Mette Kjøller

The study design and characteristics of the Danish national health interview surveys

Aims: The Danish National Institute of Public Health, University of Southern Denmark has carried out national representative health interview surveys among adult Danes in 1987, 1994, 2000 and 2005. The aim of this study is to describe the characteristics of the design, including the response rates of the four surveys. Methods: The samples in 1987 and 1994 are based on simple random sampling. The samples in 2000 and 2005 are based on stratified random sampling. In addition, all invited to the survey in 1994 were re-invited in both 2000 and 2005. Data were collected via face-to-face interview at the respondent’s home. Following the interview in 1994, 2000 and 2005, all respondents were asked to complete a self-administered questionnaire. Results: The response rate for the face-to-face interview fell from 79.9% in 1987 to 66.7% in 2005 and the response rate for the self-administered questionnaire from 68.1% in 1994 to 51.5% in 2005. The decrease is particularly marked among the young. The mean interview length has increased from 33.3 minutes in 1987 to 50.2 minutes in 2005. Conclusions: The declining response rate in the surveys is a major concern and can pose problems in generalizing data from the surveys to the Danish population. However, these surveys are essential, as the information collected cannot be gathered by means of official statistical registers. Hence, efforts to increase the response rate will be important in the forthcoming surveys.

Do age and social relations moderate the relationship between self-rated health and mortality among adult Danes?

It is well established that self-rated health (SRH) predicts mortality even after controlling for a wide range of factors. We explored the extent to which age and social relations (structural and functional) influenced the relationship between SRH and mortality (after 13 years follow-up) in a representative sample of adult Danes (N=6693). After controlling for socioeconomic status, illness, and lifestyle variables, we found that age moderated the SRH-mortality relationship such that it was present for respondents under 55 but absent for respondents over 56. In addition, weaker structural (but not functional) social relations increased mortality directly but neither structural nor functional social relations moderated the SRH-mortality relationship. We discuss the theoretical and practical implications of these findings.

Agreement between self-reported data on medicine use and prescription records vary according to method of analysis and therapeutic group

OBJECTIVE This study compared national self-reported data on medicine use and national prescription records at the individual level. STUDY DESIGN AND SETTING Data from the nationally representative Danish health survey conducted in 2000 (n=16,688) were linked at the individual level to national prescription records covering 1999-2000. Kappa statistics and 95% confidence intervals were calculated. RESULTS Applying the legend time method to medicine groups used mainly on a chronic basis revealed good to very good agreement between the two data sources, whereas medicines used as needed showed fair to moderate agreement. When a fixed-time window was applied for analysis, agreement was unchanged for medicines used mainly on a chronic basis, whereas agreement increased somewhat compared to the legend time method when analyzing medicines used as needed. CONCLUSION Agreement between national self-reported data and national prescription records differed according to method of analysis and therapeutic group. A fixed-time window is an appropriate method of analysis for most therapeutic groups.

The Danish National Cohort Study (DANCOS)

Introduction: The Danish National Cohort Study (DANCOS) is a nationally representative public health survey based on linkage of information in the repeated Danish Health Interview surveys, 1986—2005, to the national Danish registers on health and welfare. It facilitates studies of self-reported health behaviour and utilisation of healthcare services by subgroups and analysis of non-response bias. Research topics: DANCOS data are utilised in a variety of analyses presented here by a few examples that emphasise the impact of modifiable risk factors on public health, description of non-response bias, and the epidemiology of chronic pain and of osteoarthritis. Examples of DANCOS-based results are shown for each of the four topics. Smoking results in 24% of all deaths and, compared to other risk factors for public health, smoking accounts for the highest number of years of life lost. For non-response the mortality is higher among non-respondents than among respondents, but no significant bias on healthcare estimates can be seen. On average individuals with chronic pain had 12.8 contacts per year to the primary healthcare sector compared with 7.3 for individuals without. For osteoarthritis it is estimated that in 2020 there will be 22,600 incident cases. Conclusion: DANCOS is a public health survey linked with registers with many research possibilities. With this article we hope to stimulate further interest in the survey.

Health behaviour among non-Western immigrants with Danish citizenship

Aims: To compare belief in own effort to stay healthy, health behaviour and body mass index (BMI) among non-Western immigrants with Danish citizenship and citizens with Danish background. Methods: Based on the National Health Interview Survey 2005, logistic regression analyses were used to examine differences in belief in own effort to stay healthy, in health behaviour and in BMI between 136 non-Western immigrants with Danish citizenship and 9,901 citizens with Danish background in the age group 25—64 years. Results: Non-Western immigrants had lower odds for reporting that own effort is very important to maintain good health (odds ratio (OR) 0.45; 95% confidence interval (CI) 0.32—0.62) and for reporting consuming more alcohol on a weekly basis than recommended by the Danish National Board of Health (OR 0.21, 95% CI 0.09—0.51). The odds were higher for non-Western immigrants for than citizens with Danish background for reporting sedentary spare-time activities (OR 2.96, 95% CI 1.96—4.17), daily consumption of boiled vegetables (OR 2.50, 95% CI 1.77—3.53), and daily consumption of salad/raw vegetables (OR 2.84, 95% CI 2.02—3.99). We found no differences in daily smoking, daily fruit consumption, BMI≥25 or BMI≥30. Conclusions: The non-Western immigrants are healthier in terms of alcohol and vegetable consumption and unhealthier with regard to leisure-time physical activity. The non-Western immigrants are less likely to report that their own effort is important in maintaining good health.

