bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monte Carlo simulation of photon buildup factors for shielding materials in diagnostic x‐ray facilities
Authors: Kharrati Hedi , Agrebi Amel , Karoui Mohamed Karim 
Published: September 2012

Purpose:A simulation of buildup factors for ordinary concrete, steel, lead, plate glass, lead glass, and gypsum wallboard in broad beam geometry for photons energies from 10 keV to 150 keV at 5 keV intervals is presented.Methods:Monte CarloN‐particle radiation transport computer code has been used to determine the buildup factors for the studied shielding materials.Results:An example concretizing the use of the obtained buildup factors data in computing the broad beam transmission for tube potentials at 70, 100, 120, and 140 kVp is given. The half value layer, the tenth value layer, and the equilibrium tenth value layer are calculated from the broad beam transmission for these tube potentials.Conclusions:The obtained values compared with those calculated from the published data show the ability of these data to predict shielding transmission curves. Therefore, the buildup factors data can be combined with primary, scatter, and leakage x‐ray spectra to provide a computationally based solution to broad beam transmission for barriers in shielding x‐ray facilities.
OP10 Effects of socio Economic Position in Childhood and Adulthood on Cardiometabolic Risk Factors: The Jerusalem Perinatal Family Follow-Up Study
Authors: Manor O , Savitsky B , Hochner H , Meiner V , Siscovick DS , Friedlander Y 
Published: September 2012

BackgroundStudies indicate that Socio Economic Position (SEP) might be an important predictor of cardiometabolic disease mortality and morbidity; yet the importance of timing of the effect of SEP on cardiometabolic risk factors has not been fully established. Our aim was to assess the independent effect of SEP in both childhood and adulthood on cardiometabolic risk factors in young adults and to examine potential interactive effects of SEP at both time points on these risk factors.MethodsThis is a prospective follow-up of 1132 individuals, born in Jerusalem between the years 1974–76, to young adulthood with bio-medical data at mean age 32. Outcomes include Body Mass Index (BMI), Waist to Hip Ratio (WHR), blood pressure, waist circumference (WC), pelvis circumference, body fat percentage, fasting levels of Triglyceride (TG), HDL-C, LDL-C, glucose, insulin, and lifestyle characteristics, including smoking and physical activity. SEP in childhood was based on father’s occupation (scale 1–6) and in adulthood, on subject’s occupation (scale 1–5). Additional analyses used maternal and subject’s years of education. GLM and logistic regression models were used with mutual adjustment for SEP at both time points and further adjustment for gender, ethnic origin and fasting duration. Log transformation was used for TG and insulin levels.ResultsIndependently of current SEP, lower childhood SEP was significantly associated with higher logTG (β=0.013, p=0.042), higher LDL (β=1.979, p=0.023), higher body fat percentage (β=0.476, p=0.025) and higher odds of physical inactivity (OR=1.13, p=0.043). Independently of childhood SEP, lower adulthood SEP was significantly associated with lower HDL level (β=–0.934, p=0.026), higher WHR (β=0.006, p=0.002), and higher odds of smoking (OR=1.31, p=0.001) and physical inactivity (OR=1.34, p<0.0001). Significant interactions were found between SEP in both time points and LDL, WHR and WC (p for interactions=0.01, 0.024 and 0.055 respectively). The detrimental effect of lower SEP in adulthood on LDL level was strongest among subjects with high SEP in childhood (β=4.54, p<0.0001), compared with those having lower SEP in childhood. Similar trends were observed for WHR and WC (β=0.011, p<0.0001 and β=1.754, p=0.004 for associations of adulthood SEP with WHR and WC respectively, among subjects with high childhood SEP). Analyses, based on education as a measure of SEP, yielded similar interactive patterns.ConclusionAdverse SEP at both childhood and adulthood has an independent influence on physiological and behavioral risk factors. The interaction between SEP in childhood and adulthood in their effect on cardiometabolic risk factors points to the important role played by social mobility in affecting adult poorer health.
OP17 Do Low Levels of Psychological Distress Predict Mortality? Evidence from an Individual Participant Meta-Analysis of ten Prospective Cohort Studies
Authors: Russ TC , Stamatakis E , Hamer M , Starr JM , Kivimaki M , Batty GD 
Published: September 2012

