Showing papers in "Journal of Epidemiology and Community Health in 1993"

Methodology for Genetic Studies of Twins and Families

Abstract: The saimie paper suggests how susceptible individuals could reduce their total intake of aluminium. In presenting the cpidemiological evidence for a link betveen aluminium and Alzheimcr's, Nart'n suggests that although definite proof is still lacking, there is more than enough positixe evidence to fuel further epidemiological investigation. It states that such investigations might specificallx address the issue of the confounding cffect of silicon and an assessment of exposure to spccific

Validation of a severity index in female urinary incontinence and its implementation in an epidemiological survey.

Abstract: STUDY OBJECTIVE--The aim was to validate a simple severity index of female urinary incontinence for subsequent use in an epidemiological survey. DESIGN--The index was created by multiplying the reported frequency (four levels) by the amount of leakage (two levels). The resulting index value (1-8) was further categorised into slight (1-2), moderate (3-4), and severe (6-8). It was validated against a 48 hour "pad weighing" test. Thereafter, an anonymous postal questionnaire survey was performed and the index was used to assess the severity of the leakage. A question about the impact of incontinence was also included. SETTING--The outpatient clinic of the Department of Gynaecology and Obstetrics, Trondheim University Hospital and the rural community of Rissa, Norway. PARTICIPANTS--Altogether 116 incontinent women referred to the clinic by their GP and all 2366 adult women living in Rissa. RESULTS--The difference in median pad weights between moderate and slight incontinence was 9g/24h (95% confidence interval 0-27). The corresponding difference between severe and moderate incontinence was 17g/24h (95% CI 5-30). In the epidemiological survey 29.4% reported urinary incontinence (response rate 77%). The prevalence tended to be highest in middle life and old age. Forty six per cent were classified as slight, 27% moderate, and 27% severe. There was a strong correlation between severity and impact (R = 0.59, p < 0.001). CONCLUSION--The severity index may be a useful tool for assessing the severity of female urinary incontinence in epidemiological surveys. It is confirmed that urinary incontinence is very prevalent in adult women, but most should not be regarded as potential patients.

Magnitude and causes of mortality differences between married and unmarried men.

Abstract: STUDY OBJECTIVE--To determine the effect of marital status on mortality for men. In particular, to examine whether subgroups of unmarried men (widowed, single, and divorced/separated men) have a similar mortality to married men. DESIGN--Cohort study. SETTING--Whitehall civil service, London, between 1967 and 1969. PARTICIPANTS--A total of 18,403 men aged 40-64 years with 18 years' follow up. MEASUREMENTS AND MAIN RESULTS--Cause-specific mortality rates and risk factors at baseline were determined. Overall mortality was greater for all groups of unmarried men. Patterns of mortality were different in the subgroups of unmarried men. Widowed men had a significantly greater risk of dying from ischaemic heart disease (relative risk (RR) 1.46, 95% confidence interval (CI) 1.08, 1.97) which persisted after exclusion of deaths that occurred in the first two years. Divorced men had greater cancer mortality (RR 1.49; 95% CI 1.06, 2.10) that could not be explained simply by their greater consumption of cigarettes. The initial increased mortality for single men was no longer evident after adjustment for other risk factors, suggesting that single status in itself may not increase the risk. The risk for single men may have been underestimated, however, by over adjustment for possible intermediary factors. CONCLUSIONS--Previous studies, which have examined total mortality only or have grouped all unmarried men, have masked interesting differences in the cause of death between subgroups of unmarried men. The extent to which the findings are explicable by psychosocial factors or the role of other environmental factors, which may also differ in relation to marital status, is unclear. Future work should not assume that all unmarried men have similar mortality risks and must examine the life course of each subgroup to advance our understanding of the possible causal role of marital status in disease aetiology.

Developments in Biological Standardization

Abstract: developing countries is thought provoking, and so is the paper on environmental standards at the workplace-and the options for setting standards in developing countries. The authors refer to the dilemma of proposing stricter environmental standards for developing countries, because of possible differences in the health status of the population in such countries, versus adopting some practical, achievable, less stringent standard which can be gradually raised. There is also a useful catalogue of vegetable dusts which cause lung disease in developing countries, a good classification of pesticides, and a debatable approach to medical surveillance for exposure to mineral dusts-which advocate medical examinations and chest radiology as a minimum for pneumoconiosis due to mineral dusts. The problem of acute pesticide poisoning and accidents at work in developing countries is highlighted, and these are clearly much bigger problems than in developed countries. It is a fascinating book, well worth reading and definitely to be recommended as a standard text book for occupational health professionals in developing countries. It will also be an eye opener for occupational and public health physicians in developed countries with an interest in approaches to occupational health in the developing world.

Chronic respiratory diseases.

Abstract: If this is true of diet and smoking it is even more true of the social environment: housing, the nature or work, education, social relationships. The research agenda for public health now should not only ask how best to achieve change in unhealthy behaviours but how to identify the social and economic causes of ill health, whether they act by affecting behaviours or by other means related to the environment; whether they act in adulthood or whether they act early in life. 16s18 Rose's insight on blood pressure and cholesterol applies also to social differences in ill health. People at the lower end of the social distribution, the poor, the homeless and the unemployed, have worse health than those better off. But although these individuals are at high risk and require attention, they are

Health and re-employment in a two year follow up of long term unemployed.

