The increasing cost of happiness.

A fundamental question for society is how much happiness does a dollar buy? The accepted view among economists and psychologists is that income has diminishing marginal returns on happiness: money and happiness increase together up to a point after which there is relatively little further gain. In this paper we estimate the relationship between income and subjective wellbeing over a 19-year period focusing on where the greatest change in the marginal return on income occurs and whether this change point has shifted over time. We formally test for the presence of a change point as well as temporal changes in the relationship between income and affective wellbeing (happiness), and income and cognitive wellbeing (life satisfaction), using household economic data from Australia between 2001 and 2019. The results indicate that the change point between affective wellbeing and income has increased over those 19 years faster than inflation (i.e., cost of living). This suggests that inequalities in income may be driving increasing inequities in happiness between the rich and the poor, with implications for health and recent government policy-goals to monitor and improve wellbeing.

Optimising image quality and radiation dose for neonatal incubator imaging.

INTRODUCTION: Neonates often require imaging within incubators however limited evidence exists as to the optimal method and acquisition parameters to achieve these examinations. This study aims to standardise and optimise neonatal chest radiography within incubators. METHODS: A neonatal anthropomorphic phantom was imaged on two different incubators under controlled conditions using a DR system. Exposure factors, SID and placement of image receptor (direct v tray) were explored whilst keeping all other parameters consistent. Image quality was evaluated using absolute visual grading analysis (VGA) with contrast-to-noise ratio (CNR) also calculated for comparison. Effective dose was established using Monte Carlo simulation using entrance surface dose within its calculations. RESULTS: VGA and CNR reduced significantly (p < 0.05) whilst effective dose increased significantly (p < 0.05) for images acquired using the incubator tray. The optimal combinations of parameters for incubator imaging were: image receptor directly behind neonate, 0.5 mAs, 60 kV at 100 cm SID, however, if tray needs to be used then these need to be adapted to: 1 mAs at maximum achievable SID. Effective dose was highest for images acquired using both incubator tray and 100 cm SID owing to a decrease in focus to skin distance. There is significant increase (p < 0.01) in VGA between using 0.5 mAs and 1 mAs but an apparent lack of increase between 1 and 1.5 mAs. CONCLUSION: Using the incubator tray has an adverse effect on both image quality and radiation dose for incubator imaging. Direct exposure is optimal for this type of examination but if tray needs to be used, both mAs and SID need to be increased slightly to compensate. IMPLICATIONS FOR PRACTICE: This study can help inform practice in order to both standardise and optimise chest imaging for neonates in incubators.

Investigating the importance of the local food environment for fruit and vegetable intake in older men and women in 20 UK towns: a cross-sectional analysis of two national cohorts using novel methods.

BACKGROUND: Local neighbourhood environments can influence dietary behavior. There is limited evidence focused on older people who are likely to have greater dependence on local areas and may suffer functional limitations that amplify any neighbourhood impact. METHODS: Using multi-level ordinal regression analysis we investigated the association between multiple dimensions of neighbourhood food environments (captured by fine-detail, foot-based environmental audits and secondary data) and self-reported frequency of fruit and vegetable intake. The study was a cross-sectional analysis nested within two nationally representative cohorts in the UK: the British Regional Heart Study and the British Women's Heart and Health Study. Main exposures of interest were density of food retail outlets selling fruits and vegetables, the density of fast food outlets and a novel measure of diversity of the food retail environment. RESULTS: A total of 1124 men and 883 women, aged 69 - 92 years, living in 20 British towns were included in the analysis. There was strong evidence of an association between area income deprivation and fruit and vegetable consumption, with study members in the most deprived areas estimated to have 27% (95% CI: 7, 42) lower odds of being in a higher fruit and vegetable consumption category relative to those in the least deprived areas. We found no consistent evidence for an association between fruit and vegetable consumption and a range of other food environment domains, including density of shops selling fruits and vegetables, density of premises selling fast food, the area food retail diversity, area walkability, transport accessibility, or the local food marketing environment. For example, individuals living in areas with greatest fruit and vegetable outlet density had 2% (95% CI: -22, 21) lower odds of being in a higher fruit and vegetable consumption category relative to those in areas with no shops. CONCLUSIONS: Although small effect sizes in environment-diet relationships cannot be discounted, this study suggests that older people are less influenced by physical characteristics of neighbourhood food environments than is suggested in the literature. The association between area income deprivation and diet may be capturing an important social aspect of neighbourhoods that influence food intake in older adults and warrants further research.