BackgroundA series of studies have linked psychological distress (depression and anxiety) with cause-specific mortality, but the risk of lower, sub-clinically symptomatic, levels of distress – hitherto of little interest to specialist mental health practitioners – has not been quantified.MethodsWe conducted an individual participant meta-analysis of ten large prospective cohort studies from the Health Survey for England. Baseline psychological distress was measured using the 12-item General Health Questionnaire, and mortality from death certification. The analytical sample comprised 68,222 individuals from general population samples of adults aged 35 and over, free of cardiovascular disease and cancer and living in private households in England at study baseline. The main outcome measures were death from all causes (n=8,365), cardiovascular disease (n=3,382), all cancers (n=2,552), and external causes (n=386). Mean (standard deviation) follow-up was 8.2 (3.5) years.ResultsThere was a positive, dose-response association between psychological distress across the full range of severity and mortality risk (age- and sex-adjusted hazard ratio for General Health Questionnaire scores of 1–3 compared to zero: 1.20, 95% CI 1.13 to 1.27; scores 4–6: 1.43 1.31 to 1.56; and scores 7–12: 1.94, 1.66 to 2.26; p for trend <0.001). This association remained after adjustment for somatic co-morbidity plus behavioural and socioeconomic factors. A similar association was found for death from cardiovascular disease, cancer, and external causes.ConclusionPsychological distress is associated with increased risk of mortality from several major causes in a dose-response pattern. Even at lower levels of distress the mortality risk was elevated.
OP24 Assessing the Cost-Effectiveness of Alternative Care Pathways: A Case Study Evaluating Early Transfer to Neuroscience Centres for Critically ill Patients with Acute Traumatic Brain Injury
Authors: Grieve R , Harrison D , Sadique MZ , Gomes M , Menon D , Rowan K 
Published: September 2012

BackgroundAcute traumatic brain injury (TBI) is a major cause of death, disability and cost. For critically-ill adult TBI patients who present outside a neuroscience centre, and do not require neurosurgery, there is little evidence on whether early transfer to a neuroscience centre is worthwhile. NICE guidelines list the issue as a key research topic. We aimed to assess the relative cost-effectiveness of ‘early transfer’ (within 18 hours of hospital presentation) versus ‘no or late transfer’ (after 24 hours) for these patients.MethodsThe Risk Adjustment In Neurocritical care (RAIN) Study validated risk prediction models following TBI. The RAIN Study recruited admissions following acute TBI to 67 adult critical care units during 2009–11. Detailed information was collected on baseline prognostic factors, the time of transfer to neuroscience centres, and mortality. Resource use data were recorded for six months, and combined with unit costs to report total hospital and community health service costs. At the six month follow-up, data were collected on health-related quality of life (HRQoL), by the EQ–5D–3L. The lifetime cost-effectiveness analysis extrapolated from six month endpoints, informed by the literature. We report lifetime incremental cost per QALY of ‘early’ versus ‘no or late transfer’, overall and for subgroups (age <=70, vs >70; mild/moderate, vs severe TBI; major extracranial injury, vs none). To adjust for baseline differences we used the previously validated risk prediction models in regression analyses. In sensitivity analyses we considered alternative approaches for extrapolating from the six month endpoints and undertaking risk adjustment.ResultsThere were 584 patients in the ‘early’ and 263 in the ‘no or late transfer’ group. After risk adjustment, early transfer was associated, at six months, with lower mortality (odds ratio 0.52, 95% CI 0.34 to 0.80), higher HRQoL for survivors (mean gain 0.13, 0.032 to 0.225), but positive incremental costs (£15,000, £11,123 to £18,880). The lifetime cost per QALY for ‘early transfer’ was £11,000. For patients older than 70, ‘early transfer’ was associated with higher mortality, and was unlikely to be cost-effective (probability 0.15 at £20,000 per QALY). For other subgroups, the corresponding probabilities that ‘early transfer’ is cost-effective were between 0.7 and 1.ConclusionFor critically-ill patients with acute TBI aged 70 or less, early transfer to a neuroscience centre appears cost-effective. While this finding is robust to alternative methodological assumptions and choice of risk prediction model, further research is required to investigate the potential impact of unobserved confounding.
OP33 Exposure-Based Assessment of Modal Travel Risk in England Using Routine Health Data
Authors: Mindell JS , Leslie D , Wardlaw M 
Published: September 2012

