Existing data sources for clinical epidemiology: The Danish National Database of Reimbursed Prescriptions

A Novel Model for Prediction of Thromboembolic and Cardiovascular Events in Patients Without Atrial Fibrillation

Patients without atrial fibrillation (AF) constitute approximately 75% of patients suffering thromboembolism and major adverse cardiovascular events (MACE), but evidence supporting risk stratification in these patients is sparse. We aimed to develop a risk prediction model for identification of patients without AF at high risk of first-time thromboembolic events. We included 72,381 coronary angiography patients without AF and without previous ischemic stroke or transient ischemic attack. The cohort was randomly divided into a derivation cohort (80%, n = 57,680) and a validation cohort (20%, n = 14,701). The primary thromboembolic end point was a composite of ischemic stroke, transient ischemic attack, and systemic embolism. MACE was defined as a composite of cardiac death, myocardial infarction, and ischemic stroke. The final model was compared with 2 validated clinical risk models (CHADS₂ and CHA₂DS₂-VASc). The risk prediction model assigned 1 point to heart failure, hypertension, diabetes mellitus, renal disease, age 65 to 74 years, active smoking, and multivessel obstructive coronary artery disease, and 2 points to age ≥75 years and peripheral artery disease. A C-index of 0.66 (95% CI 0.64 to 0.69) for prediction of the composite thromboembolic end point was found in the validation cohort, which was higher than for CHADS₂ (C-index 0.63 [95% CI 0.60 to 0.67]; p < 0.001) and CHA₂DS₂-VASc (C-index 0.64 [95% CI 0.62 to 0.67]; p = 0.034). The model also predicted MACE (C-index 0.71 [95% CI 0.69 to 0.73]). In conclusion it is possible to identify patients without AF at high risk of first-time thromboembolic events and MACE by use of a simple clinical prediction model.

Lung Function Trajectories Leading to Chronic Obstructive Pulmonary Disease as Predictors of Exacerbations and Mortality

Rationale: Chronic obstructive pulmonary disease (COPD) can develop not only through a lung function trajectory dominated by an accelerated decline of FEV₁ from normal maximally attained FEV₁ in early adulthood (normal maximally attained FEV₁ trajectory) but also through a trajectory with FEV₁ below normal in early adulthood (low maximally attained FEV₁ trajectory).Objectives: To test whether the long-term risk of exacerbations and mortality differs between these two subtypes of COPD.Methods: The cohort included 1,170 young adults enrolled in the Copenhagen City Heart Study during the 1970s and 1980s. In 2001-2003, which served as the baseline for the present analyses, 79 participants had developed COPD through normal maximally attained FEV₁ trajectory, 65 had developed COPD through low maximally attained FEV₁ trajectory, and 1,026 did not have COPD.Measurements and Main Results: From 2001 until 2018, we observed 139 severe exacerbations of COPD and 215 deaths, of which 55 were due to nonmalignant respiratory disease. In Cox models, there was no difference with regard to risk of severe exacerbations between the two trajectories, but individuals with normal maximally attained FEV₁ had an increased risk of nonmalignant respiratory disease mortality (using inverse probability of censoring weighting with adjusted hazard ratio [HR], 6.20; 95% confidence interval [CI], 2.09-18.37; P = 0.001) and all-cause mortality (adjusted HR, 1.93; 95% CI, 1.14-3.26; P = 0.01) compared with individuals with low maximally attained FEV₁.Conclusions: COPD developed through normal maximally attained FEV₁ trajectory is associated with an increased risk of respiratory and all-cause mortality compared with COPD developed through low maximally attained FEV₁ trajectory.

Unicompartmental knee arthroplasty undertaken using a fast-track protocol

Aims

The aim of this prospective multicentre study was to describe trends in length of stay and early complications and readmissions following unicompartmental knee arthroplasty (UKA) performed at eight different centres in Denmark using a fast-track protocol and to compare the length of stay between centres with high and low utilization of UKA.

Methods

We included data from eight dedicated fast-track centres, all reporting UKAs to the same database, between 2010 and 2018. Complete ( > 99%) data on length of stay, 90-day readmission, and mortality were obtained during the study period. Specific reasons for a length of stay of > two days, length of stay > four days, and 30- and 90-day readmission were recorded. The use of UKA in the different centres was dichotomized into ≥ 20% versus < 20% of arthroplasties which were undertaken being UKAs, and ≥ 52 UKAs versus < 52 UKAs being undertaken annually.