The effect of oral intake during the immediate pre-colonoscopy time period on volume depletion in patients who receive sodium picosulfate.

Sodium picosulfate, used in combination with magnesium oxide and citric acid for bowel cleansing, can result in dehydration. We investigated whether enhanced carbohydrate fluid intake pre-colonoscopy could mitigate this effect. We enrolled 398 elective colonoscopy patients in a prospective, controlled, single-blinded study. The control group (n=194) fasted routinely (minimum seven hours) whilst the treatment group (n=197) drank 1,200 ml carbohydrate solution leading up to admission (up until two hours pre-colonoscopy). On admission a patient survey was completed, and urine specific gravity obtained. Supine blood pressure and pulse rate were measured, and repeated within three minutes of standing. The carbohydrate group had reduced symptoms and signs of dehydration, including thirst (34% versus 65%, P <0.001), dry mouth (45% versus 59%, P=0.008), dizziness (10% versus 20%, P=0.010), lower mean urine specific gravity (1.007 versus 1.017, P <0.001), lower incidence of orthostatic hypotension (2.6% versus 11%, P <0.001), and lower mean erect pulse rate (78 versus 81 /minute, P=0.047). The postural change in systolic blood pressure was less in the treatment group (mean -0.4 mmHg, median -1 mmHg [interquartile range, IQR -7 to 7]) than in the control group (mean -4.1 mmHg, median -1 mmHg [IQR -12 to 3], P=0.028). These findings indicate that hydration with carbohydrate solution in patients taking sodium picosulfate has clinical benefit.

Reducing falls among older people in general practice: The ProAct65+ exercise intervention trial.

BACKGROUND: Falls are common in the older UK population and associated costs to the NHS are high. Systematic reviews suggest that home exercise and group-based exercise interventions, which focus on progressively challenging balance and increasing strength, can reduce up to 42% of falls in those with a history of falls. The evidence is less clear for those older adults who are currently at low risk of falls. AIM: ProAct65+, a large, cluster-randomised, controlled trial, investigated the effectiveness of a home exercise programme (Otago Exercise Programme (OEP)) and a group-based exercise programme (Falls Management Exercise (FaME)) compared to usual care (UC) at increasing moderate to vigorous physical activity (MVPA). This paper examines the trial's secondary outcomes; the effectiveness of the interventions at reducing falls and falls-related injuries. SETTING & PARTICIPANTS: 1256 community-dwelling older adults (aged 65+) were recruited through GP practices in two sites (London and Nottingham). Frequent fallers (≥3 falls in last year) and those with unstable medical conditions were excluded, as were those already reaching the UK Government recommended levels of physical activity (PA) for health. METHODS: Baseline assessment (including assessment of health, function and previous falls) occurred before randomisation; the intervention period lasted 24 weeks and there was an immediate post-intervention assessment; participants were followed up every six months for 24 months. Falls data were analysed using negative binomial modelling. OUTCOME MEASURES: Falls data were collected prospectively during the intervention period by 4-weekly diaries (6 in total). Falls recall was recorded at the 3-monthly follow-ups for a total of 24 months. Balance was measured at baseline and at the end of the intervention period using the Timed Up & Go and Functional Reach tests. Balance confidence (CONFbal), falls risk (FRAT) and falls self-efficacy (FES-I) were measured by questionnaire at baseline and at all subsequent assessment points. RESULTS: 294 participants (24%) reported one or two falls in the previous year. There was no increase in falls in either exercise group compared to UC during the intervention period (resulting from increased exposure to risk). The FaME arm experienced a significant reduction in injurious falls compared to UC (incidence rate ratio (IRR) 0.55, 95% CI 0.31, 0.96; p=0.04) and this continued during the 12 months after the end of the intervention (IRR 0.73, 95% CI 0.54, 0.99; p=0.05). There was also a significant reduction in the incidence of all falls (injurious and non-injurious) in the FaME arm compared with UC (IRR 0.74, 95% CI 0.55, 0.99; p=0.04) in the 12 month period following the cessation of the intervention. There was a non-significant reduction in the incidence of all falls in the OEP arm compared with UC (IRR 0.76, 95% CI 0.53, 1.09; p=0.14) in the 12 months following the cessation of the intervention. The effects on falls did not persist at the 24 months assessment in either exercise arm. However, when those in the FaME group who continued to achieve 150min of MVPA per week into the second post-intervention year were compared to those in the FaME group who did not maintain their physical activity, there was a significant reduction in falls incidence (IRR=0.49, 95% CI 0.30, 0.79; p=0.004). CONFbal was significantly improved at 12 months post intervention in both intervention arms compared with UC. There were no significant changes in any of the functional balance measures, FES-I or FRAT, between baseline and the end of the intervention period. CONCLUSION: Community-dwelling older adults who joined an exercise intervention (FaME) aimed at increasing MVPA did not fall more during the intervention period, fell less and had fewer injurious falls in the 12 months after cessation of the intervention. However, 24 months after cessation of exercise, the beneficial effects of FaME on falls reduction ceased, except in those who maintained higher levels of MVPA. OEP exercise appears less effective at reducing falls in this functionally more able population of older adults.

