Victor M Hawthorne

Impaired lung function and mortality risk in men and women : findings from the Renfrew and Paisley prospective population study

Abstract Objective: To assess the relation between forced expiratory volume in one second (FEV1) and subsequent mortality. Design: Prospective general population study. Setting: Renfrew and Paisley, Scotland. Subjects: 7058 men and 8353 women aged 45-64 years at baseline screening in 1972-6. Main outcome measure: Mortality from all causes, ischaemic heart disease, cancer, lung and other cancers, stroke, respiratory disease, and other causes of death after 15 years of follow up. Results: 2545 men and 1894 women died during the follow up period. Significant trends of increasing risk with diminishing FEV1 are apparent for both sexes for all the causes of death examined after adjustment for age, cigarette smoking, diastolic blood pressure, cholesterol concentration, body mass index, and social class. The relative hazard ratios for all cause mortality for subjects in the lowest fifth of the FEV1 distribution were 1.92 (95% confidence interval 1.68 to 2.20) for men and 1.89 (1.63 to 2.20) for women. Corresponding relative hazard ratios were 1.56 (1.26 to 1.92) and 1.88 (1.44 to 2.47) for ischaemic heart disease, 2.53 (1.69 to 3.79) and 4.37 (1.84 to 10.42) for lung cancer, and 1.66 (1.07 to 2.59) and 1.65 (1.09 to 2.49) for stroke. Reduced FEV1 was also associated with an increased risk for each cause of death examined except cancer for lifelong nonsmokers. Conclusions: Impaired lung function is a major clinical indicator of mortality risk in men and women for a wide range of diseases. The use of FEV1 as part of any health assessment of middle aged patients should be considered. Smokers with reduced FEV1 should form a priority group for targeted advice to stop smoking. Key messages These increased risks, with the exception of the cancers, are apparent for lifelong non-smokers FEV1 is second in importance to cigarette smoking as a predictor of subsequent all cause mortality and is as important as cholesterol in predicting mortality from ischaemic heart disease FEV1 should be included in health assessment of middle aged men and women Smokers with a reduced FEV1 should be targeted with advice to stop smoking

Education and occupational social class: which is the more important indicator of mortality risk?

STUDY OBJECTIVES: In the UK, studies of socioeconomic differentials in mortality have generally relied upon occupational social class as the index of socioeconomic position, while in the US, measures based upon education have been widely used. These two measures have different characteristics; for example, social class can change throughout adult life, while education is unlikely to alter after early adulthood. Therefore different interpretations can be given to the mortality differentials that are seen. The objective of this analysis is to demonstrate the profile of mortality differentials, and the factors underlying these differentials, which are associated with the two socioeconomic measures. DESIGN: Prospective observational study. SETTING: 27 work places in the west of Scotland. PARTICIPANTS: 5749 men aged 35-64 who completed questionnaires and were examined between 1970 and 1973. FINDINGS: At baseline, similar gradients between socioeconomic position and blood pressure, height, lung function, and smoking behaviour were seen, regardless of whether the education or social class measure was used. Manual social class and early termination of full time education were associated with higher blood pressure, shorter height, poorer lung function, and a higher prevalence of smoking. Within education strata, the graded association between smoking and social class remains strong, whereas within social class groups the relation between education and smoking is attenuated. Over 21 years of follow up, 1639 of the men died. Mortality from all causes and from three broad cause of death groups (cardiovascular disease, malignant disease, and other causes) showed similar associations with social class and education. For all cause of death groups, men in manual social classes and men who terminated full time education at an early age had higher death rates. Cardiovascular disease was the cause of death group most strongly associated with education, while the non-cardiovascular non-cancer category was the cause of death group most strongly associated with adulthood social class. The graded association between social class and all cause mortality remains strong and significant within education strata, whereas within social class strata the relation between education and mortality is less clear. CONCLUSIONS: As a single indicator of socioeconomic position occupational social class in adulthood is a better discriminator of socioeconomic differentials in mortality and smoking behaviour than is education. This argues against interpretations that see cultural--rather than material--resources as being the key determinants of socioeconomic differentials in health. The stronger association of education with death from cardiovascular causes than with other causes of death may reflect the function of education as an index of socioeconomic circumstances in early life, which appear to have a particular influence on the risk of cardiovascular disease.

