Non-participants in a general population study of men, with special reference to social and alcoholic problems

Underestimation of alcohol consumption in cohort studies and implications for alcohol's contribution to the global burden of disease

BACKGROUND AND AIMS

Estimated alcohol consumption from national self-report surveys is often only 30-40% of official estimates based on sales or taxation data. Global burden of disease (GBD) estimates for alcohol adjust survey estimates up to 80% of total per capita consumption. This assumes that cohort studies needed to estimate relative risks for disease suffer less from under-reporting than typical national surveys. However, there is limited evidence on which to base that assumption. This paper aims to assess the extent of underestimation of alcohol consumption in cohort studies concerning alcohol and mortality compared with official total consumption estimates.

DESIGN

Comparisons of estimated per capita consumption from a comprehensive sample of cohort studies against official estimates by country and year.

PARTICIPANTS

A total of 1 876 046 participants in 40 cohort studies from 18 countries on alcohol use and all-cause mortality identified by systematic review.

MEASUREMENTS

Alcohol consumption data from the cohort studies were converted into usual grams of ethanol per day and then to total age 15+ per capita consumption. Matched estimates were sourced from the World Health Organization (WHO) Global Health Observatory.

FINDINGS

The cohort studies had mean coverages of age 15+ per capita alcohol consumption of 61.71% (ranging from 29.19% for Russia to 96.53% for Japan), after weighting estimates by sample size for within-country estimates and by number of studies per country for the overall estimate. Regional estimates were higher for the United States (66.22%) and lower for western European countries (55.35%).

CONCLUSIONS

Underestimation of alcohol consumption in cohort studies is less than in typical population surveys. Because some under-coverage is caused by under-sampling heavier drinkers, the current practice of uplifting survey estimates to 80% of total population consumption in global burden of disease studies appears to be appropriate.

The incidence of atrial fibrillation and the added value of thumb ECG for detecting new cases

OBJECTIVES

To evaluate the incidence of atrial fibrillation (AF) as well as the value of thumb electrocardiography (ECG) for identification of paroxysmal AF in a Swedish cohort of middle-aged men from the general population.

DESIGN

A population based random cohort of 798 men underwent screening at the age of 50 and re-examined at the age of 60 and 71 years. At the last examination, a thumb ECG recording was conducted for 2 weeks twice a day in 479 men from the original cohort. Registered hospital AF diagnoses were retrieved from the Swedish Patient Registry from 1993 to 2014.

RESULTS

During a 21-year follow-up, 77 men (9.6%) were diagnosed with AF; of these men, 49.4% (38 of 77) had permanent AF. Fifteen of 479 (3.1%) patients had paroxysmal AF. Of those, seven had been previously diagnosed with paroxysmal AF through Patient Registry. The incidence of AF increased from 2.2 per 1000 years at risk at the age of 50-54 years to 9.3 per 1000 years at risk at the age 65-70 years. The prevalence of AF at the age of 71 years was increased from 7.1% to 9.9% using thumb ECG.

CONCLUSIONS

In addition to medical history, patient register and 12-lead -ECG, the use of thumb ECG increased the number of detected paroxysmal AF by 21%.

Although Coronary Mortality Has Decreased, Rates of Cardiovascular Disease Remain High: 21 Years of Follow-Up Comparing Cohorts of Men Born in 1913 With Men Born in 1943

Background

Despite a decline in mortality rates from cardiovascular disease (CVD) in the past few decades, the burden of CVD in a contemporary population remains inadequately addressed. Therefore, this study was aimed to investigate secular trends in mortality from coronary artery disease and all‐cause mortality over 2 decades, by comparing 2 cohorts of men born 30 years apart and evaluate the prediction of the risk of CVD and all‐cause death in a contemporary random sample of Swedish men.

Methods and Results

Two cohorts of randomly selected men born in 1913 (855 men) and 1943 (798 men) were first examined at age 50 in 1963 and 1993, respectively, and followed longitudinally over 21 years. All‐cause mortality and coronary artery disease death were lower in 50‐ to 71‐year‐old men born in 1943 compared with those born in 1913, with unadjusted hazard ratios of 0.57 (0.45–0.71) and 0.34 (0.22–0.53), respectively. After adjustment for risk factors (smoking, serum cholesterol, hypertension, systolic blood pressure, diabetes mellitus, body mass index, and physical activity), the differences between the cohorts remained significant for coronary artery disease, hazard ratios 0.57 (0.34–0.94), P=0.029, but not for all‐cause mortality hazard ratios 0.82 (0.62–1.07), P=0.14. However, the rate of CVD events during follow‐up was still high (30.7%) for the men born in 1943. No statistically significant interaction by birth cohort in contribution of risk factors to death was found between 2 cohorts except physical inactivity.

Conclusions

Despite a marked reduction in the rate of coronary artery disease death over the past 30 years, the burden of CVD events and all‐cause mortality remains high. Therefore, intensified efforts to modify contributing risk factors are still required.

Longitudinal drop-out and weighting against its bias

Background

The bias caused by drop-out is an important factor in large population-based epidemiological studies. Many studies account for it by weighting their longitudinal data, but to date there is no detailed final approach for how to conduct these weights.

Methods

In this study we describe the observed longitudinal bias and a three-step longitudinal weighting approach used for the longitudinal data in the MoMo baseline (N = 4528, 4–17 years) and wave 1 study with 2807 (62%) participants between 2003 and 2012.

Results

The most meaningful drop-out predictors were socioeconomic status of the household, socioeconomic characteristics of the mother and daily TV usage. Weighting reduced the bias between the longitudinal participants and the baseline sample, and also increased variance by 5% to 35% with a final weighting efficiency of 41.67%.

Conclusions

We conclude that a weighting procedure is important to reduce longitudinal bias in health-oriented epidemiological studies and suggest identifying the most influencing variables in the first step, then use logistic regression modeling to calculate the inverse of the probability of participation in the second step, and finally trim and standardize the weights in the third step.

Quality of life following trauma before and after implementation of a physician-staffed helicopter

Background

Implementation of a physician‐staffed helicopter emergency medical service (PS‐HEMS) in Denmark was associated with lower 30‐day mortality in severely injured trauma patients and less time on social subsidy. However, the reduced 30‐day mortality in severely injured patients might be at the expense of a worse functional outcome and quality of life (QoL) in those who survive. The aim of this study was to investigate the effect of a physician‐staffed helicopter on long‐term QoL in trauma patients.

Methods

Prospective, observational study including trauma patients who survived at least 3 years after injury. A 5‐month period prior to PS‐HEMS implementation was compared with the first 12 months after PS‐HEMS implementation. QoL was assessed 4.5 years after trauma by the SF‐36 questionnaire. Primary endpoint was the Physical Component Summary score.

Results

Of the 1994 patients assessed by a trauma team, 1521 were eligible for inclusion in the study. Of these, 566 (37%) gave consent to participate and received a questionnaire by mail, and 402 (71%) of them returned the questionnaire (n = 114 before PS‐HEMS; n = 288 after PS‐HEMS implementation). Older patients, women and patients with trauma in the after PS‐HEMS period were more likely to return the questionnaire. No significant association between QoL and period (before vs. after PS‐HEMS) was found; the Physical Component Summary scores were 50.0 and 50.9 in the before and after PS‐HEMS periods, respectively (P = 0.47). We also found no difference on multivariable analysis with adjustment for sex, age and injury severity score.

Conclusion

No significant difference in QoL among trauma patients was found after implementation of a PS‐HEMS.

Selection biases in observational studies affect associations between 'moderate' alcohol consumption and mortality

Selection biases may lead to systematic overestimate of protective effects from 'moderate' alcohol consumption. Overall, most sources of selection bias favor low-volume drinkers in relation to non-drinkers. Studies that attempt to address these types of bias generally find attenuated or non-significant relationships between low-volume alcohol consumption and cardiovascular disease, which is the major source of possible protective effects on mortality from low-volume consumption. Furthermore, observed mortality effects among established low-volume consumers are of limited relevance to health-related decisions about whether to initiate consumption or to continue drinking purposefully into old age. Short of randomized trials with mortality end-points, there are a number of approaches that can minimize selection bias involving low-volume alcohol consumption.

