Kumanu Tangata: the aftermatch study - protocol to examine the health outcomes of high-level male rugby union players using linked administrative data.

There is increasing interest in the potential long-term outcomes of participation in contact and collision sports, driven by evidence of higher rates of neurodegenerative diseases among former athletes. Recent research has capitalised on large-scale administrative health data to examine health outcomes in contact sport athletes. However, there is limited research on outcomes associated with participation in rugby union, a contact sport with a relatively high incidence of head trauma and musculoskeletal injuries. Additionally, there is scope to investigate a greater range of health outcomes using large, population-based administrative data. The Kumanu Tangata project is a retrospective cohort study that will use linked information from the New Zealand Rugby Register and health records within a comprehensive deidentified whole-population administrative research database known as the Integrated Data Infrastructure. First-class male rugby union players (N=13 227) will be compared with a general population comparison group (N=2 438 484; weighting will be applied due to demographic differences) on a range of mortality and morbidity outcomes (neurodegenerative diseases, musculoskeletal conditions, chronic physical conditions, mental health outcomes). A range of player-specific variables will also be investigated as risk factors. Analyses will consist primarily of Cox proportional hazards models. Ethics approval for the study has been granted by the Auckland Health Research Ethics Committee (Ref. AH23203). Primary research dissemination will be via peer-reviewed journal articles.

Suicides, drug poisonings, and alcohol-related deaths cluster with health and social disadvantage in 4.1 million citizens from two nations.

BACKGROUND: Deaths from suicides, drug poisonings, and alcohol-related diseases ('deaths of despair') are well-documented among working-age Americans, and have been hypothesized to be largely specific to the U.S. However, support for this assertion-and associated policies to reduce premature mortality-requires tests concerning these deaths in other industrialized countries, with different institutional contexts. We tested whether the concentration and accumulation of health and social disadvantage forecasts deaths of despair, in New Zealand and Denmark. METHODS: We used nationwide administrative data. Our observation period was 10 years (NZ = July 2006-June 2016, Denmark = January 2007-December 2016). We identified all NZ-born and Danish-born individuals aged 25-64 in the last observation year (NZ = 1 555 902, Denmark = 2 541 758). We ascertained measures of disadvantage (public-hospital stays for physical- and mental-health difficulties, social-welfare benefit-use, and criminal convictions) across the first nine years. We ascertained deaths from suicide, drugs, alcohol, and all other causes in the last year. RESULTS: Deaths of despair clustered within a population segment that disproportionately experienced multiple disadvantages. In both countries, individuals in the top 5% of the population in multiple health- and social-service sectors were at elevated risk for deaths from suicide, drugs, and alcohol, and deaths from other causes. Associations were evident across sex and age. CONCLUSIONS: Deaths of despair are a marker of inequalities in countries beyond the U.S. with robust social-safety nets, nationwide healthcare, and strong pharmaceutical regulations. These deaths cluster within a highly disadvantaged population segment identifiable within health- and social-service systems.

Behavioural outcomes of children exposed to antidepressants and unmedicated depression during pregnancy.

BACKGROUND: Antenatal exposure to both antidepressants and maternal depression has been associated with child behavioural difficulties. However, previous research has not adequately distinguished between the effects of the antidepressants and the underlying maternal depression. METHODS: Child behavioural difficulties were assessed using the Strengths and Difficulties Questionnaire at 2-, 4.5-, and 8-years of age by mothers in the Growing Up in New Zealand study (N = 6233 at 2-years; N = 6066 at 4.5-years; N = 4632 at 8-years). Mothers were classified as either on antidepressants, unmedicated depression, or neither based on self-reported antidepressant intake during pregnancy and the Edinburgh Postnatal Depression Scale. Hierarchical multiple logistic regressions were used to examine whether antenatal exposure to antidepressants and unmedicated depression had a differential association with child behavioural outcomes relative to no exposure. RESULTS: When later life depression in the mother and a range of birth and sociodemographic variables were accounted for, neither antenatal exposure to unmedicated depression or antidepressants remained associated with an increased risk of behavioural difficulties at the ages investigated. However, maternal later life depression was associated with behavioural difficulties in the fully adjusted analyses at all three ages investigated. LIMITATIONS: The current study relied on mother-report of child behaviour which may be susceptible to bias due to maternal mental health problems. CONCLUSIONS: Adjusted results did not show an adverse association between antenatal antidepressant exposure or unmedicated depression in relation to child behaviour. Findings also suggest that efforts to improve child behaviour need to include more family-based approaches that support maternal wellbeing.