Does case management for patients with heart failure based in the community reduce unplanned hospital admissions? A systematic review and meta-analysis.

OBJECTIVES: The aim of this systematic review of randomised controlled trials (RCTs) and controlled trials (non-RCTs, NRCTs) is to investigate the effectiveness and related costs of case management (CM) for patients with heart failure (HF) predominantly based in the community in reducing unplanned readmissions and length of stay (LOS). SETTING: CM initiated either while as an inpatient, or on discharge from acute care hospitals, or in the community and then continuing on in the community. PARTICIPANTS: Adults with a diagnosis of HF and resident in Organisation for Economic Co-operation and Development countries. INTERVENTION: CM based on nurse coordinated multicomponent care which is applicable to the primary care-based health systems. PRIMARY AND SECONDARY OUTCOMES: Primary outcomes of interest were unplanned (re)admissions, LOS and any related cost data. Secondary outcomes were primary healthcare resources. RESULTS: 22 studies were included: 17 RCTs and 5 NRCTs. 17 studies described hospital-initiated CM (n=4794) and 5 described community-initiated CM of HF (n=3832). Hospital-initiated CM reduced readmissions (rate ratio 0.74 (95% CI 0.60 to 0.92), p=0.008) and LOS (mean difference -1.28 days (95% CI -2.04 to -0.52), p=0.001) in favour of CM compared with usual care. 9 trials described cost data of which 6 reported no difference between CM and usual care. There were 4 studies of community-initiated CM versus usual care (2 RCTs and 2 NRCTs) with only the 2 NRCTs showing a reduction in admissions. CONCLUSIONS: Hospital-initiated CM can be successful in reducing unplanned hospital readmissions for HF and length of hospital stay for people with HF. 9 trials described cost data; no clear difference emerged between CM and usual care. There was limited evidence for community-initiated CM which suggested it does not reduce admission.

The influence of neighbourhood-level socioeconomic deprivation on cardiovascular disease mortality in older age: longitudinal multilevel analyses from a cohort of older British men.

BACKGROUND: Evidence from longitudinal studies on the influence of neighbourhood socioeconomic factors in older age on cardiovascular disease (CVD) mortality is limited. We aimed to investigate the prospective association of neighbourhood-level deprivation in later life with CVD mortality, and assess the underlying role of established cardiovascular risk factors. METHODS: A socially representative cohort of 3924 men, aged 60-79 years in 1998-2000, from 24 British towns, was followed up until 2012 for CVD mortality. Quintiles of the national Index of Multiple Deprivation (IMD), a composite score of neighbourhood-level factors (including income, employment, education, housing and living environment) were used. Multilevel logistic regression with discrete-time models (stratifying follow-up time into months) were used. RESULTS: Over 12 years, 1545 deaths occurred, including 580 from CVD. The risk of CVD mortality showed a graded increase from IMD quintile 1 (least deprived) to 5 (most deprived). Compared to quintile 1, the age-adjusted odds of CVD mortality in quintile 5 were 1.71 (95% CI 1.32 to 2.21), and 1.62 (95% CI 1.23 to 2.13) on further adjustment for individual social class, which was attenuated slightly to 1.44 (95% CI 1.09 to 1.89), but remained statistically significant after adjustment for smoking, body mass index, physical activity and use of alcohol. Further adjustment for blood pressure, high-density lipoprotein cholesterol and prevalent diabetes made little difference. CONCLUSIONS: Neighbourhood-level deprivation was associated with an increased risk of CVD mortality in older people independent of individual-level social class and cardiovascular risk factors. The role of other specific neighbourhood-level factors merits further research.

