Is externalising behaviour in normal kindergarten
and first grade children associated with subsequent conduct disorder
and antisocial behaviour?
{Studies were identified by doing a systematic
search of Medline, PsycINFO, and ERIC; by reviewing the bibliographies
of relevant published reports; by searching personal files; and by
contacting colleagues and experts in the field.}*
{Studies were selected if they included a
representative non-referred sample of children (inception cohorts of
clinical samples were not included) and if at least 1 assessment of
externalising behaviour was made in the kindergarten to grade 1 range
with at least 1 subsequent follow up to assess the occurrence of
conduct disorder or antisocial behaviour.}*
Data were extracted on sample characteristics,
assessment methods, statistical analysis, outcome measures, and study
quality.
13 studies with 1 to 7 years follow up met the selection
criteria. 7 of the 13 studies reported that a statistical association
existed between early externalising behaviour and later development
of antisocial behaviour or conduct disorder. Across the 13
studies, sensitivity (the proportion of individuals with later
antisocial behaviour or conduct disorder who had externalising
behaviour earlier) ranged from 28% to 100% (15 estimates) with almost
two thirds of the estimates The value of using early externalising symptoms in
non-referred populations of kindergarten and first grade children to
predict later antisocial behaviour or conduct disorder is modest and
the level of misclassification is likely to be high.
Of substantial interest to clinicians, researchers, and policy
makers alike is the extent to which we can effectively identify and
intervene with young children at risk of conduct and behavioural
problems to prevent longer term adverse consequences that are more
difficult and costly to treat. Implementation of such a strategy,
however, rests not just on having an effective, palatable, and
affordable intervention ready to be deployed (a major feat all in
itself), but also on having a reliable and valid means of identifying
children truly in need of such interventions. Although previous reports
may have over estimated our ability to identify such children, Bennett
et al summarise information only from
studies of population based samples where follow up assessments were
conducted over time. Such studies provide unbiased estimates of the
ability to identify children at risk of long term externalising
behavioural problems. The findings of this review are at
once both heartening and bleak: based on the review, fewer than one
half of children identified with early externalising problems continued
to show these problems at later ages-a finding at some variance with
the common notion that early aggressive problems portray a picture of
uniformly grim long term consequences. On the other hand, this same
difficulty in accurately predicting later outcomes poses greater
burdens and requirements on potential interventions-they must be
sufficiently efficacious and/or cost effective to make up for the
potential problems of inadvertently labelling and/or misapplying scarce
resources to those not in need. As a strategy that might be used to
address these problems, Bennett et al note
that 2 or 3 stage screening methods might offer an efficient means of
identifying such children. In addition, they propose a unique solution,
one more akin to the types of strategies used by thoughtful
clinicians-namely, children in need might be best identified not only
through the presence of early behavioural signs and symptoms but also
through the convergence of other indicators, such as well established
risk factors for adverse outcomes independent from the behavioural
indicators themselves (eg, single parent status, family poverty,
neuropsychological functioning, etc). Although both strategies appear
to be sensible, additional research will be required to determine
whether in fact they can be deployed and used to advantage on behalf of
young children in need.
{author}Peter S Jensen, MD
Question
Data sources
Study selection
Data extraction
Main results
|LZ UNTRANSLATED CHAR ENTITY
50%. The estimates of sensitivity
>60% were associated with low levels of specificity (the proportion
of individuals without later antisocial behaviour or conduct disorder
who did not have externalising behaviour earlier). Specificity ranged
from 58% to 97% (14 estimates) and was >90% in only 2 cases. Based
on a sensitivity of 45%, a specificity of 85% and a prevalence of
10% (realistic estimates consistent with a non-referred population of
children), only 25% of children with externalising behaviour will have
antisocial behaviour or conduct disorder (the positive predictive
value, {relative risk in a longitudinal study is 3.0, 95% CI 1.2 to
6.3}†).
Conclusion
Commentary
Review: in non-referred samples of
children, early externalising behaviour is not associated with later
antisocial behaviour