Risk of Criminal Justice System Interactions in Young Adults with Attention-Deficit/Hyperactivity Disorder: Findings From a National Birth Cohort.

OBJECTIVE: To examine criminal justice system (CJS) interactions and pathways through the justice system for young adults with ADHD compared to young adults without ADHD. METHOD: Nationwide 3-year birth cohort study using linked health and CJS data. Cox proportional hazards models were employed to examine associations between ADHD and police proceedings, court charges, court convictions, and incarcerations. RESULTS: Young adults with ADHD were significantly more likely to interact with the CJS including police proceedings (hazard ratio [HR], 2.1 95% CI [2.0, 2.2]) court charges (HR, 2.2 95% CI [2.1, 2.3]), court convictions (HR, 2.3 95% CI [2.2, 2.4]), and incarceration (HR, 4.8 95% CI [4.3, 5.4]). CONCLUSIONS: Young adults with ADHD are overrepresented at all stages of the CJS. Results highlight the importance of early identification and responsivity to ADHD within the CJS and suggest that the NZ justice system may require changes to both areas to ensure that young individuals with ADHD receive equitable access to, and treatment within, the CJS.

Medication dispensing among Maori and non-Maori screened for preschool ADHD.

AIMS: To investigate whether tamariki Maori screened for attention-deficit/hyperactivity disorder (ADHD) concerns in the B4 School Check (B4SC) between 2011 to 2018 are as likely to receive ADHD medication as non-Maori children. METHODS: Using population-level data from the Integrated Data Infrastructure, we investigated whether ADHD medication dispensing differed for tamariki Maori screened for ADHD concerns relative to non-Maori children. Analyses were also stratified by area-level deprivation and urban/rural profile of residence. RESULTS: In our cohort of 414,171 children, 2.8% of Maori and 1.6% of non-Maori were screened as showing ADHD concerns. Among those with ADHD concerns, tamariki Maori had a lower likelihood of ADHD medication dispensing following the B4SC (10.8%) relative to non-Maori children (14.9%), but this effect was only significant among those living in the most deprived quintile and outside of major urban areas. CONCLUSION: Our study indicates that inequities to accessing ADHD treatment may exist for tamariki Maori living in highly deprived neighbourhoods or outside of major urban areas. Further research is needed to understand what the specific barriers may be to accessing ADHD medication treatment for Maori in these areas.

Venous thromboembolism risk screening, training and provider awareness in Australian residential aged care facilities.

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality in the geriatric post-surgical population, and its prevention is a public health priority. The aim of this study was to assess the use of VTE risk screening and training protocols, and VTE awareness in the Australian residential aged care sector. A cross-sectional survey was conducted that was directed at facility and policy managers of community aged care facilities with ≥10 residents in two Australian states and territories. Forty-nine of 301 (16.3%) providers responded, representing 249/871 (28.6%) aged care facilities and 20,958/66,121 (31.7%) residents. VTE risk screening protocols were used by 1.2% of facilities (3/249), and 79.5% (198/249) were unaware that VTE is an issue in this population. Only 0.8% (2/249) were aware that risk screening and prophylaxis is required to prevent VTE; none were acting upon this. No facility had specific VTE risk assessment or prevention processes in place. Most residential aged care facilities surveyed do not have VTE risk screening protocols and were unaware of the risk that may be associated with this omission. These results have implications for development and implementation of national and international VTE risk screening guidelines in community care.

Predictors of longitudinal seizure outcomes after epilepsy surgery in childhood.