Individual social class, area-based deprivation, cardiovascular disease risk factors, and mortality: the Renfrew and Paisley Study.

OBJECTIVE: To investigate the associations of individual and area-based socioeconomic indicators with cardiovascular disease risk factors and mortality. DESIGN: Prospective study. SETTING: The towns of Renfrew and Paisley in the west of Scotland. PARTICIPANTS: 6961 men and 7991 women included in a population-based cardiovascular disease screening study between 1972 and 1976. MAIN OUTCOME MEASURES: Cardiovascular disease risk factors and cardiorespiratory morbidity at the time of screening: 15 year mortality from all causes and cardiovascular disease. RESULTS: Both the area-based deprivation indicator and individual social class were associated with generally less favourable profiles of cardiovascular disease risk factors at the time of the baseline screening examinations. The exception was plasma cholesterol concentration, which was lower for men and women in manual social class groups. Independent contributions of area-based deprivation and individual social class were generally seen with respect to risk factors and morbidity. All cause and cardiovascular disease mortality rates were both inversely associated with socioeconomic position whether indexed by area-based deprivation or social class. The area-based and individual socioeconomic indicators made independent contributions to mortality risk. CONCLUSIONS: Individually assigned and area-based socioeconomic indicators make independent contributions to several important health outcomes. The degree of inequalities in health that exist will not be demonstrated in studies using only one category of indicator. Similarly, adjustment for confounding by socioeconomic position in aetiological epidemiological studies will be inadequate if only one level of indicator is used. Policies aimed at reducing socioeconomic differentials in health should pay attention to the characteristics of the areas in which people live as well as the characteristics of the people who live in these areas.

Height and risk of death among men and women: aetiological implications of associations with cardiorespiratory disease and cancer mortality

OBJECTIVES Height is inversely associated with cardiovascular disease mortality risk and has shown variable associations with cancer incidence and mortality. The interpretation of findings from previous studies has been constrained by data limitations. Associations between height and specific causes of death were investigated in a large general population cohort of men and women from the West of Scotland. DESIGN Prospective observational study. SETTING Renfrew and Paisley, in the West of Scotland. SUBJECTS 7052 men and 8354 women aged 45–64 were recruited into a study in Renfrew and Paisley, in the West of Scotland, between 1972 and 1976. Detailed assessments of cardiovascular disease risk factors, morbidity and socioeconomic circumstances were made at baseline. MAIN OUTCOME MEASURES Deaths during 20 years of follow up classified into specific causes. RESULTS Over the follow up period 3347 men and 2638 women died. Height is inversely associated with all cause, coronary heart disease, stroke, and respiratory disease mortality among men and women. Adjustment for socioeconomic position and cardiovascular risk factors had little influence on these associations. Height is strongly associated with forced expiratory volume in one second (FEV1) and adjustment for FEV1 considerably attenuated the association between height and cardiorespiratory mortality. Smoking related cancer mortality is not associated with height. The risk of deaths from cancer unrelated to smoking tended to increase with height, particularly for haematopoietic, colorectal and prostate cancers. Stomach cancer mortality was inversely associated with height. Adjustment for socioeconomic position had little influence on these associations. CONCLUSION Height serves partly as an indicator of socioeconomic circumstances and nutritional status in childhood and this may underlie the inverse associations between height and adulthood cardiorespiratory mortality. Much of the association between height and cardiorespiratory mortality was accounted for by lung function, which is also partly determined by exposures acting in childhood. The inverse association between height and stomach cancer mortality probably reflectsHelicobacter pylori infection in childhood resulting in—or being associated with—shorter height. The positive associations between height and several cancers unrelated to smoking could reflect the influence of calorie intake during childhood on the risk of these cancers.

