Economic difficulties and common mental disorders among Finnish and British white-collar employees: the contribution of social and behavioural factors

BACKGROUND

In addition to conventional indicators of socioeconomic position, material conditions such as economic difficulties are associated with mental health. However, there has been little investigation of these associations. This study aims to examine the association of current economic difficulties with common mental disorders (CMD) and the contribution of social and behavioural factors to this association in two cohorts of Finnish and British white-collar employees.

METHODS

Comparable survey data from the Finnish Helsinki Health Study and the British Whitehall II Study were used. CMD were measured with the GHQ-12. Inequality indices from logistic regression analysis were used to examine the association between current economic difficulties and CMD, and the contribution of other past and present socioeconomic circumstances, health behaviours, living arrangements and work-family conflicts to this association. Inequality indices show the average change in ill health for each step up in the level of economic difficulties. Analyses were conducted separately for men and women.

RESULTS

Clear associations between current economic difficulties and CMD were found. Adjusting for work-family conflicts attenuated the associations. Adjusting for indicators of past and present socioeconomic circumstances, health behaviours and living arrangements had generally negligible effects. The results were very similar among both sexes in the two cohorts.

CONCLUSIONS

Conflicts between work and family contribute to the association between economic difficulties and CMD in both Finland and Britain. Supporting people to cope not only with everyday economic difficulties but also with work-family conflicts may be important for reducing inequalities in mental health.

Trends in obesity among adults in England from 1993 to 2004 by age and social class and projections of prevalence to 2012

BACKGROUND

This study aims to project the prevalence of adult obesity to 2012 by age groups and social class, by extrapolating the prevalence trends from 1993 to 2004. Repeated cross-sectional surveys were carried out of representative samples of the general population living in households in England conducted annually (1993 to 2004).

METHODS

Participants were classified as obese if their body mass index was over 30 kg/m(2). Projections of obesity prevalence by 2012 were based on three scenarios: extrapolation of linear trend in prevalence from 1993 to 2004; acceleration (or slowing down) in rate of change based on the best fitting curve (power or exponential); and extrapolation of linear trend based on the six most recent years (1999 to 2004).

RESULTS

The prevalence of obesity increased significantly from 1993 to 2004 from 13.6% to 24.0% among men and from 16.9% to 24.4% among women. If obesity prevalence continues to increase at the same rate, it is projected that the prevalence of obesity in 2012 will be 32.1% (95% CI 30.4 to 34.8) in men and 31.0% (95% CI 29.0 to 33.1) in women. The projected 2012 prevalence for adults in manual social classes is higher (43%) than for adults in non-manual social classes (35%).

CONCLUSION

If recent trends in adult obesity continue, about a third of all adults (almost 13 million individuals) would be obese by 2012. Of these, around 43% are from manual social classes, thereby adding to the public health burden of obesity-related illnesses. This highlights the need for public health action to halt or reverse current trends and narrow social class inequalities in health.

Sickness absence as a prognostic marker for common chronic conditions: analysis of mortality in the GAZEL study

OBJECTIVES

To determine whether sickness absence is a prognostic marker in terms of mortality among people with common chronic conditions.

METHODS

Prospective occupational cohort study of 13,077 men and 4871 women aged 37-51 from the National Gas and Electricity Company, France. Records of physician-certified sickness absences over a 3-year period were obtained from employers' registers. Chronic conditions were assessed in annual surveys over the same period. The main outcome measure was all-cause mortality (803 deaths, mean follow-up after assessment of sickness absence: 13.9 years).

RESULTS

In Cox proportional hazard models adjusted for age, sex, socioeconomic position and co-morbidity, >28 annual sickness-absence days versus no absence days was associated with an excess mortality risk among those with cancer (hazard ratio 5.4, 95% CI 2.2 to 13.1), depression (1.7, 1.1 to 2.8), chronic bronchitis or asthma (2.7, 1.6 to 4.6) and hypertension (1.6, 1.0 to 2.6). The corresponding hazard ratios for more than five long (>14 days) sickness-absence episodes per 10 person-years versus no such episodes were 5.4 (2.2 to 13.1), 1.8 (1.3 to 2.7), 2.0 (1.3 to 3.2) and 1.8 (1.2 to 2.7), respectively. Areas under receiver operating characteristics curves for these absence measures varied between 0.56 and 0.73, indicating the potential of these measures to distinguish groups at high risk of mortality. The findings were consistent across sex, age and socioeconomic groups and in those with and without co-morbid conditions.