Abstract: STUDY OBJECTIVE--The aim was to examine re-employment and changes in health during a two year follow up of a representative sample of long term unemployed. DESIGN--This was a cross sectional study and a two year follow up. Health was measured by psychometric testing, Hopkins symptom checklist, General health questionnaire, and medical examination. Health related selection to continuous unemployment and recovery by re-employment was estimated by logistic regression with covariances deduced from the labour market theories of human capital and segmented labour market. SETTING--Four municipalities in Greenland, southern Norway. SUBJECTS--Participants were a random sample of 17 to 63 year old people registered as unemployed for more than 12 weeks. MAIN RESULTS--In the cross sectional study, the prevalence of depression, anxiety, and somatic illness was from four to 10 times higher than in a control group of employed people. In the follow up study, there was considerable health related selection to re-employment. A psychiatric diagnosis was associated with a 70% reduction in chances of obtaining a job. Normal performance on psychometric testing showed a two to three times increased chance of re-employment. Recovery of health following re-employment was less than expected from previous studies. CONCLUSIONS--Health related selection to long term unemployment seems to explain a substantial part of the excess mental morbidity among unemployed people. An increased proportion of the long term unemployed will be vocationally handicapped as years pass, putting a heavy burden on social services.

Computerised linking of medical records: methodological guidelines.

Abstract: OBJECTIVES--To report on the development of computer assisted methods for linking medical records and record abstracts. DESIGN--The methods include file blocking, to put records in an order which makes searching efficient; matching, which is the process of comparing records to determine whether they do or do not relate to the same person; linkage, which is the process of assembling correctly matched records into a time sequenced composite record for the individual; and validation checks and corrections, in which any inconsistencies between different records for the same person are identified and corrected. SETTING--The dataset comprising the Oxford record linkage study which includes hospital inpatient records and vital records. RESULTS AND CONCLUSIONS--Probability matching, using an array of identifiers, achieves much higher levels of correct matching than is generally achievable by exact character by character comparisons. The increasing use of information technology to store data about health and health care means that there is increasing scope to link records for research and for patient care. Sophisticated methods to achieve this on a large scale are now available.

Trends in body mass index and prevalence of obesity in Swedish men 1980-89.

Abstract: STUDY OBJECTIVE--To assess changes in the body mass index (BMI, weight (kg)/height2 (m2)) and in the prevalence of obesity in Swedish women during the 1980s. DESIGN--Data from two successive cross sectional surveys were used. SETTING--The whole of Sweden. SUBJECTS--A total of 7419 women from a 1980-81 survey (response rate 84.6%) and 6306 women from a 1988-89 survey (response rate 80.3%), aged 16-84 years, and forming a representative sample of Swedish women. MEASUREMENTS AND MAIN RESULTS--The results were based on self reported weight and height during interview. The mean BMI of the whole population, adjusted for age, education level, socioeconomic group, region, and nationality, increased by 0.17 kg/m2 (p = 0.0056) over the eight year period. The increase was particularly pronounced in the group aged 25-34 years (0.74 kg/m2; p 28.6 kg/m2) by 19% (odds ratio (OR) = 1.19; 95% confidence interval (CI): 1.04, 1.37) and of the combination of overweight and obesity (BMI > 23.8 kg/m2) by 12% (OR = 1.12; 95% CI 1.03, 1.23) in the whole female population. CONCLUSIONS--During the 1980s the mean BMI and the prevalence of overweight and obesity in adult Swedish women increased. An influence of the sociocultural environment on the body weight in women was stronger than that in men.

Use of primary health services in sparsely populated country districts by patients with musculoskeletal symptoms: consultations with a physician.

Abstract: STUDY OBJECTIVE--To examine the extent to which people consult health centre doctors about various musculoskeletal symptoms and to identify those groups of patients who are responsible for the main workload in primary health care caused by musculoskeletal complaints. DESIGN--A cross sectional investigation based on case records of people who visited health centre physicians. SETTING--The population of six Finnish health centre districts (93,000 inhabitants, 64 physicians' posts in primary care centres). SUBJECTS--6526 patients (7634 visits) who consulted a physician at any of six health centres during a two week period, of which 1380 consulted for musculoskeletal symptoms. MEASUREMENTS AND MAIN RESULTS--The reasons for the visits were abstracted from the case records and were analysed by cross tabulation. The rate of people visiting for musculoskeletal symptoms during a two week period was on average 15 per 1000 inhabitants. It was highest in men aged 45-54 years (25/1000) and in women aged 55-64 years (26/1000); the rate fell to the average in men over 54 and women over 64 years. Patients with musculoskeletal symptoms accounted for 21% of all patients and 27% of those over 15 years of age. Low back pain was the most common reason for consultation in men aged 25-54 years, while for women aged 35-74 years, the most common reason was neck and shoulder pain. CONCLUSIONS--Over one quarter of adults visiting a health centre doctor do so because of musculoskeletal disorders. This fact must be considered when developing health care services and organising basic education and further in-service training for doctors.