Multiple-stage screening and mortality in the Multiple Risk Factor Intervention Trial

Background During the design phase of a clinical trial, sample size estimates should take into account medical screening criteria, the ‘healthy volunteer’ effect, consequences of run-in phases, and secular trends in the event rate of interest. All of these have been shown to relate to subsequent event rates, and hence trial power to detect intervention effects. The Multiple Risk Factor Intervention Trial (MRFIT) used three successive screenings of 361 662 men to enroll 12 866; observed coronary heart disease (CHD) mortality after a mean of 6.9 years was substantially lower than projected during design. We explore factors which may have contributed to these mortality differences and whether they persisted throughout follow-up.

Methods Proportional hazards models were used to compare 25-year mortality according to trial eligibility, self-exclusions, medical exclusions, and participation.

Results After adjustment for baseline risk factors and age, there was higher mortality among men excluded for presence of disease [hazard ratio (HR) 1.52, 95% confidence interval (CI) 1.43–1.61, for total; HR 1.92, CI 1.75–2.11, for CHD] compared to those not excluded which persisted throughout follow-up. Volunteers had lower total (HR 0.82, CI 0.76–0.87) and CHD (HR 0.79, CI 0.70–0.88) mortality than those discontinuing participation. Men excluded with characteristics deemed likely to interfere with adherence had higher total (HR 1.19, CI 1.07–1.33) and noncardiovascular disease (CVD) (HR 1.32, CI 1.14–1.53) mortality but no higher CVD (HR 1.04, CI 0.88–1.23) or CHD (HR 0.98, CI 0.80–1.20) mortality compared to those not excluded. Differences in mortality were stronger during the first five years, but declined only slightly over 25 years.

Conclusions 25-year mortality was significantly higher for non-volunteers and exclusions. Differences between observed and predicted six-year total mortality for trial participants were largely attributable to volunteers and exclusions, but there were additional differences for CHD mortality, which were likely due to downward secular trends. These results emphasize the importance of anticipating these factors during clinical trial design, even for trials of short duration.

Who Would Pay for State Alcohol Tax Increases in the United States?

INTRODUCTION

Despite strong evidence that increasing alcohol taxes reduces alcohol-related harm, state alcohol taxes have declined in real terms during the past 3 decades. Opponents of tax increases argue that they are unfair to "responsible" drinkers and those who are financially disadvantaged. The objectives of this study were to assess the impact of hypothetical state alcohol tax increases on the cost of alcohol for adults in the United States on the basis of alcohol consumption and sociodemographic characteristics.

METHODS

The increased net cost of alcohol (ie, product plus tax) from a series of hypothetical state alcohol tax increases was modeled for all 50 states using data from the 2011 Behavioral Risk Factor Surveillance System, IMPACT Databank, and the Alcohol Policy Information System. Costs were assessed by drinking pattern (excessive vs nonexcessive) and by sociodemographic characteristics.

RESULTS

Among states, excessive drinkers would pay 4.8 to 6.8 times as much as nonexcessive drinkers on a per capita basis and would pay at least 72% of aggregate costs. For nonexcessive drinkers, the annual cost from even the largest hypothetical tax increase ($0.25 per drink) would average less than $10.00. Drinkers with higher household incomes and non-Hispanic white drinkers would pay higher per capita costs than people with lower incomes and racial/ethnic minorities.

CONCLUSION

State-specific tax increases would cost more for excessive drinkers, those with higher incomes, and non-Hispanic whites. Costs to nonexcessive drinkers would be modest. Findings are relevant to developing evidence-based public health practice for a leading preventable cause of death.

Factors relating to participation in follow-up to the 45 and up study in Aboriginal and non-Aboriginal individuals

Background

This study aimed to characterise the factors relating to participation in a postal follow-up study in Aboriginal and non-Aboriginal individuals, given the need to quantify potential biases from loss to follow-up and the lack of evidence regarding postal surveys among Aboriginal people.

Methods

The first 100,000 participants from the Sax Institute’s 45 and Up Study, a large scale cohort study, were posted a follow-up questionnaire gathering general demographic, health and risk factor data, emphasising Social, Economic and Environmental Factors (“The SEEF Study”). For each variable of interest, percentages of those invited who went on to participate in follow-up were tabulated separately for Aboriginal and non-Aboriginal participants and age- and sex-adjusted participation rate ratios (aPRR) were calculated.

Results

Of the 692 Aboriginal and 97,178 non-Aboriginal invitees to the study, 314 Aboriginal (45 %) and 59,175 non-Aboriginal (61 %) individuals responded. While Aboriginal people were less likely to respond than non-Aboriginal people (aPRR 0.72, 95 % CI 0.66–0.78), factors related to response were similar. Follow-up study participants were more likely than non-participants to have university versus no educational qualifications (1.6, 1.3–2.0 [Aboriginal]; 1.5, 1.5–1.5 [non-Aboriginal]) and an annual income of ≥70,000 versus < $20,000 (1.6, 1.3–2.0; 1.2, 1.2–1.3 [χ² = 7.7; p = 0.001]). Current smokers (0.55, 0.42–0.72; 0.76, 0.74–0.77 [χ² = 7.14; p = 0.03]), those reporting poor self-rated health (0.68, 0.47–0.99; 0.65, 0.61–0.69), poor quality of life (0.63, 0.41–0.97; 0.61, 0.57–0.66) and very high psychological distress (0.71, 0.68–0.75 [non-Aboriginal]) were less likely than other cohort members to respond.

Conclusions

Relatively large numbers of Aboriginal and non-Aboriginal individuals participated in the first 45 and Up Study follow-up suggesting that postal surveys can be used to follow Aboriginal participants in cohort studies. Despite somewhat greater loss to follow-up in Aboriginal people (after considering socio-demographic and health characteristics), factors related to follow-up participation were similar in both groups: greater loss was observed in those experiencing disadvantage, ill-health and health risk, with implications for interpretation of future findings. Aboriginal low income earners and current regular smokers had a particularly elevated likelihood of non-participation compared to non-Aboriginal people. These findings highlight the importance of identifying and addressing barriers to participation among hard-to-reach population groups.

Electronic supplementary material

The online version of this article (doi:10.1186/s12874-016-0155-x) contains supplementary material, which is available to authorized users.

Confounding and studies of 'moderate' alcohol consumption: the case of drinking frequency and implications for low-risk drinking guidelines

AIMS

Many observational studies suggest that increased drinking frequency is associated with reduced mortality among those with low-dose alcohol consumption. The purpose of this paper was to examine whether frequent drinkers consume lower-risk amounts during drinking days or have favorable risk factor profiles compared with those who drink less frequently, and discuss implications for the larger debate about the limitations of non-randomized studies about 'moderate' drinking and the development of low-risk drinking guidelines.

METHODS

Data from the 2008 Behavioral Risk Factor Surveillance System survey were used to characterize alcohol consumption characteristics and their relationship with risk factors among adult drinking men who consumed an average of fewer than two drinks per day and adult drinking adult women who consumed an average of less than one drink per day.

RESULTS

Those who drank relatively infrequently (14 or fewer days per month) consumed more during drinking days, were more likely to exceed the US Dietary Guidelines drinking limits (41.0% versus 9.7%) and had a larger proportion of drinking days that included binge drinking (13.4% versus 4.3%). Infrequent drinkers also had a higher prevalence of 13 of 15 risk factors assessed. Findings from analyses of those aged ≥40 years were similar.

CONCLUSIONS

Among those with low average alcohol consumption, infrequent drinkers drink more during drinking days and have unfavorable risk factors profiles compared with more frequent drinkers, suggesting that confounding may contribute to favorable associations with 'moderate' average alcohol consumption and increased drinking frequency observed in non-randomized studies.