BackgroundCycling can make large contributions to population health but perceived road danger is a strong disincentive to cycling. Research on cycling safety is distorted by not making like-for-like comparisons. We examined age- and sex-specific deaths and injuries in England by travel mode, considering both the ICD external codes included in official travel risk data and those excluded but required for accurate comparative assessment, to provide more precise comparisons of travel risks by mode.MethodsICD–10 external codes were grouped by type of incident for pedestrians, cyclists, and car/van drivers; the fourth digit was used to exclude non-transport casualties. Numbers of hospital admissions, from Hospital Episodes Statistics data, and deaths in England 2007–2009 were obtained for these ICD codes, by age-group and sex. Aggregated per capita distance travelled by age-group, sex and mode in England from National Travel Survey for each year 2007–2009, weighted to be nationally-representative, was multiplied by the estimated mid-year population. Time spent travelling was estimated using mean trip speeds by mode. We calculated fatal injury and hospital admission rates by distance travelled and by time spent travelling by age-group, sex, and travel mode. 95% confidence intervals for Poisson parameters were calculated using the formulae for weighted sums.ResultsFatalities per million hours’ use (f/mhu) varied little (0.15–0.45f/mhu by mode for men, 0.09–0.31f/mhu for women). Risks were similar for men aged 21–49 years for all three modes and for female pedestrians and drivers aged 21–69 years. The group most at risk for each mode were: male drivers aged 17–20 years (1.3f/mhu, 95% CI 1.2, 1.4); male cyclists aged 70 years or older (2.2 f/mhu, 1.6, 3.0) and female pedestrians aged 70 years or older (0.95 f/mhu, 0.86, 1.1). In general, fatality rates were substantially higher amongst males than females, except for drivers aged 60 years or older. Risks per hour for male drivers under 30 years were similar or higher than for male cyclists; for 17–20 year olds the risk was higher for drivers (33/Bn km, 95% CI 30, 36; 1.3f/mhu, 1.2, 1.4) than cyclists (20/Bn km, 10, 37; 0.24f/mhu, 0.12, 0.45) using distance or time.ConclusionThis is the first study in the UK to provide travel casualty rates by distance travelled and per hour, by mode, by age-group and sex, based on nationally-representative data, to enable unbiased intermodal comparisons for population sub-groups. Males aged 17–20 years old face higher risks as drivers than as cyclists, and do not achieve better safety as drivers until over 30 years. Not making like-for-like comparisons sustains the misleading stereotype that cycling is relatively hazardous.
OP35 The Health Impacts of Free Bus Travel for Young People in London
Authors: Edwards P , Steinbach R , Wilkinson P , Petticrew M , Goodman A , Jones A , Roberts H , Kelly C , Nellthorp J , Green J 
Published: September 2012

BackgroundInterventions in transport systems have potentially far-reaching impacts on public health, but can be challenging to evaluate. In 2005, young people in London gained access to free bus travel; an intervention that has a number of potential risks and benefits to health. As transport access is linked to well-being, we might expect the policy to benefit the health of young people by reducing transport exclusion. However, health effects might also include: young people doing less walking, thus reducing levels of physical activity, but also reducing exposure to pedestrian injury risk; or being more exposed to assault as they travel further.MethodsWe utilized change-on-change analyses comparing pre (2001–2004) and post (2006–2009) changes in outcomes in ‘younger people’ (intervention group, 12–17 years) to ‘adults’ (control group, 25–59 years) in London, UK. Main outcome measures included changes in travel patterns (trips made by main travel mode and distances travelled), road traffic injuries and hospital admissions for assault.ResultsPost-intervention, the total number of journeys to school or work made by younger people increased relative to adults (change-on-change ratio 1.19: 95% CI 1.13–1.25), and the proportion of short trips (<1km) by bus doubled (1.97: 1.07–3.84). There was some evidence that younger people made fewer trips where walking was the main mode of travel (0.76: 0.70–0.85), but no evidence for a change in overall distances walked by younger people post-intervention. Against background declines in road traffic injury, the decrease in road injury to young people was larger relative to adults (0.84; 0.82–0.87), however pedestrian injuries declined similarly in both groups. Rates of hospitalisation due to assaults increased in younger people relative to adults (1.20: 1.13–1.27).ConclusionA change in the distribution of travel modes used by younger people (relative to adults who had not received free bus travel) was observed post-intervention. Younger people made fewer trips where walking was their main mode of travel, but there was little overall difference in distances walked, suggesting that the policy may have generated journeys but made little overall impact on prevalence of active transport. Observed changes in road traffic injuries reflect the relative risks of changing travel modes. The intervention has been associated with a small relative increase in assaults to younger people. A change-on-change analysis has enabled us to use this ‘natural experiment’ to quantify some important health outcomes of a transport policy in the absence of evidence from a randomised trial.
OP64 Parental Suicide Attempt and Offspring Self-Harm and Suicidal Thoughts: Results from the Alspac Birth Cohort
Authors: Geulayov G , Metcalfe C , Gunnell DJ 
Published: September 2012