Cause-specific mortality: understanding uncertain tips of the disease iceberg

Abstract: STUDY OBJECTIVE--To determine the extent to which individual diseases, when recorded as being present shortly before death, were certified as causes of death. DESIGN--Retrospective cohort study in which the "subjects" were computerised linked records. SETTING--Six districts in the Oxford Regional Health Authority area (covering a population of 1.9 million people). SUBJECTS--Linked abstracts of hospital records and death certificates for people who died within four weeks and, for some diseases, within one year of hospital admission. MAIN OUTCOME MEASURES--The percentage of people with each disease for whom the disease was recorded as the underlying cause of death, was recorded elsewhere on the death certificate, or was not certified as a cause of death at all. RESULTS--Three broad patterns of certification are distinguished. Firstly, there were diseases that were usually recorded on death certificates when death occurred within four weeks of hospital care of them. Examples included lung cancer (on 91% of such death certificates), breast cancer (92%), leukaemia and lymphoma (90%), anterior horn cell disease (89%), multiple sclerosis (89%), myocardial infarction (90%), stroke (93%), aortic aneurysm (87%), and spina bifida (89%). These diseases were also usually certified as the underlying cause of death. Secondly, there were diseases which, when present within four weeks of death, were commonly recorded on death certificates but often not as the underlying cause of death. Examples included tuberculosis (on 76% of such certificates; underlying cause on 54%), thyroid disease (49%; 21%), diabetes mellitus (69%; 30%) and hypertension (43%; 22%). Thirdly, there were conditions which, when death occurred within four weeks of their treatment, were recorded on the death certificate in a minority of cases only. Examples of these included fractured neck of femur (on 25% of such certificates), asthma (37%), and anaemia (22%). Not surprisingly, there was "convergence" in certification practice towards the common cardiovascular and respiratory causes of death. There was also evidence that conditions regarded as avoidable causes of death may not have been certified when present at death in some patients. CONCLUSION--When uses are made of mortality statistics alone, it is important to know which category of certification practice the disease of interest is likely to be in. Linkage between morbidity and mortality records, and multiple cause analysis of mortality, would considerably improve the ability to quantify mortality associated with individual diseases.

Multi method approach to the assessment of data quality in the Finnish Medical Birth Registry.

Abstract: OBJECTIVE--To assess comprehensively the validity of the data in the Finnish Medical Birth Registry (MBR) by the combined use of several controls and internal analysis of the data. DESIGN--The MBR data were individually linked to a medical record sample (n = 775) and to all perinatal death certificates in 1987. The data were also compared with annual hospital statistics. The distributions of birth weights and gestational ages were examined. SUBJECTS--All stillborn and liveborn babies registered in the MBR in 1987 (n = 59,370). SETTING--The nationwide MBR data were compared with medical records from one third of the Finnish hospitals, with statistics for all hospitals, and with nationwide cause of death registry data. MEASUREMENTS AND MAIN RESULTS--With regard to most variables, the data quality was good or satisfactory (agreement with medical records 95% or more). Allowing for minor deviations in variables with continuous scales improved the agreement rates further. Explanations could be deduced for items with poor agreement values. For most variables, the amount of missing data was less than 1%. With the exception of caesarean sections, medical procedures were registered in only 30 to 72% of the cases, and the proportion varied strongly between the hospitals. Common diagnoses (32 to 86%) and primary causes of death (59 to 78%) were also poorly recorded. CONCLUSIONS--Combined use of several control materials and internal analyses was successful in investigating the whole data content. The data in the MBR were generally valid but diagnoses and most data on medical procedures were not of sufficiently good quality.

Frequency of seafood intake in pregnancy as a determinant of birth weight: evidence for a dose dependent relationship.

Abstract: STUDY OBJECTIVE--The aim was to explore whether maternal consumption of seafood is a determinant of birth weight in a dose dependent manner. DESIGN--A population based survey of lifestyle factors in pregnancy was linked with information from antenatal and obstetric records. SETTING AND PARTICIPANTS--Seventy five per cent of all 1362 women who delivered in the Faroe Islands during the study period 1986-87 who gave a structured post partum interview on lifestyle factors. MAIN RESULTS--Altogether, 2, 6, 16, 33, 26, 14, and 3% of women had consumed approximately 0, 1, 2, 3, 4, 5, and 6+ respectively seafood (fish or whale) dinner meals per week during pregnancy. The average birth weight (p = 0.02) and birth length (p = 0.002) varied significantly between the seven groups, and increased by about 0.2 kg and 1 cm, respectively between women who ate 0 and those who consumed 3 seafood meals per week. Mean birth weight and length tended to level off with further fish consumption: when fitting a second degree polynomial, the quadratic terms were negative and significant for both birth weight (p = 0.005) and length (p = 0.001). Analogous analyses for pregnancy duration were not significant, but exhibited similar trends. All analyses were adjusted for maternal height, weight, parity, age, marital status, and smoking. CONCLUSIONS--The weight and length of the newborn increased with the frequency of seafood dinner meals consumed in pregnancy but only up to a consumption level of about 3 meals per week.

