Recent Public Health Agency of Canada study contrasts sharply with controversial UK study published earlier this week
A study commissioned by the Fetal Alcohol Spectrum Disorder Initiative (Public Health Agency of Canada) uses longitudinal data from the Better Beginnings, Better Futures study to examine the relationships between prenatal exposure to alcohol and tobacco and developmental outcomes in young children from disadvantaged Ontario communities over the first four years of primary school (i.e., from 4 to 8 years of age).
The Better Beginnings, Better Futures study collected data from over 500 children and their families from disadvantaged communities in Ontario in 1993. Data was collected at birth and then again at 33 months, 48 months and at age 8. Over 400 children remained in the cohort at age 8.
One of the strengths of this study was that the researchers collected data on the impact of both alcohol and tobacco exposure, separately and combined, and also on postnatal exposure. They also used a range of child outcome measures which were assessed by parents, teachers, and researchers. The study findings point to the limitations of depending on parent reports of outcome measures.
Overall, the researchers found that children whose mothers reported higher-risk alcohol consumption during pregnancy showed long- term negative outcomes in measures of school performance and behaviour problems. Further, these problems were accentuated in children whose mothers reported both alcohol and tobacco use during the pregnancy. These effects persisted over time and increased over time. The percentage of measures demonstrating the disadvantage of children exposed to prenatal alcohol and tobacco increased from 37% at age 4 to 47% at age 8.
The researchers do an excellent job of contextualizing these findings in the research literature and provide tools for the reader to understand the difference between statistical significance and practical, everyday real-life significance. The list below of “treatment effect” places the findings in the context of other research findings.
r Treatment effect
0.03 Anti-hypertensive medication on reduced risk of stroke
0.08 Bypass in stable heart disease on 5-year survival
0.11 Anti-histamine on runny nose and sneezing
0.19 Prenatal drinking on teacher internalizing behaviour ratings
0.21 Prenatal drinking on teacher externalizing behaviour ratings
0.38 Viagra on male sexual function
The study can be downloaded for free from the Public Health Agency of Canada web site.
Public Health Agency of Canada. (2010). Early Primary School Outcomes Associated with Maternal Use of Alcohol and Tobacco During Pregnancy and with Exposure to Parent Alcohol and Tobacco Use Postnatally. Health Canada, Catalogue no. HP10-13/2010-MRC. Download from http://publications.gc.ca/site/eng/368567/publication.html