CONCLUSION

Data on sickness absence may provide useful prognostic information for common chronic conditions at the population level.

Diagnosis-specific sickness absence and all-cause mortality in the GAZEL study

BACKGROUND

This study aims to examine diagnosis-specific sickness absence as a risk marker for all-cause mortality.

METHODS

Prospective occupational cohort (the GAZEL study). Medically certified sickness absence spells >7 days for 15 diagnostic categories, 1990-1992, were examined in relation to all-cause mortality, January 1993-February 2007. The reference group for each diagnostic category was participants with no spell >7 days for that diagnosis. The participants were French public utility workers (5271 women and 13 964 men) aged 37-51 years in 1990, forming the GAZEL study. Over the follow-up period, there were 144 deaths in women and 758 in men.

RESULTS

7875 employees (41.0%) had at least one spell of sickness absence >7 days over the 3-year period. The commonest diagnoses were mental disorders, musculoskeletal diseases, respiratory diseases and external causes in both sexes; genitourinary diseases in women, and digestive and circulatory diseases in men. Of these common diagnoses, mental disorders in women, hazard ratio (95% confidence intervals) 1.24 (1.1 to 1.4), and mental disorders 1.35 (1.3 to 1.5), digestive diseases 1.29 (1.1 to 1.6) and circulatory diseases 1.35 (1.2 to 1.6) in men were associated with mortality after adjustment for age, employment grade and sickness absence in all other diagnostic categories.

CONCLUSIONS

Employees with medically certified absence spells of 1 week or more over a 3-year period had a 60% excess risk of early death. In women and men this excess risk was associated with some of the commonest diagnoses of sickness absence, in particular mental disorders. Sickness absence for mental disorders may be a useful early indicator of groups at increased risk of fatal disease.

Biological and behavioural explanations of social inequalities in coronary heart disease: the Whitehall II study

AIMS/HYPOTHESIS

We determined the degree to which metabolic syndrome components, inflammation and health behaviours account for the social gradient in CHD.

METHODS

A total of 5312 men, initially aged 39 to 63 years, were followed for 13.1 years for incident coronary death or non-fatal myocardial infarction according to socioeconomic position (employment grade). The contribution of explanatory factors to socioeconomic differences in CHD was assessed by the reduction in hazard ratios computed using Cox models. The effects of measurement error were taken into account.

RESULTS

Coronary events were more common in lower employment grades than in higher, with a hazard ratio (relative index of inequality) of 2.2 (95% CI 1.3-3.7), after adjustment for age and ethnic group. Behavioural risk factors (mainly smoking and diet) explained a third of the socioeconomic gradient in CHD incidence. Components of the metabolic syndrome and inflammatory markers predicted CHD incidence and also explained a third of the gradient. Combined, these two groups of predictors, i.e. behavioural and biological, accounted for over half of the socioeconomic gradient in incident CHD. Adding body height as a marker of the effects of early life increased this figure to about 60%.

CONCLUSIONS/INTERPRETATION

A major question has been how someone's socioeconomic position can lead to increased risk of CHD. Socioeconomic differences in components of the metabolic syndrome (and inflammatory markers) provide part of the answer. This was, to an important degree, independent of the contribution of health behaviours to the socioeconomic differentials in CHD.

Cultural identity, clothing and common mental disorder: a prospective school-based study of white British and Bangladeshi adolescents

OBJECTIVE

Cultural integration is the healthiest outcome for young people living in multicultural societies. This paper investigates the influence of different cultural identities on the risk of common mental disorders among Bangladeshi and white British pupils.