Results

A total of 3,927 procedures were included. Length of stay (mean 1.1 days (SD 1.1), median 1 (IQR 0 to 1)) was unchanged during the study period. The proportion of procedures with a length of stay > two days was also largely unchanged during this time. The percentage of patients discharged on the day of surgery varied greatly between centres (0% to 50% (0 to 481)), with centres with high UKA utilization (both usage and volume) having a larger proportion of same-day discharges. The 30- and 90-day readmissions were 166 (4.2%) and 272 (6.9%), respectively; the 90-day mortality was 0.08% (n = 3).

Conclusion

Our findings suggest general underutilization of the potential for quicker recovery following UKA in a fast-track setup. Cite this article: Bone Joint J 2020;102-B(9):1167–1175.

Constipation and risk of cardiovascular diseases: a Danish population-based matched cohort study

OBJECTIVES

To assess the risks of myocardial infarction, stroke, peripheral artery disease, venous thromboembolism, atrial fibrillation or atrial flutter and heart failure in patients with constipation compared with a general population cohort.

DESIGN

Population-based matched cohort study.

SETTING

All Danish hospitals and hospital outpatient clinics from 2004 to 2013.

PARTICIPANTS

Patients with a constipation diagnosis matched on age, sex and calendar year to 10 individuals without constipation from the general population.

MAIN OUTCOMES MEASURES

Comorbidity-adjusted and medication-adjusted hazard ratios (aHRs) for cardiovascular outcomes based on Cox regression analysis.

RESULTS

83 239 patients with constipation were matched to 832 384 individuals without constipation. The median age at constipation diagnosis was 46.5% and 41% were men. Constipation was strongly associated with venous thromboembolism (aHR 2.04, 95% CI 1.89 to 2.20), especially splanchnic venous thrombosis (4.23, 95% CI 2.45 to 7.31). Constipation was also associated with arterial events, including myocardial infarction (1.24, 95% CI 1.14 to 1.35), ischaemic stroke (1.50, 95% CI 1.41 to 1.60), haemorrhagic stroke (1.46, 95% CI 1.26 to 1.69), peripheral artery disease (1.34, 95% CI 1.20 to 1.50), atrial fibrillation or atrial flutter (1.27, 95% CI 1.20 to 1.34) and heart failure (1.52, 95% CI 1.42 to 1.62). The associations were strongest during the first year after the constipation diagnosis and strengthened with an increased number of laxative prescriptions.

CONCLUSIONS

Constipation was associated with an increased risk of several cardiovascular diseases, in particular venous thromboembolism.

Use of inhaled corticosteroids and the risk of developing type 2 diabetes in patients with chronic obstructive pulmonary disease

AIM

To determine the risk of type 2 diabetes onset associated with accumulated inhaled corticosteroids (ICS) dose during the previous year in patients with chronic obstructive pulmonary disease (COPD).

MATERIALS AND METHODS

We conducted a nationwide observational cohort study based on data from patients with COPD between 1 January 2010 and 31 December 2017 extracted from Danish health databases. Patients were followed for 7 years, until death or a type 2 diabetes event. A propensity-matched Cox model and an adjusted Cox proportional hazards model (stratified on body mass index [BMI]) were used to estimate the hazard ratio (HR) for new-onset type 2 diabetes.

RESULTS

A total of 50 148 patients with COPD were included, 3566 (7.1%) of whom had a type 2 diabetes event. During the previous year before study entry, 35 368 patients (70.5%) used ICS. The propensity-matched Cox model (N = 33 466) showed an increased risk of type 2 diabetes, which progressed with increasing accumulated ICS dose (low-ICS: HR 1.076, confidence interval [CI] 1.075-1.077, P < .0001; medium-ICS: HR 1.106, CI 1.105-1.108, P < .0001; high-ICS: HR 1.150, CI 1.148-1.151, P < .0001), compared with no ICS use. Results were confirmed in the adjusted Cox analysis on the entire study population, but only for patients with BMI <30 kg/m² .

CONCLUSIONS

In patients with COPD, ICS use was associated with a moderate dose-dependent increase in the occurrence of type 2 diabetes.

