Showing papers in "Journal of Epidemiology and Community Health in 2002"

Urban residential environments and senior citizens’ longevity in megacity areas: the importance of walkable green spaces

Abstract: Main results: The survival of 2211 and the death of 897 (98.9% follow up) were confirmed. The probability of five year survival of the senior citizens studied increased in accordance with the space for taking a stroll near the residence (p<0.01), parks and tree lined streets near the residence (p<0.05), and their preference to continue to live in their current community (p<0.01). The principal component analysis from the baseline residential environment characteristics identified two environment related factors: the factor of walkable green streets and spaces near the residence and the factor of a positive attitude to a person's own community. After controlling the effects of the residents' age, sex, marital sta- tus, and socioeconomic status, the factor of walkable green streets and spaces near the residence showed significant predictive value for the survival of the urban senior citizens over the following five years (p<0.01). Conclusions: Living in areas with walkable green spaces positively influenced the longevity of urban senior citizens independent of their age, sex, marital status, baseline functional status, and socioeco- nomic status. Greenery filled public areas that are nearby and easy to walk in should be further emphasised in urban planning for the development and re-development of densely populated areas in a megacity. Close collaboration should be undertaken among the health, construction, civil engineer- ing, planning, and other concerned sectors in the context of the healthy urban policy, so as to promote the health of senior citizens.

Criteria for evaluating evidence on public health interventions

Abstract: Public health interventions tend to be complex, programmatic, and context dependent. The evidence for their effectiveness must be sufficiently comprehensive to encompass that complexity. This paper asks whether and to what extent evaluative research on public health interventions can be adequately appraised by applying well established criteria for judging the quality of evidence in clinical practice. It is adduced that these criteria are useful in evaluating some aspects of evidence. However, there are other important aspects of evidence on public health interventions that are not covered by the established criteria. The evaluation of evidence must distinguish between the fidelity of the evaluation process in detecting the success or failure of an intervention, and the success or failure of the intervention itself. Moreover, if an intervention is unsuccessful, the evidence should help to determine whether the intervention was inherently faulty (that is, failure of intervention concept or theory), or just badly delivered (failure of implementation). Furthermore, proper interpretation of the evidence depends upon the availability of descriptive information on the intervention and its context, so that the transferability of the evidence can be determined. Study design alone is an inadequate marker of evidence quality in public health intervention evaluation.

A glossary for health inequalities

Abstract: In this glossary, the authors address eight key questions pertinent to health inequalities: (1) What is the distinction between health inequality and health inequity?; (2) Should we assess health inequalities themselves, or social group inequalities in health?; (3) Do health inequalities mainly reflect the effects of poverty, or are they generated by the socioeconomic gradient?; (4) Are health inequalities mediated by material deprivation or by psychosocial mechanisms?; (5) Is there an effect of relative income on health, separate from the effects of absolute income?; (6) Do health inequalities between places simply reflect health inequalities between social groups or, more significantly, do they suggest a contextual effect of place?; (7) What is the contribution of the lifecourse to health inequalities?; (8) What kinds of inequality should we study?

A glossary for multilevel analysis

Abstract: Multilevel analysis has recently emerged as a useful analytical technique in several fields, including public health and epidemiology. This glossary defines key concepts and terms used in multilevel analysis.

Effects of chronic job insecurity and change in job security on self reported health, minor psychiatric morbidity, physiological measures, and health related behaviours in British civil servants: the Whitehall II study

Abstract: Study objective: To determine the effect of chronic job insecurity and changes in job security on self reported health, minor psychiatric morbidity, physiological measures, and health related behaviours. Design: Self reported health, minor psychiatric morbidity, physiological measures, and health related behaviours were determined in 931 women and 2429 men who responded to a question on job insecurity in 1995/96 and again in 1997/99. Self reported health status, clinical screening measures, and health related behaviours for participants whose job security had changed or who remained insecure were compared with those whose jobs had remained secure. Setting: Prospective cohort study, Whitehall II, all participants were white collar office workers in the British Civil Service on entry to the study. Main results: Self reported morbidity was higher among participants who lost job security. Among those who gained job security residual negative effects, particularly in the psychological sphere were observed. Those exposed to chronic job insecurity had the highest self reported morbidity. Changes in the physiological measures were limited to an increase in blood pressure among women who lost job security and a decrease in body mass index among women reporting chronic job insecurity. There were no significant differences between any of the groups for alcohol over the recommended limits or smoking. Conclusion: Loss of job security has adverse effects on self reported health and minor psychiatric morbidity, which are not completely reversed by removal of the threat and which tend to increase with chronic exposure to the stressor.

Validation of self reported smoking by serum cotinine measurement in a community-based study

Abstract: Study objective: The validity of self reported smoking in population surveys remains an important question. An associated question is what would be the value of measuring serum cotinine concentrations in such surveys to obtain validated smoking data. Design: Cross sectional analysis of data on self reported smoking and serum cotinine among a random population sample of 5846 persons aged 25 to 64 years, who participated in the FINRISK-92 survey. Main results: Among self reported regular smokers, 97.2% of men and 94.9% of women had a cotinine concentration of 10 ng/ml or higher in serum. Of those participants who reported to have smoked at any time during their life but not during the previous month, 6.3% of men and 5.2% of women had a serum cotinine concentration of at least 10 ng/ml. Among never smokers 2.5% of men and 2.7% of women had detectable level of cotinine in their serum. The validity of self reporting was similar among subjects from different areas, ages, and socioeconomic groups. Conclusions: In a sample of the general population in Finland the validity of self reported smoking is high, and most of the few self reported non-smokers who had cotinine in their serum had only low or moderate levels.