DESIGN

The cultural identity of 11-14-year-old school pupils was assessed by their preferences for friends and clothes of their own or other cultural groups; using this information pupils were classified into traditional, integrated, assimilated or marginalised groups. We undertook prospective analyses of cultural identity and its impacts on the later mental health of young people.

SETTING

East London.

PARTICIPANTS

In 2001, white British (573) and Bangladeshi (682) school pupils from a representative sample of schools completed a self-report questionnaire that assessed their cultural, social and health characteristics. In 2003, 383 white British and 517 Bangladeshi pupils were resurveyed and completed measures of mental health.

MAIN OUTCOME MEASURE

Strengths and difficulties questionnaire.

RESULTS

Bangladeshi pupils preferring clothes from their own cultural group (traditional clothing) were less likely to have later mental health problems when compared with Bangladeshi pupils showing an equal preference for clothing from their own and other cultures (integrated clothing; odds ratio (OR) 0.3, 95% CI 0.1 to 0.9). In gender-specific analyses, this finding was sustained only among Bangladeshi girls (OR 0.1, 95% CI 0.1 to 0.7). Integrated clothing choices were least risky only for white British adolescents. Friendship choices showed no prospective associations with later mental health problems.

CONCLUSIONS

Cultural identity, expressed by clothing preferences, influences mental health; the effects differ by gender and ethnic group.

Fourteen-year final report of the randomized PDRG-UK trial comparing three initial treatments in PD

BACKGROUND

Ten-year follow-up results from the Parkinson's Disease Research Group of the United Kingdom trial demonstrated that there were no long-term advantages to initiating treatment with bromocriptine compared with l-dopa in early Parkinson disease (PD). Increased mortality in patients on selegiline combined with l-dopa led to premature termination of this arm after 6 years.

METHODS

Between 1985 and 1990, 782 patients were recruited into an open pragmatic multicenter trial and were randomized to l-dopa/decarboxylase inhibitor (DDCI), l-dopa/DDCI plus selegiline, or bromocriptine. The main endpoints were mortality, disability, and motor complications. For final follow-up, health-related quality of life and mental function were also assessed.

RESULTS

Median duration of follow-up at final assessment was 14 years in the 166 (21%) surviving participants who could be contacted. After adjustment for baseline characteristics, disability scores were better in the l-dopa than in the bromocriptine arm (Webster: 16.6 vs 19.8; p = 0.03; Northwestern University Disability: 34.3 vs 30.0, p = 0.05). Physical functioning (difference 20.8; 95% CI 10.0, 31.6; p < 0.001) and physical summary scores (difference 5.2; 95% CI 0.7, 9.7; p = 0.03) on the 36-item short-form health survey were also superior on l-dopa. Differences in mortality rates and prevalence of dyskinesias, motor fluctuations, and dementia were not significantly different.

CONCLUSION

Initial treatment with the dopamine agonist bromocriptine did not reduce mortality or motor disability and the initially reduced frequency in motor complications was not sustained. We found no evidence of a long-term benefit or clinically relevant disease-modifying effect with initial dopamine agonist treatment.

Low medically certified sickness absence among employees with poor health status predicts future health improvement: the Whitehall II study

BACKGROUND

High sickness absence is associated with poor health status, but it is not known whether low levels of sickness absence among people with poor health predict future health improvement.

OBJECTIVE

To examine the association between medically certified sickness absence and subsequent change in health among initially unhealthy employees.

METHODS

5210 employees (3762 men, 1448 women) whose self-rated health status remained stable (either good or poor) between data phases 1 and 2 were divided into three groups according to their rate of medically certified absences during this period (0 vs >0-5 vs >5 absence spells longer than 7 days per 10 person-years). Subsequent change in health status was determined by self-rated health at follow-up (phase 3).

RESULTS

After adjustment for age and sex, there was a strong contemporaneous association between lower sickness absence and better health status. Among participants reporting poor health, low absence was associated with subsequent improvement in health status (odds ratio 2.66, 95% CI 1.78 to 4.02 for no absence vs >5 certified spells per 10 years). This association was only partially explained by known existing morbidity, socioeconomic position and risk factors.