Factors associated with constipation in a community based sample of people aged 70 years and over.

Abstract: STUDY OBJECTIVE--The aim was to determine the prevalence and factors associated with constipation in elderly people. DESIGN--The study was a survey involving administration of a structured questionnaire, an interview, and a dietary assessment. SETTING--The survey was community based and the population studied was drawn from the practice records of all five general practitioners serving a rural township of 13,500 people. PARTICIPANTS--778 (91.8%) of the 856 people aged 70 years and over registered with the five practitioners took part. MAIN RESULTS--174 subjects had symptoms of infrequent bowel motions or frequent straining at stool or used laxatives regularly. Of this group, 34 had a bowel motion only every 3 d or less frequently and were considered to have constipation. Analysis of this subgroup showed that constipation was more common in women than men, increased with age, and was associated with the use of constipating drugs. Those whose bowels moved infrequently were a more frail group who were less physically active. Low intakes of dietary fibre, fruit, vegetables, bread and cereals, or fluid were not associated with an increased occurrence of constipation. There were 151 subjects who felt they were moderately constipated, but who had a bowel motion at least every 2 d. These people were more likely than the rest of the sample to use laxatives (55.6%), were more likely to take food for their bowels, to take hynoptics, and to regard their health as poor. CONCLUSIONS--About one third of people aged 70 years and over have some bowel problem such as infrequency, straining at stool, or frequent laxative use. Most modify their diet accordingly but laxative use remains high.

Mortality among injecting drug users: a critical reappraisal.

Abstract: STUDY OBJECTIVE--The aim was to quantify all cause mortality among injecting drug users. DESIGN--This was a retrospective analysis of 1989 data on injecting drug users and mortality obtained from three independent agencies: the Procurator Fiscal's Office, the General Register Office, and the Scottish HIV-test register. SETTING--Greater Glasgow, Scotland. SUBJECTS--Drug injectors, estimated population 9424. MAIN RESULTS--81 names were found using the three sources to identify deaths. After removing duplicates, 51 deaths were found. This represented a mortality rate of 0.54% in the estimated population. Among female injectors the mortality rate was 0.85%, significantly higher than the rate of 0.42% among male injectors (95% CI for the true difference in mortality rates between female and male injectors was 0.31%-0.55%). Over 90% of deaths were attributed to overdose or suicide. Although AIDS caused only one death, 19% of cases (5/27) whose HIV antibody status could be ascertained were positive. The mortality rate among HIV positive injectors (3.8%) was significantly higher than among HIV negative injectors (0.49%). CONCLUSIONS--Comprehensive coverage using three data sources revealed a far greater annual number of all cause deaths among injectors than would have been expected from previous research. The observed mortality rate was lower than in previous studies where the denominators used to calculate rates had an element of underenumeration. For the foreseeable future it is unlikely that AIDS will have much impact on mortality among injectors in Glasgow, because of the low prevalence of HIV infection among injectors in the city, and because HIV positive injectors are dying for reasons other than AIDS; rather, overdose and suicide will continue to be the main causes of death.

Education, reading, and familial tendency as risk factors for myopia in Hong Kong fishermen.

Abstract: STUDY OBJECTIVE--The aim was to assess the influence of childhood reading on the development of myopia after allowance for familial differences in susceptibility. DESIGN--The study was a cross sectional survey. SETTING--Four fishing harbours in Hong Kong in 1989. SUBJECTS--Participants were 408 men and women aged 15-39 years old from 159 families. MAIN RESULTS--Histories of school attendance and reading habits in childhood were obtained at interview. Myopia was assessed by retinoscopy. Associations between myopia (defined as a refractive error of at least -1.0D in one or both eyes) and indices of reading in childhood were explored. Myopia was more common in subjects who had attended school (odds ratio = 1.7, 95% CI 1.0-3.0), with the highest risks in those who had started school at the earliest ages and who had spent the most time reading and writing while at primary school. Allowance for familial tendency to myopia produced no diminution in the risks associated with reading. CONCLUSIONS--These data support the hypothesis that reading in childhood is a cause of short sight.

The Childhood Environment and Adult Disease

Abstract: variability in findings threw doubt on their value. Roche, who has worked on the Fels study for most of his career, candidly describes both the problems as well as the achievements in the history of this long term study, including its fescue on two occasions from intellectual stagnation-once in a reorientation in the 1950s when the value of the archive was recognised not only as a detailed and wide ranging data collection of information, but also as a resource for hypothesis testing; and again in 1976 when work began on risk factors for cardiovascular disease. This book summarises the study's most consistent strands of work, on growth, maturation, and development, as well as the findings on risk factors for cardiovascular illness. The main purpose of the work was the study of individual development, and there was much less work on secular trends. The book provides an invaluable bibliography of published material on these topics. The Fels study, like most of the other American developmental investigations begun at the same time, for example the Berkeley and Oakland growth studies, has also been used since the 1960s for social and psychological studies. Although discussed disappointingly little in this volume, between them these studies did indeed show the powerful effects of the great American depression on the physical and mental health, development and wellbeing of children, and the long term effects on adult life of the experience of such adversity in childhood.