Occupational status and incidences of ischemic and hemorrhagic stroke in Swedish men: a population-based 35-year prospective follow-up study

This study examined variations in stroke incidence across occupational classes over a 35-year follow-up period. We analyzed a random population-based sample of 6,994 men aged 47-56 years at baseline without prior history of stroke. Standardized incidence rates, subdistribution hazard ratios (SHRs) from competing risk regressions and cumulative incidence were calculated, after accounting for risk of death attributed to causes other than stroke. A total of 1,442 strokes were identified over the 35-year period with crude incidences of 5.50 (ischemic) and 1.16 (hemorrhagic) per 1,000 person-years. In the whole group, occupational class was not associated with either ischemic or hemorrhagic stroke. However, older men (≥51 years at baseline) with unskilled manual occupations had a significantly lower risk of ischemic stroke than those with high officials (referent). No association between occupation and stroke of either type was detected for men younger than 51 years. There was an inverse and graded risk of death from causes other than stroke; men in high official positions had the lowest cumulative risk and unskilled manual workers had the highest risk (P < 0.0001). The association between occupation and ischemic stroke in older men persisted after accounting for competing risks of death (SHR 0.62; 95 % CI 0.46-0.84). In conclusion, low socioeconomic status was not associated with an increased risk of incident hemorrhagic or ischemic stroke. Older men with the lowest occupational status i.e. unskilled manual had a significantly lower risk of ischemic stroke, even after controlling for other risk factors and competing risks of death.

The impact of a 25-cent-per-drink alcohol tax increase

BACKGROUND

Excessive alcohol consumption causes 79,000 deaths annually in the U.S., shortening the lives of those who die from it by approximately 30 years. Although alcohol taxation is an effective measure to reduce excessive consumption and related harm, some argue that increasing alcohol taxes places an unfair economic burden on "responsible" drinkers and socially disadvantaged people.

PURPOSE

To examine the impact of a hypothetic tax increase based on alcohol consumption and sociodemographic characteristics of current drinkers, individually and in aggregate.

METHODS

Data from the 2008 Behavioral Risk Factor Surveillance System survey were analyzed from 2010 to 2011 to determine the net financial impact of a hypothetic 25-cent-per-drink tax increase on current drinkers in the U.S. Higher-risk drinkers were defined as those whose past-30-day consumption included binge drinking, heavy drinking, drinking in excess of the U.S. Dietary Guidelines, and alcohol-impaired driving.

RESULTS

Of U.S. adults who consumed alcohol in the past 30 days, 50.4% (or approximately 25% of the total U.S. population) were classified as higher-risk drinkers. The tax increase would result in a 9.2% reduction in alcohol consumption, including an 11.4% reduction in heavy drinking. Compared with lower-risk drinkers, higher-risk drinkers would pay 4.7 times more in net increased annual per capita taxes, and 82.7% of the net increased annual aggregate taxes. Lower-risk drinkers would pay less than $30 in net increased taxes annually. In aggregate, groups who paid the most in net tax increases included those who were white, male, aged 21-50 years, earning ≥$50,000 per year, employed, and had a college degree.

CONCLUSIONS

A 25-cent-per-drink alcohol tax increase would reduce excessive drinking, and higher-risk drinkers would pay the substantial majority of the net tax increase.

Repeated attempts using different strategies are important for timely contact with study participants

OBJECTIVE

To study the effect of different mail- and phone-based strategies, along with patient- and research-related factors, on the time to contact with research participants.

STUDY DESIGN AND SETTING

A prospective evaluation of a 12-week standardized protocol (embedded with two randomized trials of mail- and phone-based strategies) for contacting existing research participants for recruitment into a related study.

RESULTS

Of 146 participants, 87 were eligible for contact via the standardized protocol, and 63 (72%) of these were successfully contacted within 12 weeks after multiple mail- and phone-based efforts. Using Cox proportional hazards regression analysis, the different mail and phone strategies showed no significant difference in the time to contact with participants. Of 34 patient- and research-related factors evaluated, only two were independently associated with time to contact among all 146 participants: (1) participants having their last visit conducted outside of the research clinic because of patient illness/condition had a longer time to contact and (2) those with a self-reported chronic fatigue history had a shorter time to contact.

CONCLUSION

Few patient characteristics and research-related factors accurately predict time to contact. Repeated attempts using different strategies are important for successful and timely contact with study participants.

Alcoholic intemperance, coronary heart disease and mortality in middle-aged Swedish men

High alcohol consumption is one of the major risk indicators for premature death in middle-aged men. An indicator of alcohol abuse--registration with the social authorities for alcoholic problems--was used to evaluate the role of alcohol in relation to general and cause-specific mortality in a general population sample. Altogether 1,116 men (11%) out of a total population of 10,004 men were registered for alcoholic problems. Total mortality during 11.8 years' follow-up was 10.4% among the non-registered men, compared to 20.5% among men with occasional convictions for drunkenness and 29.6% among heavy abusers. Fatal cancer as a whole was not independently associated with alcohol abuse, but oropharyngeal and oesophageal cancers together were seven times more common in the alcohol-registered groups. Total coronary heart disease (CHD) was significantly and independently associated with alcohol abuse, but nearly all the excess CHD mortality among the alcohol-registered men could be attributed to sudden coronary death. Cases with definite recent myocardial infarction were not more common in the alcoholic population. A combined effect of coronary arteriosclerosis and heart muscle damage secondary to alcohol abuse is suggested. Other causes of death strongly associated with registration for alcohol abuse include pulmonary embolism, pneumonia and peptic ulcer, as well as death from liver cirrhosis and alcoholism. Of the excess mortality among alcohol-registered subjects, 20.1% could be attributed to CHD, 18.1% to violent death, 13.6% to alcoholism without another diagnosis and 11.1% to liver cirrhosis.

Separate and combined effects of smoking and alcohol abuse in middle-aged men

Alcohol abuse is a major predictor of premature death, and also an independent risk factor for coronary death. Alcoholics are often heavy smokers. In a large primary prevention trial in middle-aged men with 7,495 participants, registration data were used to identify subjects with alcohol problems. Smokers had slightly lower blood pressure and were somewhat leaner than non-smokers, but had slightly higher serum cholesterol levels. Alcohol-registered subjects also tended to have lower blood pressure levels, and higher serum cholesterol. The relative risk of non-fatal myocardial infarction during the follow-up period of 11.8 years was essentially doubled in smokers compared to non-smokers, regardless of registration for alcohol problems. Among the non-alcoholic subjects, the relative risk of coronary death in smokers was double that of non-smokers, whereas the risk in non-smoking alcoholic subjects was not significantly increased. In smoking alcoholics the relative risk was substantially raised to 4.2 (3.0-7.0; 95% c.i.). In multivariate analysis both smoking and alcohol abuse were independently associated with coronary death. A possible mechanism might be through a combination of tobacco-induced coronary arteriosclerosis and the cardiotoxic effects of alcohol. As to total mortality, a smoking non-alcoholic man had a relative risk of dying almost double that of a non-alcoholic non-smoker. Among non-smoking alcoholics the risk was three times and, in smoking alcoholics over four times that of the non-alcoholic non-smokers.

Prevalence of cardiovascular risk factors and the metabolic syndrome in middle-aged men and women in Gothenburg, Sweden

Background

Random samples of 50-year-old men living in Gothenburg have been examined every 10^th year since 1963 with a focus on cardiovascular risk factors. The aims of the study were to acquire up-to-date information about risk factors in the fifth cohort of 50-year-old men and women, to re-examine those who were 50 years of age in 1993, and to analyse the prevalence of the metabolic syndrome (MetSyn) using different definitions.

Methods

A random sample of men and women born in 1953 were examined in 2003–2004 for cardiovascular risk factors. Men born in 1943 and that participated in the examination in 1993 were also invited. Descriptive statistics were calculated.