Testosterone and reward prediction-errors in healthy men and men with schizophrenia.

Sex hormones impact reward processing, which is dysfunctional in schizophrenia; however, the degree to which testosterone levels relate to reward-related brain activity in healthy men and the extent to which this relationship may be altered in men with schizophrenia has not been determined. We used functional magnetic resonance imaging (fMRI) to measure neural responses in the striatum during reward prediction-errors and hormone assays to measure testosterone and prolactin in serum. To determine if testosterone can have a direct effect on dopamine neurons, we also localized and measured androgen receptors in human midbrain with immunohistochemistry and quantitative PCR. We found correlations between testosterone and prediction-error related activity in the ventral striatum of healthy men, but not in men with schizophrenia, such that testosterone increased the size of positive and negative prediction-error related activity in a valence-specific manner. We also identified midbrain dopamine neurons that were androgen receptor immunoreactive, and found that androgen receptor (AR) mRNA was positively correlated with tyrosine hydroxylase (TH) mRNA in human male substantia nigra. The results suggest that sex steroid receptors can potentially influence midbrain dopamine biosynthesis, and higher levels of serum testosterone are linked to better discrimination of motivationally-relevant signals in the ventral striatum, putatively by modulation of the dopamine biosynthesis pathway via AR ligand binding. However, the normal relationship between serum testosterone and ventral striatum activity during reward learning appears to be disrupted in schizophrenia.

Identification and classification of involuntary leg muscle contractions in electromyographic records from individuals with spinal cord injury.

Involuntary muscle contractions (spasms) are common after human spinal cord injury (SCI). Our aim was to compare how well two raters independently identified and classified different types of spasms in the same electromyographic records (EMG) using predefined rules. Muscle spasms were identified by the presence, timing and pattern of EMG recorded from paralyzed leg muscles of four subjects with chronic cervical SCI. Spasms were classified as one of five types: unit, tonic, clonus, myoclonus, mixed. In 48h of data, both raters marked the same spasms most of the time. More variability in the total spasm count arose from differences between muscles (84%; within subjects) than differences between subjects (6.5%) or raters (2.6%). Agreement on spasm classification was high (89%). Differences in spasm count, and classification largely occurred when EMG was marked as a single spasm by one rater but split into multiple spasms by the other rater. EMG provides objective measurements of spasm number and type in contrast to the self-reported spasm counts that are often used to make clinical decisions about spasm management. Data on inter-rater agreement and discrepancies on muscle spasm analysis can both drive the design and evaluation of software to automate spasm identification and classification.

Low muscle mass in older men: the role of lifestyle, diet and cardiovascular risk factors.

OBJECTIVE: To explore associations between low muscle mass and a wide range of lifestyle, dietary and cardiovascular risk factors in older men including metabolic risk factors, markers of inflammation, endothelial dysfunction and coagulation. DESIGN: Cross-sectional study. SETTING: British Regional Heart Study. PARTICIPANTS: 4252 men aged 60-79 years. MEASUREMENTS: PARTICIPANTS attended a physical examination in 1998-2000, and completed a general questionnaire and a food frequency questionnaire. Low muscle mass was assessed by two measures: midarm muscle circumference (MAMC) and fat-free mass index (FFMI). Associations between risk factors and low muscle mass were analysed using logistic regression. RESULTS: Physical inactivity, insulin resistance, C-reactive protein, von Willebrand factor and fibrinogen were associated with significantly increased odds of low MAMC and FFMI after adjustment for body mass index, lifestyle characteristics and morbidity. Those with higher percent energy intake from carbohydrates showed decreased odds of low MAMC (OR: 0.73, 95% CI: 0.55-0.96) and FFMI (OR: 0.76, 95% CI: 0.58-0.99). Other dietary variables, smoking, alcohol intake, D-dimer, interleukin 6 and homocysteine showed no important associations with MAMC and FFMI. CONCLUSION: Increasing physical activity, consuming a diet with a high proportion of energy from carbohydrates, and taking steps to prevent insulin resistance and reduce inflammation and endothelial dysfunction may help to reduce the risk of low muscle mass in older men.