CONCLUSIONS

Low levels of medically certified sickness absence seem to be associated with positive change in health status among employees in poor health. Further research is needed to examine whether lower sickness absence also marks a more favourable prognosis for specific diseases.

Psychiatric morbidity and social functioning among adults with borderline intelligence living in private households

BACKGROUND

Approximately one-eighth of the population will have DSM-IV borderline intelligence. Various mental disorders and social disability are associated with it.

METHOD

The paper uses data (secondary analysis) from a UK-wide cross-sectional survey of 8450 adults living in private households. Data were collected on psychiatric disorders, intellectual level, social functioning and service use.

RESULTS

In total, 12.3% of the sample had borderline intelligence. The prevalence of psychotic disorder was not significantly increased, but the group showed significant social disadvantage and increased rates of neurotic disorders, substance misuse and personality disorders when compared with their counterparts of normal intelligence. The borderline group was more likely to receive psychiatric medication, but not talking therapies. They appear to use significantly more services, including emergency services.

CONCLUSION

Adults with borderline intelligence are more likely to suffer from treatable mental disorders and an excess of substance misuse. Services should be aware of hidden morbidity in this group.

A multi-state model for joint modelling of terminal and non-terminal events with application to Whitehall II

Serious coronary heart disease (CHD) is a primary outcome in the Whitehall II study, a large epidemiological study of British civil servants. Both fatal (F) and non-fatal (NF) CHD events are of interest and while essentially complete information is available on F events, the observation of NF events is subject to potentially informative censoring. A multi-state model with an unobserved state is introduced for the joint modelling of F and NF events. Two model-based assumptions ensure identifiability of the model and a parameter is introduced to allow sensitivity analyses concerning the assumption linked to informative censoring. Weibull transition rates, which include dependence on explanatory variables, are used in the analysis of Whitehall II data with a particular focus on the relationship between civil service grade and CHD events.

Work stress, weight gain and weight loss: evidence for bidirectional effects of job strain on body mass index in the Whitehall II study

OBJECTIVE

Previous research has focused on overall associations between work stress and body mass index (BMI) ignoring the possibility that stress may cause some people to eat less and lose weight and others to eat more. Using longitudinal data, we studied whether work stress induced weight loss in lean individuals and weight gain in overweight individuals.

DESIGN

Prospective cohort study.

SUBJECTS

A total of 7965 British civil servants (5547 men and 2418 women) aged 35-55 at study entry (The Whitehall II study).

MEASUREMENTS

Work stress, indicated by the job strain model and measured as job control, job demands and job strain, was assessed at baseline and BMI at baseline and at 5-year follow-up.

RESULTS

In men, the effect of job strain on weight gain and weight loss was dependent on baseline BMI (P</=0.03). In the leanest quintile (BMI<22 kg/m(2)) at baseline, high job strain and low job control were associated with weight loss by follow-up, whereas among those in the highest BMI quintile (>27 kg/m(2)), these stress indicators were associated with subsequent weight gain. No corresponding interaction was seen among women.

CONCLUSION

Inconsistent findings reported by previous studies of stress and BMI have generally been interpreted to indicate the absence of an association. In light of our results, the possibility of differential effects of work stress should also be taken into account.

Body mass, weight control behaviours, weight perception and emotional well being in a multiethnic sample of early adolescents

OBJECTIVE

To investigate weight perception, dieting and emotional well being across the range of body mass index (BMI) in a population-based multiethnic sample of early adolescents.

DESIGN

Cross-sectional population-based survey.

SUBJECTS

In total, 2789 adolescents 11-14 years of age from three highly deprived regional authorities in East London, in 2001.

MEASUREMENTS

Data were collected by student-completed questionnaire on weight perception, dieting history, mental and physical health, health behaviours, social capital and sociodemographic factors. Height and weight were measured by trained researchers. Overweight was defined as BMI > or =85th centile and obesity as BMI > or =98th centile. Underweight was defined as BMI< or =15th centile.