Results

The participation rate among men and women born in 1953 was 60 and 67% respectively. Among men born in 1943, the participation rate was 87%. The prevalence of obesity was from 15 to 17% (body mass index, BMI ≥ 30) in the three samples. The prevalence of known diabetes was 4% among the 50-year-old men and 6% among the 60-year-old men, and 2% among the women. Increased fasting plasma glucose varied substantially from 4 to 33% depending on cut-off level and gender. Mean cholesterol was 5.4 to 5.5 mmol/l. Smoking was more common among women aged 50 (26%) than among men aged 50 (22%) and 60 years (15%). The prevalence of the MetSyn varied with the definition used: from 10 to 15.8% among the women, from 16.1 to 26% among 50-year-old men, and from 19.9 to 35% among the 60-year-old men. Only 5% of the men and women had no risk factors.

Conclusion

This study provides up-to-date information about the prevalence of cardiovascular risk factors and the MetSyn in middle-aged Swedish men and women. Different definitions of the MetSyn create confusion regarding which definition to use.

Secular changes in cardiovascular risk factors and attack rate of myocardial infarction among men aged 50 in Gothenburg, Sweden. Accurate prediction using risk models

AIMS

Coronary risk factor changes were related to attack rate of acute myocardial infarction (AMI).

METHODS AND RESULTS

Cross-sectional population samples of 50-year-old men were examined every 10th year from 1963 to 2003. Attack rates of AMI were recorded from 1975 to 2004. Prevalence of smoking decreased from 56% in 1963 to 22% in 2003. Leisure time physical activity decreased (n.s.), while psychological stress remained the same. Diabetes prevalence increased from 3.6% to 6.6%. Body mass index (BMI) increased from 24.8 to 26.4 kg m(-2). Blood pressures decreased from 138.2/90.6 to 134.7/84.9 mmHg (P = 0.00001). Serum total cholesterol decreased from 6.42 to 5.50 mmol L(-1) (P = 0.0001), but serum triglycerides increased from 1.26 to 1.71 mmol L(-1) (P = 0.0001). The multivariable risk according to total cholesterol, blood pressure and smoking for AMI decreased from the set value 1.0 in 1963 to 0.418. From 1975-1979 to 2000-2004 attack rates for AMI for the age groups 35-44, 45-54 and 55-64 declined to 45%, 46% and 45%, respectively. The 28-day case fatality declined from 30%, 38% and 46% to 12%, 16% and 20%.

CONCLUSION

The more than 50% decline in attack rate of AMI during 30 years was comparable with the decline in risk factors.

Loss to follow up did not bias associations between early life factors and adult depression

OBJECTIVE

This study examines the consequences of nonresponse in a follow-up survey for the associations of early life factors with adult depression.

STUDY DESIGN AND SETTING

A cohort of 11,532 Danish men born in 1953 had nearly complete follow up for outcomes retrieved from the Danish Psychiatric Register and the National Prescription Register, but only 66% of 9,507 eligible cohort members participated in a follow-up survey in 2004. We examined whether characteristics measured at birth and at ages 12 and 18 years, were associated with survey response. Associations between early life characteristics and four measures of depression were described by odd ratios (OR), estimated by logistic regression. For the register-based measures the effect of nonresponse was described by a relative OR(OR(responders)/OR(entire cohort)=ROR).

RESULTS

Nonresponse at 50 years of age was related to having a single mother at birth, low educational attainment at age 18, and low cognitive function at ages 12 and 18. Hospitalizations for depression and having claimed a prescription for an antidepressive drug were also most frequent among men who did not respond in the follow up. However, the effect of this nonresponse on the estimated ORs was small, and all ROR were nonsignificant.

CONCLUSION

Although early life characteristics were related to response in a follow-up survey, the ORs for the exposure-risk associations were not biased by nonresponse.

Non-participation and mortality in different socioeconomic groups: the FINRISK population surveys in 1972-92

BACKGROUND

Declining response rates pose a serious threat to the validity of estimates derived from epidemiological studies. If respondents and non-respondents differ systematically from each other, there can be a bias in the results of the study. A population-based cohort study was conducted to investigate disparities in socioeconomic structure between respondents and non-respondents and the contribution of these disparities to socioeconomic differences in total and cardiovascular mortality.

DESIGN

Data comprised 32,354 male and female participants and 4890 non-participants aged 35-74 years who belonged to the sample in one of the five FINRISK surveys in 1972, 1977, 1982, 1987 or 1992 in Finland. They were followed up for 9 years and 6 months.

RESULTS

It was found that the lower socioeconomic groups were over-represented among non-respondents both in men and women. When comparing the relative risk of death using the highest socioeconomic group of the participants as the reference group, it was found that although the socioeconomic gradient was similar for participants and non-participants-that is, lower groups had a higher risk of death-the risk was at a higher level among non-respondents.

CONCLUSIONS

Basing analysis on participants does not distort the relative risk of death associated with socioeconomic position. However, it does underestimate the absolute risk.

Representativeness in population-based studies: a detailed description of non-response in a Danish cohort study

BACKGROUND

Decreasing rates of participation in population-based studies increasingly challenge the interpretation of study results, in both analytic and descriptive epidemiology. Consequently, estimates of possible differences between participants and non-participants are increasingly important for the interpretation of study results and generalization to the background population.

METHODS

An age-specific, population-based cohort of 1,198 individuals was examined at age 40, 45, 51, and 60. Participants were compared with non-participants and when possible also with the background population using a wide range of detailed information on somatic and mental health collected at each examination, including data from a clinical examination, biochemical measurements, questionnaires, interviews, and public registers.

RESULTS

Participation rates were higher than 80% at examinations at age 40, 45, and 51, but decreased to 65% at age 60. At the baseline investigation at age 40, analyses indicated that participants were representative of the cohort as well as the background population. However, the mortality rate was higher among non-participants in the succeeding 20 years. Among living cohort members at the 60-year examination, non-participants had lower socioeconomic status, higher hospitalization rate, and a worse overall health profile than participants.

CONCLUSIONS

The detailed data presented reinforce the contention that the health profile of non-participants is typically worse than that of participants. The results also indicate that while data from public registers give easily accessible information about non-participants, these crude proxy measures of health may not be enough to document representativeness.

Seasonality of psychopathology and circannual melatonin rhythm

The association of seasonal changes in health and disease has been known for centuries. The prevalence of psychopathological symptoms with seasonal fluctuations and the use of melatonin as a biological marker of circadian and circannual rhythms is well documented. The aim of this work was to study the variability of melatonin secretion between summer and winter in our geographical area (28 degrees N, 16 degrees W) and relate the changes to the level of psychopathology. Ten drug-free, nonsmoker, healthy subjects were studied in summer (August) and winter (December). Blood samples for melatonin assays were collected every hour at night for 5 hr, from 22:00 to 02:00 hr, and next day at noon. Melatonin was assayed by an ELISA technique. Psychopathology was evaluated by means of the 28-item version of the General Health Questionnaire (GHQ-28). All subjects had a circadian rhythm of melatonin secretion in summer and winter. There was a seasonal rhythm with melatonin levels being significantly higher at night in winter than in summer. Melatonin levels at 22:00, 23:00, 24:00 and 01:00 hr and mean melatonin area under the curve (AUC) were significantly higher in winter than in summer. Melatonin AUC increased 80% in winter compared with summer. The GHQ-28 somatic and anxiety subscales and the total GHQ-28 score were significantly higher in winter than summer. Psychopathology scores were significantly and negatively correlated with melatonin production in summer and winter. Our data strongly suggest that melatonin production and psychopathology levels present seasonal fluctuations and these variations should be taken into account when conducting research in this field.

Health, quality of life, social network and use of health care: a comparison between those granted and those not granted disability pensions

PURPOSE

The aim was to compare self-rated health, health-related quality of life (HRQoL), social networks and health care utilisation of those granted disability pension (DP) and those not granted disability pension (nDP).

