John B Carlin

Murdoch Childrens Research Institute, Melbourne, Victoria, Australia

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Publications (381)1758.98 Total impact

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    ABSTRACT: There is substantial interest in studying lung function in infants, to better understand the early life origins of chronic lung diseases such as asthma. Multiple breath washout (MBW) is a technique for measuring lung function that has been adapted for use in infants. Respiratory sighs occur frequently in young infants during natural sleep, and in accordance with current MBW guidelines, result in exclusion of data from a substantial proportion of testing cycles. We assessed how sighs during MBW influenced the measurements obtained using data from 767 tests conducted on 246 infants (50% male; mean age 43 days) as part of a large cohort study. Sighs occurred in 119 (15%) tests. Sighs during the main part of the wash-in phase (before the last 5 breaths) were not associated with differences in standard MBW measurements compared with tests without sighs. In contrast, sighs that occurred during the washout were associated with a small but discernible increase in magnitude and variability. For example, the mean lung clearance index increased by 0.36 (95% CI: 0.11-0.62) and variance increased by a multiplicative factor of 2 (95% CI: 1.6-2.5). The results suggest it is reasonable to include MBW data from testing cycles where a sigh occurs during the wash-in phase, but not during washout, of MBW. By recovering data that would otherwise have been excluded, we estimate a boost of about 10% to the final number of acceptable tests and 6% to the number of individuals successfully tested. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.
    04/2015; 3(4). DOI:10.14814/phy2.12347
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    ABSTRACT: The modern environment is associated with an increasing burden of non-communicable diseases (NCDs). Mounting evidence implicates environmental exposures, experienced early in life (including in utero), in the aetiology of many NCDs, though the cellular/molecular mechanism(s) underlying this elevated risk across the life course remain unclear. Epigenetic variation has emerged as a candidate mediator of such effects. The Barwon Infant Study (BIS) is a population-derived birth cohort study (n = 1074 infants) with antenatal recruitment, conducted in the south-east of Australia (Victoria). BIS has been designed to facilitate a detailed mechanistic investigation of development within an epidemiological framework. The broad objectives are to investigate the role of specific environmental factors, gut microbiota and epigenetic variation in early-life development, and subsequent immune, allergic, cardiovascular, respiratory and neurodevelopmental outcomes. Participants have been reviewed at birth and at 1, 6, 9 and 12 months, with 2- and 4-year reviews under way. Biological samples and measures include: maternal blood, faeces and urine during pregnancy; infant urine, faeces and blood at regular intervals during the first 4 years; lung function at 1 month and 4 years; cardiovascular assessment at 1 month and 4 years; skin-prick allergy testing and food challenge at 1 year; and neurodevelopmental assessment at 9 months, 2 and 4 years. Data access enquiries can be made at [www.barwoninfantstudy.org.au] or via [peter.vuillermin@deakin.edu.au]. © The Author 2015; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.
    International Journal of Epidemiology 03/2015; DOI:10.1093/ije/dyv026 · 9.20 Impact Factor
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    ABSTRACT: As there is limited knowledge regarding the longitudinal development and early ontogeny of naïve and regulatory CD4(+) T-cell subsets during the first postnatal year, we sought to evaluate the changes in proportion of naïve (thymic and central) and regulatory (resting and activated) CD4(+) T-cell populations during the first postnatal year. Blood samples were collected and analyzed at birth, 6 and 12 months of age from a population-derived sample of 130 infants. The proportion of naïve and regulatory CD4(+) T-cell populations was determined by flow cytometry, and the thymic and central naïve populations were sorted and their phenotype confirmed by relative expression of T cell-receptor excision circle DNA (TREC). At birth, the majority (94%) of CD4(+) T cells were naïve (CD45RA(+)), and of these, ~80% had a thymic naïve phenotype (CD31(+) and high TREC), with the remainder already central naïve cells (CD31(-) and low TREC). During the first year of life, the naïve CD4(+) T cells retained an overall thymic phenotype but decreased steadily. From birth to 6 months of age, the proportion of both resting naïve T regulatory cells (rTreg; CD4(+)CD45RA(+)FoxP3(+)) and activated Treg (aTreg, CD4(+)CD45RA(-)FoxP3(high)) increased markedly. The ratio of thymic to central naïve CD4(+) T cells was lower in males throughout the first postnatal year indicating early sexual dimorphism in immune development. This longitudinal study defines proportions of CD4(+) T-cell populations during the first year of postnatal life that provide a better understanding of normal immune development.