Short-term effects of particulate air pollution on cardiovascular diseases in eight European cities

Abstract: Study objective: As part of the APHEA project this study examined the association between airborne particles and hospital admissions for cardiac causes (ICD9 390–429) in eight European cities (Barcelona, Birmingham, London, Milan, the Netherlands, Paris, Rome, and Stockholm). All admissions were studied, as well as admissions stratified by age. The association for ischaemic heart disease (ICD9 410–413) and stroke (ICD9 430–438) was also studied, also stratified by age. Design: Autoregressive Poisson models were used that controlled for long term trend, season, influenza epidemics, and meteorology to assess the short-term effects of particles in each city. The study also examined confounding by other pollutants. City specific results were pooled in a second stage regression to obtain more stable estimates and examine the sources of heterogeneity. Main results: The pooled percentage increases associated with a 10 µg/m3 increase in PM10 and black smoke were respectively 0.5% (95% CI: 0.2 to 0.8) and 1.1% (95% CI: 0.4 to 1.8) for cardiac admissions of all ages, 0.7% (95% CI: 0.4 to 1.0) and 1.3% (95% CI: 0.4 to 2.2) for cardiac admissions over 65 years, and, 0.8% (95% CI: 0.3 to 1.2) and 1.1% (95% CI: 0.7 to 1.5) for ischaemic heart disease over 65 years. The effect of PM10 was little changed by control for ozone or SO2, but was substantially reduced (CO) or eliminated (NO2) by control for other traffic related pollutants. The effect of black smoke remained practically unchanged controlling for CO and only somewhat reduced controlling for NO2. Conclusions: These effects of particulate air pollution on cardiac admissions suggest the primary effect is likely to be mainly attributable to diesel exhaust. Results for ischaemic heart disease below 65 years and for stroke over 65 years were inconclusive.

Impact of hot temperatures on death in London: a time series approach

Abstract: Study objective: This study investigated the relation between heat and mortality in London to determine the temperature threshold at which death rates increase and to quantify the effect of extreme temperatures on mortality. Design: Daily data on all cause mortality and temperature were obtained for a 21 year period and the relation between them investigated both graphically and by using non-parametric time series methods of analysis. Setting: Greater London. Participants: Daily mortality counts in Greater London between January 1976 and December 1996. Main results: A plot of the basic mortality-temperature relation suggested that a rise in heat related deaths began at about 19°C. Average temperatures above the 97th centile value of 21.5°C (excluding those days from a 15 day “heatwave” period in 1976) resulted in an increase in deaths of 3.34% (95% CI 2.47% to 4.23%) for every one degree increase in average temperature above this value. It was found that the 1976 heatwave resulted in a particularly large number of deaths in comparison with other hot periods. Conclusions: These results suggest that heat related deaths in London may begin at relatively low temperatures. Hot days occurring in the early part of any year may have a larger effect than those occurring later on; and analysis of separate heatwave periods suggest that episodes of long duration and of highest temperature have the largest mortality effect.

Does a higher number of siblings protect against the development of allergy and asthma? A review

Abstract: Study objective: To review the “protective” effects of having a higher number of siblings for the risk of atopic eczema, asthma wheezing, hay fever, and allergic sensitisation. Method: Review of the literature (Medline since 1965 and references). Main results: 53 different studies were identified. For eczema, 9 of 11 studies reported an inverse relation with number of siblings; for asthma and wheezing, 21 of 31 reported the inverse association; for hay fever, all 17 studies showed the effect; for allergic sensitisation or immunoglobulin E reactivity 14 of 16 studies supported the “protective” effect of a higher number of siblings. The studies emphasise a “theory” that is based exclusively on epidemiological associations. Conclusions: Research has not yet answered the question of which causal factors explain the sibling effect. Causal factors must meet two criteria; they must vary with sibship size and they must protect against atopic manifestations. The prevailing “hygiene hypothesis” failed to explain the findings adequately. Alternative explanations include in utero programming or endocrine explanatory models. The epidemiology research into siblings and atopic disorders has entered an intellectually challenging phase. Possessing sufficient knowledge about the causal factors might prevent at least 30% of all cases of asthma, eczema, and hay fever.

