OBJECTIVES: To examine possible associations of ABO blood types with the risk of venous thromboembolism (VTE) in pregnancy and the puerperium. PATIENTS AND METHODS: We conducted a nested case-control study within a cohort of 71,729 women who gave birth to 126,783 children in the North Jutland County, Denmark, from 1980 to 2001. We identified 129 cases with VTE in pregnancy (n = 61) or the puerperium (n = 68), and 258 controls with no VTE. We collected information on ABO blood groups and possible maternal confounding factors and estimated the relative risk [odds ratio (OR)]. RESULTS: Women with an A or AB blood group had elevated risk estimates of VTE in pregnancy or the puerperium compared with women with a O blood group [adjusted ORs 2.4, 95% confidence interval (CI) 1.3, 4.3, and 2.0, 95% CI 0.7, 5.8, respectively]. No increased risk estimate was found for group B (adjusted OR 1.2, 95% CI 0.5, 3.0). The increased risk estimates of VTE for blood groups A and AB appeared present in both pregnancy (adjusted ORs of 3.9, 95% CI 1.5, 9.7, and 2.2, 95% CI 0.4, 12.5) and in the puerperium (adjusted ORs of 2.4, 95% CI 1.0, 4.9 and 2.7, 95% CI 0.8, 9.3). Furthermore, blood groups A and AB appeared to be associated with increased risk estimates for both DVT and pulmonary embolism. CONCLUSION: Keeping the modest statistical precision of our study in mind, blood groups A and AB may be associated with increased risk estimates for VTE in pregnancy and the puerperium.
This study examined the possible age- and gender-related differences in the use of secondary medical prevention following primary vascular reconstruction in a population-based long-term follow-up study.
Using information from nationwide Danish registers, we identified all patients undergoing primary vascular reconstruction in-between 1996 and 2006 (n = 20,761). Data were obtained on all filled prescriptions 6 months and 3, 5 and 10 years after primary vascular reconstruction. Comparisons were made across age and gender groups, using men 40-60 years old as a reference.
Compared to current guidelines the overall use of secondary medical prevention was moderate to low (e.g., lipid-lowering drugs 49.5%, angiotensin-converting enzyme inhibitors and angiotensin II receptor antagonists (ACE/ATII) 43.4%, combination of lipid-lowering drugs and anti-platelet therapy and any anti-hypertensive therapy 44.7%). A decline was observed between 6 months and 3 years after surgery. Patients >80 years old were less likely to be prescribed lipid-lowering drugs and combination therapy (e.g.: adjusted risk ratio (RR) 5 years after surgery for men and women 0.63 (95% confidence interval (CI): 0.39-1.02) and 0.48 (95%CI: 0.31-0.75), respectively, whereas smaller and statistical non-significant gender-related differences were observed. The age- and gender-related differences appeared eliminated or substantially reduced in the latest part of the study period (2001-2007).
We found moderate to low use of secondary medical prevention in Denmark compared with recommendations from clinical guidelines. However, the use has increased in recent years and age- and gender-related differences have been reduced or even eliminated.
OBJECTIVES: A pooled analysis of randomized trials has shown that oral anticoagulation therapy reduces the risk of ischaemic stroke with 68% in patients with atrial fibrillation. We examined the effectiveness of oral anticoagulation on risk of stroke of any nature (fatal and nonfatal ischaemic and/or haemorrhagic stroke) in patients with nonvalvular atrial fibrillation or flutter living in the County of North Jutland, Denmark. DESIGN: Cohort study. SUBJECTS AND METHODS: We used the Hospital Discharge Registry covering the county (490 000 inhabitants) from 1991 to 1998 to identify 2699 men and 2425 women with atrial fibrillation or flutter, aged 60-89 years. Data on prescriptions of anticoagulation were obtained from the National Health Service. We defined use of oral anticoagulation as date of prescription or reiteration plus 90 days. Patients were followed in the County Hospital Discharge Registry until a diagnosis of stroke (fatal and nonfatal ischaemic and/or haemorrhagic stroke), emigration, death or the end of 1998. We used Cox regression analyses to estimate the relative risk of stroke associated with use of oral anticoagulation compared with no use, adjusted for age, diabetes and underlying cardiovascular diseases. RESULTS: Eight hundred and thirty-eight of 2699 men (31%) and 552 of 2425 women (23%) with atrial fibrillation had one or more recorded prescriptions of oral anticoagulation. The incidence rates of stroke were 31 per 1000 person-years of follow-up in men, and 30 per 1000 person-years of follow-up in women. The adjusted relative risks of stroke during anticoagulation were 0.6 [95% confidence interval (CI) 0.4-1.0] in men, and 1.0 (95% CI 0.7-1.6) in women compared with nonuse periods. CONCLUSIONS: The effectiveness of oral anticoagulation in clinical practice may be lesser than the efficacy of oral anticoagulation reported from randomized trials.
