Catalog of 199 register-based definitions of chronic conditions.

INTRODUCTION: The aim of the current study was to present and discuss a broad range of register-based definitions of chronic conditions for use in register research, as well as the challenges and pitfalls when defining chronic conditions by the use of registers. MATERIALS AND METHODS: The definitions were defined based on information from nationwide Danish public healthcare registers. Medical and epidemiological specialists identified and grouped relevant diagnosis codes that covered chronic conditions, using the International Classification System version 10 (ICD-10). Where relevant, prescription and other healthcare data were also used to define the chronic conditions. RESULTS: We identified 199 chronic conditions and subgroups, which were divided into four groups according to a medical judgment of the expected duration of the conditions, as follows. Category I: Stationary to progressive conditions (maximum register inclusion time of diagnosis since the start of the register in 1994). Category II: Stationary to diminishing conditions (10 years of register inclusion after time of diagnosis). Category III: Diminishing conditions (5 years of register inclusion after time of diagnosis). Category IV: Borderline conditions (2 years of register inclusion time following diagnosis). The conditions were primarily defined using hospital discharge diagnoses; however, for 35 conditions, including common conditions such as diabetes, chronic obstructive lung disease and allergy, more complex definitions were proposed based on record linkage between multiple registers, including registers of prescribed drugs and use of general practitioners' services. CONCLUSIONS THIS STUDY PROVIDED A CATALOG OF REGISTER-BASED DEFINITIONS FOR CHRONIC CONDITIONS FOR USE IN HEALTHCARE PLANNING AND RESEARCH, WHICH IS, TO THE AUTHORS' KNOWLEDGE, THE LARGEST CURRENTLY COMPILED IN A SINGLE STUDY.

Impact of exercise on patients with depression and anxiety.

BACKGROUND: Persons with common mental disorders are at risk of lowered physical activity. AIMS: To investigate if patients with depressive and/or anxiety disorders can achieve a level of physical activity meeting public health recommendations, increase their physical fitness and quality of life (QoL) through participation in a physical exercise programme. METHODS: In a non-blinded controlled study, 48 patients referred by private psychiatric clinics and private general practices were either treated in an intervention (n=27) or a control group (n=21). The intervention group took part in 20 weeks of group exercise consisting of aerobic training and non-aerobic weight-lifting. All participants were interviewed and tested at baseline, week 20 and at week 32. RESULTS: The intervention group increased in physical activity (120 min/week) and VO(2)max (0.48 ml O(2)/min). The VO(2)max increase was maintained after a 12-week follow-up period. Findings should be conservatively interpreted because of high attrition rate. CONCLUSIONS: Patients with anxiety and/or depressive disorders who participated in a structured, supervised exercise programme achieved in accordance with public health recommendations a higher level of physical activity and VO(2)max. CLINICAL IMPLICATIONS: The clinical implications of the study may be a suggestion of offering physical exercise to milder and moderate severe cases of depression and anxiety.

Socioeconomic correlates of drug use based on prescription data: a population-based cross-sectional register study in Denmark 1999.

INTRODUCTION: In the public health system we study medical treatment which is ideally provided according to need and independently of economic means. We report use of prescription drugs according to socioeconomic classifications in North Jutland County in Denmark in 1999. METHOD: We conducted a register-based cross-sectional study of 385,879 persons aged 18 years or older. Data from the computerized accounting system from the pharmacies were linked with records of socioeconomic status (SES) in the Prevention Registry at Statistics Denmark. We identified all prescriptions redeemed in North Jutland County from 1 January through 31 December 1999 and classified the socioeconomic status for each individual based on the annual registration of income/social benefits, employer, occupation and education. We computed the proportion of persons redeeming at least one prescription and computed weighted averages of prescription proportions for each SES. RESULTS: The highest prevalence of medication use was by persons in early retirement, old age pensioners, people on disability pension and others outside the workforce. We found only minor differences among different economically active groups with slightly more male top managers using cardiovascular drugs. People in the upper half of the socioeconomic scale were somewhat less likely to redeem prescriptions for treating muscle, joints and bone, and central nervous system. CONCLUSION: Social or economic barriers in buying medicine are generally small in Denmark and do probably not provide a likely explanation for the social differences in morbidity and mortality.

The Health-Related Quality of Life for Patients with Myalgic Encephalomyelitis / Chronic Fatigue Syndrome (ME/CFS).