How patients in Denmark acquire their medicines: overview, data sources and implications for pharmacoepidemiology

The means by which patients acquire their medications differ between countries, and a knowledge of this is essential when conducting and interpreting pharmacoepidemiological studies. The aim of this paper is to provide an overview of how patients obtain medicines in Denmark, to relate these to nationwide registries available for research and to discuss the implications for research. Health services are predominantly tax-funded in Denmark, with dentistry and some medicine bought at community pharmacies being exceptions, involving partial reimbursement of charges. The paper gives an overview of prescription medicines acquired from community pharmacies (including magistral preparations), over-the-counter medicines, vaccinations and in-hospital medicine including so-called "free medicine" (in Danish: "vederlagsfri medicin"). "Free medicine" is medicines for a defined list of diseases and indications that is provided free of charge to patients in outpatient clinics. The paper also describes the content of the various Danish data sources about medicine use, summarizes their strengths and limitations, and exemplifies the ways of evaluating their completeness. An example is provided of the regional variation in the means by which medicines are acquired.

Creatinine increase following initiation of antihypertensives is associated with cardiovascular risk: a nationwide cohort study

OBJECTIVE

Abrupt decline in renal function following initiation of renin-angiotensin system inhibitor is associated with increased risk of cardiovascular disease, but studies of other antihypertensive drugs are sparse. We investigated the risk of cardiovascular event associated with increased plasma creatinine after initiating first-line antihypertensive treatment.

METHODS

In a nationwide cohort study, we identified adult Danish primary care patients initiating either renin-angiotensin system inhibitor, calcium channel blocker or thiazide, between 2008 and mid-2018. Patients with prior end-stage renal disease, renal transplantation, or cardiovascular disease were excluded. Percentual plasma creatinine increase was calculated between the nearest creatinine measurement up to 1 year before redeeming the prescription (baseline), and the nearest measurement 90 days or less after (index). Multiple logistic regression and restricted cubic splines were applied to estimate the 6-month absolute risk of cardiovascular event (ischemic heart disease, heart failure or stroke) associated with this creatinine increase.

RESULTS

We included 20 789 patients. Within the first 6 months of follow-up, 283 (1.4%) cardiovascular events and 93 (0.4%) all-cause deaths were registered. With a creatinine increase of 0 and 30%, 6-month absolute risk [CI] of cardiovascular event was 1.4% [1.1-1.9] and 3.5% [2.4-5.2], respectively (in men aged 50-79 years with estimated glomerular filtration rate at least 60 ml/min per 1.73 m and no diabetes). Higher age and reduced renal function, but not the type of antihypertensive treatment, were associated with higher cardiovascular risk.

CONCLUSION

In primary care, patients initiating first-line antihypertensive treatment, an increase in plasma creatinine above 30% was associated with increased absolute 6-month risk of cardiovascular event.

Grief symptoms and primary care use: a prospective study of family caregivers

BACKGROUND

Family caregivers to patients who are severely ill have high use of primary health care and psychotropic medication. However, it remains sparsely investigated whether healthcare services target the most vulnerable caregivers.

AIM

This study aimed to examine associations between family caregivers' grief trajectories of persistent high-grief symptom level (high-grief trajectory) versus persistent low-grief symptom level (low-grief trajectory), as well as early contacts with GPs or psychologists and the use of psychotropic medication.

DESIGN & SETTING

A population-based cohort study of family caregivers (n = 1735) in Denmark was undertaken.

METHOD

The Prolonged Grief-13 (PG-13) scale measured family caregivers' grief symptoms at inclusion (during the patient's terminal illness), 6 months after bereavement, and 3 years after bereavement. Multinomial regression was used to analyse register-based information on GP consultations, psychologist sessions, and psychotropic medication prescriptions in the 6 months before inclusion.

RESULTS

A total of 1447 (83.4%) family caregivers contacted their GP, and 91.6% of participants in the high-grief trajectory had GP contact. Compared with family caregivers in the low-grief trajectory, family caregivers in the high-grief trajectory had ≥4 face-to-face GP consultations (odds ratio [OR] = 2.6; 95% confidence interval [CI] = 1.3 to 5.0), more GP talk therapy (OR =4.4; 95% CI = 1.9 to 10.0), and more psychotropic medication, but not significantly more psychologist sessions (OR = 1.7; 95% CI = 0.5 to 6.6).