Five-year results of a randomised controlled trial comparing mobile and fixed bearings in total knee replacement.

There is conflicting evidence about the merits of mobile bearings in total knee replacement, partly because most randomised controlled trials (RCTs) have not been adequately powered. We report the results of a multicentre RCT of mobile versus fixed bearings. This was part of the knee arthroplasty trial (KAT), where 539 patients were randomly allocated to mobile or fixed bearings and analysed on an intention-to-treat basis. The primary outcome measure was the Oxford Knee Score (OKS) plus secondary measures including Short Form-12, EuroQol EQ-5D, costs, cost-effectiveness and need for further surgery. There was no significant difference between the groups pre-operatively: mean OKS was 17.18 (sd 7.60) in the mobile-bearing group and 16.49 (sd 7.40) in the fixed-bearing group. At five years mean OKS was 33.19 (sd 16.68) and 33.65 (sd 9.68), respectively. There was no significant difference between trial groups in OKS at five years (-1.12 (95% confidence interval -2.77 to 0.52) or any of the other outcome measures. Furthermore, there was no significant difference in the proportion of patients with knee-related re-operations or in total costs. In this appropriately powered RCT, over the first five years after total knee replacement functional outcomes, re-operation rates and healthcare costs appear to be the same irrespective of whether a mobile or fixed bearing is used.

Epidemiological evidence against a role for C-reactive protein causing leptin resistance.

OBJECTIVE: It has been suggested that elevated levels of C-reactive protein (CRP) might interfere with leptin signalling and contribute to leptin resistance. Our aim was to assess whether plasma levels of CRP influence leptin resistance in humans, and our hypothesis was that CRP levels would modify the cross-sectional relationships between leptin and measures of adiposity. DESIGN AND METHODS: W assessed four measures of adiposity: BMI, waist circumference, fat mass and body fat (%) in 2113 British Regional Heart Study (BRHS) men (mean (s.d.) age 69 (5) years), with replication in 760 (age 69 (6) years) European Male Ageing Study (EMAS) subjects. RESULTS: IN BRHS subjects, leptin correlated with CRP (SPEARMAN'S R=0.22, P0.0001). Leptin and crp correlated with all four measures of adiposity (R VALUE RANGE: 0.22-0.57, all P<0.0001). Age-adjusted mean levels for adiposity measures increased in relation to leptin levels, but CRP level did not consistently influence the ß-coefficients of the regression lines in a CRP-stratified analysis. In BRHS subjects, the BMI vs leptin relationship demonstrated a weak statistical interaction with CRP (P=0.04). We observed no similar interaction in EMAS subjects and no significant interactions with other measures of adiposity in BRHS or EMAS cohorts. CONCLUSION: We have shown that plasma CRP has little influence on the relationship between measures of adiposity and serum leptin levels in these middle-aged and elderly male European cohorts. This study provides epidemiological evidence against CRP having a significant role in causing leptin resistance.

Computer-based interventions for sexual health promotion: systematic review and meta-analyses.

This systematic review was conducted to determine the effects of self-help interactive computer-based interventions (ICBIs) for sexual health promotion. We searched 40 databases for randomized controlled trials (RCTs) of computer-based interventions, defining 'interactive' as programmes that require contributions from users to produce personally relevant material. We conducted searches and analysed data using Cochrane Collaboration methods. Results of RCTs were pooled using a random-effects model with standardized mean differences for continuous outcomes and odds ratios (ORs) for binary outcomes, with heterogeneity assessed using the I(2) statistic. We identified 15 RCTs of ICBIs (3917 participants). Comparing ICBIs to minimal interventions, there were significant effects on sexual health knowledge (standardized mean difference [SMD] 0.72, 95% confidence interval [CI] 0.27-1.18); safer sex self-efficacy (SMD 0.17, 95% CI 0.05-0.29); safer-sex intentions (SMD 0.16, 95% CI 0.02-0.30); and sexual behaviour (OR 1.75, 95% CI 1.18-2.59). ICBIs had a greater impact on sexual health knowledge than face-to-face interventions did (SMD 0.36, 95% CI 0.13-0.58). ICBIs are effective tools for learning about sexual health, and show promising effects on self-efficacy, intention and sexual behaviour. More data are needed to analyse biological outcomes and cost-effectiveness.