RESULTS

In all, 73% were from ethnic groups other than white British. Valid BMI were available for 2522 subjects (90.4%) of whom 14% were obese. Only 20% of overweight boys and 51% of overweight girls assessed their weight accurately. Accuracy of weight perception did not vary between ethnic groups. In all, 42% of girls and 26% of boys reported current dieting to lose weight. Compared with white British teenagers, a history of dieting was more common among Bangladeshi, Indian and mixed ethnicity boys and less likely among Pakistani girls. Self-esteem was not associated with BMI in girls but was significantly lower in obese boys than those of normal weight (P=0.02). Within ethnic subgroups, self-esteem was significantly lower in overweight white British boys (P=0.03) and obese Bangladeshi boys (P=0.01) and Bangladeshi girls (P=0.04), but significantly higher in obese black African girls (P=0.01) than those of normal weight. Obese young people had a higher prevalence of psychological distress (P=0.04), except among Bangladeshi teenagers, where overweight and obese young people had less psychological distress than those of normal weight (P=0.02). Birth outside the UK was associated with reduced risk of obesity in girls (P=0.02) but not with history of dieting, weight perception or psychological factors in either gender.

CONCLUSION

High levels of current dieting for weight control and inaccurate perception of body mass are common across all ethnic groups. However, dieting history and the associations of obesity with self-esteem and psychological distress vary between ethnic groups. Interventions to prevent or treat obesity in black or minority ethnicity groups must consider cultural differences in the relationship between body mass, self-esteem and psychological distress.

Injustice at work and incidence of psychiatric morbidity: the Whitehall II study

BACKGROUND

Previous studies of organisational justice and mental health have mostly examined women and have not examined the effect of change in justice.

AIM

To examine effects of change in the treatment of employees by supervisors (the relational component of organisational justice) on minor psychiatric morbidity, using a cohort with a large proportion of men.

METHODS

Data are from the Whitehall II study, a prospective cohort of 10 308 white-collar British civil servants (3143 women and 6895 men, aged 35-55 at baseline) (Phase 1, 1985-88). Employment grade, relational justice, job demands, job control, social support at work, effort-reward imbalance, physical illness, and psychiatric morbidity were measured at baseline. Relational justice was assessed again at Phase 2 (1989-90). The outcome was cases of psychiatric morbidity by Phases 2 and 3 (1991-93) among participants case-free at baseline.

RESULTS

In analyses adjusted for age, grade, and baseline physical illness, women and men exposed to low relational justice at Phase 1 were at higher risk of psychiatric morbidity by Phases 2 and 3. Adjustment for other psychosocial work characteristics, particularly social support and effort-reward imbalance, partially attenuated these associations. A favourable change in justice between Phase 1 and Phase 2 reduced the immediate risk (Phase 2) of psychiatric morbidity, while an adverse change increased the immediate and longer term risk (Phase 3).

CONCLUSION

This study shows that unfair treatment by supervisors increases risk of poor mental health. It appears that the employers' duty to ensure that employees are treated fairly at work also has benefits for health.

Aircraft and road traffic noise and children's cognition and health: a cross-national study

BACKGROUND

Exposure to environmental stressors can impair children's health and their cognitive development. The effects of air pollution, lead, and chemicals have been studied, but there has been less emphasis on the effects of noise. Our aim, therefore, was to assess the effect of exposure to aircraft and road traffic noise on cognitive performance and health in children.

METHODS

We did a cross-national, cross-sectional study in which we assessed 2844 of 3207 children aged 9-10 years who were attending 89 schools of 77 approached in the Netherlands, 27 in Spain, and 30 in the UK located in local authority areas around three major airports. We selected children by extent of exposure to external aircraft and road traffic noise at school as predicted from noise contour maps, modelling, and on-site measurements, and matched schools within countries for socioeconomic status. We measured cognitive and health outcomes with standardised tests and questionnaires administered in the classroom. We also used a questionnaire to obtain information from parents about socioeconomic status, their education, and ethnic origin.

