Validation of a 5-year risk score of hip fracture in postmenopausal women. The Danish Nurse Cohort Study.

SUMMARY: We evaluated the Women's Health Initiative (WHI) hip fracture risk score in 15,648 postmenopausal Danish nurses. The algorithm was well calibrated for Denmark. However, the sensitivity was poor at common decision making thresholds. Obtaining sensitivity better than 80% led to a low specificity of 61.4%. INTRODUCTION: A new score based on data from the WHI has been designed to predict 5-year risk of hip fracture in postmenopausal women. The performance of the algorithm has not been validated in populations with different lifestyle characteristics and ethnicity. The aim of this study was to test the clinical performance of the algorithm in a large Danish cohort of postmenopausal Caucasian women against hip fracture. METHODS: The Danish Nurse Cohort is a prospective risk factor and hormone therapy (HT) study established in 1993. Participants in the present analysis were 15,648 postmenopausal nurses. The calibration and diagnostic performance of the WHI algorithm was evaluated using fracture events captured in the Danish National Hospital Registry. RESULTS: During 5 years of follow-up, 122 participants suffered a hip fracture (1.8/1,000 person years). The WHI algorithm predicted that 107 hip fractures would occur, indicating an underestimation of the number of fractures by 12%. To obtain sensitivity better than 80%, the cut-off value for 5-year risk was set to 0.5%, which was accompanied by a low positive predictive value of 1.9% and a low specificity of 61.4%. The algorithm predicted too many fractures in HT-users (12 observed, 22 expected) and too few in non HT-users (107 observed, 81 expected). CONCLUSIONS: While the WHI algorithm was well calibrated on the Danish population, the clinical utility of the WHI algorithm in Danish postmenopausal women was limited by poor sensitivity at common decision-making thresholds and suboptimal in non-HT-users.

Doctoral prepared nurses in Denmark and their scientific production between 1976 and 2005.

BACKGROUND: Nursing research in Denmark has evolved over the last 30 years. By 2005, 48 Danish nurses had earned a doctoral degree. The Danish Nurses Organization formalized a strategy for development of nursing research for the period 1999-2002. The strategy was evaluated in 2004. One point in the evaluation was that the nurses' publication of peer-reviewed articles in journals with an Impact Factor did not show in the bibliographic measure used in health sciences. PURPOSE: The purpose of this study is to identify the number of Danish nurses holding a doctoral degree by the end of 2005 and to document their scientific production. METHODS: A descriptive design based on a national register of all nurses in Denmark holding doctoral degrees was used to explore the curricula vitae and publication lists of 38 out of 48 (79%) nurses on the register. Authorship of all 48 graduated nurses was sought in the databases: PubMed and CINAHL. CONCLUSIONS: A pattern of growing engagement in publishing peer-reviewed articles was identified among the Danish nurses holding a doctoral degree. Fifty per cent of these doctoral prepared nurses published peer-reviewed papers. The majority apparently pursued a career in health sciences. Nursing as an academic discipline is evolving in Denmark but, with its roots in clinical nursing, scientists may have to be aware of the necessity to prevail as a discipline through scientific production.

Drinking pattern and mortality in Danish nurses.

BACKGROUND/OBJECTIVE: Moderate alcohol consumption has beneficial effects on survival. Sex differences, however, have been suggested implying less beneficial effect among women. We examined the impact of alcohol consumed on weekdays and at weekends, respectively, on risk of death among women. SUBJECTS AND METHODS: At baseline in 1993, a total of 17 772 female members of the Danish Nurse Association completed questionnaires on alcohol intake and other lifestyle factors. The influence of alcohol intake on risk of death was analyzed using Cox proportional hazard model. RESULTS: Alcohol intake of 1-3 drinks per week was associated with the lowest risk of death. Intake above six drinks per weekend (Friday through Sunday) increased risk of death from all causes by 3% for each additional drink consumed per weekend (corresponding to an increased risk by 9% per drink per weekend day). Consumption of one or more drinks per weekday (Monday, Tuesday, Wednesday or Thursday) increased risk by 4% for each additional drink consumed per day. CONCLUSIONS: The results indicated an increasing risk of death for intake above six drinks per weekend and of one or more drinks per weekday.

