Are active children and young people at increased risk of injuries resulting in hospital admission or accident and emergency department attendance? Analysis of linked cohort and electronic hospital records in Wales and Scotland.

INTRODUCTION: Children and young people (CYP) are encouraged to increase time spent being physically active, especially in moderate and vigorous intensity pursuits. However, there is limited evidence on the prospective association of activity levels with injuries resulting in use of hospital services. We examined the relationship between objectively-measured physical activity (PA) and subsequent injuries resulting in hospital admissions or accident and emergency department (A&E) attendances, using linked electronic hospital records (EHR) from a nationally representative prospective cohort of CYP in Wales and Scotland. METHODS: We analysed accelerometer-based estimates of moderate to vigorous (MVPA) and vigorous PA (VPA) from 1,585 (777 [46%] boys) seven-year-old Millennium Cohort Study members, living in Wales or Scotland, whose parents consented to linkage of cohort records to EHRs up until their 14th birthday. Negative binomial regression models adjusted by potential individual, household and area-level confounders, were fitted to estimate associations between average daily minutes of MVPA, and VPA (in 10-minute increments), and number of injury-related hospital admissions and/or A&E attendances from age nine to 14 years. RESULTS: CYP spent a median of 59.5 and 18.1 minutes in MVPA and VPA/day respectively, with boys significantly more active than girls; 47.3% of children experienced at least one injury-related admission or A&E attendance during the study period. Rates of injury-related hospital admission and/or A&E attendance were positively associated with MVPA and VPA in boys but not in girls: respective adjusted incidence rate ratios (95% CI) for boys: 1.09 (1.01, 1.17) and 1.16 (1.00, 1.34), and for girls: 0.94 (0.86, 1.03) and 0.85 (0.69, 1.04). CONCLUSION: Boys but not girls who engage in more intense PA at age seven years are at higher risk of injury-related hospital admission or A&E attendance when aged nine to 14 years than their less active peers. This may reflect gender differences in the type and associated risks of activities undertaken. EHRs can make a useful contribution to injury surveillance and prevention if routinely augmented with information on context and setting of the injuries sustained. Injury prevention initiatives should not discourage engagement in PA and outdoor play given their over-riding health and social benefits.

Association of violence with emergence of persecutory delusions in untreated schizophrenia.

OBJECTIVE: Psychosis is considered an important risk factor for violence, but studies show inconsistent results. The mechanism through which psychotic disorders influence violence also remains uncertain. The authors investigated whether psychosis increased the risk of violent behavior among released prisoners and whether treatment reduced this risk. They also explored whether active symptoms of psychosis at the time of violent behavior explained associations between untreated psychosis and violence. METHOD: The U.K. Prisoner Cohort Study is a prospective longitudinal study of prisoners followed up in the community after release. Adult male and female offenders serving sentences of 2 or more years for a sexual or violent offense were classified into four groups: no psychosis (N=742), schizophrenia (N=94), delusional disorder (N=29), and drug-induced psychosis (N=102). Symptoms of psychosis, including hallucinations, thought insertion, strange experiences, and delusions of persecution, were measured before and after release. Information on violence between release and follow-up was collected through self-report and police records. RESULTS: Schizophrenia was associated with violence but only in the absence of treatment (odds ratio=3.76, 95% CI=1.39-10.19). Untreated schizophrenia was associated with the emergence of persecutory delusions at follow-up (odds ratio=3.52, 95% CI=1.18-10.52), which were associated with violence (odds ratio=3.68, 95% CI=2.44-5.55). The mediating effects of persecutory delusions were confirmed in mediation analyses (ß=0.02, 95% CI=0.01-0.04). CONCLUSIONS: The results indicate that the emergence of persecutory delusions in untreated schizophrenia explains violent behavior. Maintaining psychiatric treatment after release can substantially reduce violent recidivism among prisoners with schizophrenia. Better screening and treatment of prisoners is therefore essential to prevent violence.

Acute alcohol-related dysfunction as a predictor of employment status in a longitudinal study of working-age men in Izhevsk, Russia.