FINDINGS

We identified linear exposure-effect associations between exposure to chronic aircraft noise and impairment of reading comprehension (p=0.0097) and recognition memory (p=0.0141), and a non-linear association with annoyance (p<0.0001) maintained after adjustment for mother's education, socioeconomic status, longstanding illness, and extent of classroom insulation against noise. Exposure to road traffic noise was linearly associated with increases in episodic memory (conceptual recall: p=0.0066; information recall: p=0.0489), but also with annoyance (p=0.0047). Neither aircraft noise nor traffic noise affected sustained attention, self-reported health, or overall mental health.

INTERPRETATION

Our findings indicate that a chronic environmental stressor-aircraft noise-could impair cognitive development in children, specifically reading comprehension. Schools exposed to high levels of aircraft noise are not healthy educational environments.

Social position and minor psychiatric morbidity over time in the British Household Panel Survey 1991-1998

STUDY OBJECTIVE

To examine social inequalities in minor psychiatric morbidity as measured by the GHQ-12 using lagged models of psychiatric morbidity and changing job status.

DESIGN

GHQ scores were modelled using two level hierarchical regression models with measurement occasions nested within individuals. The paper compares and contrasts three different ways of describing social position: income, social advantage and lifestyle (the Cambridge scale), and social class (the new National Statistics Socio-Economic Classification), and adjusts for attrition.

SETTING

Survey interviews for a nationally representative sample of adults of working age living in Britain.

PARTICIPANTS

8091 original adult respondents in 1991 who remain of working age during 1991-1998 from the British Household Panel Survey (BHPS).

MAIN RESULTS

There was a relation of GHQ-12 to social position when social position was combined with employment status. This relation itself varied according to a person's psychological health in the previous year.

CONCLUSIONS

The relation between social position and minor psychiatric morbidity depended on whether or not a person was employed, unemployed, or economically inactive. It was stronger in those with previously less good psychological health. Among employed men and women in good health, GHQ-12 varied little according to social class, status, or income. There was a "classic" social gradient in psychiatric morbidity, with worse health in less advantaged groups, among the economically inactive. Among the unemployed, a "reverse" gradient was found: the impact of unemployment on minor psychiatric morbidity was higher for those who were previously in a more advantaged social class position.

Children's cognition and aircraft noise exposure at home--the West London Schools Study

The association of aircraft noise exposure with cognitive performance was examined by means of a cross-sectional field survey. Two hundred thirty six children attending 10 primary schools around Heathrow Airport in west London were tested on reading comprehension, immediate/delayed recall and sustained attention. In order to obtain the information about their background, a questionnaire was delivered to the parents and 163 answers were collected. Logistic regression models were used to assess performance on the cognitive tests in relation to aircraft noise exposure at home and possible individual and school level confounding factors. A significant dose-response relationship was found between aircraft noise exposure at home and performance on memory tests of immediate/delayed recall. However there was no strong association with the other cognitive outcomes. These results suggest that aircraft noise exposure at home may affect children's memory.

The psychosocial work environment and alcohol dependence: a prospective study

AIMS

To examine whether a stressful psychosocial work environment predicts alcohol dependence.

METHODS

Alcohol dependence of participants in the Whitehall II occupational cohort of London based civil servants (1985-88) was measured in 1991-93 using the CAGE questionnaire. The psychosocial work environment was measured by self report questions on the job demand-support-control model and on the model of effort-reward imbalance. Potential mediators including physical illness and poor mental health (GHQ) were measured at follow up in 1989.

RESULTS

Effort-reward imbalance at work was associated with alcohol dependence in men after adjustment for employment grade and other baseline factors related to alcohol dependence. Although effort-reward imbalance predicted future longstanding illness, poor mental health and negative aspects of close relationships, the association between effort-reward imbalance and alcohol dependence in men was only partially mediated through these health and social support measures. In women, low decision latitude was related to alcohol dependence to some extent, but alcohol dependence among women was more prevalent in higher occupational grades. Men with high job demands or with low work social supports had a slightly reduced risk of alcohol dependence. No association was found between objectively assessed demands, job control, and alcohol dependence in either men or women.