Social class gradients in health during adolescence

Abstract: Study objective: To review existing data on social class gradients in adolescent health and to examine whether such gradients exist in new data concerning US adolescents. Design: Review of relevant publications and unpublished data; regression analyses using adolescent self reported health status data to determine whether there are gradients by social class, using three classes categorised by adolescent reported parental work status and education. Participants: Adolescents of ages 11–17. Main results: Findings from the literature indicate the presence of social class gradients in some but not all aspects of adolescent health. Results from new data showed social class gradients in several domains of health and in profiles of health. The likelihood of being satisfied with one9s health, of being more resilient (better family involvement, better problem solving, more physical activity, better home safety), having higher school achievement, and of being in the best health profiles were significantly and progressively greater as social class rose. Moreover, the probability of being in the poorest health profile type group was progressively higher as social class declined. Conclusions: The review of existing data and the new findings support the existence of social class gradients in satisfaction with one9s health, in resilience to health threats, in school achievement, and in being in the best health overall (as manifested by the health profiles composed of four major domains of health). The study had two especially notable findings: (1) the paucity of studies using the same or similar indicators, and (2) the consistent existence of social class gradients in characteristics related to subsequent health, particularly intake of nutritional foods and physical activity. The sparseness of existing data and the different aspects of health investigated in the relatively few studies underscore the need for (1) the development of conceptual models specifically focused on adolescent health and social class; (2) additional inquiry into the measurement of social class and adolescent perceptions of class; (3) inclusion of contextual variables in study design; and (4) longitudinal cohort studies to better understand the specific determinants of health during adolescence.

Psychosocial work environment and myocardial infarction: improving risk estimation by combining two complementary job stress models in the SHEEP Study

Abstract: Objectives: Associations between two alternative formulations of job stress derived from the effort-reward imbalance and the job strain model and first non-fatal acute myocardial infarction were studied. Whereas the job strain model concentrates on situational (extrinsic) characteristics the effort-reward imbalance model analyses distinct person (intrinsic) characteristics in addition to situational ones. In view of these conceptual differences the hypothesis was tested that combining information from the two models improves the risk estimation of acute myocardial infarction. Methods: 951 male and female myocardial infarction cases and 1147 referents aged 45–64 years of The Stockholm Heart Epidemiology (SHEEP) case-control study underwent a clinical examination. Information on job stress and health adverse behaviours was derived from standardised questionnaires. Results: Multivariate analysis showed moderately increased odds ratios for either model. Yet, with respect to the effort-reward imbalance model gender specific effects were found: in men the extrinsic component contributed to risk estimation, whereas this was the case with the intrinsic component in women. Controlling each job stress model for the other in order to test the independent effect of either approach did not show systematically increased odds ratios. An improved estimation of acute myocardial infarction risk resulted from combining information from the two models by defining groups characterised by simultaneous exposure to effort-reward imbalance and job strain (men: odds ratio 2.02 (95% confidence intervals (CI) 1.34 to 3.07); women odds ratio 2.19 (95% CI 1.11 to 4.28)). Conclusions: Findings show an improved risk estimation of acute myocardial infarction by combining information from the two job stress models under study. Moreover, gender specific effects of the two components of the effort-reward imbalance model were observed.

Housing and inequalities in health: a study of socioeconomic dimensions of housing and self reported health from a survey of Vancouver residents

Abstract: Study objective: To investigate the relation between housing, socioeconomic status, and self reported general and mental health. This study is an empirical investigation of social and economic dimensions of housing, specifically, demand, control, and material (affordability, dwelling type) and meaningful (pride in dwelling, home as a refuge) dimensions of everyday life as they occur in the domestic environment. Design: A cross sectional telephone survey was administered to a random sample of households. Survey items included measures of demand, control, and meaningfulness of the domestic environment, as well as standard measures of socioeconomic status and social support. Main outcome measures were self reported health (excellent, very good, good, fair, poor) and self reported frequency of feeling “downhearted and blue” in the two weeks before interview (from the Rand Mental Health Index). Setting: Households (n=650) from 12 neighbourhood areas in the city of Vancouver, Canada. Participants: One randomly selected adult from each of 650 households completed the interview and constitute the sample for this study. Main results: In bivariate analyses, measures of housing demand, control and meaningfulness exhibited strong and significantly graded relations with self reported health and somewhat less strong relations with mental health. In logistic regression analyses housing demand and control variables made significant contributions to health both general and mental health. Respondents were more likely to report fair/poor health if they: reported that they couldn’t stand to be at home sometimes (OR=2.29, p<0.05); rated their domestic housework as somewhat or quite a strain (OR=5.71, p<0.001); were somewhat or very dissatisfied with their social activities (OR=3.41, p<0.001); and reported that they were constantly under stress a good bit of the time or more (OR=3.56, p<0.05). In terms of mental health, respondents were more likely to report poorer mental health if they: lived longer in their neighbourhood (OR=1.05, p<0.05); reported their housework duties to be somewhat or quite a strain (OR=5.55, p<0.001); reported that they did not have somebody that could help them if they needed it (OR=9.28, p<0.001); and reported that they were constantly under stress a good bit of the time or more in the two weeks before the interview (OR=5.26, p<0.001). One of the main hypotheses investigated—that meaningful dimensions of housing are associated with health status—found support in bivariate analyses without controls, but did not contribute to multivariable models. Conclusions: The influence of housing demand and control variables superseded a well known correlate of health status, educational attainment, attesting to their importance. The findings of this paper lend support to the hypothesis that features of the domestic environment, especially as they pertain to the exercise of control and the experience of demand, are significant predictors of self reported general and mental health status. Housing is a concrete manifestation of socioeconomic status, which has an important part to play in the development of explanations of the social production of health inequalities.