Lack of cortico-limbic coupling in bipolar disorder and schizophrenia during emotion regulation.

Bipolar disorder (BD) and schizophrenia (Sz) share dysfunction in prefrontal inhibitory brain systems, yet exhibit distinct forms of affective disturbance. We aimed to distinguish these disorders on the basis of differential activation in cortico-limbic pathways during voluntary emotion regulation. Patients with DSM-IV diagnosed Sz (12) or BD-I (13) and 15 healthy control (HC) participants performed a well-established emotion regulation task while undergoing functional magnetic resonance imaging. The task required participants to voluntarily upregulate or downregulate their subjective affect while viewing emotionally negative images or maintain their affective response as a comparison condition. In BD, abnormal overactivity (hyperactivation) occurred in the right ventrolateral prefrontal cortex (VLPFC) during up- and downregulation of negative affect, relative to HC. Among Sz, prefrontal hypoactivation of the right VLPFC occurred during downregulation (opposite to BD), whereas upregulation elicited hyperactivity in the right VLPFC similar to BD. Amygdala activity was significantly related to subjective negative affect in HC and BD, but not Sz. Furthermore, amygdala activity was inversely coupled with the activity in the left PFC during downregulation in HC (r=-0.76), while such coupling did not occur in BD or Sz. These preliminary results indicate that differential cortico-limbic activation can distinguish the clinical groups in line with affective disturbance: BD is characterized by ineffective cortical control over limbic regions during emotion regulation, while Sz is characterized by an apparent failure to engage cortical (hypofrontality) and limbic regions during downregulation.

Characteristics of a population-wide sample of smokers recruited proactively for the ESCAPE trial.

OBJECTIVES: To describe the characteristics of a sample of smokers recruited proactively into a smoking cessation trial, and to compare these characteristics with the wider population using data from the General Household Survey (GHS) and National Statistics Omnibus Survey. STUDY DESIGN: Sample recruited for a randomized controlled trial. METHODS: Between August 2007 and October 2008, 123 general practices mailed questionnaires to smokers in the U.K. identified from computer records. Smokers willing to participate in a trial of personalized computer-tailored feedback returned the questionnaires to the research team. The characteristics of the sample were compared with the wider population using data from the GHS and National Statistics Omnibus Survey, and Index of Material Deprivation scores. RESULTS: A response rate of 11.4% (n = 6697) was achieved. The sample was demographically similar to the population sample, with an even distribution of participants from areas of both high and low deprivation. The sample was more dependent than the GHS sample, but less dependent than clinic samples. Distribution by motivation and readiness to quit was similar to population estimates. CONCLUSIONS: Public health strategies targeting the entire population of smokers are needed to counter the low recruitment rates resulting from the traditional reactive methods of recruitment to smoking cessation studies. Using computerized records to identify and contact patients who are smokers is a simple method of recruiting a larger, more representative sample of smokers.

Prospective study of seasonal patterns in hemostatic factors in older men and their relation to excess winter coronary heart disease deaths.

BACKGROUND: In England and Wales, approximately 20% extra deaths from coronary heart disease (CHD) occur between December and March, among older people. Circulating concentrations of tissue plasminogen activator (t-PA), von Willebrand factor (VWF) and fibrin D-dimer are associated with arterial disease, and tend to peak in winter. The potential contributions of these hemostatic activation measures to excess winter mortality are unknown. OBJECTIVES: To estimate contributions of hemostatic factors to excess winter mortality. METHODS: Seasonal patterns in t-PA, VWF and D-dimer were investigated in 4088 men aged 60-79 years from 24 British towns. Data on established coronary risk factors were collected by questionnaire, physical examination and blood sampling. The adjusted mean increase in hemostatic markers during winter months, after adjustment for a range of coronary risk factors, was combined with associations of each marker with CHD mortality obtained from 9 years' follow-up of participants, to predict degree of excess CHD winter mortality. Associations of hemostatic markers with CHD incidence from large meta-analyses were also used. RESULTS: All three markers showed peaks in winter; the adjusted mean increases during winter months were 0.21, 0.15 and 0.12 standard deviations for t-PA, VWF and log(D-dimer), respectively. Predicted excess hazard ratios for winter CHD mortality were 3.0%, 2.4% and 3.1%, respectively, in combination, representing an 8.6% excess. This increased to 14% when applying meta-analysis estimates. CONCLUSIONS: Seasonal patterns in three hemostatic markers predict at least 8.6% excess CHD mortality in winter in Great Britain, potentially accounting for over half the excess observed in recent years.