Alcohol consumption and mortality from all causes, coronary heart disease, and stroke: results from a prospective cohort study of Scottish men with 21 years of follow up

Abstract Objectives: To relate alcohol consumption to mortality. Design: Prospective cohort study. Setting: 27 workplaces in the west of Scotland. Participants: 5766 men aged 35-64 when screened in 1970-3 who answered questions on their usual weekly alcohol consumption. Main outcome measures: Mortality from all causes, coronary heart disease, stroke, and alcohol related causes over 21 years of follow up related to units of alcohol consumed per week. Results: Risk for all cause mortality was similar for non-drinkers and men drinking up to 14 units a week. Mortality risk then showed a graded association with alcohol consumption (relative rate compared with non-drinkers 1.34 (95% confidence interval 1.14 to 1.58) for 15-21 units a week, 1.49 (1.27 to 1.75) for 22-34 units, 1.74 (1.47 to 2.06) for 35 or more units). Adjustment for risk factors attenuated the increased relative risks, but they remained significantly above 1 for men drinking 22 or more units a week. There was no strong relation between alcohol consumption and mortality from coronary heart disease after adjustment. A strong positive relation was seen between alcohol consumption and risk of mortality from stroke, with men drinking 35 or more units having double the risk of non-drinkers, even after adjustment. Conclusions: The overall association between alcohol consumption and mortality is unfavourable for men drinking over 22 units a week, and there is no clear evidence of any protective effect for men drinking less than this.

Passive smoking and cardiorespiratory health in a general population in the west of Scotland.

OBJECTIVE-To assess the risk of cardiorespiratory symptoms and mortality in non-smokers who were passively exposed to environmental smoke. DESIGN--Prospective study of cohort from general population first screened between 1972 and 1976 and followed up for an average of 11.5 years, with linkage of data from participants in the same household. SETTING--Renfrew and Paisely, adjacent burghs in urban west Scotland. SUBJECTS--15,399 Men and women (80% of all those aged 45-64 resident in Renfrew or Paisley) comprised the original cohort; 7997 attended for multiphasic screening with a cohabitee. Passive smoking and control groups were defined on the basis of a lifelong non-smoking index case and whether the cohabitee had ever smoked or never smoked. MAIN OUTCOME MEASURE--Cardiorespiratory signs and symptoms and mortality. RESULTS--Each of the cardiorespiratory symptoms examined produced relative risks greater than 1.0 (though none were significant) for passive smokers compared with controls. Adjusted forced expiratory volume in one second was significantly lower in passive smokers than controls. All cause mortality was higher in passive smokers than controls (rate ratio 1.27 (95% confidence interval 0.95 to 1.70)), as were all causes of death related to smoking (rate ratio 1.30 (0.91 to 1.85] and mortality from lung cancer (rate ratio 2.41 (0.45 to 12.83)) and ischaemic heart disease (rate ratio 2.01 (1.21 to 3.35)). When passive smokers were divided into high and low exposure groups on the basis of the amount smoked by their cohabitees those highly exposed had higher rates of symptoms and death. CONCLUSION--Exposure to environmental tobacco smoke cannot be regarded as a safe involuntary habit.

Plasma cholesterol, coronary heart disease, and cancer in the Renfrew and Paisley survey.

The relation between plasma cholesterol concentration and mortality from coronary heart disease, incidence of and mortality from cancer, and all cause mortality was studied in a general population aged 45-64 living in the west of Scotland. Seven thousand men (yielding 653 deaths from coronary heart disease, 630 new cases of cancer, and 463 deaths from cancer) and 8262 women (322 deaths from coronary heart disease, 554 new cases of cancer, and 395 deaths from cancer) were examined initially in 1972-6 and followed up for an average of 12 years. All cause mortality was not related to plasma cholesterol concentration. This was largely a consequence of a positive relation between cholesterol values and mortality from coronary heart disease being balanced by inverse relations between cholesterol and cancer and between cholesterol and other causes of death. These changes were highly significant for coronary heart disease and cancer in men and significant for coronary heart disease and other causes of death in women. The inverse association between cholesterol concentration and cancer in men was strongest for lung cancer, was not merely a function of the age at which a subject died, was present for the incidence of cancer as well as mortality from cancer, and persisted when new cases or deaths occurring within the first four years of follow up were excluded from the analysis.

Cigarette smoking and male lung cancer in an area of very high incidence. II. Report of a general population cohort study in the West of Scotland.

