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Project title
A longitudinal study of causal pathways linking Low Birth Weight and Childhood Problem
Behaviour in large population studies.
Supervisors
Dr Oliver Perra, Professor Richard Layte and Professor Linda Johnston
Background
Low birth weight (LBW) represents a risk factor not only for infants’ health but also for their
future adjustment. Several studies have indicated that LBW (defined as birth weight below 2500
g) is associated with increased risk for psychopathology in childhood and in adolescence.
Indeed, a twin-study suggested that LBW may be a continuous risk factor for problem behaviour
during childhood in a general population.
Given the importance of LBW as a risk factor for childhood problem behaviour, it is important to
understand the mechanisms through which LBW may influence development. Risk factors such
as LBW are unlikely to act in isolation: rather, they may initiate a chain of events that contribute
to the development of maladaptive behaviour. Some of the likely intervening factors in the
pathway from LBW to childhood problem behaviour may be attention and temperamental
difficulties. Links between LBW and attention difficulties and temperament suggest that LBW
children may display more extreme and maladaptive temperament traits. Extreme temperament
may, in turn, predispose LBW children to problem behaviour. These links suggest that individual
differences in temperament may mediate the association between LBW and onset of problem
behaviour.
Different studies have highlighted that parenting behaviour and parental well-being play an
important role in moderating the longitudinal links between temperament and problem
behaviour. Studies are also starting to acknowledge that the influences between temperament
and parenting may be bidirectional across time. Infants’ extreme temperamental traits may thus
evoke maladaptive parental practises, contributing in this way to the onset of problem behaviour
in childhood.
Studies that consider the effects of LBW on childhood problem behaviour also need to
acknowledge that LBW is often associated with other risk factors for problem behaviour such as
maternal tobacco smoking before birth, lower Socio-Economic Status, and so on. In order to
disentangle the effects of these multiple risk factors it is necessary to study large samples in
prospective studies.
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Aim of study
The study proposed will investigate the mechanisms that link LBW and problem behaviour
using data from population studies collected in the UK (Millennium Cohort Study) and the
Republic of Ireland (Growing Up in Ireland). These studies provide large representative samples
of infants and their families observed over time. Furthermore, these studies collected
comparable measures of family Socio-Economic Status and demographic characteristics,
parental health, parental styles and behaviour, children’s characteristics and behaviour.
Datasets from these studies are freely available to academics and provide opportunities for
analyses of the processes that affect children’s development over time.
The study proposed aims to use these datasets to investigate the associations between LBW
and problem behaviour in childhood as well as the mechanisms that may explain these
associations. One of the possible mechanisms proposed concerns infants’ early-appearing
individual differences in temperament: LBW may influence problem behaviour indirectly
through its effects on temperament. The study will also investigate how factors such as
parental practises, parental attachment and parental well-being intervene in the pathway from
LBW to problem behaviour. To summarise, the study will test if:
(a) LBW is related to problem behaviour in childhood after controlling for other confounders.
(b) LBW infants display more extreme temperamental traits from an early age, which may put
them at increased risk of developing problem behaviour.
(c) Individual differences in temperament mediate the association between LBW and problem
behaviour.
(d) Other intervening factors such as parental practises and attachment mediate the association
between temperament and problem behaviour in LBW infants.
Methodology
Advanced quantitative analyses will be conducted using multilevel regression and Structural
Equation Modelling.
Required qualifications
Applicants must have (or be about to attain) at least an upper-second class honours bachelor’s
degree or master’s degree in the field of nursing, midwifery or a cognate discipline in the social
and health sciences
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Desired research skills
A necessary prerequisite is the potential to become proficient in advanced statistical methods. A
good grounding in the theory and application of multivariate and regression analyses (e.g. OLS
regression) is highly desirable. Experience using statistical software such as Stata or R will be
advantageous. Another desired research skill is the ability to manage large datasets: precision
and attention to details are therefore key skills for the successful candidate.