Physical inactivity is an independent risk factor for hip fracture in the elderly.

Abstract: STUDY OBJECTIVE--To test the hypothesis that physical inactivity is an independent risk factor for hip fracture in the elderly. DESIGN--Population based, case-control study. SETTING--Metropolitan borough of Newcastle upon Tyne. PARTICIPANT--A total of 197 patients aged 50 years and over, resident in Newcastle, and admitted consecutively with a hip fracture, and 382 community controls, matched by age and sex, who had not suffered a hip fracture. MEASUREMENTS AND MAIN RESULTS--Validated methods were used to assess customary physical activity. Information on body build, cigarette smoking, and alcohol consumption was also obtained. Grip strength was measured. Physical inactivity was strongly associated with the risk of hip fracture in men and women. Subjects who did not regularly weight-bear, perform muscle-loading activities such as climbing stairs, and perform productive activities such as gardening, were all more than twice as likely to sustain a hip fracture, when compared with subjects at the higher end of the activity spectrum. These increases in risk remained after adjusting for body mass index, smoking, alcohol consumption, and dependence in daily living activities. CONCLUSIONS--Customary physical inactivity is an independent determinant of hip fracture in the elderly. Strategies to improve the day to day activity of elderly people require urgent exploration.

Reported incidence of occupational asthma in the United Kingdom, 1989-90.

Abstract: STUDY OBJECTIVE--To estimate the incidence of occupational asthma seen by respiratory and occupational physicians in the UK in 1989 and 1990. DESIGN--New cases of occupational asthma were taken from a national reporting scheme, the Surveillance of Work-related and Occupational Respiratory Disease Project (SWORD). Estimates of the working population from the Labour Force Survey were used to calculate reported incidence by age group, sex, occupation, and region. SETTING--The SWORD project is a scheme for the reporting of new cases of work-related respiratory disease by thoracic and occupational physicians from throughout the UK which began in 1989. PATIENTS--In 1989 and 1990, of 4229 cases reported, 1085 (26%) were in patients with occupational asthma. MAIN RESULTS--Only half the reported cases were attributed to agents prescribed under the Industrial Injuries Scheme. There was considerable diversity in risk by occupation, with highest annual rates in welders, solderers, and electronic assemblers (175/million), laboratory workers (188/million), metal treaters (267/million), bakers (334/million), plastics workers (337/million), chemical processors (364/million), and spray painters (658/million). Crude rates in men were higher than in women, but rates within occupations were similar in both sexes. Rates of disease rose with age; adjustment for occupation increased the gradient. Regional differences were only partly explained by diversity of industry and were probably mainly due to variation in levels of ascertainment and reporting. CONCLUSIONS--Asthma is the most commonly reported occupational lung disease in the UK. The incidence in the general population is unknown, but it was estimated that the incidence of new cases seen by respiratory and occupational physicians was about three times that reported. High relative risks were found in a number of occupations in which effective control of the work environment is urgently required.

Assessing the need for health status measures.

Abstract: The current reorganisation of the NHS obliges health authorities to purchase a pattern of health care provision which accords with the health needs of the local population.' This seemingly unexceptionable expectation has revealed considerable uncertainty as to how needs assessment should be carried out in practice. The broad characteristics of the population are reflected in a range of demographic, socioeconomic and mortality data. While these sources of data offer broad insights into patterns of need, they cannot support more intimate decisions. In particular, they are fundamentally incapable of generating valid measures of morbidity.2 Aspects of morbidity are reflected in health services utilisation data, but their interpretation suffers from the necessary deficiency that patterns of demand and supply are inseparable from patterns of need. Routine data sources are therefore inadequate for determining those attributes of each population that should inform purchasing decisions. Adequate needs assessment must depend upon sketching some relief onto this unacceptable void in the portrayal of the population's experience of health and illness. One option which is advocated is the administration of generic measures of health status to samples of the population in the expectation that the resultant profiles and indices may offer a representative view of the perceived need for health care. In this paper we consider the relevance of generic health status measures to those responsible for advising on the purchase of what may constitute an appropriate mix of services. TYPES OF HEALTH STATUS MEASURES General health measures Measures such as the Nottingham Health Profile (NHP),6 7 Sickness Impact Profile,8 9 and the Medical Outcomes Study Instrument/SF36'0 \"I aim to provide global profiles of health, including well being, function, and social and emotional health. There is also the single item global health measure which asks if the respondent rates her or his health as excellent, good, fair, or poor (see 12 14)

Air pollution, lagged effects of temperature, and mortality: The Netherlands 1979-87.

