OR 0.84/10 mL/kg increase; 95% CI 0.76-0.93; p < 0.001), and baseline clinical dehydration score (OR 0.75/unit increase; 95% CI 0.58-0.97; p < 0.001). Revisits requiring intravenous rehydration and hospitalization were associated with higher bicarbonate values (21.2 ± 4.6 mEq, p = 0.001, and 22.3 ± 5.0 mEq/L, p < 0.001, respectively). Lower serum bicarbonate values at the time of intravenous rehydration are not associated with unfavorable outcomes after discharge.
    Journal of Emergency Medicine 08/2013; 46(1). DOI:10.1016/j.jemermed.2013.04.044 · 1.18 Impact Factor
  • Patricia C Parkin, Jonathon L Maguire
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    ABSTRACT: • The true prevalence of nutritional iron deficiency (ID) in childhood is unclear because of the uncertainty over its definition and the insensitivity of markers of ID. • The major cause in developed countries is likely to be the excessive and early use of cow’s milk and a diet poor in haem iron. • Recent neuro-physiological observations support the many field studies correlating ID with cognitive and motor developmental delay in young children, although proof of causality has not been established because of environmental confounding. • Population iron supplementation is a potentially effective means of prevention of ID but is limited by poor compliance and the risk of increased morbidity and mortality in malarious regions. • Fortification of milk and essential infant foods is likely to be the most cost-effective means of improving the iron status of child populations. Key WordsRisk factors-psychomotor development-iron supplementation and fortification-anaemia screening
    Canadian Medical Association Journal 08/2013; 185(14). DOI:10.1503/cmaj.130150 · 5.81 Impact Factor
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    ABSTRACT: OBJECTIVE: To determine if children aged 1-6 years from non-Western immigrant families have lower serum 25-hydroxyvitamin D (25(OH)D) levels than children from Western-born families and examine which factors influence this relationship. DESIGN: Cross-sectional study. SETTING: Toronto, Canada. SUBJECTS: Healthy children (n 1540) recruited through the TARGet Kids! practice-based research network. Serum 25(OH)D concentrations of non-Western immigrants were compared with those of children from Western-born families. Children from non-Western immigrant families were defined as those born, or their parents were born, outside a Western country. Univariate and multiple linear regression analyses were used to identify factors which might influence this relationship. RESULTS: Median age was 36 months, 51 % were male, 86 % had 'light' skin pigmentation, 55 % took vitamin D supplements, mean cow's milk intake was 1·8 cups/d and 27 % were non-Western immigrants. Median serum 25(OH)D concentration was 83 nmol/l, with 5 % having 25(OH)D < 50 nmol/l. Univariable analysis revealed that non-Western immigrant children had serum 25(OH)D lower by 4 (95 % CI 1·3, 8·0) nmol/l (P = 0·006) and increased odds of 25(OH)D < 50 nmol/l (OR = 1·9; 95 % CI 1·3, 2·9). After adjustment for known vitamin D determinants the observed difference attenuated to 0·04 (95 % CI -4·8, 4·8) nmol/l (P = 0·99), with higher cow's milk intake (P < 0·0001), vitamin D supplementation (P < 0·0001), summer season (P = 0·008) and increased age (P = 0·04) being statistically significant covariates. Vitamin D supplementation was the strongest explanatory factor of the observed difference. CONCLUSIONS: There is an association between non-Western immigration and lower 25(OH)D in early childhood. This difference appears related to known vitamin D determinants, primarily vitamin D supplementation, representing opportunities for intervention.
    Public Health Nutrition 06/2013; 17(07):1. DOI:10.1017/S136898001300181X · 2.48 Impact Factor