    03/2015; 4(3):e34. DOI:10.1038/cti.2015.2
  • Pediatrics 01/2015; 135(2). DOI:10.1542/peds.2014-1832 · 5.30 Impact Factor
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    ABSTRACT: We describe Pseudomonas aeruginosa acquisitions in children with cystic fibrosis (CF) aged ≤5-years, eradication treatment efficacy, and genotypic relationships between upper and lower airway isolates and strains from non-CF sources. Of 168 CF children aged ≤5-years in a bronchoalveolar lavage (BAL)-directed therapy trial, 155 had detailed microbiological results. Overall, 201/271 (74%) P. aeruginosa isolates from BAL and oropharyngeal cultures were available for genotyping, including those collected before and after eradication therapy. Eighty-two (53%) subjects acquired P. aeruginosa, of which most were unique strains. Initial eradication success rate was 90%, but 36 (44%) reacquired P. aeruginosa, with genotypic substitutions more common in BAL (12/14) than oropharyngeal (3/11) cultures. Moreover, oropharyngeal cultures did not predict BAL genotypes reliably. CF children acquire environmental P. aeruginosa strains frequently. However, discordance between BAL and oropharyngeal strains raises questions over upper airway reservoirs and how to best determine eradication in non-expectorating children. Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.
    Journal of cystic fibrosis: official journal of the European Cystic Fibrosis Society 01/2015; 14(3). DOI:10.1016/j.jcf.2014.12.007 · 3.82 Impact Factor
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    ABSTRACT: As there is limited knowledge regarding the longitudinal development and early ontogeny of naı ̈ve and regulatory CD4+ T-cell subsets during the first postnatal year, we sought to evaluate the changes in proportion of naı ̈ve (thymic and central) and regulatory (resting and activated) CD4+ T-cell populations during the first postnatal year. Blood samples were collected and analyzed at birth, 6 and 12 months of age from a population-derived sample of 130 infants. The proportion of naı ̈ ve and regulatory CD4+ T-cell populations was determined by flow cytometry, and the thymic and central naı ̈ve populations were sorted and their phenotype confirmed by relative expression of T cell-receptor excision circle DNA (TREC). At birth, the majority (94%) of CD4+ T cells were naı ̈ ve (CD45RA+), and of these, ~ 80% had a thymic naı ̈ ve phenotype (CD31+ and high TREC), with the remainder already central naı ̈ve cells (CD31− and low TREC). During the first year of life, the naı ̈ve CD4+ T cells retained an overall thymic phenotype but decreased steadily. From birth to 6 months of age, the proportion of both resting naı ̈ve T regulatory cells (rTreg; CD4+CD45RA+FoxP3+) and activated Treg (aTreg, CD4+CD45RA−FoxP3high) increased markedly. The ratio of thymic to central naı ̈ve CD4+ T cells was lower in males throughout the first postnatal year indicating early sexual dimorphism in immune development. This longitudinal study defines proportions of CD4+ T-cell populations during the first year of postnatal life that provide a better understanding of normal immune development.
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    ABSTRACT: Objectives: To describe the incidence rate and clinical outcomes of intussusception in Australia in children aged <24 months prior to the use of rotavirus vaccines in Australia, and to explore associations between patient characteristics and outcomes in children with intussusception.Methods: This study used Australian national hospital discharge data on intussusception from July 2000 to June 2006 for children aged <24 months and data from the Australian Bureau of Statistics (ABS) as a proxy for population numbers to estimate incidence. Logistic regression was used to examine associations between patient characteristics (age, sex, ethnicity) and outcomes (length of hospital stay >2 days and the need for surgical intervention).Results: The overall incidence rate of intussusception was 5.4 per 10,000 child-years in children under 24 months (95%CI 5.17–5.70). There was a declining rate over the study period (p<0.001). Age at time of intussusception was strongly associated with length of hospital stay and surgery.Conclusions: This study provides an estimate of the pre-rotavirus vaccine incidence of intussusception across Australia, which is important for monitoring the occurrence of intussusceptions post the introduction of rotavirus vaccine.
    Australian and New Zealand Journal of Public Health 12/2014; 39(1). DOI:10.1111/1753-6405.12297 · 1.90 Impact Factor
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    The Lancet Respiratory Medicine 11/2014; 2(12). DOI:10.1016/S2213-2600(14)70273-5
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    ABSTRACT: Neonatal illness is a leading cause of death worldwide; sepsis is one of the main contributors. The etiologies of community-acquired neonatal bacteremia in developing countries have not been well characterized.