Depression and falls among community dwelling elderly people: a search for common risk factors

Abstract: Study objectives: Depression and falls are two common conditions that impair the health of older people. Both are relatively underdiagnosed and undertreated problems in primary care. The study objective was to investigate whether there was a common set of risk factors that could predict an increased risk of both falls and depression. Design: This was a cohort study drawn from a primary care clinic, with a one year follow up. Dependent measures included: reporting two or more falls in the past year and a score of 7 or over on the S-GDS (Short Geriatric Depression Scale). A parsimonious set of risk factors was selected that predicted both outcomes based on a series of discriminant function analyses. Participants and setting: The setting was a primary care clinic serving a mixed socioeconomic population, in Beer Sheva, Israel. The sample included 283 General Sick Fund members, aged 60 and over, who completed both baseline assessments and one year follow up interviews. Main results: At the one year follow up, 12% of the sample reported frequent falls in the past year and 25.5% of the sample screened positive for depressive symptoms. A set of five risk factors that included: poor self rated health, poor cognitive status, impaired ADL, two or more clinic visits in the past month, and slow walking speed (g10 seconds over five metres) was successful at discriminating between fallers and non-fallers (86% discrimination) and between those with and without depressive symptoms (76%). For every risk factor added, there was a significant increase in the proportion of respondents who had depressive symptoms. A similar result was found for falls. Conclusions: These results show that there is a common set of risk factors that increase the risk of two common outcomes in geriatric medicine, falls and depression. For a general practitioner or a geriatric physician, it might be easier to detect these risk factors than to diagnose depression or high risk for falls. When these risk factors are detected in patients the physician can then be more active in direct probing about depression and falls.

Employment security and health

Abstract: Design: Cross sectional survey. Setting: Municipal sector employees in eight Finnish towns. Participants: 5981 employees with a permanent contract and 2786 employees with a non-permanent contract (2194 fixed term contract, 682 government subsidised contract). Outcome measures: Poor self rated health, chronic disease, and psychological distress. Results: Compared with permanent employees, fixed term men and women had better self rated health (men odds ratio 0.70; 95% confidence intervals 0.50 to 0.98, women 0.70 (0.60 to 0.82) and less chronic disease (men 0.69; 0.52 to 0.91; women 0.89; 0.79 to 1.02), but women had more psychological distress (1.26; 1.09 to 1.45). The only difference between subsidised employees and permanent employees was the high level of psychological distress in women (1.35; 1.09 to 1.68). Low perceived employment security was associated with poor health across all three indicators. The association of low perceived security with psychological distress was significantly stronger in permanent employees than among fixed term and subsidised employees, indicating that perceived security is more important for mental health among employees with a permanent contract. Conclusions: Contractual security and perceived security of employment are differently associated with health. It is therefore important to distinguish between these aspects of employment security in studies of labour market status and health. Such studies will also need to control for health selection, which is unlikely to operate in the same way among permanent and non-permanent employees.

Validation of self reported smoking

Abstract: The use of cotinine as a biomarker for exposure to smoking Self reported smoking status has been widely used to assess detrimental health effects of smoking and to orient counselling and other preventive interventions. Self reporting, however, can be unreliable if the subject is under pressure because of social or medical disapproval. Furthermore, the quantity of smoke products actually inhaled and absorbed varies by the manner of smoking. Because of these difficulties, increased emphasis has been placed on measuring exposure through the use of biological markers to provide more accurate estimates of smoking status and of the dose received. In the past two decades, an increasing number of epidemiological studies have used biomarkers in assessing tobacco smoke exposure from active and passive smoking. Biomarkers can be used to classify people as exposed or unexposed, identify deceivers (people misreporting their smoking status), or estimate relative degree of exposure. Cotinine, a major metabolite of nicotine, is currently regarded as the best biomarker for exposure of active smokers and non-smokers to environmental tobacco smoke (ETS).1 As a marker cotinine has the advantage of being almost specific to tobacco. The few exceptions include occupational exposure to tobacco leaves and nicotine products, use of smokeless tobacco products, chewing of nicotine gum, and use of nicotine patches or other aids for smoking cessation. Low levels of nicotine have been found in diet vegetables, but their impact in cotinine levels can be regarded as insignificant. Cotinine can be measured in blood (that is, in serum), urine, saliva, and hair. The average half life of cotinine in different body fluids in adults is approximately 20 hours, making it a good indicator of the integrated exposure over the previous two to three days.1 Studies comparing non-smokers and smokers have consistently found that measurement of cotinine in the …

Assessing socioeconomic status in adolescents: the validity of a home affluence scale

Abstract: Study objective: To examine the completion rate, internal reliability, and external validity of a home affluence scale based on adolescents' reports of material circumstances in the home as a measure of family socioeconomic status.Design: Cross sectional survey.Setting: Data were collected from a school based study in seven schools in the north of England Cheshire over a five month period from September 1999 to January 2000.Participants: 1824 students (1248 girls, 567 boys) aged 13-15 years who were attending normal classes in Years 9 and 10 in 7 schools on the days of data collection.Main results: Comparatively poor completion rates were found for questions on parental education and occupation while material deprivation items had much higher completion rates. There was evidence that students with poorer material circumstances were less able to report parental education and occupation whereas material based questions showed less bias. A home affluence scale composed of material items was found to have adequate internal reliability and good external validity.Conclusions: A home affluence scale based on material markers provides a useful alternative in assessing family affluence in adolescents. Additionally, it prevents exclusion of those less materially well off adolescents who fail to complete conventional socioeconomic status items.