Abstract: OBJECTIVE--To explore whether the apparent low threshold for the mortality effects of air pollution could be the result of confounding. DESIGN--The associations between mortality and sulphur dioxide (SO2) were analysed taking into account potential confounding factors. SETTING--The Netherlands, 1979-87. MEASUREMENTS AND MAIN RESULTS--The number of deaths listed by the day on which the death occurred and by the cause of death were obtained from the Netherlands Central Bureau of Statistics. Mortality from all causes and mortality from four large groups of causes (neoplasms, cardiovascular diseases, respiratory diseases, and external causes) were related to the daily levels of SO2 air pollution and potential confounders (available from various sources) using log-linear regression analysis. Variables considered as potential confounders were: average temperature; difference between maximum and minimum temperatures; amount of precipitation; air humidity; wind speed; influenza incidence; and calendar year, month, and weekday. Both lagged and unlagged effects of the meteorological and influenza variables were considered. Average temperature was represented by two variables--'cold', temperatures below 16.5 degrees C, and 'warm', those above 16.5 degrees C--to allow for the V shaped relation between temperature and mortality. The positive regression coefficient for the univariate effect of SO2 density on mortality from all causes dwindles to close to zero when all potential confounding variables are taken into account. The most important of these represents the lagged (one to five days) effect of low temperatures. Low temperatures have strong lagged effects on mortality, and often precede relatively high SO2 densities in the Netherlands. Results were similar for separate causes of death. While univariate associations suggest an effect of air pollution on mortality in all four cause of death groups, multivariate analyses show these effects, including that on mortality from respiratory diseases, are a result of confounding. CONCLUSIONS--The SO2 density (or that of compounds closely associated with SO2) does not seem to have any short term effect on mortality in the Netherlands. SO2 levels higher than those currently reached in the Netherlands (above 200 micrograms/m3) may have a measurable effect on mortality and this should be investigated. Furthermore, analyses of the public health impact of outdoor air pollution should properly control for the lagged effects of temperature.

Sleeping tablet consumption, self reported quality of sleep, and working conditions. Group of Occupational Physicians of APSAT.

Abstract: STUDY OBJECTIVE--The aim was to assess the frequency of sleep disorders in relation to working conditions. DESIGN--This was a cross sectional study. Data were collected prospectively, on a standardised form, by 13 occupational physicians. The quality of sleep was assessed by self perceived sleep disturbances and consumption of sleeping tablets. Working conditions were described by the worksite physician as well as by the participants. SETTING--2769 small or medium sized firms in the Paris area. PARTICIPANTS--A random sample of 7629 wage earners was studied. Among the participants, 61% were men and 39% women; 44% were blue collar workers. MAIN RESULTS--The prevalence of sleeping tablet consumption was 6.1% and 11.3% respectively for men and women. Sixteen percent of men and 26% of women stated that they had sleep disturbances (p < 0.001). In both sexes, drug consumption and sleep disturbances increased with age and were highest among individuals aged 55 years and more. No association between working conditions (exposure to noise, assembly line working, or physical workload) and sleep disturbances or drug consumption was found. Sleeping tablet consumption was higher among subjects reporting a bad atmosphere at work; the same was true for men with little interest in their job and for women working under time pressure. For both sexes, subjects reporting any of these conditions were more likely to report sleep disturbances. CONCLUSIONS--A high prevalence of self reported sleep problems and related drug consumption was observed. Physical working conditions were not related to the quality of sleep in contrast to perceived job conditions. The results suggest that sleep quality might be a useful health indicator for the occupational physician.

Respiratory symptoms and lung function effects of domestic exposure to tobacco smoke and cooking by gas in non-smoking women in Singapore.

Abstract: STUDY OBJECTIVES--To investigate the effects of passive exposure to tobacco smoke and gas cooking at home on respiratory symptoms and lung function of non-smoking women. SETTING--Evidence on the effects of passive smoking and exposure to nitrogen dioxide from gas cooking on the respiratory health of adults is limited and variable. Over 97% of women in Singapore do not smoke, and a principal source of indoor air pollution for housewives is passive smoking and gas cooking. DESIGN--This was a cross sectional (prevalence) study of a population based sample of 2868 adults aged 20 to 74 years in Singapore. A structured questionnaire administered by trained interviewers was used to collect data on passive smoking, gas cooking, respiratory symptoms, and other relevant variables. Passive smoking was defined as exposure to cigarette smoke from one or more members of the household who had ever smoked. Gas cooking was defined in terms of the weekly frequency of gas cooking, as well as the frequency with which the respondent's kitchen was filled with heavy cooking fumes (rarely, occasionally, often). Forced expiratory volume in one second (FEV1) was measured by using a portable Micro-spirometer. Multivariate analyses were used to estimate relative odds of association for respiratory symptoms and FEV1 effect, with adjustment for potential confounding variables. PARTICIPANTS--Of a total of 1438 women in the sample, 1282 women who had never smoked provided questionnaire data and 1008 women provided acceptable readings of FEV1 for analysis. MAIN RESULTS--Passive smoking was significantly associated with greater relative odds of usual or chronic cough and phlegm, wheezing, and breathlessness on exertion, as well as lower FEV1. Greater relative odds of respiratory symptoms were also associated with the weekly frequency of gas cooking, although these results were statistically insignificant. Chronic cough and phlegm and breathlessness on exertion, however, were significantly associated with the frequency with which the kitchen was filled with heavy cooking fumes. A lower FEV1 was found in women who cooked frequently (more than thrice a week). CONCLUSION--Domestic exposure to cigarette smoke and gas cooking is associated with increased risks of respiratory symptoms and impairment of lung function in non-smoking women in Singapore.