Breast cancer with different prognostic characteristics developing in Danish women using hormone replacement therapy.

The aim of this study is to investigate the risk of developing prognostic different types of breast cancer in women using hormone replacement therapy (HRT). A total of 10 874 postmenopausal Danish Nurses were followed since 1993. Incident breast cancer cases and histopathological information were retrieved through the National Danish registries. The follow-up ended on 31 December 1999. Breast cancer developed in 244 women, of whom 172 were invasive ductal carcinomas. Compared to never users, current users of HRT had an increased risk of a hormone receptor-positive breast cancer, but a neutral risk of receptor-negative breast cancer, relative risk (RR) 3.29 (95% confidence interval (CI): 2.27-4.77) and RR 0.99 (95% CI: 0.42-2.36), respectively (P for difference=0.013). The risk of being diagnosed with low histological malignancy grade was higher than high malignancy grade with RR 4.13 (95% CI: 2.43-7.01) and RR 2.17 (95% CI: 1.42-3.30), respectively (P=0.063). For breast cancers with other prognostic characteristics, the risk was increased equally for the favourable and non favourable types. Current users of HRT experience a two- to four-fold increased risk of breast cancer with various prognostic characteristics, both the favourable and non favourable types. For receptor status, the risk with HRT was statistically significantly higher for hormone receptor-positive breast cancer compared to receptor-negative breast cancer.

Relation between hormone replacement therapy and ischaemic heart disease in women: prospective observational study.

OBJECTIVE: To investigate the risk of ischaemic heart disease and myocardial infarction among women using hormone replacement therapy, especially the potential modifying effect of cardiovascular risk factors. DESIGN: Prospective observational study. SETTING: Denmark. PARTICIPANTS: 19 898 nurses aged 45 and over completing a questionnaire on lifestyle and use of hormone replacement therapy in 1993. MAIN OUTCOME MEASURES: All cases of death and incident cases of ischaemic heart disease and myocardial infarction until the end of 1998. RESULTS: Current users of hormone replacement therapy smoked more, consumed more alcohol, had lower self rated health, but were slimmer and had a lower prevalence of diabetes than never users. In current users compared with never users, hormone replacement therapy had no protective effect on ischaemic heart disease (hazard ratio 1.2, 0.9 to 1.7) or myocardial infarction (1.0, 0.6 to 1.7), whereas current users with diabetes had an increased risk of death (3.2, 1.4 to 7.5), ischaemic heart disease (4.2, 1.4 to 12.5), and myocardial infarction (9.2, 2.0 to 41.4) compared with never users with diabetes. CONCLUSION: Hormone replacement therapy showed no protective effect on ischaemic heart disease, but there was a significantly increased risk of death from all causes and ischaemic heart disease among women with diabetes.

Use of hormone replacement therapy among Danish nurses in 1993.

BACKGROUND: To describe the prevalence of women using systemic hormone replacement therapy in various age groups. To identify their reasons for choosing or not choosing the therapy, reasons for discontinuing the treatment, the prevalence of side effects among current users, and to estimate the duration of treatment. METHODS: The study is based on postal questionnaires sent to 23,000 female Danish nurses above the age of 44 years. Out of these 19,953 (86%) responded. The questionnaire gave information on age, use of hormone replacement therapy, use of oral contraceptives, family predisposition and diseases. Duration of hormone replacement therapy was calculated by Cox regression analysis. Chi square tests were used to evaluate differences and 5% was used as the level of significance. RESULTS: Overall, 6673 (33%) had ever used hormone replacement therapy. The prevalence was highest in the age group 55-59, where 29.3% were currently using hormones. The most cited reasons for choosing hormone replacement therapy were vasomotor symptoms (62%) and prevention of osteoporosis (44%). Among never users 43% had not experienced climacteric symptoms, 24% found the therapy unnatural, and 22% were afraid of side effects. It was estimated that 70% still were using hormones five years after the start of therapy, 57% after ten years, and 48% after fifteen years. Women with a family history of osteoporosis used hormones longer than women without this predisposition. CONCLUSIONS: One third of all the women had ever used hormone replacement therapy and more than half of ever users used the therapy for more than ten years.