Early unemployment can contribute to adult health problems: results from a longitudinal study of school leavers

Abstract: Study objective: To investigate the long term effects of early unemployment (a total of more than half a year of unemployment between the ages of 16 and 21) on health behaviour and psychological and somatic symptoms. Design: A 14 year follow up of a cohort of school leavers was conducted from 1981 to 1995. Information was collected by questionnaires. Setting: An industrial town in northern Sweden. Participants: The original cohort was defined as all pupils in a middle sized municipality in the last year of compulsory school at age 16 (n=1083). The participants were followed up between the ages of 16 and 30. The analysis included 96% of the original sample, 547 men and 497 women Main results: After controlling for initial health behaviour and symptoms as well as for working class background and late unemployment, early unemployment among young men and women showed a significant explanatory effect on smoking, psychological symptoms and—among men only—somatic symptoms after a follow up of 14 years. No correlation was found between early unemployment and late excess alcohol consumption. Conclusions: Early unemployment can contribute to adult health problems. Thus, youth unemployment constitutes a significant public health problem, which to a certain extent remains in adult age.

Persistent toxic chemicals in the US food supply

Abstract: Persistent organic pollutants (POPs) have spread throughout the global environment to threaten human health and damage ecosystems, with evidence of POPs contamination in wildlife, human blood, and breast milk documented worldwide. Based on data from the US Food and Drug Administration, this article provides a brief overview of POPs residues in common foods in the United States food supply. The analysis focuses on 12 chemical compounds now targeted for an international phase out under the Stockholm Convention on POPs. The available information indicates that POPs residues are present in virtually all categories of foods, including baked goods, fruit, vegetables, meat, poultry, and dairy products. Residues of five or more persistent toxic chemicals in a single food item are not unusual, with the most commonly found POPs being the pesticides DDT (and its metabolites, such as DDE) and dieldrin. Estimated daily doses of dieldrin alone exceed US Environmental Protection Agency and US Agency for Toxic Substances Disease Control reference dose for children. Given the widespread occurrence of POPs in the food supply and the serious health risks associated with even extremely small levels of exposure, prevention of further food contamination must be a national health policy priority in every country. Implementation of the Stockholm Convention will prevent further accumulation of persistent toxic chemicals in food. Early ratification and rapid implementation of this treaty should be an urgent priority for all governments.

Employee control over working times: associations with subjective health and sickness absences

Abstract: Study objective: To investigate the impact of employees9 worktime control on health, taking into account other aspects of job control. Design: Analysis of questionnaire data in 1997 and register data on sickness absence during 1996–1998. Setting: Eight towns in Finland. Participants: 6442 municipal employees (1490 men and 4952 women) representing the staff of the towns studied. Follow up was 17 706 person years. Main results: In women, poor health and psychological distress were more prevalent among those in the lowest quartile of worktime control than those in the highest (after adjustment for potential confounders including other aspects of job control, odds ratios and their 95% confidence intervals for poor health and psychological distress were 1.8 (1.5 to 2.3) and 1.6 (1.3 to 2.0), respectively). Correspondingly, the adjusted sickness absence rate was 1.2 (1.1 to 1.2) times higher in women with low worktime control than in women with high worktime control. In men, no significant associations between worktime control and health were found. These results, obtained from the total sample, were replicable within a homogeneous occupational group comprising women and men. Conclusions: Exploration of specific aspects of job control provides new information about potentially reversible causes of health problems in a working population. Worktime control is an independent predictor of health in women but not in men. Dissimilarities in the distribution of occupations between men and women are not a probable explanation for this difference.

The concern for equity in health

Abstract: This issue of the journal contains papers presented to the first meeting of the International Society for Equity in Health, Havana, Cuba, June 2000.

Is housework good for health? Levels of physical activity and factors associated with activity in elderly women. Results from the British Women's Heart and Health Study

Abstract: Objective: To determine the prevalence of achieving new recommended levels of physical activity, the types of activity involved, and their determinants among elderly British women. Design: National cross sectional survey. Participants: 2341 women aged 60 to 79 from 15 British towns. Main outcome measures: Prevalence of subjects achieving recommended levels of physical activity. Results: Over two thirds of the participants were active at new recommended levels. This was mainly achieved through participation in heavy housework. If domestic activities were excluded only 21% were regularly active. Women who participated in brisk walking for at least 2.5 hours per week had reduced odds of being overweight: odds ratio (95% confidence intervals) 0.5 (0.3 to 0.6) after adjustment for other forms of activity, health status, smoking, and socioeconomic position. Participating in at least 2.5 hours of heavy housework was not associated with reduced odds of being overweight 1.1 (0.8 to 1.4). Age, self reported poor health status, coronary heart disease, and respiratory disease were independently associated with reduced odds of participating in all types of activity. In addition participation in brisk walking and physical exercise were less likely in current smokers, those from the lowest socioeconomic class, and those living in the north of the country. Participation in heavy housework was less likely in women reporting depression but was not associated with smoking, socioeconomic class, or area of residence. Conclusions: If new physical activity recommendations, which include domestic activities, are used to assess population levels of physical activity then it seems that the majority of elderly women are sufficiently active. Heavy housework is not associated with reduced levels of being overweight and prospective studies are necessary to demonstrate an independent health benefit of participating in domestic activities.