There is a paucity of data on longitudinal seizure outcome of children undergoing epilepsy surgery. All children (n = 132) who underwent resective epilepsy surgery from January 1998 to December 2015 were identified. Relevant clinical, neurophysiological, imaging, surgical and seizure outcome data were extracted. Multivariable logistic regression analysis and Kaplan-Meier survival with Cox proportional hazard modelling were performed. The mean age at surgery was 7.8 years (range 0.2-17.9). 71% were seizure-free at a mean follow up of 5.3 ± 2.7 years. Of those who were seizure-free, 65 patients were able to completely wean off anti- seizure medications successfully. Using survival analysis, the probability of Engel Class I outcome at one year after surgery was 81% (95% confidence interval [CI] 87%-75%). This dropped to 73% at two years (95% CI 81%-65%), 58% at five years (95% CI 67.8%-48%), and 47% at ten years. Proportional hazard modelling showed that the presence of moderate to severe developmental disability (HR 6.5; p = 0.02) and lack of complete resection (HR 0.4; p = 0.02) maintain association as negative predictors of seizure-free outcome. Our study demonstrates favorable long-term seizure control following pediatric epilepsy surgery and highlights important predictors of seizure outcome guiding case selection and counseling of expectations prior to surgery.

Longitudinal Associations of Mental Disorders With Dementia: 30-Year Analysis of 1.7 Million New Zealand Citizens.

IMPORTANCE: Mental disorders are an underappreciated category of modifiable risk factors for dementia. Developing an evidence base about the link between mental disorders and dementia risk requires studies that use large, representative samples, consider the full range of psychiatric conditions, ascertain mental disorders from early life, use long follow-ups, and distinguish between Alzheimer disease and related dementias. OBJECTIVE: To test whether mental disorders antedate dementia across 3 decades of observation. DESIGN, SETTING, AND PARTICIPANTS: This population-based administrative register study of mental disorders and Alzheimer disease and related dementias included all individuals born in New Zealand between 1928 and 1967 who resided in the country for any time during the 30-year observation period between July 1988 and June 2018. Data were from the New Zealand Integrated Data Infrastructure, a collection of whole-of-population administrative data sources linked at the individual level. Data were analyzed from October 2020 to November 2021. EXPOSURES: Diagnoses of mental disorders were ascertained from public-hospital records. MAIN OUTCOMES AND MEASURES: Diagnoses of dementia were ascertained from public-hospital records, mortality records, and pharmaceutical records. RESULTS: Of 1 711 386 included individuals, 866 301 (50.6%) were male, and individuals were aged 21 to 60 years at baseline. Relative to individuals without a mental disorder, those with a mental disorder were at increased risk of developing subsequent dementia (relative risk [RR], 4.24; 95% CI, 4.07-4.42; hazard ratio, 6.49; 95% CI, 6.25-6.73). Among individuals with dementia, those with a mental disorder developed dementia a mean of 5.60 years (95% CI, 5.31-5.90) earlier than those without a mental disorder. Associations held across sex and age and after accounting for preexisting chronic physical diseases and socioeconomic deprivation. Associations were present across different types of mental disorders and self-harm behavior (RRs ranged from 2.93 [95% CI, 2.66-3.21] for neurotic disorders to 6.20 [95% CI, 5.67-6.78] for psychotic disorders), and were evident for Alzheimer disease (RR, 2.76; 95% CI, 2.45-3.11) and all other dementias (RR, 5.85; 95% CI, 5.58-6.13). CONCLUSIONS AND RELEVANCE: In this study, mental disorders were associated with the onset of dementia in the population. Ameliorating mental disorders in early life might also ameliorate neurodegenerative conditions and extend quality of life in old age.

Associations between antenatal maternal diet and other health aspects with infant temperament in a large multiethnic cohort study: a path analysis approach.

OBJECTIVES: The aim of this study was to assess the association of antenatal maternal dietary patterns (DPs) and other health aspects with infant temperament in a large multiethnic cohort, taking maternal personality and prenatal stress into account. DESIGN AND METHODS: Using data from 3968 children born in 2009/2010 and their mothers from the Growing Up in New Zealand cohort, infant temperament was assessed at 9 months using the Infant Behavior Questionnaire-Revised Very Short Form. Maternal antenatal diet and other health aspects were assessed antenatally. Maternal DPs (n=4) were derived using principal components analysis based on food intake reported on a 44-item food frequency questionnaire. Path analyses investigated factors associated with infant temperament, namely maternal personality, prenatal maternal stress, DPs and other health aspects, including potential inter-relations and mediating effects. RESULTS: Women who scored higher in the fusion DP (standardised beta (ß)=0.05; 95% CI 0.02 to 0.09) and healthy DP (ß=0.05; 95% CI 0.02 to 0.09), who exercised more (ß=0.04; 95% CI 0.01 to 0.07), and who drank less alcohol (ß=-0.05; 95% CI -0.08 to -0.02) were more likely to have infants with an overall less difficult temperament. Sex-specific differences were found in the associations between maternal DP and infant temperament. Maternal personality and prenatal stress were significantly associated with all dimensions of infant temperament. The strongest predictors for a more difficult temperament were prenatal stress (ß=0.12; 95% CI 0.08 to 0.15) and the personality dimensions neuroticism (ß=0.10; 95% CI 0.07 to 0.14) and extraversion (ß=-0.09; 95% CI -0.12 to -0.06). CONCLUSIONS: Associations of antenatal maternal diet and health aspects with infant temperament were statistically significant but small. While they should not be overinterpreted as being deterministic, the findings of this study support the link between maternal modifiable health-related behaviours and infant temperament outcomes.