Coffee and tea consumption and the prevalence of coronary heart disease in men and women: results from the Scottish Heart Health Study.

Abstract: STUDY OBJECTIVES--The aim was to determine if there was a relationship between coffee or tea consumption and the prevalence of coronary heart disease in Scotland. DESIGN--The relationship between self reported coffee and tea consumption and the prevalence of coronary heart disease (history, symptoms, or electrocardiographic evidence) was investigated using multiple logistic regression analysis in the Scottish Heart Health Study (SHHS), a cross sectional study. SETTING--Twenty two Scottish districts were surveyed for the SHHS between 1984 and 1986. SUBJECTS--A total of 10,359 men and women aged 40-59 years were studied. MEASUREMENTS AND MAIN RESULTS--Of the 9740 subjects who were assigned a category, 21.8% (2122) were classified as having indications of coronary heart disease. Men and women were combined in the odds ratio analysis because they showed almost identical patterns in the prevalence of coronary heart disease across the coffee and tea quarters (grouped according to consumption). Those who did not drink coffee had a significantly higher (p < 0.05) prevalence of coronary heart disease than the three groups for coffee drinkers. Adjustments for risk factors including cigarette smoking, total blood cholesterol, and diastolic blood pressure did not remove the significance of the odds ratios. There was a positive dose-response effect between tea consumption and coronary heart disease which was removed after adjustment for various risk factors. CONCLUSIONS--These findings do not support a positive relationship between coffee or tea consumption and coronary heart disease in this British study where most coffee consumed is instant coffee.

Evidence for longevity differences between left handed and right handed men: an archival study of cricketers.

Abstract: STUDY OBJECTIVE--The aim was to examine the relationship between handedness and longevity. DESIGN--This was an archival (retrospective) survey of a cohort of adult men who had played 'first-class cricket'. SETTING--The United Kingdom PARTICIPANTS--The subjects consisted of all of the deceased players included in an encyclopedia of 'first-class cricket' whose bowling hand had been recorded (n = 3165). The study also considered a further 2314 players, born before 1951 but still alive at the time the book was published (1984). MEASUREMENTS AND MAIN RESULTS--Using the bowling hand as an indicator of handedness it was possible to compare the lifespans of 2580 right handed men and 585 left handed men. The average life spans of the two groups differed by 25 months (right = 65.62, left = 63.52), a highly significant difference (p = 0.006). An examination of cause of death (where noted) strongly indicated that the left handed men were more likely to die prematurely in accidents or in warfare. As a consequence, when these unnatural deaths were removed from the sample the longevity difference between the right handers and left handers was considerably reduced. There was no evidence that these results related to any longitudinal change in the proportion of right handers to left handers across the time course of the sample. CONCLUSION--The study found clear evidence that left handedness was associated with a decrease in longevity among a cohort of adult, athletic men. A major factor responsible for this result seemed to be a differential likelihood of accidental death or death during warfare.

Factors affecting response to an invitation to attend for a health check.

Abstract: OBJECTIVE--To describe the characteristics of general practice patients who fail to respond to an invitation to attend for a health check, in relation to demographic variables, risk factor status, health status, and attitudes to behaviour modification. DESIGN--Postal questionnaire before invitation to attend a health check and subsequent record of attendance. SETTING--Five urban general practices in Bedfordshire, UK. SUBJECTS--A total of 2678 patients aged 35-64 years were invited for a health check in 1989-90. RESULTS--The number of patients who did not attend was low overall but was higher among men than women (21 v 15%, p < 0.001), and in unmarried than married patients (24 v 16%, p < 0.001). Failure to attend was also higher among people in manual than in non-manual occupations (21 v 15%, p < 0.001), in people living in rented accommodation than in homeowners (29 v 16%, p < 0.001), and in those without access to a car than in car users (27 v 16%, p < 0.001). There was no difference in non-attendance rate according to age at completion of full time education. After adjustment for age, sex, marital state, and social class, the odds ratio for non-attendance was 1.74 (95% confidence interval (CI) 1.41, 2.14) for smokers; 1.07 (95% CI 0.76, 1.51) for heavy drinkers; 1.91 (95% CI 1.41, 2.58) for those with a less healthy diet; and 1.50 (95% CI 1.09, 2.07) for those who were obese. Patients who had visited their general practice more frequently and those who indicated a willingness to change their behaviour were significantly more likely to attend the health check. CONCLUSIONS--Health check attendance was lowest among patients who rarely attended the surgery and those who reported higher risk behaviour. Attendance was not, however, confined to the 'worried well'. Equal numbers of those with and without chest pain attended, as did at least three quarters of those in each risk group. This high rate of attendance reflects the time and effort invested in systematic recruitment. The development of a robust recruiting strategy is essential if substantial numbers, and particularly those at highest risk, are to be reached.