METHOD

Demographic data and medical diagnoses were obtained from the records of the social insurance office. Data concerning self-reported health, HRQoL social networks, and use of health care were collected by a postal questionnaire. The nDP group included all those not granted full DPs between 1999 and 2000 (n = 99). The DP group were a random sample of those granted full DPs, during the same period (n = 197).

RESULTS

The nDP group had more often multiple diagnoses, and lower self-reported health and HRQoL compared to those granted DP. In particular, their average scores were lower on the SF-36 scales social functioning, role limitations due to physical problems and mental health. The nDP group also had significantly smaller social networks.

CONCLUSIONS

Contrary to expectations, those not granted a disability pension do not seem to have better health, but rather to suffer from more sickness than those who were granted a disability pension.

Total and cause specific mortality among participants and non-participants of population based health surveys: a comprehensive follow up of 54 372 Finnish men and women

STUDY OBJECTIVE

To assess total and cause specific mortality among participants and non-participants of large population based health surveys.

DESIGN

A prospective follow up study. Baseline surveys were conducted in 1972, 1977, 1982, 1987, and 1992. Study end points were overall, cardiovascular, cancer and violent mortality, and deaths related to smoking and alcohol. Study cohorts were followed up until the end of 2000 through computerised record linkage. All analyses were adjusted for age.

SETTING

Finland.

PARTICIPANTS

Participants and non-participants of five population based risk factor surveys. The samples included 54 372 men and women aged 25 to 64 years at baseline.

MAIN RESULTS

The average participation rate was 81.7% among men and 87% among women. At eight year follow up, the non-participating men had twice and non-participating women 2.5-fold higher overall mortality than the participating men and women. Non-participants had also significantly higher cause specific mortality, except cancer and smoking related mortality among women. Relative differences in mortality were largest in violent and alcohol related deaths. Non-participants had considerably higher overall mortality than smoking participants, and their mortality was threefold compared with non-smoking participants.

CONCLUSIONS

Observed differences in mortality show that health behaviour and health status substantially differ between non-participants and participants. Low participation rate may considerably bias the results of population based health surveys.

Population characteristics in cervical cancer trials: search for external validity

OBJECTIVE

The purpose of this study was to compare the characteristics of patients with cervical cancer who were enrolled in cooperative group trials with characteristics of the cervical cancer population of the United States and to determine the generalizability of the results of those trials to the disease population in the United States.

STUDY DESIGN

Phase III trials in cervical cancer that were conducted by cooperative groups in the United States from 1981 through 1997 were identified. These groups were placed into 4 categories on the basis of disease stage and primary treatment modality: Stage IB, negative pelvic nodes that were treated with radical hysterectomy (n = 277 patients); Stage IB-IIA, positive pelvic nodes that were treated with radical hysterectomy (n = 239 patients); Stage IB 2 , negative pelvic and para-aortic nodes that were treated with radiation therapy (n = 369 patients); and Stage IIB-IVA, negative para-aortic nodes that were treated with radiation therapy (n = 1190 patients). For each category, comparable patients from the Surveillance, Epidemiology, and End Results (SEER) database were identified. The age and ethnic distributions of each study population and the distributions of the SEER program were compared.

RESULTS

The age distributions were equivalent, except for patients with IB 2 disease that was treated with radiation therapy where cooperative group subjects were more likely to be younger than 50 years, (odds ratio, 0.17; 95% CI, 0.11-0.26). A statistically significant higher proportion of black and Hispanic women enrolled in cooperative group studies in comparison with surveillance, epidemiology, and end results.

CONCLUSION

Hispanic and black women were recruited proportionately to cooperative group randomized cervical cancer trials in comparison to the United States population. The age distribution of the clinical trial population is also comparable to that of the general population.

Non-participants in a preventive health examination for cardiovascular disease: characteristics, reasons for non-participation, and willingness to participate in the future

OBJECTIVE

To describe the non-participants in a preventive health examination for cardiovascular diseases and their reasons for not participating.

DESIGN

A preventive health examination, self-administered questionnaire, and telephone interview.

SETTING

A municipality of 6200 inhabitants in the middle of Sweden.

SUBJECTS

309 persons, 35 or 40 years of age, invited to participate in a health examination.

MAIN OUTCOME MEASURES

Reasons for non-participation, willingness to participate in future health examinations, and smoking.

RESULTS

The most important reason for non-participating was lack of time or hindrances at work (52%). Other important reasons were already being in contact with the health services (33%) and feeling quite healthy at present (21%). Over half of the non-participants (55%) would be willing to participate in a similar health examination in the future. The proportion of smokers was significantly higher among the non-participants than among the participants in the health examination (31.3% and 18.6% respectively).

CONCLUSION

More than half of the non-responders were willing to participate in a similar health examination in the future. If special measures to encourage participation in preventive health examinations were undertaken, it would not be unrealistic to aim for a participation rate of nearly 90%.

Serum lipids in fathers and sons at middle age: the study of sons to men born in 1913

OBJECTIVE

To relate lipid levels in middle-aged men to that of their fathers at 50 years of age measured 30 years earlier.

DESIGN AND SUBJECTS

In 1963, 855 men born in 1913 took part in a cardiovascular risk factor survey when they were at 50 years of age. In 1993, 475 sons to these men, aged 44-56, were invited to another examination; 263 of these men were examined (response rate: 56%) and compared with their 217 fathers when they were examined at 50 years of age in 1963. In the 1993 survey, 798 men aged 50, were also examined, from a general population sample of men born in 1943 (response rate: 55%).

SETTING

City of Göteborg, Sweden.

MAIN OUTCOME MEASURES

Serum lipids in sons as a function of lipids in their fathers.

RESULTS

Compared with the men born in 1913, both sons and men born in 1943 had lower mean serum cholesterol, but higher body mass index (BMI) and serum triglycerides. There was a significant relation between serum cholesterol in sons and their fathers (r = 0.25; P < 0.0001). Amongst sons to fathers in the highest cholesterol quartile (>6.9 mmol x L(-1)), 37% had serum cholesterol above 6.5 mmol x L(-1), compared with 16% amongst sons to fathers in the lowest quartile (<5.7 mmol x L(-1)) [adjusted odds ratio 3.73 (1.52-9.12)]. Sons to fathers with the highest serum cholesterol levels had slightly lower BMI; otherwise there was no relation between serum cholesterol in the father and any other lifestyle or biological risk factor in the sons. Serum triglyceride concentration in the father was unrelated to any variable in the son.

CONCLUSIONS

There was a moderately strong association between serum cholesterol concentration in fathers and sons at middle age. However, secular trends were also important in determining serum cholesterol concentrations in those born at a later period, indicating a major role of environmental factors.

Invitation to a population-based cohort study: differences between subjects recruited using various strategies

AIM

The present study compares subjects recruited to a population-based prospective cohort study by community versus personal invitation, and subjects responding late versus early to personal invitation. Subjects were compared with respect to sociodemographic characteristics, selected lifestyle factors, cancer incidence and mortality.

METHODS

The Malmö Diet and Cancer Study recruited a total of 28,098 subjects between 1991 and 1996. Entire birth-year cohorts, born 1923-50, were recruited using community directed (passive) invitation, and a personal letter of invitation (active recruitment). Information on sociodemography and lifestyle was obtained using a self-administered questionnaire. Anthropometric measurements were assessed at a physical examination. Cancer incidence and cause of death were retrieved using record linkage with national registries.

RESULTS

Subjects responding to community directed invitation were older, and more often females, than participants recruited using personal invitation. Furthermore, participants recruited through passive invitation had a comparably more favourable situation with regard to sociodemographic and lifestyle factors. They also had a lower frequency of prevalent disease, lower incidence of cancer and lower mortality. Contrary to this, men were more likely to respond late to a personal letter of invitation and late responders were also older, as compared with subjects responding early to personal invitation. Furthermore, those who responded late had a comparatively unfavourable socioeconomic situation and were characterized by a high prevalence of current smoking, obesity, weight change, and prevalent disease.