Disambiguating ventral striatum fMRI-related BOLD signal during reward prediction in schizophrenia.

Reward detection, surprise detection and prediction-error signaling have all been proposed as roles for the ventral striatum (vStr). Previous neuroimaging studies of striatal function in schizophrenia have found attenuated neural responses to reward-related prediction errors; however, as prediction errors represent a discrepancy in mesolimbic neural activity between expected and actual events, it is critical to examine responses to both expected and unexpected rewards (URs) in conjunction with expected and UR omissions in order to clarify the nature of ventral striatal dysfunction in schizophrenia. In the present study, healthy adults and people with schizophrenia were tested with a reward-related prediction-error task during functional magnetic resonance imaging to determine whether schizophrenia is associated with altered neural responses in the vStr to rewards, surprise prediction errors or all three factors. In healthy adults, we found neural responses in the vStr were correlated more specifically with prediction errors than to surprising events or reward stimuli alone. People with schizophrenia did not display the normal differential activation between expected and URs, which was partially due to exaggerated ventral striatal responses to expected rewards (right vStr) but also included blunted responses to unexpected outcomes (left vStr). This finding shows that neural responses, which typically are elicited by surprise, can also occur to well-predicted events in schizophrenia and identifies aberrant activity in the vStr as a key node of dysfunction in the neural circuitry used to differentiate expected and unexpected feedback in schizophrenia.

Two-stage method to remove population- and individual-level outliers from longitudinal data in a primary care database.

PURPOSE: In the UK, primary care databases include repeated measurements of health indicators at the individual level. As these databases encompass a large population, some individuals have extreme values, but some values may also be recorded incorrectly. The challenge for researchers is to distinguish between records that are due to incorrect recording and those which represent true but extreme values. This study evaluated different methods to identify outliers. METHODS: Ten percent of practices were selected at random to evaluate the recording of 513,367 height measurements. Population-level outliers were identified using boundaries defined using Health Survey for England data. Individual-level outliers were identified by fitting a random-effects model with subject-specific slopes for height measurements adjusted for age and sex. Any height measurements with a patient-level standardised residual more extreme than ±10 were identified as an outlier and excluded. The model was subsequently refitted twice after removing outliers at each stage. This method was compared with existing methods of removing outliers. RESULTS: Most outliers were identified at the population level using the boundaries defined using Health Survey for England (1550 of 1643). Once these were removed from the database, fitting the random-effects model to the remaining data successfully identified only 75 further outliers. This method was more efficient at identifying true outliers compared with existing methods. CONCLUSIONS: We propose a new, two-stage approach in identifying outliers in longitudinal data and show that it can successfully identify outliers at both population and individual level. Copyright © 2011 John Wiley & Sons, Ltd.

Changing patterns in endotracheal intubation for anaesthesia trainees: a retrospective analysis of 80,000 cases over 10 years.

Several overseas studies have suggested that opportunities for anaesthesia trainees to learn and practise endotracheal intubation have decreased over time. We analysed the operating theatre data collection system at a large Australian metropolitan teaching hospital from 1998 to 2008 to determine if numbers for trainees' caseloads in general, and endotracheal intubation in particular had changed. The total caseload per trainee of approximately 800 cases per year was stable throughout the study period. The number of gastrointestinal endoscopies per trainee increased significantly with a corresponding decrease in the number of other cases. The mean number of endotracheal intubations per trainee per year fell by 10% and of supraglottic devices by 16%, neither of which was statistically significant. Endotracheal intubation for caesarean sections did however fall significantly from an average of nine to an average of six cases per trainee per year. Our findings contrast with other reports of much larger decreases in the number of endotracheal intubations performed by trainees over the last decade, but suggest that our local practice is similar to the international experience of decreasing opportunities for endotracheal intubation in obstetric anaesthesia.