    The Pediatric Infectious Disease Journal 11/2014; DOI:10.1097/INF.0000000000000549 · 3.14 Impact Factor
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    ABSTRACT: Multiple imputation has entered mainstream practice for the analysis of incomplete data. We have used it extensively in a large Australian longitudinal cohort study, the Victorian Adolescent Health Cohort Study (1992-2008). Although we have endeavored to follow best practices, there is little published advice on this, and we have not previously examined the extent to which variations in our approach might lead to different results. Here, we examined sensitivity of analytical results to imputation decisions, investigating choice of imputation method, inclusion of auxiliary variables, omission of cases with excessive missing data, and approaches for imputing highly skewed continuous distributions that are analyzed as dichotomous variables. Overall, we found that decisions made about imputation approach had a discernible but rarely dramatic impact for some types of estimates. For model-based estimates of association, the choice of imputation method and decisions made to build the imputation model had little effect on results, whereas estimates of overall prevalence and prevalence stratified by subgroup were more sensitive to imputation method and settings. Multiple imputation by chained equations gave more plausible results than multivariate normal imputation for prevalence estimates but appeared to be more susceptible to numerical instability related to a highly skewed variable.
    American Journal of Epidemiology 10/2014; 180(9). DOI:10.1093/aje/kwu224 · 4.98 Impact Factor
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    ABSTRACT: Objective Cardiorespiratory fitness and adiposity may influence cardiovascular risk through their effects on inflammation. The long-term effects of these modifiable factors on adult inflammation remain uncertain. The associations of childhood and adulthood cardiorespiratory fitness and adiposity with adult inflammation (C-reactive protein (CRP), fibrinogen) were examined.Methods1,976 children examined in 1985 and re-examined as young adults in 2004-2006 were included. Cardiorespiratory fitness and adiposity were assessed at both waves. CRP and fibrinogen were measured at follow-up.ResultsHigher childhood fitness was associated with lower adult inflammation in both sexes. After adjusting for childhood adiposity, the association with CRP attenuated in males, but remained in females (average reduction of CRP 18.1% (95% CI 11.3-24.4%) per 1-SD increase in childhood fitness). Higher adult fitness, adjusting for childhood fitness (an increase in fitness from childhood to adulthood), was associated with lower adult CRP in females and lower fibrinogen in males. Higher childhood and adulthood adiposity (an increase in adiposity from childhood to adulthood) were associated with higher adult inflammation in both sexes.Conclusions Prevention programs to increase fitness and reduce adiposity in childhood, and maintain a favorable fitness and weight into adulthood, may lead to reduction in adult systemic inflammation.
    Obesity 10/2014; DOI:10.1002/oby.20871 · 4.39 Impact Factor
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    ABSTRACT: It is now recognized that preterm infants <=28 weeks gestation can be effectively supported from the outset with nasal continuous positive airway pressure. However, this form of respiratory therapy may fail to adequately support those infants with significant surfactant deficiency, with the result that intubation and delayed surfactant therapy are then required. Infants following this path are known to have a higher risk of adverse outcomes, including death, bronchopulmonary dysplasia and other morbidities. In an effort to circumvent this problem, techniques of minimally-invasive surfactant therapy have been developed, in which exogenous surfactant is administered to a spontaneously breathing infant who can then remain on continuous positive airway pressure. A method of surfactant delivery using a semi-rigid surfactant instillation catheter briefly passed into the trachea (the "Hobart method") has been shown to be feasible and potentially effective, and now requires evaluation in a randomised controlled trial.Methods/design: This is a multicentre, randomised, masked, controlled trial in preterm infants 25-28 weeks gestation. Infants are eligible if managed on continuous positive airway pressure without prior intubation, and requiring FiO2 >= 0.30 at an age <=6 hours. Randomisation will be to receive exogenous surfactant (200 mg/kg poractant alfa) via the Hobart method, or sham treatment. Infants in both groups will thereafter remain on continuous positive airway pressure unless intubation criteria are reached (FiO2 >= 0.45, unremitting apnoea or persistent acidosis). Primary outcome is the composite of death or physiological bronchopulmonary dysplasia, with secondary outcomes including incidence of death; major neonatal morbidities; durations of all modes of respiratory support and hospitalisation; safety of the Hobart method; and outcome at 2 years. A total of 606 infants will be enrolled. The trial will be conducted in >30 centres worldwide, and is expected to be completed by end-2017.
