Search results

ABSTRACT
ObjectivesAlcohol, tobacco and cannabis can cross the placenta, and could have long-lasting effects on the brain of the developing foetus. We examine whether exposure to these substances is associated with educational attainment in adolescence (Key Stage 4 [KS4], aged 16yrs), and consider whether any associations are due to an intrauterine causal mechanism.
ApproachWe use two main approaches: (1) a comparison of the risks associated with maternal substance use during pregnancy with the risks associated with paternal substance use at the same time, and (2) Mendelian Randomisation (MR). The population-based sample are from the Avon Longitudinal Study of Parents and Children. Educational attainment at KS4 was determined through linkage to the National Pupil Database: capped score of eight best subjects (converted to percentage). Mothers and their partners reported use of substances during the mother's pregnancy via questionnaire. In observational complete-case analysis (n=6018), multilevel (child level 1, school level 2) linear models were used to examine the association between maternal and paternal substance use and KS4 attainment adjusted for potential confounders. In MR analysis, genetic markers associated with maternal alcohol (rs1229984) and tobacco (rs1051730) use were used to estimate the unconfounded effect of the exposures.
ResultsMaternal substance use in pregnancy was common (72% reported any alcohol, 22% any tobacco, and 2% any cannabis) and socially patterned (tobacco associated with deprivation, moderate alcohol and light cannabis with higher maternal education). In adjusted observational analyses, children of mothers who smoked had lower KS4 percentage scores (β -2.7, 95% CI -3.7 to -1.7) but a similar association was observed for paternal smoking (β -3.0, -3.8 to -2.2). Compared to children of non-drinkers in first trimester, children whose mothers drank ≥7 units per week had lower KS4 scores (β -4.6, -7.9 to -1.4), but children of lighter drinkers did not. The MR analyses were under-powered but provisional results suggest no association between maternal smoking and KS4 score, but that small amounts of alcohol could have a detrimental effect. Neither maternal nor paternal cannabis use was associated with educational attainment in observational analyses, but few mothers in our sample used cannabis regularly in pregnancy.
ConclusionsThe negative association in observational analysis between maternal smoking in pregnancy and child KS4 attainment is likely due to residual confounding rather than an intrauterine mechanism. Conversely, residual confounding may be masking a negative association between lower levels of alcohol drinking and KS4 attainment in observational analysis.

BackgroundPolicing in the UK is increasingly taking a public health approach to tackling crime. Birth cohort studies are potentially well-placed to provide evidence on the most important risk and preventative factors. Linking official police records to cohort data offers considerable potential for future research, but data privacy concerns mean achieving such linkage is challenging. As a pilot, the Ministry of Justice provided ALSPAC with an anonymous extract (cannot be linked to study data) detailing consenting participants' criminal convictions and cautions held within the Police National Computer (PNC).
Main AimTo use anonymised PNC data to inform the potential for future research using ALSPAC and individual-level linked crime data.
MethodsWe examine criminality (type, when and where committed) in the cohort participants who were sent for linkage to the PNC in 2013 when they were aged approximately 21 years (n=7358). We consider the representativeness of these participants by comparing their self-reported crime-related behaviours during adolescence to those of participants who did not consent to linkage (n=7604). Finally, we consider these self-reported measures by present-day crime linkage consent status.
ResultsOf those sent for PNC linkage, 885 were linked to a criminal record(s) comprising 2635 convictions and 1365 cautions. A third related to serious crimes, and >90% were committed in Avon and Somerset constabulary. Those sent for linkage self-reported fewer criminal behaviours than those not sent for linkage. Regarding present-day consent status, those who have explicitly opted-in generally self-report fewer criminal behaviours and have less missing data than those who have not responded to the consent campaign.
ConclusionIf future linkage to individual police records was only achieved for explicit consenters, this would under-estimate criminality in the cohort. The geographical clustering of the crimes means local police records, which are more detailed than those of the PNC, could also be used.

ObjectiveTo use longitudinal birth cohort data linked to police records to examine whether the relationship between adverse childhood experiences (ACEs) and police-recorded serious violence depends on the type, timing or duration of ACEs.
MethodsThe sample are 5070 participants (born 1991-1992) from the Avon Longitudinal Study of Parents and Children who allowed linkage to Avon and Somerset (A&S) local police data, lived in A&S from age 16-24 years, and had exposure and confounder data. The binary outcome (no, yes) is having a police record for a serious violence (SV) offence from age 16-24. ACEs were parent-reported from birth to age 11 and include measures of parental physical and emotional abuse. Logistic regression was used to examine associations between the timing of different ACEs and SV, adjusted for child sex, ethnicity, and family socioeconomic position.
Results6% of the participants had experienced physical abuse, 17% emotional abuse, and 121 individuals (2.4%) had at least one SV record. In adjusted models, there was evidence of an association between physical (OR 1.90, 95% 1.08-3.35) but not emotional (0.96, 0.60-1.54) abuse and risk of SV. Results suggest that those who experienced physical abuse in both early (<4 years) and later (4-11 years) childhood, or later childhood only, might have been at greater risk of SV than those who experienced it only during early childhood, although numbers were small and confidence intervals were consequently wide.
ConclusionResults to date suggest that associations with SV differ between ACE types, and that timing may be important. In our presentation, we will also present findings for other ACEs.