CONCLUSION

A stressful psychosocial work environment in terms of effort-reward imbalance was found to be a risk factor for alcohol dependence in men. In view of the public health importance of alcohol dependence in working populations these findings call for more emphasis on psychosocial factors in occupational health research and prevention.

TRPV1 receptors mediate particulate matter-induced apoptosis

Exposure to airborne particulate matter (PM) is a world-wide health problem mainly because it produces adverse cardiovascular and respiratory effects that frequently result in morbidity. Despite many years of epidemiological and basic research, the mechanisms underlying PM toxicity remain largely unknown. To understand some of these mechanisms, we measured PM-induced apoptosis and necrosis in normal human airway epithelial cells and sensory neurons from both wild-type mice and mice lacking TRPV1 receptors using Alexa Fluor 488-conjugated annexin V and propidium iodide labeling, respectively. Exposure of environmental PMs containing residual oil fly ash and ash from Mount St. Helens was found to induce apoptosis, but not necrosis, as a consequence of sustained calcium influx through TRPV1 receptors. Apoptosis was completely prevented by inhibiting TRPV1 receptors with capsazepine or by removing extracellular calcium or in sensory neurons from TRPV1(-/-) mice. Binding of either one of the PMs to the cell membrane induced a capsazepine-sensitive increase in cAMP. PM-induced apoptosis was augmented upon the inhibition of PKA. PKA inhibition on its own also induced apoptosis, thereby suggesting that this pathway may be endogenously protective against apoptosis. In summary, it was found that inhibiting TRPV1 receptors prevents PM-induced apoptosis, thereby providing a potential mechanism to reduce their toxicity.

Social inequalities in depressive symptoms and physical functioning in the Whitehall II study: exploring a common cause explanation

STUDY OBJECTIVE

This study investigated which risk factors might explain social inequalities in both depressive symptoms and physical functioning and whether a common set of risk factors might account for the association between depressive symptoms and physical functioning.

DESIGN

A longitudinal prospective occupational cohort study of female and male civil servants relating risk factors at baseline (phase 1: 1985-8) to employment grade gradients in depressive symptoms and physical functioning at follow up (phase 5: 1997-9). Analyses include the 7270 men and women who participated at phase 5.

SETTING

Whitehall II Study: 20 London based white collar civil service departments.

PARTICIPANTS

Male and female civil servants, 35-55 years at baseline.

MAIN RESULTS

Depressive symptoms were measured by a subscale of items from the 30 item General Health Questionnaire. Physical functioning was measured by a subscale of the SF-36. Employment grade was used as a measure of socioeconomic position as it reflects both income and status. The grade gradient in depressive symptoms was entirely explained by risk factors including work characteristics, material disadvantage, social supports, and health behaviours. These risk factors only partially explained the gradient in physical functioning. The correlation between depressive symptoms and physical functioning was reduced by adjustment for risk factors and baseline health status but not much of the association was explained by adjustment for risk factors. Among women, the association between depression and physical functioning was significantly stronger in the lower grades both before and after adjustment for risk factors and baseline health. For women, there was only a significant grade gradient in depressive symptoms among those reporting physical ill health.

CONCLUSIONS

Some risk factors contribute jointly to the explanation of social inequalities in mental and physical health although their relative importance differs. Work is most important for inequalities in depressive symptoms in men, and work and material disadvantage are equally important in explaining inequalities in depressive symptoms in women while health behaviours are more important for explaining inequalities in physical functioning. These risk factors did not account for the association between mental health and physical health or the greater comorbidity seen in women of lower socioeconomic status. The risk of secondary psychological distress among those with physical ill health is greater in the low employment grades.

Multilevel modelling of aircraft noise on performance tests in schools around Heathrow Airport London

STUDY OBJECTIVE

To examine the effects of chronic exposure to aircraft noise on children's school performance taking into account social class and school characteristics.