    BMC Pediatrics 08/2014; 14(1):213. DOI:10.1186/1471-2431-14-213 · 1.92 Impact Factor
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    ABSTRACT: Objectives To determine whether bronchoalveolar lavage (BAL)-directed therapy for infants and young children with cystic fibrosis (CF), rather than standard therapy, was justified on the grounds of a decrease in average costs and whether the use of BAL reduced treatment costs associated with hospital admissions. Study design Costs were assessed in a randomized controlled trial conducted in Australia and New Zealand on infants diagnosed with CF after newborn screening and assigned to receive either BAL-directed or standard therapy until they reached 5 years of age. A health care funder perspective was adopted. Resource use measurement was based on standardized data collection forms administered for patients across all sites. Unit costs were obtained primarily from government schedules. Results Mean costs per child during the study period were Australian dollars (AUD)92 860 in BAL-directed therapy group and AUD90 958 in standard therapy group (mean difference AUD1902, 95% CI AUD-27 782 to 31 586, P = .90). Mean hospital costs per child during the study period were AUD57 302 in the BAL-directed therapy group and AUD66 590 in the standard therapy group (mean difference AUD-9288; 95% CI AUD-35 252 to 16 676, P = .48). Conclusions BAL-directed therapy did not result in either lower mean hospital admission costs or mean costs overall compared with managing patients with CF by a standard protocol based upon clinical features and oropharyngeal culture results alone. Following on our previous findings that BAL-directed treatment offers no clinical advantage over standard therapy at age 5 years, flexible bronchoscopy with BAL cannot be recommended for the routine management of preschool children with CF on the basis of overall cost savings.
    Journal of Pediatrics 07/2014; 165(3). DOI:10.1016/j.jpeds.2014.05.031 · 3.74 Impact Factor
  • Journal of Paediatrics and Child Health 06/2014; 50(12). DOI:10.1111/jpc.12597 · 1.19 Impact Factor
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    ABSTRACT: Background Aortic intima-media thickness measured by transabdominal ultrasound (aIMT) is an intermediate phenotype of cardiovascular risk. We aimed to (1) investigate the reproducibility of aIMT in a population-derived cohort of infants; (2) establish the distribution of aIMT in early infancy; (3) compare measurement by edge-detection software to that by manual sonographic calipers; and (4) assess the effect of individual and environmental variables on image quality. Methods Participants were term infants recruited to a population-derived birth cohort study. Transabdominal ultrasound was performed at six weeks of age by one of two trained operators. Thirty participants had ultrasounds performed by both operators on the same day. Data were collected on environmental (infant sleeping, presence of a sibling, use of sucrose, timing during study visit) and individual (post-conception age, weight, gender) variables. Two readers assessed image quality and measured aIMT by edge-detection software and a subset by manual sonographic calipers. Measurements were repeated by the same reader and between readers to obtain intra-observer and inter-observer reliability. Results Aortic IMT was measured successfully using edge-detection in 814 infants, and 290 of these infants also had aIMT measured using manual sonographic calipers. The intra-reader intra-class correlation (ICC) (n = 20) was 0.90 (95% CI 0.76, 0.96), mean difference 1.5 μm (95% LOA −39, 59). The between reader ICC using edge-detection (n = 20) was 0.92 (95% CI 0.82, 0.97) mean difference 2 μm (95% LOA −45.0, 49.0) and with manual caliper measurement (n = 290) the ICC was 0.84 (95% CI 0.80, 0.87) mean difference 5 μm (95% LOA −51.8, 61.8). Edge-detection measurements were greater than those from manual sonographic calipers (mean aIMT 618 μm (50) versus mean aIMT 563 μm (49) respectively; p < 0.001, mean difference 44 μm, 95% LOA −54, 142). With the exception of infant crying (p = 0.001), no associations were observed between individual and environmental variables and image quality. Conclusion In a population-derived cohort of term infants, aIMT measurement has a high level of intra and inter-reader reproducibility. Measurement of aIMT using edge-detection software gives higher inter-reader ICC than manual sonographic calipers. Image quality is not substantially affected by individual and environmental factors.