Prenatal determinants of depressive symptoms in childhood: Evidence from Growing Up in New Zealand.

BACKGROUND: Young people who experience depression are at an increased risk of adverse psychosocial and developmental outcomes that can persist over the lifecourse. Identifying maternal prenatal risk factors that may contribute to childhood depressive symptoms can be useful when considering mental health intervention. METHODS: The current study included 3,925 children from the Growing Up in New Zealand (GUiNZ) study who had complete data for self-reported depressive symptoms and mothers' antenatal information. Depressive symptoms were measured at age 8 using the Centre for Epidemiological Studies Depression Scale for Children (CESD-10) short form questionnaire. Hierarchical linear regression was used to determine the relationship between prenatal factors and depressive symptoms at age 8. RESULTS: When controlling for sociodemographic characteristics, our hierarchical linear regression revealed that the most significant maternal prenatal predictors of high depressive symptoms at age 8 were maternal perceived stress, smoking during pregnancy, body mass index (BMI) in the overweight/obese range, and paracetamol intake. LIMITATIONS: One limitation with the current study was a reduction in the sample due to attrition. This may have affected our statistical power, reflected in our modest effect sizes. The sample remained both socioeconomically and ethnically diverse, however our results should be interpreted with respect to the sample and not the whole New Zealand population. CONCLUSIONS: A combination of maternal mental health and lifestyle factors contribute to depressive symptoms for children, possibly through foetal programming. Our results emphasise the importance of mental and physical health support for expectant mothers.

Use of Population-Level Administrative Data in Developmental Science.

Population-level administrative data-data on individuals' interactions with administrative systems (e.g., health, criminal justice, and education)-have substantially advanced our understanding of life-course development. In this review, we focus on five areas where research using these data has made significant contributions to developmental science: (a) understanding small or difficult-to-study populations, (b) evaluating intergenerational and family influences, (c) enabling estimation of causal effects through natural experiments and regional comparisons, (d) identifying individuals at risk for negative developmental outcomes, and (e) assessing neighborhood and environmental influences. Further advances will be made by linking prospective surveys to administrative data to expand the range of developmental questions that can be tested; supporting efforts to establish new linked administrative data resources, including in developing countries; and conducting cross-national comparisons to test findings' generalizability. New administrative data initiatives should involve consultation with population subgroups including vulnerable groups, efforts to obtain social license, and strong ethical oversight and governance arrangements.

Prevalence of antidepressant use and unmedicated depression in pregnant New Zealand women.

BACKGROUND: Throughout pregnancy, women are at an increased risk of depression, with prevalence estimates between 6.5% and 18%. Global prevalence of antenatal antidepressant use is considerably lower at 3%. OBJECTIVE: The present study determined the proportion of women taking antidepressants across pregnancy in New Zealand. We investigated whether variation exists across age bands, area-level deprivation and ethnicities, and identified how many women experienced unmedicated depression. METHOD: Antenatal data (n = 6822) consisted of primarily third-trimester interviews conducted with mothers participating in Growing Up in New Zealand, a longitudinal study investigating child development. Women were asked about their antidepressant intake during pregnancy and assessed on antenatal depression symptoms using the Edinburgh Postnatal Depression Scale. Antidepressant use data were also compared to population-level data from Statistics New Zealand's Integrated Data Infrastructure. RESULTS: Antidepressant prevalence across pregnancy was 3.2%, with a 2.7% prevalence in trimester one and 2.6% following the first trimester. There was no significant difference in usage within age bands and area-level deprivation quintiles. Ethnicity-specific data revealed that Pasifika and Asian ethnicities had the lowest antidepressant use, and New Zealand Europeans the highest. The rate of unmedicated depression, where women met the Edinburgh Postnatal Depression Scale criteria for significant depressive symptoms but did not receive antidepressants during pregnancy, was 11.8%, indicating that antenatal depression treatment may be inadequate. Greater rates of unmedicated depression were seen for younger women (⩽24 years), those living in high deprivation areas and mothers of Pasifika, Asian and Maori ethnicities. CONCLUSIONS: Antenatal antidepressant use in New Zealand follows global prevalence estimates and highlights possible undertreatment of antenatal depression in New Zealand. Future research including other treatment types (e.g. behavioural therapy) is needed to evaluate whether undertreatment occurs across all treatment options.