BackgroundExposure to parental self-harm has been linked to an increased risk of self-harm and suicidal thoughts in their offspring. Much of the available evidence is from population registers or clinical samples and relates to parental death by suicide; few studies have investigated associations of non-fatal suicide attempts in parents with community presenting non-fatal self-harm and suicidal thoughts in offspring. We studied the association of parental suicide attempt (SA) with offspring self-harm and suicidal thoughts using a large two-generational prospective cohort.MethodsThe sample comprised 4,396 children, their mothers and 2,541 of the mothers’ partners from the Avon Longitudinal Study of Parents and Children (ALSPAC). Parents were asked to report on incident episodes of SA on 10 separate occasions from pregnancy until the children were 11 years old. Information on lifetime childhood self-harm, with and without suicidal intent, and suicidal thoughts, with and without suicidal plan, was collected through child-completed questionnaires at the age of 16–17 years.ResultsBased on preliminary results, SA was reported by 1.5% of the mothers and 0.7% of the partners. Adjusting for sociodemographic factors and parental depression, maternal SA was associated with 3-fold increased risk of self-harm with suicidal intent in their children [Adjusted odds ratio (AOR) 3.0, 95% confidence interval (CI) 1.4–6.1] but not with self-harm with no suicidal intent (AOR 0.8, 95% CI 0.3–1.9). Children exposed to maternal SA were more likely than unexposed children to report both suicidal thoughts with and without suicidal plan (AOR 5.2, 95% CI 2.3–11.6; AOR 2.2, 95% CI 1.1–4.4, respectively). Partner SA was associated with 2.3-fold increased risk of self-harm with suicidal intent (95% CI 0.5–10.6) and with an increased risk of suicidal thoughts with suicidal plan (AOR 3.5, 95% CI 0.8–16.0) but these results are consistent with chance. There was no evidence of an association between partner suicide attempt with offspring self-harm with no suicidal intent (AOR 0.4, 95% CI 0.1–3.5) or with offspring suicidal thoughts without a suicidal plan (AOR 0.6, 95% CI 0.1–4.5).ConclusionParental SA in childhood increases the risk of self-harm with suicidal intent in offspring but is unrelated to risk of self-harm without suicide intent. Parental SA is associated with larger effect size on suicidal thoughts with a suicidal plan than without a plan. Findings provide limited evidence that maternal SA is a more potent risk factor than partner SA.
OP70 Place of Cancer Deaths in England, 2001-2010: Time Trends and Determinants
Authors: Gao W , Ho Y , Verne J , Glickman M , Higginson IJ 
Published: September 2012