DESIGN

This is a cross sectional study using the National Standardised Scores (SATs) in mathematics, science, and English (11 000 scores from children aged 11 years). The analyses used multilevel modelling to determine the effects of chronic aircraft noise exposure on childrens' school performance adjusting for demographic, socioeconomic and school factors in 123 primary schools around Heathrow Airport. Schools were assigned aircraft noise exposure level from the 1994 Civil Aviation Authority aircraft noise contour maps.

SETTING

Primary schools.

PARTICIPANTS

The sample were approximately 11 000 children in year 6 (approximately 11 years old) from 123 schools in the three boroughs surrounding Heathrow Airport.

MAIN RESULTS

Chronic exposure to aircraft noise was significantly related to poorer reading and mathematics performance. After adjustment for the average socioeconomic status of the school intake (measured by percentage of pupils eligible for free school meals) these associations were no longer statistically significant.

CONCLUSIONS

Chronic exposure to aircraft noise is associated with school performance in reading and mathematics in a dose-response function but this association is confounded by socioeconomic factors.

Ten-year follow-up of three different initial treatments in de-novo PD: a randomized trial

BACKGROUND

The long-term effectiveness of three different initial drug regimes in patients with early, mild PD was evaluated by the PD Research Group of the United Kingdom (PDRGUK). In 1995, the selegiline arm of the trial was terminated following an interim analysis.

METHOD

This was an open, randomized trial. Between 1985 and 1990, 782 patients with de-novo PD were recruited and randomized to one of three treatment arms: levodopa plus dopa decarboxylase inhibitor; levodopa plus decarboxylase inhibitor and selegiline; or bromocriptine. The main endpoints were mortality, disability, and adverse events. Intention-to-treat analysis was used.

RESULTS

There was no significant difference in mortality between the bromocriptine and the levodopa arms (hazard ratio 1.15 [95% CI 0.90, 1.47]). Patients initially randomized to bromocriptine had slightly worse disability scores throughout follow-up. This difference was significant during the first years. Patients in the bromocriptine arm returned to pretreatment disability levels one year earlier than those in the levodopa arm. Patients randomized to bromocriptine had a significantly lower incidence of dyskinesias than those randomized to levodopa (rate ratio 0.73 [95% CI 0.57, 0.93]). However, this difference was not significant when only moderate to severe dyskinesias were considered. Patients in the bromocriptine arm had slightly lower rates of dystonias and on-off fluctuations, but moderate and severe forms were equally frequent in both arms.

CONCLUSION

Starting treatment with the dopamine agonist bromocriptine does not reduce mortality in PD. A slightly lower incidence of motor complications is achieved at the expense of significantly worse disability scores throughout the first years of therapy.

The West London Schools Study: the effects of chronic aircraft noise exposure on child health

BACKGROUND

Previous field studies have indicated that children's cognitive performance is impaired by chronic aircraft noise exposure. However, these studies have not been of sufficient size to account adequately for the role of confounding factors. The objective of this study was to test whether cognitive impairments and stress responses (catecholamines, cortisol and perceived stress) are attributable to aircraft noise exposure after adjustment for school and individual level confounding factors and to examine whether children exposed to high levels of social disadvantage are at greater risk of noise effects.

METHODS

The cognitive performance and health of 451 children aged 8-11 years, attending 10 schools in high aircraft noise areas (16 h outdoor Leq > 63 dBA) was compared with children attending 10 matched control schools exposed to lower levels of aircraft noise (16 h outdoor Leq < 57 dBA).

RESULTS

Noise exposure was associated with impaired reading on difficult items and raised annoyance, after adjustment for age, main language spoken and household deprivation. There was no variation in the size of the noise effects in vulnerable subgroups of children. High levels of noise exposure were not associated with impairments in mean reading score, memory and attention or stress responses. Aircraft noise was weakly associated with hyperactivity and psychological morbidity.

CONCLUSIONS

Chronic noise exposure is associated with raised noise annoyance in children. The cognitive results indicate that chronic aircraft noise exposure does not always lead to generalized cognitive effects but, rather, more selective cognitive impairments on difficult cognitive tests in children.