CONCLUSIONS

Subjects who are recruited using different strategies in population-based cohort studies may have different sociodemographic and lifestyle characteristics, and may vary with regard to prevalent disease, cancer incidence and subsequent mortality.

The Malmö Diet and Cancer Study: representativity, cancer incidence and mortality in participants and non-participants

In order to investigate potential selection bias in population-based cohort studies, participants (n = 28098) and non-participants (n = 40807) in the Malmö Diet and Cancer Study (MDCS) were compared with regard to cancer incidence and mortality. MDCS participants were also compared with participants in a mailed health survey with regard to subjective health, socio-demographic characteristics and lifestyle. Cancer incidence prior to recruitment was lower in non-participants, Cox proportional hazards analysis yielded a relative risk (RR) with a 95% confidence interval of 0.95 (0.90-1.00), compared with participants. During recruitment, cancer incidence was higher in non-participants, RR: 1.08 (1.01-1.17). Mortality was higher in non-participants both during, 3.55 (3.13-4.03), and following the recruitment period, 2.21 (2.03-2.41). The proportion reporting good health was higher in the MDCS than in the mailed health survey (where 74.6% participated), but the socio-demographic structure was similar. We conclude that mortality is higher in non-participants than in participants during recruitment and follow-up. It is also suggested that non-participants may have a lower cancer incidence prior to recruitment but a higher incidence during the recruitment period.

The use of analgesics and hypnotics in relation to self-rated health and disability pension — A prospective study of middle-aged men

Aims: This cohort study on urban middle-aged men investigates the association between the use of analgesics and hypnotics, self-rated health (SRH) and disability pension. Methods: Five birth-year cohorts of middle-aged, urban, Swedish men were invited to a screening programme and were followed for approximately 11 years. Results: Out of all the subjects ( n=5798), 12.4% received a disability pension during follow-up, 27.0% rated their health as less than perfect, 10.6% used analgesics and 2.9% used hypnotics. Compared with non-users of analgesics and hypnotics, the adjusted hazard ratio of disability pension for the simultaneous use of both drugs was 7.0 (95% CI: 4.3, 11.6) and the adjusted odds ratio of poor SRH was 16.5 (6.3, 43.5). Thus, the use of analgesics and hypnotics was positively related to poor SRH and predicted award of a disability pension within an 11-year follow-up. This may reflect that the use of analgesics and hypnotics is a proxy of disease but an independent negative effect on health cannot be excluded. Conclusions: Information on the use of these drugs could be used to predict the award of a disability pension, such as in different geographical areas or population groups.

Prevention of cardiovascular disease and diabetes: lessons from the Malmö Preventive Project

Major public health problems such as cardiovascular disease and type 2 diabetes pose a challenge to both the medical profession and the health care system of most Western countries. In spite of widespread knowledge about risk factors and pathophysiological processes, it has been difficult to find effective preventive mass strategies based on evidence from controlled clinical trials. In the Malmö Preventive Project, Sweden, 33 346 subjects were screened for risk factors between 1974 and 1992, and a quarter of them were offered preventive help for cardiovascular disease risk or alcohol abuse. The overall finding of the project was that benefits of screening and prevention on mortality risk could only be shown in certain subgroups of younger men and women, not in the total screened cohort, as compared with a nonscreened reference population. These findings therefore question the effectiveness of preventive methods and drugs used during previous decades. New preventive methods are therefore needed and should be properly evaluated to form a basis for evidence-based prevention (EBP) in cardiovascular medicine.

Dyslipidaemia and impaired well-being in middle-aged women reporting low Sense of Coherence. The Women's Health in the Lund Area (WHLA) Study

OBJECTIVE

A low Sense of Coherence (SOC) is a concept related to a feeling of ill health. Not much is known about possible relationships between SOC and biological factors.

SETTING

Population-based study of middle-aged women.

SUBJECTS AND METHODS

Four-hundred-and-fifty women participated as a subgroup of a larger study of cardiovascular risk factor screening. A self-administered questionnaire with 29 questions related to SOC was completed in addition to questions on social background factors and medical history.

RESULTS

The mean score of SOC was 150.9 (SD 23.4). HDL cholesterol was lower (p < 0.05) and triglyceride levels higher (p < 0.05) in women with low SOC (1.5 and 2.1 mmol/L) compared to women with medium (1.8 and 1.4 mmol/L) or high SOC (1.7 and 1.5 mmol/L). In multiple regression analysis, a low HDL cholesterol level was still significantly associated with low SOC (p < 0.05) after adjustment for possible confounders. Women reporting low SOC were further characterised by a higher proportion of subjects with regular clinical visits for health care (49% vs 35% and 29%).

CONCLUSIONS

Middle-aged women reporting low SOC showed lower HDL cholesterol and higher triglyceride levels, and reported more clinical visits and medical symptoms than women with higher SOC.

Long-term outcome of the Malmö preventive project: mortality and cardiovascular morbidity

OBJECTIVES

To analyse the effects on mortality and cardiovascular morbidity in a population-based sample, invited to an intervention programme incorporating a baseline screening examination and treatment programmes for subjects with cardiovascular risk factors, high alcohol intake and, in women, suspicion of breast cancer on mammography.

SETTING

Section of Preventive Medicine, Department of Medicine, University Hospital, Malmö, Sweden.

SUBJECTS

Birth cohorts (aged 32-51 years) invited to screening examination (men = 9. 923; women = 4.422) were compared to birth cohorts not invited (men = 6.655; women = 4.290). Mean participation rate in the invited cohorts was 71% (range 64-78%). SCREENING EXAMINATION: Between 1974 and 1992 a baseline screening including a physical examination, blood pressure, a questionnaire regarding, e.g. family history, lifestyle, and socio-economic factors, laboratory tests of serum cholesterol, triglycerides, gamma-glutamyl-transferase, blood glucose before and after an oral glucose load, as well as a mammography examination in women, was performed.

INTERVENTIONS

Subjects with hypertension; hyperlipidaemia; diabetes or glucose intolerance; high alcohol intake; or, in women, suspicion of breast cancer were referred to special outpatient clinics.

MAIN OUTCOME MEASURES

Total and cause-specific mortality, nonfatal myocardial infarction, and stroke, from the screening examination until the end of 1995, was followed in both the intervention and control groups, using national and/or local registries.

RESULTS

Total mortality did not differ significantly between the intervention group and control group. Cause-specific deaths were also similar except for 'other' deaths amongst men being significantly lower in the intervention group, mainly due to a lower mortality from 'other' causes (suicide, alcohol related deaths) in men under 40 years of age at baseline. Women under 40 years of age had a significantly lower mortality from cancer in the intervention group than in the control group. Nonfatal myocardial infarction and stroke did not differ between intervention and control group in either sex. Within the invited birth cohorts, nonparticipants had a higher total and cause-specific mortality.

CONCLUSIONS

Risk factor screening for major diseases such as cardiovascular disease, alcohol abuse, diabetes mellitus and breast cancer, and subsequent treatment of the detected risk factors/diseases - The Malmö Preventive Project - did not reduce total mortality in the intervention group as a whole. In subjects under 40 years of age at entry, total mortality was lower in the intervention group than in the control group. In men, this seemed to be due to a reduction of alcohol-related deaths, whilst in women death from cancer was reduced.

Secular changes in cardiovascular risk factors over 30 years in Swedish men aged 50: the study of men born in 1913, 1923, 1933 and 1943

OBJECTIVES

To study secular trends in cardiovascular risk factors in men aged 50 over a period of 30 years.

DESIGN

Cross-sectional studies of successive cohorts of men from 1963 to 1993.

SETTING

City of Göteborg, Sweden.

SUBJECTS

Four random population samples of men born in 1913, 1923, 1933 and 1943, aged 50 when they were examined in 1963, 1973, 1983, and 1993 (n = 855, 226, 776, and 798, respectively).

MAIN OUTCOME MEASURES

Anthropometric measurements, blood pressure, serum cholesterol and triglycerides and smoking habits over three decades.