BackgroundPlace of death is an important quality indicator for end of life care. Understanding where patients with cancer die and what factors are associated with place of death is important for improving end of life care and has significant health care cost implications. There is, however, limited up-to-date evidence to guide practice.MethodsThis is a whole population-based observational study. All deaths with cancer as the underlying cause of death (ICD–10 codes: C00-C97), which occurred in the period 2001–2010, were extracted from death registrations in England. The time trends in place of death (coded as hospital, home, hospice, nursing home and elsewhere) were described and tested by using the Cochran-Armitage Trend Test. Factors associated with hospital death (age, gender, year of death, cancer site, index of multiple deprivation (IMD), region) were evaluated using the generalised linear model. The clustering effect within region was accounted for using an exchangeable working correlation structure.ResultsA total of 1,270, 071 cancer deaths were recorded over the 10 years period, of which 47.4% occurred in hospitals, 24.1% in homes, 17.1% in hospices, 6.6% in nursing homes and 4.8% elsewhere. In the study period, deaths in hospital decreased from 49.7% to 42.2% (annual decrease 0.8%; Pz=59.6<0.001), and home deaths increased from 22.3% to 27.6% (annual increase 0.4%; Pz=48.7<0.0001). Independent risk factors for dying in hospitals were: being older (Adjusted OR75–84 vs 18–54(AOR): 1.25; 95% confidence interval (95%CI): 1.24–1.26) and living in deprived areas (AORs:1.06–1.31). Leukaemia (AORref=lung: 3.66; 95%CI: 3.65–3.68), Non-Hodgkin’s Lymphoma (AORref=lung: 2.89; 95%CI: 2.88–2.90) and Bladder cancer (AORref=1.46; 95%CI: 1.45–1.47) were the top three cancer deaths most likely to occur in hospitals. Men had a slightly higher chance than women of dying in hospitals (AOR: 1.13; 95%CI: 1.13–1.14). Cancer deaths in hospitals were more likely to occur in London than in South West (AORs range: 0.84 in South East Coast to 1.27 in London).ConclusionWe found an overall reducing trend in hospital deaths and an increasing trend in home deaths in the past ten years. However, significant inequality in place of death still exists. Future research needs to explore the underlying reasons.
OP75 The Relative Importance of Objective and Subjective Socio-Economic and School-Based Social Status for Adolescent Health and Substance use
Authors: Sweeting H , Hunt K , Bhaskar A 
Published: September 2012

BackgroundContrasting with findings from adults and children, most studies of adolescents find little variation in health according to conventional (objective) socio-economic status (SES) measures. Adolescent smoking is patterned by SES, but relationships between SES and drinking are weaker or non-existent.Subjectivestatus captures perceptions of relative rank and may also be important for health. Most studies of health and subjective status focus on adults, use subjective SES and explore self-reported health rather than behaviours. However, subjectiveschool-basedstatus may be more important than subjective SES for health in adolescence. This study examines the relative importance of objective SES, subjective SES and school-based social status for adolescent self-reported health and health behaviours.MethodsData were obtained via schools-based self-completion questionnaires in 2010 with follow-up in 2011 when 2,503 (85% of baseline) 13–15 year olds participated. Variables allowing derivation of family affluence were included in 2010; all other data were obtained in 2011. Scottish Index of Multiple Deprivation (SIMD) was derived via postcodes. Pupils rated subjective SES via the MacArthur Scale of Youth Subjective Social Status, a 10-rung ladder with the top representing ‘the best off people in Scotland’. Seven ladders asked them to rate various aspects of their own status, compared to their school year-group. Questionnaires also asked about self-rated health, psychological distress (GHQ–12), smoking and drinking. Analyses suggested three subjective school-based social status dimensions: ‘peer’, ‘scholastic’ and ‘sports’. Objective SES and all social status measures were each collapsed into three categories for inclusion in logistic regression analyses which were conducted on those with full data (N=1,819) on these measures.ResultsCorrelations between objective SES and all subjective status measures were weak. In preliminary multivariate logistic regression analyses, adjusted for gender and age, family affluence was not associated with health, smoking or drinking and deprivation was not associated with health. However, each subjective school-based status measure was associated with both health and behaviours. For example, odds (95% confidence intervals) of fair/poor self-rated health among those ‘low’ compared with ‘high’: family affluence 1.1 (0.68–1.81); SIMD 1.23 (0.86–1.76); subjective SES 1.42 (0.97–2.08); subjective ‘peer’ status 1.73 (1.20–2.50); ‘scholastic’ 2.93 (2.01–4.27); ‘sports’ 2.93 (1.98–4.35). Odds of ever smoking among those low (vs. high): family affluence 1.43 (0.93–2.21); SIMD 2.28 (1.67–3.13); subjective SES 1.20 (0.84–1.71); ‘peer’ 0.30 (0.21–0.42); ‘scholastic’ 11.80 (8.05–17.29); ‘sports’ 2.00 (1.41–2.84).ConclusionSubjective school-based social status is more important for adolescent health and substance use than either objective or subjective SES measures.