INTRODUCTION: Myalgic encephalomyelitis (ME)/chronic fatigue syndrome (CFS) is a common, severe condition affecting 0.2 to 0.4 per cent of the population. Even so, no recent international EQ-5D based health-related quality of life (HRQoL) estimates exist for ME/CFS patients. The main purpose of this study was to estimate HRQoL scores using the EQ-5D-3L with Danish time trade-off tariffs. Secondary, the aims were to explore whether the results are not influenced by other conditions using regression, to compare the estimates to 20 other conditions and finally to present ME/CFS patient characteristics for use in clinical practice. MATERIAL AND METHODS: All members of the Danish ME/CFS Patient Association in 2013 (n=319) were asked to fill out a questionnaire including the EQ-5D-3L. From these, 105 ME/CFS patients were identified and gave valid responses. Unadjusted EQ-5D-3L means were calculated and compared to the population mean as well as to the mean of 20 other conditions. Furthermore, adjusted estimates were calculated using ordinary least squares (OLS) regression, adjusting for gender, age, education, and co-morbidity of 18 self-reported conditions. Data from the North Denmark Health Profile 2010 was used as population reference in the regression analysis (n=23,392). RESULTS: The unadjusted EQ-5D-3L mean of ME/CFS was 0.47 [0.41-0.53] compared to a population mean of 0.85 [0.84-0.86]. The OLS regression estimated a disutility of -0.29 [-0.21;-0.34] for ME/CFS patients in this study. The characteristics of ME/CFS patients are different from the population with respect to gender, relationship, employment etc. CONCLUSION: The EQ-5D-3L-based HRQoL of ME/CFS is significantly lower than the population mean and the lowest of all the compared conditions. The adjusted analysis confirms that poor HRQoL of ME/CFS is distinctly different from and not a proxy of the other included conditions. However, further studies are needed to exclude the possible selection bias of the current study.

Having children with multiple partners is associated with reduced risk of malignant melanoma: an observation seeking a plausible explanation.

OBJECTIVE: We examined the association between the number of partners that mothers and fathers have children with and occurrence of cutaneous malignant melanoma (CMM). METHODS: We conducted a complete registry-based follow-up of all Danish mothers born after 1935 from the birth of their second child until CMM, death, emigration, or end of study in 2002. We conducted a similar follow-up of the corresponding fathers. Incidence rate ratios (IRR) and confidence intervals (CI) were estimated by Poisson regression. RESULTS: THIS STUDY CORROBORATES THAT WOMEN HAVING CHILDREN WITH THREE OR MORE MEN ARE HALF AS LIKELY TO HAVE CMM AS WOMEN WHO HAVE CHILDREN WITH ONE MAN: incidence rate ratio (IRR) = 0.51, 95% CI: 0.29, 0.91; having children by two fathers reduces risk among women by 20%: IRR = 0.80, 95% CI: 0.70, 0.91. Fathers with multiple partners tend to face a similar risk reduction. CONCLUSION: The similar patterns of mothers and fathers challenge us to consider and propose likely mechanisms common to both sexes. The patterns of reduced risk have now been reported in two large independent complete population-based studies in Sweden and Denmark.

Paternal age and congenital malformations.

BACKGROUND: Spontaneous mutations in germ cells increase with male age, but an association between paternal age and congenital malformations is not well established. We conducted a population-based cohort study to estimate this association. METHODS: A study population of couples and their firstborn children were identified in the Danish Fertility Database between 1980 and 1996 (n = 71937). Diagnoses of congenital malformations in children were obtained by linkage to the nationwide hospital register (1980-1999). RESULTS: Overall, there were no differences in the prevalence of malformations as a function of paternal age. However, the prevalence of malformations of extremities and syndromes of multiple systems, as well as Down's syndrome, increased with increasing paternal age. For example, in comparison with fathers age 20-29 years, adjusted hazard ratio of syndromes of multiple systems was 1.15 [95% confidence interval (CI) 0.81-1.65] for age 35-39 years, 1.33 (95% CI 0.79-2.25) for age 40-44 years, 1.73 (95% CI 0.82-3.65) for age 45-49 years, and 3.20 (95% CI 1.37-7.48) for age > or = 50 years (test for trend P = 0.01). CONCLUSIONS: Our data suggest that advanced paternal age may be associated with an excess occurrence of some specific malformations. The association could be caused by mutations of the gametes in men induced by biological or environmental factors.

Socioeconomic gradient in use of statins among Danish patients: population-based cross-sectional study.

AIMS: Socioeconomic inequalities in statin use are a public health concern but they may also confound observational studies of statins' effectiveness. We conducted a population-based cross-sectional study in Denmark to examine the association between socioeconomic status (SES) and statin use. METHODS: We obtained data on socioeconomic status of all persons in North Jutland County, Denmark, between 1995 and 1999 from the Prevention Registry at Statistics Denmark. Data on filled statin prescriptions were identified through the County Prescription Database. We compared the 1-year prevalence proportions of statin use for different socioeconomic groups, adjusted for age and urbanization. Separate analyses were done for patients with a history of cardiovascular disease as recorded in the County Hospital Discharge Registry. RESULTS: Among men with cardiovascular disease, statin use in 1995 was higher in those with the highest socioeconomic status (adjusted relative prevalence proportion (RPP) among top managers 1.86, 95% CI: 1.17-2.96), and lower among retired men (RPP (95% CI) 0.63 [0.43-0.93] in old-age pensioners, and 0.66 [0.45-0.98] in the early retired), when compared with basic-level workers. The socioeconomic differences in statin use among men decreased in magnitude over time but remained throughout the study period. We found no clear social gradient in statin use among women. CONCLUSIONS: Even in a health care system that claims to ensure a high degree of equity in medical care, we found clear indications of a socioeconomic gradient in statin use among men in the years after the launching of these drugs.