Danish registers contain information on many important health and social issues. Because all Danish citizens have a unique personal identification number, linkage at the individual level between these nationwide registers and other data sources is possible and feasible. In this paper we briefly introduce selected Danish registers and the data structure and requirements for getting access to data at Statistics Denmark, which is the main provider of register data. We introduce the Danish Data Archive and briefly present the Act on Processing of Personal Data, which is the legal foundation for analyses of register-based data in Denmark.

Background and Purpose — As part of the Danish contribution to the World Health Organization (WHO) MONICA (Monitoring Trends and Determinants in Cardiovascular Disease) Project, a register of patients with stroke was established in 1982. The purpose of the present study was to analyze long-term survival and causes of death after a first stroke and to compare them with those of the background population. Methods — The study population comprised all subjects aged 25 years or older who were resident in a geographically defined region in Copenhagen County. All stroke events in the study population during 1982–1991 were ascertained and validated according to standardized criteria outlined for the WHO MONICA Project. After completion of the stroke registry at the end of 1991, all patients were followed up by record linkage to official registries. Standardized mortality ratios were calculated for various causes of death and periods after the stroke. Results — The estimated cumulative risks for death at 28 days, 1 year, and 5 years after onset were 28%, 41%, and 60%, respectively. Compared with the general population, nonfatal stroke was associated with an almost 5-fold increase in risk for death between 4 weeks and 1 year after a first stroke and a 2-fold increase in the risk for death subsequent to 1 year. The excess mortality rate in stroke patients was due mainly to cardiovascular diseases but also to cancer, other diseases, accidents, and suicide. The probability for long-term survival improved significantly during the observation period for patients with ischemic or ill-defined stroke. Conclusions — Stroke is a medical emergency associated with a very high risk for death in the acute and subacute phases and with a continuous excess risk of death. Better prevention and management of strokes may improve the long-term survival rate.

Unfavorable health trends among the lowly educated have recently been reported from the United States. We analyzed health trends by education in European countries, paying particular attention to the possibility of recent trend interruptions, including interruptions related to the impact of the 2008 financial crisis. We collected and harmonized data on mortality from ca. 1980 to ca. 2014 for 17 countries covering 9.8 million deaths and data on self-reported morbidity from ca. 2002 to ca. 2014 for 27 countries covering 350,000 survey respondents. We used interrupted time-series analyses to study changes over time and country-fixed effects analyses to study the impact of crisis-related economic conditions on health outcomes. Recent trends were more favorable than in previous decades, particularly in Eastern Europe, where mortality started to decline among lowly educated men and where the decline in less-than-good self-assessed health accelerated, resulting in some narrowing of health inequalities. In Western Europe, mortality has continued to decline among the lowly and highly educated, and although the decline of less-than-good self-assessed health slowed in countries severely hit by the financial crisis, this affected lowly and highly educated equally. Crisis-related economic conditions were not associated with widening health inequalities. Our results show that the unfavorable trends observed in the United States are not found in Europe. There has also been no discernible short-term impact of the crisis on health inequalities at the population level. Both findings suggest that European countries have been successful in avoiding an aggravation of health inequalities. Significance Inequalities in mortality and morbidity among socioeconomic groups are a highly persistent phenomenon despite having been the focus of public health policy in many countries. The United States has recently witnessed a widening of health inequalities due to rising mortality and morbidity among the lowly educated. Our study shows that, despite the financial crisis, most European countries have experienced an improvement in the health of the lowly educated in recent years. In Eastern Europe, this even represents a reversal as compared with previous decades. The 2008 financial crisis has had mixed effects without widening health inequalities. Our results suggest that European countries have been successful in avoiding an aggravation of health inequalities.

The Danish Multiple Sclerosis Registry contains information about all Danish patients in whom multiple sclerosis has been diagnosed since 1948. The purpose of this study was to analyse trends in survival and causes of death of these patients and to compare them with those of the general population. The study comprised all patients with onset in the period 1949–1996. All case records were validated and classified according to standardized diagnostic criteria. Data on emigration and death were obtained by record linkage to official registers. The end of follow‐up was 1 January 2000 for emigration and death, and 1 January 1999 for cause‐specific deaths. Standardized mortality ratios and excess death rates were calculated for various causes of death and periods after multiple sclerosis onset, and time trends in survival probability were analysed by Cox regression. The study comprised 9881 patients, of whom 4254 had died before end of follow‐up. The median survival time from onset was ∼10 years shorter for multiple sclerosis patients than for the age‐matched general population, and multiple sclerosis was associated with an almost threefold increase in the risk for death. According to death certificates, more than half (56.4%) of the patients had died from multiple sclerosis. They also had excess mortality rates from other diseases, except cancer, and from accidents and suicide. The probability for survival improved significantly during the observation period. Thus, the 10‐year excess mortality was almost halved in comparison with that in the middle of the 1900s.

Background: The EQ-5D is a widely used generic health-related quality of life instrument that has been used to describe population health and health outcomes in clinical trials and health economic evaluations. Aims: To generate Danish population norms for the EQ-5D index score, stratified by age and gender. Methods: The EQ-5D data from three population health surveys were pooled, thus providing EQ-5D profile data for 15,700 individuals aged 20-79 years. The Danish TTO scoring algorithm was used to weight each respondent's profile data to derive a single index score. Mean values were computed by gender and 10-year age groups, and educational groups. Results: In a random sample from the general Danish population, the mean EQ-5D index score ranged between 0.93 for 20—29 year-olds and 0.83 for 70—79 year-olds. Men had a significantly higher score than women in all age groups. Longer education was associated with higher EQ-5D index score in most age groups. Conclusions: The calculated mean values for the EQ-5D index score may be used as reference values for comparative purposes in future Danish population health and evaluative studies.