Importance of light smoking and inhalation habits on risk of myocardial infarction and all cause mortality. A 22 year follow up of 12 149 men and women in The Copenhagen City Heart Study

Abstract: Study objective: To determine risk of myocardial infarction (MI) and all cause mortality associated with light smoking and inhalation habits in men and women. Design: Prospective cohort study with follow up of MI and all cause mortality through record linkage. Setting: The Copenhagen City Heart Study, a cardiovascular study based on a sample of the general population established in 1976. Participants: 6505 women and 5644 men followed up until 1998 for first MI and for death from all causes. Main results: During follow up 476 women and 872 men suffered a MI whereas 2305 women and 2883 men died. After adjusting for major cardiovascular risk factors there was a dose-response relation between smoking with and without inhaling and both MI and all cause mortality. Among inhaling smokers significantly increased risks were found in women at a consumption of only 3–5 grams of tobacco per day with relative risks (RR) of MI and all cause mortality of 2.14 (95% CI 1.11 to 4.13) and 1.86 (95% CI 1.37 to 2.51), respectively. In men increased risks were seen when smoking 6–9 grams per day with RR of MI and all cause mortality of 2.10 (95% CI 1.40 to 3.14) and 1.76 (95% CI 1.39 to 2.23), respectively. Risks were also increased in non-inhaling smokers, although in men only significantly so for all cause mortality. After adjusting for inhalation and quantity smoked, cigarette smokers had a higher risk of all cause mortality (RR 1.16 (95% CI 1.07 to 1.26)) but not of MI (RR 1.11 (95% CI 0.95 to 1.30)). The RR associated with smoking were significantly higher in women than in men for both MI and all cause mortality. Conclusions: Smoking as little as 3–5 grams of tobacco per day or not inhaling the smoke was shown to carry a significantly increased risk of developing MI and of all cause mortality with higher RR found in women than in men. The study emphasises the importance of recognising that even very limited tobacco consumption has detrimental health effects.

“Walk in to Work Out”: a randomised controlled trial of a self help intervention to promote active commuting

Abstract: Study objective: To determine if a self help intervention, delivered via written interactive materials (the “Walk in to Work Out” pack), could increase active commuting behaviour (walking and cycling). Design: Randomised controlled trial. The intervention group received the “Walk in to Work Out” pack, which contained written interactive materials based on the transtheoretical model of behaviour change, local information about distances and routes, and safety information. The control group received the pack six months later. Focus groups were also conducted after six months. Setting: Three workplaces in the city of Glasgow, Scotland, UK. Participants: 295 employees who had been identified as thinking about, or doing some irregular, walking or cycling to work. Main results: The intervention group was almost twice as likely to increase walking to work as the control group at six months (odds ratio of 1.93, 95% confidence intervals 1.06 to 3.52). The intervention was not successful at increasing cycling. There were no distance travelled to work, gender, or age influences on the results. Twenty five per cent (95% confidence intervals 17% to 32%) of the intervention group, who received the pack at baseline, were regularly actively commuting at the 12 month follow up. Conclusion: The “Walk in to Work Out” pack was successful in increasing walking but not cycling. The environment for cycling must be improved before cycling will become a popular option.

Descriptive epidemiology of body mass index of an urban adult population in western India

Abstract: Study objective: To describe height, weight, and body mass index (BMI) of the adult urban population in Mumbai, western India and to estimate the prevalence and severity of thinness and overweight in this population. To describe the association of BMI with education, age, and tobacco habits in an urban Indian population. Design: Cross sectional representative survey of 99 598 adults (40 071 men and 59 527 women). Setting: The survey was carried out in the city of Mumbai (formerly known as Bombay) in western India. Participants: Men and women aged ≥35 years who were residents of the main city of Mumbai. Main results: The mean height, weight, and BMI were 161.0 (SD 6.7) cm, 56.7 (SD 11.0) kg, and 21.8 (SD 3.8) kg/m2 for men and 148.0 (SD 6.2) cm, 49.8 (SD 11.2) kg, and 22.7 (SD 4.7) kg/m2 for women, respectively. Some 19% of men and women were thin (BMI<18.5 kg/m2), while 19% of men and 30% of women were overweight (BMI≥25kg/m2). Multivariable logistic regression analyses showed that age, level of education, and tobacco use were independently associated with BMI. The odds ratio (OR) and 95% confidence intervals (CI) for thinness (BMI<18.5 kg/m2) were OR 6.52, 95%CI 5.38 to 7.89 for men and OR 4.83, 95%CI 3.71 to 6.28 for women, respectively, (p<0.001) for the lowest level of education (illiterate group). The OR and 95%CI for overweight were 2.25, 2.20 to 2.58 for college educated men and 1.90, 1.64 to 2.20 for college educated women, respectively, p<0.001. Both smoking (2.33, 2.09 to 2.59; 2.89, 1.77 to 4.72 for men and women, respectively, p<0.001) and smokeless tobacco use (1.65, 1.52 to 1.80; 2.26, 2.14 to 2.38 for men and women, respectively p<0.0001) were significantly associated with low BMI. Conclusions: Sequelae of thinness and overweight represent major public health problems. The results of this study, indicating an equal prevalence of thinness and overweight in an urban area and their association with age, level of education, and tobacco use raise concerns of an emerging public health crisis in urban India.