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    ABSTRACT: BACKGROUND:Modifiable behaviours during early childhood may provide opportunities to prevent disease processes before adverse outcomes occur. Our objective was to determine whether young children's eating behaviours were associated with increased risk of cardiovascular disease in later life. METHODS:In this cross-sectional study involving children aged 3-5 years recruited from 7 pri mary care practices in Toronto, Ontario, we assessed the relation between eating behaviours as assessed by the NutriSTEP (Nutritional Screening Tool for Every Preschooler) questionnaire (completed by parents) and serum levels of non-high-density lipoprotein (HDL) cholesterol, a surrogate marker of cardiovascular risk. We also assessed the relation between dietary intake and serum non-HDL cholesterol, and between eating behaviours and other laboratory indices of cardiovascular risk (low-density lipoprotein [LDL] cholesterol, apolipoprotein B, HDL cholesterol and apoliprotein A1). RESULTS:A total of 1856 children were recruited from primary care practices in Toronto. Of these children, we included 1076 in our study for whom complete data and blood samples were available for analysis. The eating behaviours subscore of the NutriSTEP tool was significantly associated with serum non-HDL cholesterol (p = 0.03); for each unit increase in the eating behaviours subscore suggesting greater nutritional risk, we saw an an increase of 0.02 mmol/L (95% confidence interval [CI] 0.002 to 0.05) in serum non-HDL cholesterol. The eating behaviours subscore was also associated with LDL cholesterol and apolipoprotein B, but not with HDL cholesterol or apolipoprotein A1. The dietary intake subscore was not associated with non-HDL cholesterol. INTERPRETATION:Eating behaviours in preschoolaged children are important potentially modifiable determinants of cardiovas cular risk and should be a focus for future studies of screening and behavioural interventions.
    Canadian Medical Association Journal 06/2013; 185(11). DOI:10.1503/cmaj.121834 · 5.81 Impact Factor
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    ABSTRACT: OBJECTIVE:To determine whether there is an association between the total breastfeeding duration and iron stores, iron deficiency, and iron deficiency anemia in healthy urban children.METHODS:A cross-sectional study of healthy children, aged 1 to 6 years, seen for primary health care between December 2008 and July 2011 was conducted through the TARGet Kids! practice-based research network. Univariate and adjusted regression analyses were used to evaluate an association between total breastfeeding duration and serum ferritin, iron deficiency, and iron deficiency anemia.RESULTS:Included were 1647 healthy children (median age 36 months) with survey, anthropometric, and laboratory data. An association was found between increasing duration of breastfeeding and lower serum ferritin (P = .0015). Adjusted logistic regression analysis revealed the odds of iron deficiency increased by 4.8% (95% confidence interval: 2%-8%) for each additional month of breastfeeding. Exploratory analysis suggested an increasing cumulative probability of iron deficiency with longer total breastfeeding duration with an adjusted odds ratio of 1.71 (95% confidence interval: 1.05-2.79) for iron deficiency in children breastfed over versus under 12 months of age. The relationship between total breastfeeding duration and iron deficiency anemia did not meet statistical significance.CONCLUSIONS:Increased total breastfeeding duration is associated with decreased iron stores, a clinically important association warranting additional investigation.
    PEDIATRICS 04/2013; 131(5). DOI:10.1542/peds.2012-2465 · 5.30 Impact Factor
  • Canadian Journal of Diabetes 04/2013; 37:S285. DOI:10.1016/j.jcjd.2013.03.333 · 0.46 Impact Factor
  • Canadian Journal of Diabetes 04/2013; 37:S284. DOI:10.1016/j.jcjd.2013.03.332 · 0.46 Impact Factor

Publication Stats

2k Citations
485.76 Total Impact Points


  • 1996–2014
    • University of Toronto
      • • Department of Paediatrics
      • • Division of Paediatric Medicine
      • • Faculty of Medicine
      • • Hospital for Sick Children
      Toronto, Ontario, Canada
  • 1993–2014
    • SickKids
      • • Division of Paediatric Medicine
      • • Department of Paediatrics
      • • Division of Paediatric Emergency Medicine
      Toronto, Ontario, Canada
  • 2011
    • Saint Michael's Medical Center
      Newark, New Jersey, United States
  • 2010
    • Université de Montréal
      • Department of Pediatrics
      Montréal, Quebec, Canada