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J Hallqvist

Publications and source records attributed to J Hallqvist.

32 records · Page 2Linked to original sources

Association between job characteristics and plasma fibrinogen in a normal working population: a cross sectional analysis in referents of the SHEEP Study. Stockholm Heart Epidemiology Program.

STUDY OBJECTIVE: To explore the association between job characteristics and plasma fibrinogen concentrations. DESIGN: Cross sectional design. SETTING: The Greater Stockholm area. SUBJECTS: A total of 1018 men and 490 women aged 45-70 who were randomly selected from the general population during 1992-1994. They were all employed and had no history of myocardial infarction. MAIN RESULTS: The self reported job characteristics were measured by a Swedish version of the Karasek demand-control questionnaire. For inferred scoring of job characteristics, psychosocial exposure categories (job control and psychological demands) were assigned by linking each subject's occupational history with a work organisation exposure matrix. Job strain was defined as the ratio between demands and control. In univariate analyses, expected linear trends were found in three of four tests of association between high plasma fibrinogen and low control (the self reported score for women and the inferred score for both sexes), in one of four tests of association between high plasma fibrinogen and high demands (the inferred score for women) and in two of four tests of association between high plasma fibrinogen and job strain (the inferred score for both sexes). Multiple logistic regression analyses showed that men in the inferred job strain group have an increased risk of falling into the increased plasma fibrinogen concentration group (above median level of the distribution) (odds ratio (OR) 1.2; 95% CI 1.0, 1.5) after adjustment for the variables that were associated with plasma fibrinogen in the univariate analyses. In women, low self reported control, high inferred demand, and inferred job strain were significantly associated with increased plasma fibrinogen concentration (OR 1.3; 95% CI 1.0, 1.8, OR 1.5; 95% CI 1.0, 2.2, OR 1.5; 95% CI 1.1, 2.2, respectively). CONCLUSIONS: These results indicate that adverse job characteristics may be related to plasma fibrinogen concentrations and this relation is more relevant in female workers. The clearest evidence for psychosocial effects on plasma fibrinogen seems to be with job control and the associations are clearer for the objective than for the self report variables.

Aged↗

Exposure-dependent misclassification of exposure in interaction analyses.

The objectives of this paper are to analyze the consequences of exposure misclassification on effect estimates in interaction analysis, and to develop a mathematical equation for the potentially biased estimate. The main point is to identify situations in which misclassification of the first exposure, dependent on the second exposure but independent on outcome status, leads to overestimation or underestimation of the interaction effect. We show that misclassification theoretically can cause overestimation of the interaction effect. Nevertheless, because the categories that yield overestimation due to misclassification are fewer than the categories that yield underestimation, and misclassification in reality mostly is multidimensional (more than one category are biased simultaneously), it is more likely that the effect of misclassification is underestimation rather than overestimation. Misclassification in the categories that lead to overestimation is compensated by misclassification in the categories that lead to underestimation. The magnitude of the biased estimate depends on the prevalences of the misclassified exposure, stratified for the second exposure and the outcome-the lower the prevalence, the smaller the bias.

Bias↗

Is the effect of job strain on myocardial infarction risk due to interaction between high psychological demands and low decision latitude? Results from Stockholm Heart Epidemiology Program (SHEEP).

The objectives are to examine if the excess risk of myocardial infarction from exposure to job strain is due to interaction between high demands and low control and to analyse what role such an interaction has regarding socioeconomic differences in risk of myocardial infarction. The material is a population-based case-referent study having incident first events of myocardial infarction as outcome (SHEEP: Stockholm Heart Epidemiology Program). The analysis is restricted to males 45-64 yr of age with a more detailed analysis confined to those still working at inclusion. In total, 1047 cases and 1450 referents were included in the analysis. Exposure categories of job strain were formed from self reported questionnaire information. The results show that high demands and low decision latitude interact with a synergy index of 7.5 (95% C.I.: 1.8-30.6) providing empirical support for the core mechanism of the job strain model. Manual workers are more susceptible when exposed to job strain and its components and this increased susceptibility explains about 25-50% of the relative excess risk among manual workers. Low decision latitude may also, as a causal link, explain about 30% of the socioeconomic difference in risk of myocardial infarction. The distinction between the interaction and the causal link mechanisms identifies new etiologic questions and intervention alternatives. The specific causes of the increased susceptibility among manual workers to job strain and its components seem to be an interesting and important research question.