Patterns of risk exposure in first 1,000 days of life and health, behavior, and education-related problems at age 4.5: evidence from Growing Up in New Zealand, a longitudinal cohort study.

BACKGROUND: Children who are high priority candidates for early intervention need to be identified to reduce their risk for experiencing problems in development. Those exposed to multiple risk factors are more likely to exhibit problems in development than those exposed to a single or no risk factor. We examined the longitudinal associations between persistence and timing of exposure to cumulative risk (CR) on three occasions by age 2 and problems in development at age 4.5 in health, behavior, and education-related domains. METHODS: Data are from Growing Up in New Zealand (NZ), a prospective longitudinal study of a birth cohort first assessed during their last trimester in 2009-10 and followed at ages 9 months and 2 and 4.5 years. All women with an expected delivery date in a 12-month period who resided within a defined region were invited to participate, with no additional eligibility criteria. Exposure was measured for 12 sociodemographic and maternal health risk factors at third trimester and ages 9 months and 2 years, from which developmental trajectories were constructed capturing persistence and timing of CR exposure. Ten developmental outcomes were measured at age 4.5 to classify problems in overall health status, obesity, and injuries; internalizing and externalizing behavior problems; and letter naming, counting forward and backward, and expectations for starting school and completing education. RESULTS: Analyses of data from 6156 children (49% female, 33% Non-European ethnicity) who participated in the 4.5-age assessment uniformly showed associations between exposure to more than consistently zero CR across early development and higher prevalence of being classified with problems for 9 of 10 outcomes. Persistent exposure to a CR ≥ 4 was generally associated with a higher prevalence of problems for 7 of 10 outcomes, whereas the timing of first exposure to CR ≥ 4 showed a less consistent association with problem outcomes. CONCLUSIONS: These findings are concerning because over 50% of NZ children are exposed to at least one of these risk factors at some point in early development. Routine screening of most of these risk factors during pregnancy is feasible and can identify priority candidates for intervention.

Longitudinal Associations of Mental Disorders With Physical Diseases and Mortality Among 2.3 Million New Zealand Citizens.

Importance: Excess risk of physical disease and mortality has been observed among individuals with psychiatric conditions, suggesting that ameliorating mental disorders might also be associated with ameliorating the later onset of physical disability and early mortality. However, the temporal association between mental disorders and physical diseases remains unclear, as many studies have relied on retrospective recall, used cross-sectional designs or prospective designs with limited follow-up periods, or given inadequate consideration to preexisting physical illnesses. Objective: To examine whether mental disorders are associated with subsequent physical diseases and mortality across 3 decades of observation. Design, Setting, and Participants: This population-based cohort study used data from the New Zealand Integrated Data Infrastructure, a collection of nationwide administrative data sources linked at the individual level, to identify mental disorders, physical diseases, and deaths recorded between July 1, 1988, and June 30, 2018, in the population of New Zealand. All individuals born in New Zealand between January 1, 1928, and December 31, 1978, who resided in the country at any time during the 30-year observation period were included in the analysis. Data were analyzed from July 2019 to November 2020. Exposures: Nationwide administrative records of mental disorder diagnoses made in public hospitals. Main Outcomes and Measures: Chronic physical disease diagnoses made in public hospitals, deaths, and health care use. Results: The study population comprised 2 349 897 individuals (1 191 981 men [50.7%]; age range at baseline, 10-60 years). Individuals with a mental disorder developed subsequent physical diseases at younger ages (hazard ratio [HR], 2.33; 95% CI, 2.30-2.36) and died at younger ages (HR, 3.80; 95% CI, 3.72-3.89) than those without a mental disorder. These associations remained across sex and age and after accounting for preexisting physical diseases. Associations were observed across different types of mental disorders and self-harm behavior (relative risks, 1.78-2.43; P < .001 for all comparisons). Mental disorders were associated with the onset of physical diseases and the accumulation of physical disease diagnoses (incidence rate ratio [IRR], 2.00; 95% CI, 1.98-2.03), a higher number of hospitalizations (IRR, 2.43; 95% CI, 2.39-2.48), longer hospital stays for treatment (IRR, 2.70; 95% CI, 2.62-2.79), and higher associated health care costs (b = 0.115; 95% CI, 0.112-0.118). Conclusions and Relevance: In this study, mental disorders were likely to begin and peak in young adulthood, and they antedated physical diseases and early mortality in the population. These findings suggest that ameliorating mental disorders may have implications for improving the length and quality of life and for reducing the health care costs associated with physical diseases.

