ALSPAC is an important resource in the study of child development. Researchers using the cohort have shown an association between factors such as antenatal diet, maternal and paternal anxiety and depression and later child development.(1-5) There is strong evidence that child development and school performance are also influenced by socioeconomic factors including: parental occupation, marital status, income and parental education. (6-10) Maternal smoking and social adversity, specifically during pregnancy, were independently associated with an increase in risk of child symptoms of inattention and hyperactivity in a large multi-centre study of environmental risk factors for ADHD.(11) However, the causal mechanism of how childhood adversity affects development is unclear.

Early parent-child interaction is the basis of the attachment relationship which in turn allows the child to develop a template for social and emotional relationships.(12) Although there has been work looking at the effect of parenting and childhood attachment difficulties on general health, behaviour and self regulation, potentially mediated through the hypothalamic-pituitary-adrenal axis, the evidence base for the effect of parenting on other aspects of childhood development and later scholastic competence is less clear.(13, 14) The NICHD Study of Early Child Care and Youth Development, looking at 1000 US families, showed that early attachment predicted emotional development and language skills in younger children but not cognitive functioning; however the effect of attachment was dependent on socioeconomic background.(15, 16)

Dr Waylen and Professor Stewart-Brown have worked extensively with ALSPAC and have developed and validated a parenting measure which incorporates parental reports of attitude, behaviours and feelings towards the child. This measure of parenting has been shown to be independently associated with maternal reported child health.(17) In addition, ALSPAC has repeated measures of self-reported parenting activity scores between 6 months and 38 months. Professor Emond, Dr Deave and Dr Lingam have experience in the analysis of the modified Denver Developmental Screening Test (modified DDST) measured at 6, 18, 30 and 42 months along with measures of later development including motor coordination, speech and language skills, non verbal skills, social communication, and academic ability (reading and spelling).(2, 18)

Research questions

1. What is the effect of parenting on child development measured using standardised tests, controlling for potential confounding and modifying factors?
2. To what extent does parenting mediate the effect of known risk factors for child development such as socioeconomic status and parental education?

Methods

The primary exposure variable will be the parenting measure developed by Dr Waylen and Professor Stewart-Brown. A secondary exposure variable Parenting Activity will be developed using the ALSPAC parenting activity scores.

Outcome variables will be the modified Denver Developmental Screening Test (modified DDST) measured at 6, 18 and 30 months and later developmental measures including inattention and hyperactivity using the Development and Well-Being Assessment- DAWBA; difficulties in social cognition (The Social and Communication Disorders Checklist- SCDC; poor reading skills (using the Weschler Objective Reading Dimensions- WORD and NARA II); expressive language and comprehension using the WOLD, nonverbal impairment using the DANVA and Cognitive ability using the abbreviated WISK III measured between 7 and 9 years. (19-25)

A series of multivariable linear regression and logistic regression models (for continuous and binary outcomes respectively) will be created to look at the associations between parenting measures and child development accounting for potential confounding and mediating factors identified from the literature. Adjustment will be made for the bias introduced by missing data using multiple imputation by chained equation.(26)

Variable needed

Dr Lingam already has a dataset containing the developmental variables and some of the parenting activity scores needed for the analysis as part of his PhD looking at the causes and consequences of developmental coordination disorder. Use of the derived parenting measure has been granted by Dr Waylen and Professor Stewart Brown. Full details of all the variables in the analysis are attached in table 1.

Power calculation

The prevalence of suboptimal parenting (increased hostility, resentment and hitting/shouting) has been reported in between 10 and 30% of the ALSPAC cohort at different time points.(17) Taking 7000 to be the study population (approximate children that attended focus at 7) and our outcome variable to be the lowest 10% of a given developmental trait, the relative risk that it will possible to be 80% sure of detecting at the 5% level of significance is between 1.27 and 1.42.

References

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18. Lingam R, Hunt L, Golding J, Jongmans M, Emond A. Prevalence of developmental coordination disorder using the DSM-IV at 7 years of age: a UK population-based study. Pediatrics. 2009 Apr;123(4):e693-700.

19. Frankenburg WK, Dodds J, Archer P. The Denver II: a major revision and restandardization of the Denver Developmental Screening Test Pediatrics. 1992;89 (1):91-7.

20. Goodman R, Ford T, Richards H, Gatward R, Meltzer H. The Development and Well-Being Assessment: description and initial validation of an integrated assessment of child and adolescent psychopathology. Journal of Child Psychology and Psychiatry. 2000 Jul;41(5):645-55.

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26. Stuart EA, Azur M, Frangakis C, Leaf P. Multiple imputation with large data sets: a case study of the Children's Mental Health Initiative. Am J Epidemiol. 2009 May 1;169(9):1133-9.