Outreach and improved access to specialist services for indigenous people in remote Australia: the requirements for sustainability

Abstract: Design: A process evaluation of a specialist outreach service, using health service utilisation data and interviews with health professionals and patients. Setting: The Top End of Australia's Northern Territory, where Darwin is the capital city and the major base for hospital and specialist services. In the rural and remote areas outside Darwin there are many small, predominantly indigenous communities, which are greatly disadvantaged by a severe burden of disease and limited access to medical care. Participants: Seventeen remote health practitioners, five specialists undertaking outreach, five regional health administrators, and three patients from remote communities. Main results: The barriers faced by many remote indigenous people in accessing specialist and hospital care are substantial. Outreach delivery of specialist services has overcome some of the barriers relating to distance, communication, and cultural inappropriateness of services and has enabled an over fourfold increase in the number of consultations with people from remote communities. Key issues affecting sustainability include: an adequate specialist base; an unmet demand from primary care; integration with, accountability to and capacity building for a multidisciplinary framework centred in primary care; good communication; visits that are regular and predictable; funding and coordination that recognises responsibilities to both hospitals and the primary care sector; and regular evaluation. Conclusions: In a setting where there is a disadvantaged population with inadequate access to medical care, specialist outreach from a regional centre can provide a more equitable means of service delivery than hospital based services alone. A sustainable outreach service that is organised appropriately, responsive to local community needs, and has an adequate regional specialist base can effectively integrate with and support primary health care processes. Poorly planned and conducted outreach, however, can draw resources away and detract from primary health care.

Stress and suicide in the Nurses' Health Study

Abstract: Study objectives: Although stress is thought to be a risk factor for suicide, most research has been retrospective or has focused on attempted suicides or suicide ideation. This study examined prospectively the associations between self perceived stress, diazepam use, and death from suicide among adult women. Design: A cohort study was conducted with 14 years of follow up. Stress at home and at work were assessed by questionnaire and scored on a four point scale: minimal, light, moderate, or severe. Setting: Eleven states within the United States. Participants: Female nurses (n=94 110) who were 36 to 61 years of age when they answered questions on stress and diazepam use in 1982. Results: During 1 272 000 person years of observation 73 suicides were identified. After adjustment for age, smoking, coffee consumption, alcohol intake, and marital status, the relation between self reported stress and suicide remained U shaped. Compared with the light home and work stress categories, which had the lowest incidences of suicide, risks were increased among women reporting either severe (relative risk (RR) = 3.7, 95% confidence intervals (CI) 1.7 to 8.3) or minimal (RR=2.1, 95% CI 1.0 to 4.5) home stress and either severe (RR=1.9, 95% CI 0.8 to 4.7) or minimal (RR=2.4, 95% CI 0.9 to 6.1) work stress. When responses to home and work stress were combined, there was an almost fivefold increase in risk of suicide among women in the high stress category. Risk of suicide was over eightfold among women reporting high stress or diazepam use compared with those reporting low stress and no diazepam use. Conclusions: The relation between self reported stress and suicide seems to be U shaped among adult women. The excess risk for those reporting minimal stress may reflect denial or undiagnosed depression or an association with some other unmeasured risk factor for suicide.

Equity in prevention and health care

Abstract: STUDY OBJECTIVE: There is an increasing body of evidence about socioeconomic inequality in preventive use, mostly for cancer screening. But as far as needs of prevention are unequally distributed, even equal use may not be fair. Moreover, prevention might be unequally used in the same way as health care in general. The objective of the paper is to assess inequity in prevention and to compare socioeconomic inequity in preventive medicine with that in health care. DESIGN: A cross sectional Health Interview Survey was carried out in 1997 by face to face interview and self administered questionnaire. Two types of health care utilisation were considered (contacts with GPs and with specialists) and four preventive care mostly delivered in a GP setting (flu vaccination, cholesterol screening) or in a specialty setting (mammography and pap smear). SETTING: Belgium. PARTICIPANTS: A representative sample of 7378 residents aged 25 years and over (participation rate: 61%). Outcome measure: Socioeconomic inequity was measured by the HI(wvp) index, which is the difference between use inequality and needs inequality. Needs was computed as the expected use by the risk factors or target groups. MAIN RESULTS: There was significant inequity for all medical contacts and preventive medicine. Medical contacts showed inequity favouring the rich for specialist visits and inequity favouring the poor for contacts with GPs. Regarding preventive medicine, inequity was high and favoured the rich for mammography and cervical screening; inequity was lower for flu immunisation and cholesterol screening but still favoured the higher socioeconomic groups. In the general practice setting, inequity in prevention was higher than inequity in health care; in the specialty setting, inequity in prevention was not statistically different from inequity in health care, although it was higher than in the general practice setting. CONCLUSIONS: If inequity in preventive medicine is to be lowered, the role of the GP must be fostered and access to specialty medicine increased, especially for cancer screening.