Case-Control Studies↗

Socioeconomic differences in risk of myocardial infarction 1971-1994 in Sweden: time trends, relative risks and population attributable risks.

BACKGROUND: The general trend in incidence of myocardial infarction (MI) in the Stockholm area changed from increasing to decreasing around 1980. The objective of this study is to examine time trends in incidence in major socioeconomic strata, relative risk between socioeconomic groups and population risk attributable to socioeconomic differences during this period. METHODS: All cases of MI from 1971 to 1986 were identified from hospital discharge and cause-of-death registers. Person-years for each year of follow-up were calculated from the population register in the Stockholm region 1971-1986. Census registers were used for information on socioeconomic status. Register information was individually linked through the Swedish personal identification number. Supplementary information for 1992-1994 was taken from the case-control study SHEEP (Stockholm Heart Epidemiology Program). RESULTS: The decline in MI risk among male high- and middle-level employees started in 1976 and in male manual workers in 1981. For women incidence increased from 1971 to 1986 among manual workers and decreased among high- and middle-level employees. The increase over time of the relative risk from low socioeconomic position continued into the 1990s. Despite the reduction of the category of manual workers, the population attributable risk from socioeconomic differences also increased over time. The process of social change influencing the size of the socioeconomic groups contributes to the change in time trends of MI morbidity. CONCLUSIONS: The increase over time of relative and population attributable risks of MI from low socioeconomic status add to the public health importance of social inequity.

Adult↗

Trends in occupational mortality among middle-aged men in Sweden 1961-1990.

BACKGROUND: Many European countries have in recent decades reported growing socioeconomic differentials in mortality. While these trends have usually paralleled high unemployment and increasing income disparities, Sweden had low unemployment and narrowing income differences. This study describes trends, 1961-1990, in total and cardiovascular mortality among men, 45-69 years of age, in major occupational classes in Sweden. METHODS: From census data four cohorts were created from those enumerated in 1960, 1970, 1980 and 1985. Through record linkage with the Swedish cause of death registry the mortality in each cohort was followed for 5-10 years. Age-standardized mortality trends 1961-1990 were calculated for occupational groups, categorized according to sector of the economy. RESULTS: The increase in mortality among middle-aged men in Sweden 1965-1980 was mainly a result of increasing cardiovascular mortality among industrial workers and farmers. In the 1980s the trend for these groups changed into a last decrease in mortality similar to that for non-manual occupations for the whole period. Consequently the rate ratio for industrial workers in comparison with men having a professional/managerial type of occupation increased from 0.98 to 1.43. The slowest decrease is now found among unqualified occupations in services and transportation. CONCLUSIONS: While Sweden, during the period studied, had narrowing income differentials and low unemployment this result points to the importance of working conditions in understanding trends and distribution of male adult mortality.

Aged↗

How to evaluate interaction between causes: a review of practices in cardiovascular epidemiology.

To increase the knowledge of interaction or synergy between risk factors in an important task in medical research. Still, current literature in cardiovascular epidemiology reflects major misconceptions as how to evaluate interaction. This paper presents Rothman's model of causation from which strict empirical criteria of interaction can be derived. In principle, the method to apply consists of comparing risk differences for one risk factor of interest across strata of the other. Commonly used but incorrect approaches are exemplified and discussed. These include reporting risk of disease among those with combined exposure, comparing relative risks for one exposure after stratification by level of the other, and including an interaction term in the regression model and drawing conclusions from its P-value.

Cardiovascular Diseases↗

Socioeconomic differences in smoking in an urban Swedish population. The bias introduced by non-participation in a mailed questionnaire.

Stockholm Health of the Population Study is a cross-sectional study carried out from 1984-85. Postal questionnaires, telephone interviews and health interviews were used to get information from a sample of 5,199 persons, 18-64 years of age, on health status, risk exposures, healthcare consumption and social factors. Non-participation with respect to the postal questionnaire was 36.8%. With subsequent telephone interviews and an invitation to a health interview, non-participation was reduced to 17.8%. The estimated prevalence of daily smoking increased from 36.1% to 38.7. The non-responders had a higher prevalence of daily smoking in all sub-groups. This effect of the efforts to reduce non-participation differed socially. The prevalence of smoking for men, 40-64 years of age, who were reached by telephone was 60.3%. Male professionals and intermediate non-manual workers, 40-64 years of age reached by telephone had a prevalence of smoking, which was twice as high as for the responders of the questionnaire (62.5 and 26.8%, respectively). In the younger age-group, non-responders had the same socioeconomic pattern in smoking as the responders. Independent of socioeconomic group, there was a tendency of ill or disabled smokers to respond more quickly than healthy smokers. Using a postal questionnaire with a high non-response rate might lead to an overestimation of socioeconomic differences and an underestimation of smoking prevalence.