AIMS: To investigate longitudinally the effect of alcohol consumption and related acute alcohol-related dysfunction on employment status. DESIGN, SETTING AND PARTICIPANTS: A total of 1143 men aged 25-55 years in regular paid employment and resident in the city of Izhevsk, Russia were interviewed between 2003-06 and then re-interviewed (2008-09) and their employment status ascertained. MEASUREMENTS: Exposures of interest were baseline alcohol intake (yearly total volume of ethanol consumed and non-beverage alcohols) and alcohol-related dysfunction, measured by a latent variable defined in terms of frequency of alcohol-related dysfunctional behaviours and by one or more episodes of zapoi (a period of continuous drunkenness lasting 2 or more days). The outcome of interest was whether or not men were still in regular paid employment at follow-up. The inter-relationship between these variables was investigated using structural equation modelling. FINDINGS: Total volume of ethanol consumed had no substantive effect on future employment status; however, taking into account education and other socio-demographic factors, there was strong evidence that loss of regular paid employment at follow-up was influenced by non-beverage alcohol consumption [odds ratio = 2.30 for non-beverage drinkers compared with beverage-only drinkers, 95% confidence interval (CI) = 1.21, 4.40)], latent acute alcohol-related dysfunction (odds ratio = 1.50 per standard deviation increase in dysfunction score, 95% CI = 1.20, 1.88) and zapoi (odds ratio = 3.08, 95% CI = 1.71, 5.55). Acute alcohol-related dysfunction was an important mediator of the relationship between non-beverage alcohol use and employment status. CONCLUSIONS: Acute alcohol-related dysfunction is an important factor in determining whether men remain in employment and an important mediator of the effects of alcohol intake.

Gang membership, violence, and psychiatric morbidity.

OBJECTIVE: Gang members engage in many high-risk activities associated with psychiatric morbidity, particularly violence-related ones. The authors investigated associations between gang membership, violent behavior, psychiatric morbidity, and use of mental health services. METHOD: The authors conducted a cross-sectional survey of 4,664 men 18-34 years of age in Great Britain using random location sampling. The survey oversampled men from areas with high levels of violence and gang activities. Participants completed questionnaires covering gang membership, violence, use of mental health services, and psychiatric diagnoses measured using standardized screening instruments. RESULTS: Violent men and gang members had higher prevalences of mental disorders and use of psychiatric services than nonviolent men, but a lower prevalence of depression. Violent ruminative thinking, violent victimization, and fear of further victimization accounted for the high levels of psychosis and anxiety disorders in gang members, and with service use in gang members and other violent men. Associations with antisocial personality disorder, substance misuse, and suicide attempts were explained by factors other than violence. CONCLUSIONS: Gang members show inordinately high levels of psychiatric morbidity, placing a heavy burden on mental health services. Traumatization and fear of further violence, exceptionally prevalent in gang members, are associated with service use. Gang membership should be routinely assessed in individuals presenting to health care services in areas with high levels of violence and gang activity. Health care professionals may have an important role in promoting desistence from gang activity.

Health differentials in the older population of England: an empirical comparison of the materialist, lifestyle and psychosocial hypotheses.

BACKGROUND: In developed countries with old age structures most deaths occur at older ages and older people account for the majority of those in poor health, which suggests a particular need to investigate health inequalities in the older population. METHODS: We empirically compared the materialist, psychosocial and lifestyle/behavioural theoretical mechanisms of explanation for socio-economic variation in health using data from two waves of the English Longitudinal Study of Ageing (ELSA), a nationally representative multi-purpose sample of the population aged 50 and over living in England. Three dimensions of health were examined: somatic health, depression and well-being. RESULTS: The materialist and lifestyle/behavioural paths had the most prominent mediating role in the association between socio-economic position and health in the older population, whereas the psychosocial pathway was less influential and exerted most of its influence on depression and well-being, with part of its effect being due to the availability of material resources. CONCLUSIONS: From a policy perspective there is therefore an indication that population interventions to reduce health differentials and thus improve the overall health of the older population should focus on material circumstances and population based interventions to promote healthy lifestyles.

Main morbidities recorded in the women's international study of long duration oestrogen after menopause (WISDOM): a randomised controlled trial of hormone replacement therapy in postmenopausal women.