RESULTS

Over 30 years, men increased in weight from a mean (SD) of 75.9 (11.0) kg to 82.8 (12.1) kg and gained 3.4 cm in height, with a net increase in body mass index from 24.8 (3.2) to 26.0 (3.4) kg m-2 (P < 0.0001), and a concomitant increase in waist circumference. The proportion of men who were overweight but not obese (BMI = 25-30 kg m-2) increased from 38 to 47%, whereas the prevalence of frank obesity (more than 30 kg m-2) increased from 6% in 1963 to 11% in 1993. Despite the increase in weight, mean systolic blood pressure fell by almost 10 mmHg (P < 0.0001). Mean serum cholesterol concentration decreased from 6.42 (1.12) to 5.88 (1.04) (P < 0.0001). Serum triglycerides increased from 1.26 (0.77) to 1.69 (1.04) mmol L-1 (P = 0.001). The proportion of men who smoked decreased from 56% in 1963 to 30% in 1993 (P < 0.0001). This was due more to an increase in smoking cessation rates than to an increase in the proportion of men who had never smoked. In particular, smokers and former smokers are now more obese than the corresponding categories 30 years ago and smokers are no longer leaner than men who have never smoked.

CONCLUSIONS

Over a period of 30 years, serum cholesterol as well as systolic blood pressure and the prevalence of smoking decreased. This favourable decline in coronary risk factors was offset by an appreciable increase in body mass index and waist circumference.

Alcohol consumption and disability pension among middle-aged men

PURPOSE

To analyze the relation between alcohol consumption and the risk of disability pension among middle-aged men.

METHODS

In the mid-seventies, complete birth-year cohorts of middle-aged male residents in Malmö, Sweden, were invited to participate in a general health survey. The 3751 men with complete data who constituted the cohort in this study were followed for 11 years. Alcohol consumption was estimated from the scores obtained from a test designed to identify subjects with alcohol related problems.

RESULTS

Of the 498 men granted disability pension during follow-up, 48 stated to be teetotalers. The cumulative incidence of disability pension among teetotalers was 19%, whereas, it was 12% and 16%, respectively, among men with low and high alcohol consumption. The adjusted relative risk (RR) for acquiring a disability pension (using the group with low alcohol consumption as reference) was 1.8 among abstainers and 1.3 among men with high alcohol consumption.

CONCLUSIONS

Alcohol overconsumption, as well as teetotalism, showed a positive relation to disability pension, and a moderate alcohol intake was found to be beneficial with respect to the risk of future disability pension.

Natural history of myocardial infarction and angina pectoris in a general population sample of middle-aged men: a 16-year follow-up of the Primary Prevention Study, Göteborg, Sweden

OBJECTIVES

Although many studies have described prognosis in patients with coronary heart disease (CHD), few have compared outcome in men with clinical evidence of CHD with healthy men from the general population over an extended follow-up. This study aimed to compare long-term prognosis in men with a history of myocardial infarction (MI) and in men with angina pectoris (AP) without MI, with men without clinical signs of CHD.

DESIGN

Longitudinal general population study.

SETTING

City of Göteborg, Sweden.

SUBJECTS

From a general population sample, 195 men who had survived an MI for 0-19 years (median 3 years) and 314 men with AP but no MI (uncomplicated AP) at baseline in 1974-77 were identified and compared with 6591 men without clinical coronary disease. All were aged 51-59 years. Incident non-fatal and fatal cases occurring until the beginning of 1983 were also followed (n = 317).

MAIN OUTCOME MEASURES

Death from CHD, from other causes and from all causes during a follow-up of at least 16 years.

RESULTS

Overall survival was 72% amongst men without coronary disease, 53% amongst men with uncomplicated AP and 34% amongst men with past MI at baseline. In survivors of MI the risk-factor-adjusted relative risk (RR) of coronary death during follow-up was 6.67 (95% confidence interval (CI) 5.29-8.39), of dying from non-cardiovascular causes 1.35 (0.96-1.91), and of dying from any cause 3.20 (2.67-3.83). During the first 4 years after the baseline examination, the adjusted RR of CHD death was 15.96 (10. 29-24.74), and of dying from any cause 5.22 (3.68-7.41). During the last 4 years of follow-up, relative risk was still 5.87 (3.44-10.01) for CHD death and 2.93 (2.05-4.18) for death from any cause. In men with uncomplicated AP, the adjusted relative risk of CHD death during the first 4 years was 4.05 (2.27-7.22) and 3.23 (2.10-4.96) during the last 4-year period. After the first year, the incident MI cases had the same average annual mortality (about 5%) as the prevalent cases.

CONCLUSIONS

In survivors of MI, mortality risk remained high even after an extended follow-up. Men with angina had a better prognosis, but still a compromised survival compared with the general population.

Socioeconomic differences in health indices, social networks and mortality among Swedish men. A study of men born in 1933

BACKGROUND

In previous survey we found large socioeconomic differences in mortality among urban Swedish men which remained unexplained after controlling for smoking and standard coronary risk factors. The present analysis was undertaken in order to investigate a broader set of possible explanatory factors in another cohort of Swedish men.

STUDY POPULATION AND METHODS

Occupation was coded into five occupational classes for 717 of 776 participant men from a random population sample of 1016 men who were born in 1933. All were living in Göteborg and were 50 years old at the baseline examination. After 12 years' follow-up, 68 of the 717 men had died (9.5%).

RESULTS

Low occupational class was associated with a higher prevalence of smoking at baseline, but no association was found with systolic blood pressure, body mass index, waist to hip ratio, serum triglycerides or serum cholesterol. Subjects from higher socioeconomic strata were taller, had higher maximum peak respiratory flow, lower plasma fibrinogen and lower body temperature. Low occupational class was associated with low social integration, low home activity levels, low levels of activity outside home and low social activity levels (p = 0.001 for all) and with low emotional support (p = 0.018). There were also associations between low occupational class and poor self-perceived health, as well as with several cardiovascular symptoms. During 12 years' follow-up, there was a graded and inverse relationship between occupational class and mortality from all causes. The highest mortality was found among the men who could not be classified (23 per 1,000 person years) Of the men in the lowest occupational class, 12 per 1,000 died, compared to 3 per 1,000 in the highest class (relative risk 3.7 (1.4-9.8)). After controlling for smoking, the relative risk decreased to 3.2 (1.2-8.6) and after further adjustment for emotional support, self-perceived health, activity level at home, and peak expiratory flow, the relative risk was still twofold but not significantly so (RR 2.1 (0.8-5.8)).

CONCLUSION

We were able to confirm earlier results as to the wide mortality differentials in urban middle-aged men in Sweden. There were also large differences in several other factors, including constitutional factors, health variables, lifestyle and social support indices, which explained important parts of the social mortality gradient, the most prominent being smoking, respiratory function, social network factors and subjective health.

A comparison of mortality rates in three prospective studies from Copenhagen with mortality rates in the central part of the city, and the entire country. Copenhagen Center for Prospective Population Studies

Valid generalizations of results from population-based epidemiological surveys requires knowledge about how representative the sample is. The Copenhagen Center for Prospective Population Studies have assessed mortality on the basis of pooled data from three research programmes in the region of Copenhagen. In two of the studies, subjects were randomly selected, using the Danish Central Population Registry, within certain age groups and area-restricted sectors of the Greater Copenhagen. In the third study, men employed in 14 companies participated. Participation rates were between 78% and 87% in the three programmes. Standardized mortality rates (SMR) were calculated in relation to mortality rates in the municipality of Copenhagen and in the whole country in three age groups and the two genders. SMR values in the whole sample including non-participants were similar to rates for Copenhagen in the Copenhagen City Heart Study, whereas mortality rates in the Glostrup Population Studies were similar to rates for the whole country. The mortality rates among participants were lower than in the whole sample, and differences existed in relation to region and selection criteria of the cohorts. The Copenhagen Male Study, where only employed men were included, showed the lowest mortality rates, and higher rates were found in the study from the central part of the City (the Copenhagen City Heart Study) compared to the study from the suburbs (the Glostrup Population Studies). The difference between mortality rates in the cohorts and in Copenhagen City decreased with increasing age. The SMR converged towards 1.00 with increasing observation time. In conclusion, high participation rates were found in all three studies, resulting in SMR values for participants only slightly lower than in the source population in the two randomly selected samples, but 30% lower values in the sample of employed men. As mortality rates in the total samples including non-participants were markedly higher than among the participants, generalizations of results for participants to the whole population should be made with caution, especially during the first years of observation.