To explore the associations between beta-blocker use and clinical outcomes (death, hospitalisation with myocardial infarction (MI) or stroke, major amputation and recurrent vascular surgery) after primary vascular reconstruction.
Patients who had primary vascular surgical or endovascular reconstruction due to symptomatic peripheral arterial disease, in Denmark between 1996 and 2007 were included. We obtained data on filled prescriptions, clinical outcomes and confounding factors from population-based healthcare registries. Beta-blocker users were matched to non-users by propensity score, and Cox-regression was performed. All medications were included as time-dependent variables.
We studied 16,945 matched patients (7828 beta-blocker users and 9117 non-users) with a median follow-up period of 582 days (range, 30-4379 days). The cumulative risks were as follows: all-cause mortality, 17.9%; MI, 5.3%; stroke, 5.6%; major amputation, 9.1%; and recurrent vascular surgery, 23.1%. When comparing beta-blocker users with non-users: adjusted hazard ratio: MI, 1.52 (95% CI, 1.31-1.78); stroke, 1.21 (95% CI, 1.03-1.43); and major amputation, 0.80 (95% CI, 0.70-0.93).
Beta-blocker use after primary vascular surgery was associated with a lower risk of major amputation but an increased risk of hospitalisation with MI and stroke. No associations were found between beta-blocker use and all-cause mortality or the risk of recurrent vascular surgery. However, our results are not sufficient to alter the indication for beta-blocker use among symptomatic peripheral arterial disease patients.
BACKGROUND: Pregnancy and puerperium are associated with an increased risk of venous thromboembolism. Low-molecular-weight heparin is the anticoagulant of choice in pregnant women because, unlike warfarin, it does not cross the placenta. However, there are limited data on the risk of adverse birth outcomes following use of low-molecular-weight heparin in pregnancy. PATIENTS AND METHODS: We performed a population-based cohort study to examine the safety of low-molecular-weight heparin use in pregnancy using data from the Pharmacoepidemiological Prescription Database, The Danish Medical Birth Registry and the Regional Hospital Discharge Registry in North Jutland County, Denmark. The birth outcomes in a cohort of 66 pregnant women treated with low-molecular-weight heparin between 1991-98 were compared with the birth outcomes of 17,259 pregnant women who did not receive any prescriptive drugs during pregnancy. RESULTS: No increased risk of malformations, low birth weight or stillbirth was found. However, an increased risk of pre-term delivery was found (odds ratio: 2.11, 95%, confidence interval: 0.96-4.65), which could reflect inherited thrombophilia as an indication of low-molecular-weight heparin. CONCLUSION: We have provided additional evidence of the safety of low-molecular-weight heparin use in pregnancy.
We studied 335,682 county residents, of whom 113,298 had been prescribed antihypertensive treatment (AHT), in the period 1989-2002 in North Jutland County, Denmark to examine the relation between different AHTs and the risk of renal cell carcinoma (RCC). An internal comparison was performed among the different classes of AHT users with users of beta blockers as the reference, in order to address potential confounding and bias. The average follow-up was 10 years (range 0-13). Use of any AHT was associated with RCC (relative rate (RR)=1.6, 95% confidence interval (CI) 1.3-1.9) compared with nonusers in the general population. Specific classes of AHTs were nonsignificantly associated with RCC, but compared with users of beta blockers, the numbers observed were close to expectation. Analyses by duration of follow-up and number of prescriptions revealed no clear trends for any antihypertensive agent and after 5-years of follow-up, the RRs for all classes of AHT decreased. The elevated RRs for RCC among users of AHTs compared with the general population are unlikely to be causal, but rather reflect confounding due to failure to control for pre-existing hypertension, and protopathic bias, due to the presence of hypertension as an early sign of kidney disease.
