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Mogens Trab Damsgaard

Publications and source records attributed to Mogens Trab Damsgaard.

7 recordsLinked to original sources

The mediation proportion: a structural equation approach for estimating the proportion of exposure effect on outcome explained by an intermediate variable.

It is often of interest to assess how much of the effect of an exposure on a response is mediated through an intermediate variable. However, systematic approaches are lacking, other than assessment of a surrogate marker for the endpoint of a clinical trial. We review a measure of "proportion explained" in the context of observational epidemiologic studies. The measure has been much debated; we show how several of the drawbacks are alleviated when exposures, mediators, and responses are continuous and are embedded in a structural equation framework. These conditions also allow for consideration of several intermediate variables. Binary or categorical variables can be included directly through threshold models. We call this measure the mediation proportion, that is, the part of an exposure effect on outcome explained by a third, intermediate variable. Two examples illustrate the approach. The first example is a randomized clinical trial of the effects of interferon-alpha on visual acuity in patients with age-related macular degeneration. In this example, the exposure, mediator and response are all binary. The second example is a common problem in social epidemiology-to find the proportion of a social class effect on a health outcome that is mediated by psychologic variables. Both the mediator and the response are composed of several ordered categorical variables, with confounders present. Finally, we extend the example to more than one mediator.

Adult↗

Social position and functional decline among non-disabled old men and women.

BACKGROUND: To examine the relation between different aspects of social position and functional decline at 5 year follow-up in 75 year old men and women. METHODS: The study includes 606 non-disabled 75 year old participants living in Glostrup, Denmark. Functional ability was measured by the Mob-H Scale which measures need of help in six common mobility activities. Three outcome measures were used: a) functional decline, alive, b) functional decline, including death, and c) death. Measures of social position were vocational training, income and tenure. RESULTS: Income and tenure which reflect material wealth were related to functional decline and death in both men and women, but the patterns differed: housing tenure was related to functional decline and death among the men, while income was related to functional decline and death among the women. The associations were not attenuated when adjusted by behavioural factors. CONCLUSION: The results indicate that poor material wealth is associated with functional decline independent of behavioural factors in a selected population of non-disabled older adults. Thus, the cumulative influence of material wealth throughout the life-course cannot be avoided in old age just by a healthy behaviour once you have reached old age.

Activities of Daily Living↗

Revitalising the Metropolit 1953 Danish male birth cohort: background, aims and design.

Recent research indicates that factors operating during childhood are related to adult health. Thus, longitudinal studies with information on subsequent phases may be key to understanding later health outcomes. The main objective of this paper is to describe the history and design of a Danish birth cohort, and its revitalisation. In 1965, information from birth certificates for 11 591 of a total of 12 270 males born in 1953 in the Metropolitan area of Copenhagen, Denmark were traced. These boys were the study population of a sociological investigation conducted with the aim of describing social mobility. At age 12 years, 9537 of these cohort members completed a questionnaire in school, which included cognitive measures and information on social aspirations and leisure time activities. In 1966 educational performance tests were administered for these boys and, in 1968, mothers of 2890 cohort members were interviewed regarding family social backgrounds. With the establishment of the Civil Registration System (CRS) in 1968, it was possible to identify 11 532 cohort members. In 2002 we began the process of revitalising this study with the aim of investigating the influence of early life factors on later health. We succeeded in ascertaining the vital status of all subjects in the CRS. This showed that 863 subjects had died between 1968 and 2002. Linkages to the Register of Causes of Death, the National Hospital Register, Psychiatric Central Register and Danish Cancer Registry have been completed. In total, 7969 cohort members had been hospitalised for any somatic illness and, according to the Psychiatric Central Register, 1382 men had been admitted to a psychiatric hospital or ward. In the Cancer Registry we found 363 of our study participants. Analyses exploring the influence of social conditions in early life, birth dimensions, and childhood cognition on adult health experience are at various stages of completion. A questionnaire-based postal follow-up survey is planned. Thus, the Metropolit study provides an important opportunity to examine the processes by which factors that operate over the life course influence adult health.

Birth Weight↗

Cohabitation and marital status as predictors of mortality--an eight year follow-up study.

In a follow-up study of 1265 women and men aged 50, 60 and 70 years, we analysed how mortality was associated with cohabitation status (living alone/not living alone), living with/without a partner, and marital status respectively. Data originate from a longitudinal questionnaire study of a random sample of people born in 1920, 1930 and 1940 with baseline in 1990. Survival time for all individuals were established during the next 8 years until May 1998. Multivariate Cox analysis stratified by age and gender showed that individuals living alone experienced a significantly increased mortality compared to individuals living with somebody HR = 1.42(1.04-1.95) adjusted for functional ability, self-rated health, having children, smoking, diet and physical activity. Similar analyses were performed for the variable living with/without a partner HR = 1.38(1.01-1.88) and marital status HR = 1.25(0.93-1.69), adjusted for the same covariates. Inclusion of the health behaviour variables--smoking, diet and physical activity--one by one to a model with functional ability, self-rated health and one of the three determinants (cohabitation status, living with/without partner, marital status) showed no effect on the association with mortality. Hereby, we found no evidence of an indirect effect of health behaviours on the association between living arrangements and mortality. In contrast to many previous studies, we found no significant gender and age differences in the association between living arrangement and mortality. We suggest that in future studies of social relations and mortality, cohabitation status is considered to replace marital status as this variable may account for more of the variation in mortality.

Activities of Daily Living↗

Tiredness in daily activities among nondisabled old people as determinant of onset of disability.

The purpose of this article was to examine whether self-reported tiredness in daily activities at age 75 is an independent determinant of onset of disability at 5-year follow-up. The investigation is based on two subgroups of nondisabled participants of 75 year olds who survived and participated in the follow-up study 5 years later (n = 510 and 429). Persons who felt tired in their daily activities had a larger risk of becoming disabled in mobility (OR = 3.2, 95% CI = 1.4-7.6) and in daily activities (OR = 2.1, 95% CI = 1.0-4.2) compared to persons without tiredness. In addition, persons with poor cognitive function, little diversity in social relations and no physical activity had an independent risk of onset of disability. The results indicate that it is important to take it seriously when older people complain about tiredness in daily activities, as these people are at higher risk of becoming disabled than others.

Activities of Daily Living↗

Cynical hostility, socioeconomic position, health behaviors, and symptom load: a cross-sectional analysis in a Danish population-based study.

OBJECTIVE: To analyze the cross-sectional association between cynical hostility and high symptom load in a Danish population-based study. Furthermore, the aim was to investigate to what extent health risk behaviors mediated this association. METHODS: Data were based on a postal questionnaire in a Danish random sample of 3426 men and 3699 women aged 40 or 50 years. Cynical hostility was measured by the 8-item Cynical Distrust Scale. High symptom load was assessed by physiological and mental symptoms experienced within the last 4 weeks. Confounders were age and socioeconomic position, while potential mediators were alcohol consumption, smoking, physical activity, and BMI. RESULTS: Higher cynical hostility was associated with self-reported symptom load. Health behaviors did not seem to mediate this effect. Socioeconomic position was a strong confounder for the effect on both health and health behaviors. After adjustment the effects of hostility on health remained with odds ratios of 2.1 (1.7-2.6) for women and 2.3 (1.8-2.8) for men. CONCLUSION: After adjustment for socioeconomic position, cynical hostility has an effect on self-reported high symptom load, and this effect is not mediated by health behaviors.

Adult↗