The Prospective Population Study of Women in Gothenburg, Sweden, 1968-69 to 1992-93. A 24-year follow-up study with special reference to participation, representativeness, and mortality

OBJECTIVE

To describe the fourth phase of the Prospective Population Study of Women in Gothenburg, Sweden, with special reference to participation and survival.

DESIGN

Prospective population study.

SETTING

City of Gothenburg with about 430,000 inhabitants.

PARTICIPANTS

1462 participants and 128 refusers aged 38-60 years at the time of the initial study in 1968-69, 282 women who were sampled but not invited to the study in 1968-69, and 266 women participating since 1980-81 and 32 women for the first time in 1992-93.

MAIN OUTCOME MEASURES

Participation rate, survival, anthropometric and metabolic characteristics.

RESULTS

The participation rate throughout the study period was high. The participants were mainly characteristic of women of the same ages in the general population even after 24 years. The mortality after 24 years was higher in non-participants than in participants, while there was no difference in survival between women who were invited and women who were not invited to the study.

CONCLUSIONS

The initial participants were mainly characteristic of the general population, also after a long follow-up period. The long-term survival was lower in initial refusers than in initial participants.

Underestimation of the true benefits of antihypertensive treatment: an assessment of some important sources of error

The treatment of arterial hypertension is based on results from several large prospective randomized intervention trials that demonstrated significant benefits from antihypertensive therapy in terms of reduced cardiovascular morbidity and mortality, mainly from strokes, but also from myocardial infarction, congestive heart failure and other vascular or renal complications. Nonetheless, it is obvious that such studies, for a number of reasons, underestimate the true benefit of lowering elevated arterial pressure. Active treatment given to patients allocated randomly to be administered placebo is an important factor, particularly since active treatment is given preferentially to the placebo patients with the highest risk. Recruitment of low-risk patients into studies is another reason for the underestimation of benefit. Moreover, significant loss of patients to follow-up plays a role. Two recent epidemiological surveys, in Framingham and Göteborg, showed markedly beneficial blood pressure-related changes in those populations, suggesting that the long-term effects of antihypertensive therapy may in fact have been underestimated by intervention studies

Characteristics of non-participants and reasons for non-participation in a population survey in Kin-Hu, Kinmen

The aim was to characterize non-participants and to investigate reasons for non-participation in a health survey in Kin-Hu township, Kinmen, Republic of China. The non-participants represented 25.6% of the target population of 4,451 registered residents aged 30 and older. Baseline demographic characteristics and two-year mortality for the participants and non-participants were compared. A house-to-house visit was attempted to all of the non-participants for reasons of refusal. The mean age of the non-participants was significantly older than that of the participants (54.3 versus 48.5 years, p < 0.001). The response rate for women was significantly higher than that for men (77.2% versus 71.6%, p < 0.001). The probability of death was significantly different between the two groups (1.2% versus 8.8% for participants and non-participants, respectively, p < 0.001). Major reason for not having participated in the health survey was 'not notified or informed of the examination' (32.7%). These data suggest that non-participants were less healthy.

Physical activity protects against coronary death and deaths from all causes in middle-aged men. Evidence from a 20-year follow-up of the primary prevention study in Göteborg

We set out to examine the long-term effect of work-related and leisure time physical activity on risk of death from coronary heart disease (CHD) and other causes. Data were obtained from a large prospective population study of 7142 participant men aged 47 to 55 years at baseline in 1970-1973 and without symptomatic CHD. Data on physical activity at work and at leisure were assessed by way of a questionnaire. After 20 years follow-up men with physically demanding work had a slightly higher mortality from all causes, but not from CHD. The association with all-cause mortality disappeared after controlling for smoking, occupational class, and alcohol abuse. Men who were physically active during leisure time had a lower risk of death from CHD, cancer, and all causes. After controlling for smoking, diastolic blood pressure, serum cholesterol, body mass index, diabetes alcohol abuse, and low occupational class, the most active men had a relative risk (RR) of dying from CHD of 0.72 (0.56-0.92 95% CI) and of all causes of 0.70 (0.61-0.80 95% CI). The adjusted relative risk for cancer death was of borderline significance. Noncardiovascular deaths other than cancer showed a strong relationship with low physical activity in the present study that remained after controlling for smoking, alcohol abuse, and other factors (adjusted RR 0.55 (0.42-0.73 95% CI)). The protective effect of CHD and on mortality was present after excluding the first 8 years of follow-up, and at all levels of other risk factors, such as smoking, diastolic blood pressure, serum cholesterol, and body mass index. In conclusion, this long-term study demonstrates the protective effect of leisure time physical activity on CHD death, cancer death, and on death from all causes. The effect on coronary death and on death from all causes was independent of other risk factors.

Alcohol consumption and regular benzodiazepine use in 55-year-old female Malmö residents: results of a health screening

The main objective of the present study was to examine the relationship between regular benzodiazepine (BZD) use and drinking patterns in 55-year-old female residents of Malmö, Sweden. All women born in 1935 (a total of 1223 subjects) were invited to a health screening at the Preventive Medicine Section, Malmö General Hospital; 69% agreed to participate. The screening included an extensive health questionnaire, and the responses to 33 items assessing social background, including immigrant status, use of BZD and analgesics, alcohol consumption (the revised Malmö-MAST), smoking and morbidity were analysed. A psychiatric symptoms scale including five of these items was constructed, yielding a Cronbach's alpha of 0.57. Present use of BZD hypnotics and/or tranquillizers was acknowledged by 6% of the women. BZD use at any time in the past or present was endorsed by 23%. Endorsement of > or = 3 revised Malmö-MAST items, indicating problem drinking, occurred in 3% of the participants; 16% were teetotallers and about 25% were regular weekend drinkers. BZD use was significantly more likely to occur in women with the following characteristics: early retirement, pain symptoms, longstanding use of analgesics, multiple psychiatric symptoms. Drinking patterns in relation to BZD use indicated that regular weekend drinkers were significantly less likely to be current and/or previous BZD users than problem drinkers and teetotallers. Logistic regression analyses indicated that use of BZDs was mainly predicted by endorsement of multiple psychiatric symptoms.

Is hypertension changing? Blood pressure development in cohorts of 50-year-old men between 1963 and 1993

OBJECTIVE

To study secular trends in the prevalence and treatment of hypertension in the general population, and the disease course.

DESIGN

Health examinations of cohorts of 50-year-old men in 1963, 1973, 1983 and 1993.

SETTING

The city of Göteborg, Sweden (about 400,000 inhabitants).

PARTICIPANTS

Random population samples of 50-year-old men.

MAIN OUTCOME MEASURE

Mean blood pressure (BP) levels in the populations and among treated hypertensives, proportions of hypertensives, and frequency of high BP values (> or = 160/and or 95, and > or = 175/115 mmHg, respectively).

RESULTS

The mean population BP decreased from 138.4/89.0 mm to 128.7/84.4 mmHg during the 30-year period (p < 0.0001). Mean BP levels among treated hypertensives decreased from 170/113 to 142/94 mmHg (p < 0.0001), and the proportion of men with high BP values diminished from 3.9 to 0.1%. Also BP levels among normotensives decreased significantly (p < 0.0001).

CONCLUSION

The findings could partly be seen as a result of successful case-finding and treatment of hypertension in the region, but alteration of the natural course of hypertension cannot be excluded.