    Cardiovascular Ultrasound 06/2014; 12(1):18. DOI:10.1186/1476-7120-12-18 · 1.28 Impact Factor
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    ABSTRACT: Multiple imputation (MI) was developed as a method to enable valid inferences to be obtained in the presence of missing data rather than to re-create the missing values. Within the applied setting, it remains unclear how important it is that imputed values should be plausible for individual observations. One variable type for which MI may lead to implausible values is a limited-range variable, where imputed values may fall outside the observable range. The aim of this work was to compare methods for imputing limited-range variables, with a focus on those that restrict the range of the imputed values. Using data from a study of adolescent health, we consider three variables based on responses to the General Health Questionnaire (GHQ), a tool for detecting minor psychiatric illness. These variables, based on different scoring methods for the GHQ, resulted in three continuous distributions with mild, moderate and severe positive skewness. In an otherwise complete dataset, we set 33% of the GHQ observations to missing completely at random or missing at random; repeating this process to create 1000 datasets with incomplete data for each scenario.For each dataset, we imputed values on the raw scale and following a zero-skewness log transformation using: univariate regression with no rounding; post-imputation rounding; truncated normal regression; and predictive mean matching. We estimated the marginal mean of the GHQ and the association between the GHQ and a fully observed binary outcome, comparing the results with complete data statistics. Imputation with no rounding performed well when applied to data on the raw scale. Post-imputation rounding and imputation using truncated normal regression produced higher marginal means than the complete data estimate when data had a moderate or severe skew, and this was associated with under-coverage of the complete data estimate. Predictive mean matching also produced under-coverage of the complete data estimate. For the estimate of association, all methods produced similar estimates to the complete data. For data with a limited range, multiple imputation using techniques that restrict the range of imputed values can result in biased estimates for the marginal mean when data are highly skewed.
    BMC Medical Research Methodology 04/2014; 14(1):57. DOI:10.1186/1471-2288-14-57 · 2.17 Impact Factor
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    ABSTRACT: The aim of this study was to describe the distribution of magnetic resonance imaging (MRI) patterns in a large population sample of children with cerebral palsy (CP) and to examine associations between MRI patterns, and antenatal and perinatal variables. Data were retrieved from the Victorian CP Register for 884 children (527 males, 357 females) born between 1999 and 2006. Postneonatal MRI was classified for 594 children. For 563 children (329 males, 234 females) for whom classification was to a single MRI pattern, the frequency of each variable was compared between patterns and with the population frequency. White matter injury was the most common MRI pattern (45%), followed by grey matter injury (14%), normal imaging (13%), malformations (10%), focal vascular insults (9%), and miscellaneous patterns (7%). Parity, birth gestation, level of neonatal care, Apgar score, and time to established respiration varied between MRI patterns (p<0.01). Nulliparity was most strongly associated with focal vascular insults, whereas multiparity was associated only with malformations. Grey matter injury was not associated with birth in a tertiary unit, but was strongly associated with severe perinatal compromise. The frequency of neonatal seizures and of nursery admissions was lowest among children with malformations. As known risk factors for CP are differentially associated with specific MRI patterns, future exploration of causal pathways might be facilitated when performed in pathogenically defined groups.
    Developmental Medicine & Child Neurology 02/2014; 56(2):178-84. DOI:10.1111/dmcn.12331 · 3.29 Impact Factor
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    Katherine J Lee, John B Carlin
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    ABSTRACT: The self-controlled case series method is a statistical approach to investigating associations between acute outcomes and transient exposures. The method uses cases only and compares time at risk after the transient exposure with time at risk outside the exposure period within an individual, using conditional Poisson regression. The risk of outcome and exposure often varies over time, for example, with age, and it is important to allow for such time dependence within the analysis. The standard approach for modelling time-varying covariates is to split observation periods into blocks according to categories of the covariate and then to model the relationship using indicators for each category. However, this can be inefficient and can lead to problems with collinearity if the exposure occurs at approximately the same time in all individuals. As an alternative, we propose using fractional polynomials to model the relationship between the time-varying covariate and incidence of the outcome. We present the results from an analysis exploring the association between rotavirus vaccination and intussusception risk as well as a simulation study. We conclude that fractional polynomials provide a useful approach to adjusting for time-varying covariates but that it is important to explore the sensitivity of the results to the number of categories and the method of adjustment. Copyright © 2013 John Wiley & Sons, Ltd.