Population-based data on the rate and outcome of complications related to blood donation are sparse.
Data from a survey conducted in 2003 in Aarhus County, Denmark, were used to assess the overall rate of donor complications. Additional nationwide data on moderate and severe donor complications were obtained from the Danish Register of Complications Related to Blood Donation, with records of all moderate and severe donor complications in Denmark occurring during the period 1997-2003.
In the regional survey, we identified 340 complications of any type among 41 274 donations, corresponding to a rate of 824/100,000 donations [95% confidence interval (CI): 741-916]. All complications were either needle injuries or vasovagal reactions. In the nationwide register, a total of 752 moderate and severe complications were recorded among 2,575,264 donations, corresponding to a rate of 29/100,000 donations (95% CI: 27-31). The rates of complications leading to long-term morbidity or disablement (> 5% loss of working capacity) were 5/100,000 donations (95% CI: 4.2-5.9) and 2.3/100,000 donations (95% CI: 1.8-2.9), respectively.
The risk of complications related to blood donation is low. However, attention towards donor complications is warranted, given the non-negligible rate of complications resulting in long-term morbidity and disablement.
To examine real-life time trends in early glycaemic control in patients with type 2 diabetes between 2000 and 2012.
We used population-based medical databases to ascertain the association between achievement of glycaemic control with initial glucose-lowering treatment in patients with incident type 2 diabetes in Northern Denmark. Success in reaching glycated haemoglobin (HbA1c) goals within 3-6?months was examined using regression analysis.
Of 38?418 patients, 91% started with oral glucose-lowering drugs in monotherapy. Metformin initiation increased from 32% in 2000-2003 to 90% of all patients in 2010-2012. Pretreatment (interquartile range) HbA1c levels decreased from 8.9 (7.6-10.7)% in 2000-2003 to 7.0 (6.5-8.1)% in 2010-2012. More patients achieved an HbA1c target of
BACKGROUND: Population-based data on the early postoperative outcome after surgery for gastric cancer are very sparse. We examined the development in the quality of surgery and early postoperative outcomes in Denmark following centralization of gastric cancer surgery and implementation of national clinical guidelines. METHODS: All patients in Denmark who underwent resection with curative intent for gastric cancer between 1st July 2003 and 31st December 2008 in one of five university hospitals were registered in a national database. Data on surgical quality and mortality were obtained from the database and compared with the results from the period before centralization (1999-2003). RESULTS: A total of 416 patients underwent resection in the study period. The risk of anastomotic leakages for the whole period was 5.0% (95%CI; 3.2-7.7) compared to 6.1% (95%CI; 4.3-8.6) before centralization, whereas the 30-days hospital mortality was 2.4% (95%CI; 1.2-4.4) compared to 8.2% (95%CI; 6.0-10.4) before centralization. In addition, the percentage of patients with at least 15 lymph nodes removed increased during the study period from 19 in 2003 to 76 in 2008. CONCLUSIONS: Centralization of gastric cancer surgery in Denmark and implementation of national clinical guidelines monitored by a national database was associated with improvements in surgical quality and substantially lower in-hospital mortality.
During the past decade, studies have shown an inverse association between birth weight and blood pressure and risk of coronary heart disease in adult life. From old public archives we were able to trace the birth records of 545 out of 905 persons (60.2%) aged 31-51 years who participated in the Ebeltoft Health Promotion Project in Denmark. We examined the associations between birth weight, length at birth, Ponderal Index and systolic and diastolic blood pressure. No associations were found for women. For men, the mean systolic blood pressure fell from 131.1 mmHg with a birth weight of less than 3300 g to 129.6 mmHg with a birth weight of more than 4000 g, and for diastolic blood pressure 81.6 mmHg to 80.3 mmHg, respectively. For men, the mean systolic blood pressure fell from 135.7 mm Hg with a birth length of 30-51 cm to 131.6 with a birth length of 55-62 cm, and for diastolic blood pressure 83.0 mmHg to 78.8 mmHg, respectively. The associations may reflect organ programming in fetal life.