Environmental Epidemiology: Public Health and Hazardous Wastes

Abstract: developing countries is thought provoking, and so is the paper on environmental standards at the workplace-and the options for setting standards in developing countries. The authors refer to the dilemma of proposing stricter environmental standards for developing countries, because of possible differences in the health status of the population in such countries, versus adopting some practical, achievable, less stringent standard which can be gradually raised. There is also a useful catalogue of vegetable dusts which cause lung disease in developing countries, a good classification of pesticides, and a debatable approach to medical surveillance for exposure to mineral dusts-which advocate medical examinations and chest radiology as a minimum for pneumoconiosis due to mineral dusts. The problem of acute pesticide poisoning and accidents at work in developing countries is highlighted, and these are clearly much bigger problems than in developed countries. It is a fascinating book, well worth reading and definitely to be recommended as a standard text book for occupational health professionals in developing countries. It will also be an eye opener for occupational and public health physicians in developed countries with an interest in approaches to occupational health in the developing world.

Sunlight exposure, antioxidant status, and cataract in Hong Kong fishermen.

Abstract: STUDY OBJECTIVES--The aim was to test whether cataract is associated with higher lifetime exposure to sunlight, and whether antioxidants protect against cataract. DESIGN--This was a cross sectional survey of eye disease, with assessment of antioxidant status in a subgroup. SETTING--Hong Kong fishing communities in 1989. PARTICIPANTS--685 men and women aged 55 to 74 years old were included in the study, of whom 367 (54%) attended hospital for detailed examination. MEASUREMENTS AND MAIN RESULTS--At a mobile clinic visual acuity and lens opacities were assessed, and using a questionnaire, occupational history and lifetime exposure to sunlight. At hospital ophthalmic measurements were repeated and blood was taken for measurement of plasma vitamin C, vitamin E, and total carotenoids, and red cell activities of glucose-6-phosphate dehydrogenase, glutathione peroxidase, superoxide dismutase, and catalase. Higher grades of cataract (particularly nuclear cataract) tended to be more common in subjects with the most sun exposure, although not to the point of statistical significance. In contrast to earlier studies, no association was found with antioxidant status. CONCLUSIONS--The findings give some support to the hypothesis that sunlight causes cataract. The absence of a relation to antioxidant status may be because blood levels of antioxidants at one point in time do not adequately reflect a subject's past metabolic state, and particularly the past activity of antioxidants in the lens.

Physical activity and risk of peripheral arterial disease in the general population: Edinburgh Artery Study.

Abstract: STUDY OBJECTIVE--To determine associations between physical activity at age 35-45 years with peripheral arterial disease and cardiovascular risk factors at age 55-74 years. DESIGN--Cross sectional survey of the general population--Edinburgh Artery Study. The presence of peripheral arterial disease was determined using the WHO/Rose questionnaire on intermittent claudication, and the ankle brachial pressure index at rest and during reactive hyperaemia. Levels of physical activity undertaken at the time of the survey and at the times the subjects were aged 35-45 years were measured by self administered recall questionnaire. SETTING--City of Edinburgh, Scotland. PARTICIPANTS--Altogether 1592 men and women aged 55 to 74 years, selected from the age-sex registers of 10 general practices spread geographically and socioeconomically throughout the city. MAIN RESULTS--Participation in moderate or strenuous activity when aged 35-45 years was reported by 66% of men and 40% of women. In men, but not in women, less peripheral arterial disease (measured by an increasing trend in the ankle brachial pressure index) was found with increasing amounts of exercise at age 35-45 years (p 0.05). CONCLUSION--The risk of peripheral arterial disease, particularly among male smokers, is inversely related to previous physical activity in early middle age, suggesting a protective effect of exercise.

Birth weight and body mass index in childhood, adolescence, and adulthood as predictors of blood pressure at age 36.

Abstract: STUDY OBJECTIVE--The purpose of this study was to investigate the relation between blood pressure at age 36, and birth weight and body mass index (BMI) in childhood, adolescence and adulthood. DESIGN--Prospective longitudinal survey over a period of 36 years in England, Scotland, and Wales. PARTICIPANTS--A nationally representative sample consisting of 3332 men and women born in one week in March 1946. Altogether 82% of these subjects had complete data for the present analysis. MAIN RESULTS--There was an inverse linear relation between birth weight and blood pressure at age 36. The relation between BMI and blood pressure at age 36 was initially inverse and became increasingly positive throughout life. Weight gain in childhood was positively associated with adult blood pressure, although less important than weight change in later life. The associations between blood pressure and birth weight, and blood pressure and adult BMI were independent, and together they accounted for no more than 4% of the variation in adult blood pressure. Both low birth weight (birth weight 30kg/m2) were associated with hypertension (> 140/90mmHg), but the per cent population risk of hypertension attributable to low birth weight was less than 5%, and to high BMI less than 12%. CONCLUSIONS--Low birth weight and high BMI at age 36 were independently related to high blood pressure. A reduction in the percentage of low birthweight babies born in the fourth decade of this century would only have a negligible effect on the incidence of adult hypertension 30-40 years later.