    Statistics in Medicine 01/2014; 33(1). DOI:10.1002/sim.5911 · 2.04 Impact Factor
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    ABSTRACT: Most adults with common mental disorders report their first symptoms before 24 years of age. Although adolescent anxiety and depression are frequent, little clarity exists about which syndromes persist into adulthood or resolve before then. In this report, we aim to describe the patterns and predictors of persistence into adulthood. We recruited a stratified, random sample of 1943 adolescents from 44 secondary schools across the state of Victoria, Australia. Between August, 1992, and January, 2008, we assessed common mental disorder at five points in adolescence and three in young adulthood, commencing at a mean age of 15·5 years and ending at a mean age of 29·1 years. Adolescent disorders were defined on the Revised Clinical Interview Schedule (CIS-R) at five adolescent measurement points, with a primary cutoff score of 12 or higher representing a level at which a family doctor would be concerned. Secondary analyses addressed more severe disorders at a cutoff of 18 or higher. 236 of 821 (29%; 95% CI 25-32) male participants and 498 of 929 (54%; 51-57) female participants reported high symptoms on the CIS-R (≥12) at least once during adolescence. Almost 60% (434/734) went on to report a further episode as a young adult. However, for adolescents with one episode of less than 6 months duration, just over half had no further common mental health disorder as a young adult. Longer duration of mental health disorders in adolescence was the strongest predictor of clear-cut young adult disorder (odds ratio [OR] for persistent young adult disorder vs none 3·16, 95% CI 1·86-5·37). Girls (2·12, 1·29-3·48) and adolescents with a background of parental separation or divorce (1·62, 1·03-2·53) also had a greater likelihood of having ongoing disorder into young adulthood than did those without such a background. Rates of adolescent onset disorder dropped sharply by the late 20s (0·57, 0·45-0·73), suggesting a further resolution for many patients whose symptoms had persisted into the early 20s. Episodes of adolescent mental disorder often precede mental disorders in young adults. However, many such disorders, especially when brief in duration, are limited to the teenage years, with further symptom remission common in the late 20s. The resolution of many adolescent disorders gives reason for optimism that interventions that shorten the duration of episodes could prevent much morbidity later in life. Australia's National Health and Medical Research Council.
    The Lancet 01/2014; DOI:10.1016/S0140-6736(13)62116-9 · 39.21 Impact Factor

Publication Stats

19k Citations
1,758.98 Total Impact Points

Institutions

  • 2001–2015
    • Murdoch Childrens Research Institute
      • • Clinical Epidemiology & Biostatistics (CEBU)
      • • Research Group for Healthy Mothers Healthy Families
      • • Centre for Adolescent Health
      Melbourne, Victoria, Australia
  • 1991–2015
    • University of Melbourne
      • Department of Paediatrics
      Melbourne, Victoria, Australia
  • 1994–2011
    • Victoria University Melbourne
      Melbourne, Victoria, Australia
  • 1992–2011
    • The Royal Children's Hospital
      • • Centre for Community Child Health
      • • Clinical Epidemiology and Biostatistics Unit (CEBU)
      • • Centre for Adolescent Health
      • • Department of Respiratory Medicine
      Melbourne, Victoria, Australia
  • 2010
    • University of Bristol
      • Faculty of Medicine and Dentistry
      Bristol, England, United Kingdom
    • Geelong Hospital
      Geelong, Victoria, Australia
  • 2002–2010
    • University of New South Wales
      • National Drug and Alcohol Research Centre
      Kensington, New South Wales, Australia
  • 2009
    • Ministry of Health, Fiji
      Suva City, Central, Fiji
  • 2008
    • Sydney Children's Hospital
      Sydney, New South Wales, Australia
    • University of KwaZulu-Natal
      • Department of Paediatrics and Child Health
      Durban, KwaZulu-Natal, South Africa
  • 2007
    • University of Queensland
      • Institute for Molecular Bioscience
      Brisbane, Queensland, Australia
    • National Maternity Hospital
      Dublin, Leinster, Ireland
    • Biomedical Informatics Centre
      Chandigarh, Chandīgarh, India
    • All India Institute of Medical Sciences
      New Dilli, NCT, India
  • 2006
    • Alfred Hospital
      • Department of Allergy, Immunology & Respiratory Medicine (AIRmed)
      Melbourne, Victoria, Australia
    • Cancer Council Victoria
      • Centre for Behavioural Research in Cancer
      Melbourne, Victoria, Australia
  • 2005
    • Harvard University
      Cambridge, Massachusetts, United States
    • University of Adelaide
      Tarndarnya, South Australia, Australia
  • 2000–2003
    • Royal Melbourne Hospital
      Melbourne, Victoria, Australia
    • Birmingham Children's Hospital NHS Foundation Trust
      Birmingham, England, United Kingdom