Medication dispensing for attention-deficit/hyperactivity disorder to New Zealand youth.

AIMS: Global trends show an increase in medication dispensing for attention-deficit/hyperactivity disorder (ADHD) in young people over time. The current study aimed to examine whether similar trends were observed in New Zealand youth over the period of 2007/08 to 2016/17. METHODS: We estimated the prevalence in ADHD medication dispensing using national pharmaceutical data for each fiscal year from 2007/08 to 2016/17 in approximately 2.4 million New Zealand youth aged 1-24 years. We also examined whether trends varied by sociodemographic factors. RESULTS: The total dispensing prevalence almost doubled from 516 per 100,000 to 996 per 100,000 over the study period. Males had a consistently higher dispensing prevalence relative to females. Young people aged 7-17 years had the highest dispensing prevalence. The most deprived quintile had a slightly lower dispensing prevalence relative to other quintiles. Ethnic differences in dispensing prevalence were apparent, with deprivation differences also existing within most ethnic groups. CONCLUSIONS: Overall, our study showed an increase in ADHD medication use by young people in New Zealand, similar to international findings. Further research is needed into why disparities in dispensing prevalence occur across ethnic and socioeconomic groups.

Clustering of health, crime and social-welfare inequality in 4 million citizens from two nations.

Health and social scientists have documented the hospital revolving-door problem, the concentration of crime, and long-term welfare dependence. Have these distinct fields identified the same citizens? Using administrative databases linked to 1.7 million New Zealanders, we quantified and monetized inequality in distributions of health and social problems and tested whether they aggregate within individuals. Marked inequality was observed: Gini coefficients equalled 0.96 for criminal convictions, 0.91 for public-hospital nights, 0.86 for welfare benefits, 0.74 for prescription-drug fills and 0.54 for injury-insurance claims. Marked aggregation was uncovered: a small population segment accounted for a disproportionate share of use-events and costs across multiple sectors. These findings were replicated in 2.3 million Danes. We then integrated the New Zealand databases with the four-decade-long Dunedin Study. The high-need/high-cost population segment experienced early-life factors that reduce workforce readiness, including low education and poor mental health. In midlife they reported low life satisfaction. Investing in young people's education and training potential could reduce health and social inequalities and enhance population wellbeing.

The Association Between Persistence and Change in Early Childhood Behavioural Problems and Preschool Cognitive Outcomes.

The link between behavioural and cognitive difficulties is well established. However, research is limited on whether persistence and change in behavioural difficulties relates to cognitive outcomes, particularly during preschool. We used a large New Zealand birth cohort to investigate how persistence and change in serious behavioural problems from ages 2 to 4.5 years related to measures of cognitive delay at 4.5 years (n = 5885). Using the Strengths and Difficulties total problems score at each time point, children were categorised as showing no difficulties, improved behaviour, concurrent difficulties, and persistent difficulties. Cognitive measures assessed included receptive language, early literacy ability, and executive control. Our results showed that children with concurrent and persistent behavioural difficulties were at a greater risk of showing delays within specific cognitive domains relative to children with no difficulties and were also more likely to show comorbid delays across multiple cognitive domains.

Antenatal determinants of early childhood talking delay and behavioural difficulties.