Obesity and prevalence of risk behaviour for eating disorders among young Danish women.

Aims: Danish women aged 16—29 from two nationwide, representative, cross-sectional interview/questionnaire surveys from 2000 and 2005 are analyzed for trends in prevalence of risk behaviour for developing eating disorders and associations to BMI and age. Methods: Participants completed the Danish Health Interview Survey and an 8-item screen, RiBED-8, for risk behaviour for eating disorders. To analyze how the prevalence of risk behaviour depends on age, BMI, and year of survey, logistic regression analyses were applied. On acceptance of no interaction, the effect of each variable was tested and described using odds ratios with 95% confidence intervals. Results: Women aged 16—19 or with a BMI of>25 had the greatest chance of reporting risk behaviour for eating disorders. However, many women in their 20s also had risk behaviour. Prevalence of risk behaviour for eating disorders did not change from 2000 to 2005. Conclusions: The shared risk factors for obesity and eating disorders require further investigation for development of collaborative prevention and treatment strategies that should also be directed towards young women in their 20s as well as young teenagers.

Readiness to change level of physical activity in leisure time among physically inactive Danish adults

Aims: The study examined readiness to change the level of physical activity in leisure time among physically inactive adults, the sociodemographic, lifestyle-related and social factors associated with readiness to change, and finally the various kinds of help to become more physically active required by people who are ready to change and by those not ready to change. Materials and methods: Data were derived from the national representative Danish Health Interview Survey 2005 and included 9,160 physically inactive persons between 16 and 79 years of age. Data were analysed using multiple logistic regression and multiple correspondence analysis. Results: In all, 52 % of the physically inactive respondents stated they were ready to change their level of physical activity. Men had higher odds of being ready to change than women. Readiness to change decreased with age and increased with increasing levels of education. Those ready to change led an active and social lifestyle characterized by considerable health-oriented engagement, while the opposite characterised those not ready to change. Those ready to change wanted help to become more physically active in the form of e.g. opportunities for physical activity at work or help and support from the family. Those not ready to change wanted help from a general practitioner or did not want help at all. Conclusions: Those ready to change and those not ready to change were characterized by very different sociodemographic, lifestyle-related and social factors. This knowledge will benefit prevention initiatives and elucidates the necessity of targeting the initiatives.

Are hospitals also for relatives? A survey of hospitals' activities regarding relatives of cardiac patients

Aim: Patients and their close relatives both feel the burden of cardiovascular disease. Relatives of heart patients experience lower quality of life and increased mortality than the general population and relatives of patients with other diseases. Nevertheless, knowledge on health services aimed at relatives of patients with cardiac diseases is sparse. This study aimed to survey the prevalence of health services for relatives of cardiac patients in Denmark. Methods: We surveyed activities offered by Danish hospitals to the relatives of cardiac patients. Data were obtained from an Internet-based survey and 50 of 55 invited hospital departments participated. Results: Almost all departments offer activities to relatives of cardiac patients, but only one-quarter have activities specifically aimed at supporting relatives. Large departments offer activities for relatives more often than smaller departments. Participation rates for relatives are generally low, and the departments experience numerous barriers in providing activities for relatives of heart patients. Conclusions: Danish hospitals focus very little on relatives of cardiac patients, and this seems to be due to several factors, including lack of resources, lack of interest and knowledge among staff, and practical and psychological barriers among patients and relatives. More research is needed on health services concerning relatives of cardiac patients, regarding both the prevalence of activities and barriers to these.

What characterizes persons with poor mental health? A nationwide study in Denmark

Background: The aim of the study was to identify and characterize groups with poor mental health defined by the SF-12 Mental Component Summary (MCS-12) scale. Methods: The study is based on the Danish Health and Morbidity Survey 2005 and includes 10,082 participants (16 years or older). Data were analysed by means of logistic regression models. Results: Men and women with poor mental health are characterized by being single, having a long-term illness, not being able to rely on help from others in case of illness and by feeling that family and friends demand too much of them. Men with poor mental health were further characterized by being a heavy smoker, and having a BMI below 25. Women with poor mental health were further characterized by being 16–44 years old and sedentary in leisure time. Conclusions: The prevalence of poor mental health is higher among women than men, and different factors characterize men and women with poor mental health. The present findings support the notion that both socio-demographics and lifestyle factors are independently related with poor mental health. We suggest taking into account all these areas of life when planning activities to prevent poor mental health and when promoting mental health.