A general population cohort of 7055 men aged 45-64 and resident in Renfrew and Paisley, two urban burghs in the West of Scotland, has been followed for 10 1/2 years. Analysis of the cigarette smoking and lung cancer (incidence and mortality) relation has been undertaken in order to establish whether unusual results found in a case-control study of cigarette smoking and lung cancer in the adjacent city of Glasgow could be confirmed. Lung cancer incidence and mortality rates increased markedly for exposure categories up to an average consumption of 15-24 cigarettes per day. Above this level the rates increased only marginally. Expressing these rates relative to that estimated for the never-smoked group and comparing them with the relative risks estimated in the case-control study revealed a similarity in terms of both the shape and the level of the dose-response relation. Comparison of the lung cancer rates found in this cohort with those observed in other cohort studies in the literature (UK doctors, US Veterans, and American Cancer Society volunteers) suggested that the West of Scotland rates were substantially higher at all levels of cigarette exposure.

The education of one spouse and the fatness of the other spouse

As shown in 702 wives with 9–12 years of education and 612 husbands similarly educated, the summed skinfolds of one spouse are influenced by the educational level of the other spouse, considerably so for the husbands. Women with 9–12 years of education married to men of lower educational attainment are higher in the sum of four skinfolds while women of similar years of schooling married to men of college education and beyond are leaner (P=0.001). Possible explanations for the effect of the education of one spouse on the fatness level of the other spouse include selective mating in the direction set by the husbands socioeconomic milieu and fatness “drift” on the part of the wives, again in the direction of the husbands socioeconomic status (SES). While these findings do not lend themselves to a simple biological explanation, they do reiterate the effects of socioeconomic variables on fatness level within populations and even within families.

Social mobility, health, and cardiovascular mortality

R S BHOPAL (Department of Epidemiology and Public Health, University of Newcastle upon Tyne) Introduction The description ofhuman characteristics, including health, by racial group has beguiled researchers in many disciplines, including epidemiology. Some careers have been ruined in hindsight by racist, prejudiced, or simply misguided work in this highly complex and controversial arena of research. With the concept of race under attack, ethnicity has now occupied the vacated ground. Ethnicity has become a key, almost routine, epidemiological variable and there is strong pressure on researchers to collect information on it. There have been repeated and enthusiastic claims, by researchers, policy makers, and health planners, about the value of ethnicity and health research. This paper presents a critical analysis of the past and potential value of ethnicity, race, and health research based on epidemiological methods. The key questions are whether such research can inform our understanding of disease causation or help develop appropriate health services (enlightenment), add to our collection of unexplained associations (blackbox epidemiology), or is merely information of little value (junk). Approach to the paper A historical analysis will subject the claims of race and health researchers in the past to the reality of today. In addition, hypotheses will be extracted from the epidemiological literature of the 1970s and 1980s. The number of hypotheses which have been pursued and either rejected or supported by subsequent work will be the critical factor in assessing the value of ethnicity and health research in understanding disease causation. Furthermore, the quality of the research that has been done and is underway will be explored in relation to the definition of terms, validity of measurement of ethnicity, quality control of data collection, and the statement of hypotheses which permits their testing. The extent to which studies done in the late 1970s and early 1980s have been used to create appropriate health policy and health plans will be reviewed. Results of the analysis to date The work for this paper is not complete but the preliminary findings are that claims of race, ethnicity, and health researchers are highly exaggerated and that information from these studies is hard to utilise for aetiological or service applications. There are grave problems with the way researchers have collected and presented information on ethnicity and health, and with the validity of data collection used in cross cultural studies. The health services have found it difficult to respond to meet the needs of ethnic minority groups and it is unclear whether research has helped or hindered. From a historical point of view it will be argued that race research has done more harm than good, with many studies breaching research ethics and principles. It is highly pertinent to examine whether ethnicity and health research may also be breaching such principles. This analysis will argue for a deeper analysis of the value of ethnicity and health research in epidemiology so that its strengths and limitations can be more widely understood; exaggerated claims are not made; and expectations of researchers, policy makers, and ethnic minorities are maintained at realistic levels.