The determinants of talking delay alone or its comorbidity with behavioural difficulties was examined in 5768 two-year-old members of the Growing Up in New Zealand longitudinal study. Using the MacArthur-Bates Communicative Development inventories and the total difficulties score from the preschool Strengths and Difficulties Questionnaire, a composite measure was created so that children were categorised as showing no language or behavioural concerns (72.5%), behavioural only difficulties (6.1%), language only difficulties (18.1%), and comorbid language and behavioural difficulties (3.3%). Analyses revealed that antenatal factors such as maternal perceived stress, inadequate folate intake, vitamin intake, alcohol consumption during the first trimester and maternal smoking all had a significant effect on child outcomes. In particular, low multivitamin intake and perceived stress during pregnancy were associated with coexisting language and behavioural difficulties. These findings support international research in showing that maternal factors during pregnancy are associated with developmental outcomes in the early childhood period, and demonstrate these associations within a NZ context. Interventions which address maternal stress management and health behaviours during pregnancy could be beneficial to offspring development.

Microsimulation model of child and adolescent overweight: making use of what we already know.

BACKGROUND: New Zealand has high rates of child overweight and obesity when compared with other countries. Despite an abundance of research documenting the problem, it is unclear what the most effective policy changes or interventions are, and how policy changes might unfold over time within complex systems. METHODS: We use estimates derived from meta-analyses to create a dynamic microsimulation model of child overweight (including obesity). Using census records we created a synthetic birth cohort of 10,000 children. Information on parental education, ethnicity and father's socio-economic position at birth were taken from census records. We used the New Zealand Health Survey to estimate population base rates for the prevalence of overweight and obesity. Information on other modifiers (such as maternal smoking, breastfeeding, preterm birth, regular breakfast consumption and so forth) were taken from three birth cohorts: Christchurch Health and Development Study, The Dunedin Multidisciplinary Health and Development Study and the Pacific Islands Families Study. Published intervention studies were used to derive plausible estimates for changes to modifiers. RESULTS: Reducing the proportion of mothers classified as overweight and obesity (-3.31(95% CI -3.55; -3.07) percentage points), reducing the proportion of children watching two or more hours of TV (-3.78(95% CI -4.01; -3.54)), increasing the proportion of children eating breakfast regularly (-1.71(95% CI -1.96; -1.46)), and reducing the proportion of children born with high birth weights (-1.36(95% CI -1.61; -1.11)), lead to sizable decreases in the estimated prevalence of child overweight (including obesity). Reducing the proportion of mothers giving birth by caesarean (-0.23(95% CI -0.49; -0.23)) and increasing parental education (-0.07(95% CI -0.31; 0.18)) did not impact upon child overweight rates. CONCLUSIONS: We created a working simulation model of New Zealand children that can be accessed by policy makers and researchers to determine known relationships between predictors and child overweight, as well as potential gains from targeting specific pathways.

Persistence and change in behavioural problems during early childhood.

BACKGROUND: Behavioural problems and psychopathology can present from as early as the preschool period. However there is evidence that behavioural difficulties may not be stable over this period. Therefore, the current study was interested in evaluating the persistence and change in clinically relevant behavioural problems during early childhood in a population-based New Zealand birth cohort. METHODS: Behaviour was assessed in 5896 children when they were aged 2 and 4.5 years using the Strengths and Difficulties Questionnaire (SDQ). Correlations and mean differences in subscale and total difficulties scores were examined. Scores were then dichotomised into normal/borderline and abnormal ranges to evaluate the persistence and change in significant behavioural problems. Chi-square analyses and ANOVAs were used to determine the association between sociodemographic and birth variables, and preschool behavioural stability. RESULTS: Raw scores at ages 2 and 4.5 years were moderately correlated, with most measures showing a small but significant decrease in mean scores over time. The majority of children who showed abnormal behaviour at 2 years improved at 4.5 years (57.9% for total difficulties). However, a notable proportion persisted in their difficulties from 2 to 4.5 years (42.1% for total difficulties). There was a small percentage of children who were categorised as abnormal only at 4.5 years. Children with difficulties at one or both time points had a greater proportion who were the result of an unplanned pregnancy, lived in highly deprived urban areas, and had mothers who were younger, of Maori and Pacific ethnicity and were less educated. CONCLUSIONS: Not all children who show early behavioural difficulties persist in these difficulties. Those whose difficulties persist were more likely to experience risk factors for vulnerability relative to children with no difficulties. Results suggest that repeated screening for early childhood behavioural difficulties is important.