OBJECTIVE: To assess the long term risks and benefits of hormone replacement therapy (combined hormone therapy versus placebo, and oestrogen alone versus combined hormone therapy). DESIGN: Multicentre, randomised, placebo controlled, double blind trial. SETTING: General practices in UK (384), Australia (91), and New Zealand (24). PARTICIPANTS: Postmenopausal women aged 50-69 years at randomisation. At early closure of the trial, 56,583 had been screened, 8980 entered run-in, and 5692 (26% of target of 22,300) started treatment. INTERVENTIONS: Oestrogen only therapy (conjugated equine oestrogens 0.625 mg orally daily) or combined hormone therapy (conjugated equine oestrogens plus medroxyprogesterone acetate 2.5/5.0 mg orally daily). Ten years of treatment planned. PRIMARY OUTCOMES: major cardiovascular disease, osteoporotic fractures, and breast cancer. SECONDARY OUTCOMES: other cancers, death from all causes, venous thromboembolism, cerebrovascular disease, dementia, and quality of life. RESULTS: The trial was prematurely closed during recruitment, after a median follow-up of 11.9 months (interquartile range 7.1-19.6, total 6498 women years) in those enrolled, after the publication of early results from the women's health initiative study. The mean age of randomised women was 62.8 (SD 4.8) years. When combined hormone therapy (n=2196) was compared with placebo (n=2189), there was a significant increase in the number of major cardiovascular events (7 v 0, P=0.016) and venous thromboembolisms (22 v 3, hazard ratio 7.36 (95% CI 2.20 to 24.60)). There were no statistically significant differences in numbers of breast or other cancers (22 v 25, hazard ratio 0.88 (0.49 to 1.56)), cerebrovascular events (14 v 19, 0.73 (0.37 to 1.46)), fractures (40 v 58, 0.69 (0.46 to 1.03)), and overall deaths (8 v 5, 1.60 (0.52 to 4.89)). Comparison of combined hormone therapy (n=815) versus oestrogen therapy (n=826) outcomes revealed no significant differences. CONCLUSIONS: Hormone replacement therapy increases cardiovascular and thromboembolic risk when started many years after the menopause. The results are consistent with the findings of the women's health initiative study and secondary prevention studies. Research is needed to assess the long term risks and benefits of starting hormone replacement therapy near the menopause, when the effect may be different. TRIAL REGISTRATION: Current Controlled Trials ISRCTN 63718836.

How good is probabilistic record linkage to reconstruct reproductive histories? Results from the Aberdeen Children of the 1950s study.

BACKGROUND: Probabilistic record linkage is widely used in epidemiology, but studies of its validity are rare. Our aim was to validate its use to identify births to a cohort of women, being drawn from a large cohort of people born in Scotland in the early 1950s. METHODS: The Children of the 1950s cohort includes 5868 females born in Aberdeen 1950-56 who were in primary schools in the city in 1962. In 2001 a postal questionnaire was sent to the cohort members resident in the UK requesting information on offspring. Probabilistic record linkage (based on surname, maiden name, initials, date of birth and postcode) was used to link the females in the cohort to birth records held by the Scottish Maternity Record System (SMR 2). RESULTS: We attempted to mail a total of 5540 women; 3752 (68%) returned a completed questionnaire. Of these 86% reported having had at least one birth. Linkage to SMR 2 was attempted for 5634 women, one or more maternity records were found for 3743. There were 2604 women who reported at least one birth in the questionnaire and who were linked to one or more SMR 2 records. When judged against the questionnaire information, the linkage correctly identified 4930 births and missed 601 others. These mostly occurred outside of Scotland (147) or prior to full coverage by SMR 2 (454). There were 134 births incorrectly linked to SMR 2. CONCLUSION: Probabilistic record linkage to routine maternity records applied to population-based cohort, using name, date of birth and place of residence, can have high specificity, and as such may be reliably used in epidemiological research.

Limits to causal inference based on Mendelian randomization: a comparison with randomized controlled trials.

"Mendelian randomization" refers to the random assortment of genes transferred from parent to offspring at the time of gamete formation. This process has been compared to a randomized controlled trial of genetic variants. This could greatly aid observational epidemiology by potentially allowing an unbiased estimate of the effects of gene products on disease outcomes. However, studies utilizing Mendelian randomization to estimate effects of gene products on outcomes should be interpreted with caution. In this paper, the authors discuss some of the challenges facing epidemiologists in the analysis and interpretation of Mendelian randomization studies, particularly those that become apparent when the analogy with randomized controlled trials is closely examined. The authors conclude that Mendelian randomization is a powerful addition to etiologic research tools. However, care must be taken, because drawing valid causal inferences from its application depends upon more extensive assumptions than are required in randomized controlled trials.