Adolescent↗

The relationship between stressful working conditions and high alcohol consumption and severe alcohol problems in an urban general population.

The relationship between 15 measures of stressful working conditions and high alcohol consumption (35 g 100% ethanol per day or more for men and 25 g or more for women) was studied, using cross-sectional data from a general population survey of 1344 males and 1494 females; the ages 25-64 years in metropolitan Stockholm in 1984. In a longitudinal component of the study, hospitalization and mortality with alcohol-related diagnosis was assessed during 1984-90, and also the association between previous experience of unemployment and high alcohol consumption. Some of the associations, expressed as age-adjusted odds ratios, were positive and some were negative when high alcohol consumption was the endpoint, but there was a clear variation by sex and social class. Generally the positive associations were stronger among male non-manual employees. Among males, there was a clear association between stressful working conditions and subsequent risk of severe medical alcohol-related problems, but the precision of the estimates was low due to low number of cases. The odds ratio was 6.18 (95% confidence interval 1.86, 20.61) for twisted working positions and 6.74 (95% confidence interval 1.67, 27.19). Previous unemployment among males was associated with increased risk for high alcohol consumption, with an odds ratio of 5.71 (95% CI 1.39, 15.97) among those who had been unemployed more than once, and 1.67 (95% CI 0.76, 3.64) among those who had been unemployed once during the previous 5 years. Those and other increased odds ratios were lower when subjects with an alcohol diagnosis at inpatient care during 1980-84 were excluded in the analyses. On the whole, our findings are not conclusive. The strong, but imprecise associations between stressful working conditions and severe alcohol problems, are however challenging, and warrants further studies, preferably with longitudinal design and repeated measurements of both working condition and alcohol habits.

Adult↗

Participation of primary health care personnel in the Stockholm Health of the Population Study--a preliminary report.

The 1984/85 Stockholm Health of the Population Study (HPS) was a cross sectional study including a questionnaire and a health examination. It was conducted through the ordinary health personnel of four Primary Health Care (PHC) districts in the Stockholm County. The main objective was to broaden the scope for planning health care. One of the goals of the study was to involve those working in PHC in planning their activities after local needs and to use more time for prevention work. The main effort to reach this objective was through involvement of the PHC personal from the early planning phase. This strategy was very time consuming but, on the other hand experiences from the HPS have led to both new screening activities of e.g high consumers of alcohol and the elderly, and preventive work aimed at those with smoking and overweight problems in the local PHC area. In the implementation process and through education the scientific approach level and interest in primary health care increased. A keen interest of survey data for local planning is obvious.

Attitude of Health Personnel↗

Do episodes of anger trigger myocardial infarction? A case-crossover analysis in the Stockholm Heart Epidemiology Program (SHEEP).

OBJECTIVE: Our objectives were to study anger as a trigger of acute myocardial infarction (MI) and to explore potential effect modification by usual behavioral patterns related to hostility. METHODS: This study was a case-crossover study within the Stockholm Heart Epidemiology Program. Exposure in the period immediately preceding MI was compared with exposure during a control period for each case. From April 1993 to December 1994, 699 patients admitted to coronary care units in Stockholm County were interviewed. RESULTS: During a period of 1 hour after an episode of anger, with an intensity of at least "very angry," the relative risk of MI was 9.0 (95% CI, 4.4-18.2). In patients with premonitory symptoms, the time of disease initiation may be misclassified. When restricting the analyses to those without such symptoms, the trigger risk was 15.7 (95% CI, 7.6-32.4). The possibility of examining effect modification was limited by a lack of statistical power (eight exposed cases). Results of the analyses suggested, however, an increased trigger effect among subjects reporting nonhostile usual behavior patterns, nonovert strategies of coping with aggressive situations (not protesting when being treated unfairly), and nonuse of beta-blockers. CONCLUSIONS: The hypothesis that anger may trigger MI is further supported, with an increased risk lasting for approximately 1 hour after an outburst of anger. It is suggested that the trigger risk may be modified by personal behavior patterns.

Adult↗