Objectives
• To compare self-reported and police-recorded serious violence using data from a longitudinal UK birth cohort linked to local (Avon and Somerset Constabulary) police records
• To assess the risk of police-recorded serious violence according to study participation status across the lifecourse
ApproachWe linked data from the Avon Longitudinal Study of Parents and Children (ALSPAC) to local police records on charges, cautions and other out of court disposals. We compared the risk of self-reported serious violence at 8 time points from 15 to 25 years to police-recorded serious violence at these ages. We then compared the risk of police-recorded serious violence among those actively participating in ALSPAC to those not participating at various time points from pregnancy onwards. We used logistic regression to examine whether differences in risk could be explained by socio-demographic and family characteristics associated with ALSPAC participation.
ResultsThe sample included 12,662 participants who had received fair processing materials and had not opted out of linkage to police records. They linked to a total of 6,283 offences, of which 933 were classified as serious violence (involving a total of 530 individuals). Self-reported serious violence in the past year was particularly high at 15 years (23.5%); at other ages it ranged from 3.7% (22 years) to 8.7% (20 years). Police-recorded serious violence was lower at all ages, peaking at 1.0% at 17 and 18 years. The risk of police-recorded serious violence was higher among those not participating in ALSPAC than among active participants, particularly during adolescence and early adulthood. This difference was only partially explained by socio-demographic and other factors.
ConclusionA key advantage of linkage to police records is it enables outcomes to be measured irrespective of study participation status as relying only on active participants leads to bias. Combining self-reported and police-recorded outcomes allows us to derive measures of offending that take account of the biases inherent in each.

ABSTRACT
Objectives"Clearly, details about an individual's mental health, for example, are generally much more 'sensitive' than whether they have a broken leg."
UK Information Commissioners Office
There is a perceived wisdom – based on issues such as social taboos, religious sensitivities, or financial implications linked to health status – that some health data is more sensitive than others. This distinction is present in many of the regulatory interpretations of privacy law (e.g. the UK Information Commissioners Office interpretation of the EU Data Directive, illustrated above), and is factored into the thinking of ethics and other regulatory decision-making committees. However, these particularly 'sensitive' data are defined at a regulatory level in broad terms (e.g. mental health), yet need implementing by researchers in precise terms. In 2013 our longitudinal research study was given approval by the UK Secretary of State for Health to access identifiable patient health records with the exception of those relating to mental health, sexual health or termination of pregnancy. Our objective therefore was to develop a generalisable informatics approach which enabled us to filter out sensitive records at the point of extraction.
ApproachWe developed a methodology based on the Cochrane systematic review approach: firstly using internationally recognised definitions of health concepts and reference texts (e.g. British National Formulary drug manual) we identified keywords associated with sensitive health events (including symptom and diagnostic terms, drug and appliance codes, community and secondary care references); secondly, through data-mining code terminologies – using both code terms and information embedded within the structure of the schema itself - we identified code values relating to these terms; thirdly we minimised our results through filtering out spurious results via manual review; finally, the resulting code lists were then crossed-referenced with other terminologies to ensure interoperability.
ResultsWe produced separate definitions of mental health and sexual health events initially using Read codes. Using NHS cross-reference tables we were able to translate Read observation and diagnostic codes to the SNOMED CT vocabulary, but were unable to translate Read drug codes into the SNOMED/DM+D vocabulary.
ConclusionWe have demonstrated a systematic and partially interoperable approach to defining 'sensitive' health information. However, any such exercise is likely to include decisions which will be open to interpretation and open to change over time. As such, the application of this technique should be embedded within an appropriate governance framework which can accommodate misclassification while minimising potential patient harm.

ABSTRACT
ObjectivesIn the UK, some children undertake National Cycle Proficiency Scheme [NCPS]/Bikeability training in primary school. It aims to promote cycling and safe cycling behaviours but there has been little scientific evaluation of its effectiveness. We aimed to examine the impact of cycle training on cycle-related behaviours and accidents in adolescence using self-report and hospital episode statistics (HES) data.
ApproachThe sample (n=5415) were participants in the Avon Longitudinal Study of Parents and Children who reported whether or not they had received NCPS training. Self-reported outcomes at 14 and 16 years included: cycling to school, ownership of cycle helmet, use of cycle helmet and high-visibility clothing on last cycle, and involvement in a cycle accident. Hospital admittance due to a cycle accident from 11-16 years was also included for a subsample (n=2222) who have been linked to HES. The association between cycle training and each of the outcomes was analysed using multilevel logistic regression (individual level 1, school level 2 [pseudo-ID of school attended obtained from linkage to National Pupil Database]), adjusted for a range of potential confounders.
ResultsApproximately 40% had received NCPS training. At 14 and 16 years, trained children were more likely to cycle to school (at 16 years: adjusted OR 1.56, 95% CI 1.20-2.02) and to own a helmet (16 years: 2.03, 1.72-2.41) than those who had not attended a course. They were also more likely to have worn a helmet on their last cycle at age 14 (1.26, 1.07-1.49), and to have worn high-visibility clothing at age 16 (1.70, 1.22-2.39). Training was not associated with self-reported involvement in a cycle accident, and only six participants with HES data had been admitted to hospital due to a cycle accident. Irrespective of training, results indicate very low use of high-visibility clothing (5%), very few girls cycling to school (<2%), and less than half of helmet owners wearing one on their last cycle. Ownership and use of helmets was particularly low in children from lower socio-economic position families.
ConclusionCycle training for children can have benefits that persist into adolescence. However, the low use of cycle helmets and high-visibility clothing indicate the further potential for interventions to encourage safe cycling behaviours in young people. Our hospital admissions outcome only captures individuals who sustained serious injuries; more minor cycle injuries would have been treated in A&E but a lack of detail in admission codes precludes analysis of such data.