Total and HDL cholesterol and risk of stroke. EUROSTROKE: a collaborative study among research centres in Europe

Abstract: Background: Controversy remains on the relation between serum lipids levels and stroke risk. This paper investigated the association of total and HDL cholesterol level to fatal and non-fatal, and haemorrhagic and ischaemic stroke in four European cohorts participating in EUROSTROKE. Methods: EUROSTROKE is a collaborative project among ongoing European cohort studies on incidence and risk factors of stroke. EUROSTROKE is designed as a nested case-control study. For each stroke case, two controls were sampled. Strokes were classified according to MONICA criteria or reviewed by a panel of four neurologists. At present, data on stroke and risk factors were available from cohorts in Cardiff (84 cases), Kuopio (74 cases), Rotterdam (157 cases), and Novosibirsk (79 cases). Results: Pooled analyses showed no significant association between total cholesterol and risk of stroke (odds ratio for increase of 1 mmol/l in cholesterol of 0.98 (95% CI 0.88 to 1.09)). Analyses for haemorrhagic stroke and cerebral infarction revealed odds ratios of 0.80 (95% CI 0.61 to 1.05) and 1.06 (95% CI 0.94 to 1.19), respectively. The association of HDL cholesterol to stroke was different in men compared with women. In men, there was a general trend towards a lower risk of stroke with an increase in HDL (odds ratio per 1 mmol/l increase in HDL cholesterol 0.68 (95% CI 0.40 to 1.16)). In women, however, an increase in HDL was associated with a significant increased risk of non-fatal stroke and of cerebral infarction (odds ratios of 2.46 (95% 0.1.20 to 5.04) and 2.52 (95% CI 1.15 to 5.50), respectively. The difference between men and women in the association of HDL with stroke seemed to differ mainly in smokers and never smokers, but not among ex smokers. Conclusion: This analysis of the EUROSTROKE project could not disclose an association of total cholesterol with fatal, non-fatal, haemorrhagic or ischaemic stroke. HDL cholesterol however, seemed to be related to stroke differently in men than in women.

Alcohol consumption and the incidence of type II diabetes

Abstract: Background: This study examines the relation between alcohol and type II diabetes and the possible mediating effects of HDL-cholesterol and serum insulin. Methods: Prospective study of 5221 men aged 40–59 years with no history of coronary heart disease, diabetes, or stroke drawn from general practices in 18 British towns. Results: During the mean follow up of 16.8 years there were 198 incident cases of type II diabetes. Occasional drinkers were the reference group. A non-linear relation was seen between alcohol intake and age adjusted risk of diabetes, with risk lowest in light and moderate drinkers and highest in heavy drinkers (quadratic trend p=0.03). Further adjustment for body mass index decreased risk in heavy drinkers. After additional adjustment for physical activity, smoking, and (undiagnosed) pre-existing coronary heart disease, only moderate drinkers showed significantly lower risk than occasional drinkers (RR=0.66 95% CI 0.44 to 0.99). Alcohol intake was inversely associated with serum insulin and positively associated with HDL-cholesterol. Adjustment for these factors reduced the "protective" effect in moderate drinkers (adjusted RR=0.73 95% CI 0.48 to 1.10) but the quadratic trend remained significant (p=0.02). Conclusion: There is a non-linear relation between alcohol intake and the risk of type II diabetes. Serum insulin and HDL-cholesterol explained a small amount (20%) of the reduction in risk of type II diabetes associated with moderate drinking. The adverse effect of heavy drinking seemed to be partially mediated through its effect on body weight.

Confounding by indication in non-experimental evaluation of vaccine effectiveness: the example of prevention of influenza complications

Abstract: Randomised allocation of vaccine or placebo is the preferred method to assess the effects of the vaccine on clinical outcomes relevant to the individual patient. In the absence of phase 3 trials using clinical end points, notably post-influenza complications, alternative non-experimental designs to evaluate vaccine effects or safety are often used. The application of these designs may, however, lead to invalid estimates of vaccine effectiveness or safety. As patients with poor prognosis are more likely to be immunised, selection for vaccination is confounded by patient factors that are also related to clinical end points. This paper describes several design and analytical methods aimed at limiting or preventing this confounding by indication in non-experimental studies. In short, comparison of study groups with similar prognosis, restriction of the study population, and statistical adjustment for dissimilarities in prognosis are important tools and should be considered. Only if the investigator is able to show that confounding by indication is sufficiently controlled for, results of a non-experimental study may be of use to direct an evidence based vaccine policy.