Associations between problems with crying, sleeping and/or feeding in infancy and long-term behavioural outcomes in childhood: a meta-analysis.

BACKGROUND: Excessive crying, sleeping or feeding problems are found in approximately 20% of infants and may predict behavioural problems in childhood.
METHODS: A quantitative meta-analysis of 22 longitudinal studies from 1987 to 2006 that statistically tested the association between infant regulatory problems and childhood internalising, externalising and attention-deficit/hyperactivity disorder (ADHD) problems was carried out; 1935 children with regulatory problems were tested. Cohen's d was used to express the association between regulatory problems and behavioural problems. Heterogeneity of the effect sizes was assessed using the I(2) statistic and meta-analysis of variance and meta-regressions were conducted to assess the influence of moderators. Rosenthal's classic fail-safe N and correlation of sample sizes to effect sizes were used to assess publication bias.
RESULTS: The weighted mean effect size for the main regulatory problems-behavioural problems association was 0.41 (95% CI 0.28 to 0.54), indicating that children with previous regulatory problems have more behavioural problems than controls. Externalising and ADHD problems were the strongest outcome of any regulatory problem, indicated by the highest fail-safe N and lowest correlation of sample size to effect size. Meta-analyses of variance revealed no significant moderating influences of regulatory problem comorbidity (I(2)=44.0, p>0.05), type (I(2)=41.8, p>0.05) or duration (I(2)=44.0, p>0.05). However, cumulative problems and clinical referral increased the risk of behavioural problems.
CONCLUSIONS: The meta-analyses suggest that children with previous regulatory problems have more behavioural problems than controls, particularly in multi-problem families. Further studies are required to assess the behavioural outcomes of previously sleep, feeding or multiply disturbed children.