CONCLUSION

Family caregivers in the high-grief trajectory had more contact with their GP, but their persisting grief symptoms suggest that primary care interventions for family caregivers should be optimised. Future research is warranted in such interventions and in the referral patterns to specialised mental health care.

Effect of Predeployment Psychiatric Diagnoses on Postdeployment Long-Term Sickness Absence and Mental Health Problems Among Danish Military Personnel

Military personnel may withhold information on mental health problems (MHPs) for fear of not being permitted to deploy. Past or current MHPs may, however, increase the risk of postdeployment MHPs. Using psychiatric diagnoses rather than self-report assessments in predeployment screening may be a more effective screening strategy for determining deployment fitness. This retrospective follow-up study investigated (a) the extent to which predeployment childhood and adult psychiatric diagnoses predicted postdeployment MHPs, measured as psychiatric diagnosis and the purchase of psychiatric drugs, and long-term sickness absence among formerly deployed Danish military personnel and (b) whether perceived combat exposure moderated or mediated the effect of predeployment psychiatric diagnoses. Complete data were available for 7,514 Danish military personnel who answered questions on perceived combat exposure between 6-8 months after returning from their first deployment to the Balkans, Iraq, or Afghanistan. Data on all psychiatric diagnoses given at Danish hospitals, all medicine purchases, and all sickness absences were retrieved from nationwide research registers. Personnel with predeployment psychiatric diagnoses had a statistically significant higher risk for both postdeployment long-term sickness absence, hazard ratio (HR) = 2.06, 95% CI [1.52, 2.80]; and postdeployment MHPs, HR = 2.38, 95% CI [1.73, 3.27], than personnel without a predeployment psychiatric diagnosis. Personnel with a predeployment psychiatric diagnosis demonstrated a higher risk of reporting high levels of perceived combat exposure. Perceived combat exposure was not found to moderate or mediate the effect of a predeployment psychiatric diagnosis on the two outcomes. Additional findings, limitations, and implications are discussed.

Risk of Upper Gastrointestinal Bleeding and Gastroduodenal Ulcers in Persons With Schizophrenia: A Danish Cohort Study

There is little evidence about gastrointestinal (GI) disorders in patients with schizophrenia. We examined association of schizophrenia with upper GI bleeding (UGIB) and nonbleeding ulcers and associated risk factors and mortality.

Fast-track hip and knee arthroplasty in older adults-a prospective cohort of 1,427 procedures in patients ≥85 years

INTRODUCTION

fast-track protocols in total hip and knee arthroplasty (THA/TKA) have improved postoperative recovery and reduced postoperative morbidity. Additionally, increasing life expectancy and improved surgical techniques have led to an increasing number of older adult patients undergoing THA/TKA. However, no large detailed studies on fast-track THA/TKA in older adults are available. Consequently, we aimed to describe the length of stay (LOS) and postoperative morbidity in a large cohort of patients ≥85 years within a continuous multicentre fast-track collaboration.

METHODS

we used a prospective observational cohort design with unselected consecutive data between 2010 and 2017 on primary elective THA and TKA patients ≥85 years. Data were obtained from nine centres reporting to the Lundbeck Foundation Centre for Fast-track Hip and Knee Replacement database and the Danish National Patient Registry on LOS, readmissions and mortality. Causes of morbidity were determined by review of health records.

RESULTS

we included 1,427 (3.9% of all THA/TKA) procedures with 62.3% THA. Median age was 87 (IQR: 85-88) years with 71% women. LOS decreased from median 4 (3-6) days in 2010 to 2 (2-3) days in 2017. The proportion with LOS > 4 days decreased from 32 to 18%. Readmission and mortality rate remained at about 11.7 and 0.9% after 30 days and 16.0 and 1.5% after 90 days, respectively.

CONCLUSION

this detailed large multicentre fast-track THA/TKA study in patients ≥85 years found major reductions in LOS without increase in readmission or mortality rates. The unchanged readmission rate poses an area for further improvements.

Association of CHA2 DS2 -VASc Score with Stroke, Thromboembolism, and Death in Hip Fracture Patients

OBJECTIVES

Patients undergoing hip fracture surgery have a 10 times increased risk of stroke compared with the general population. We aimed to evaluate the association between the CHA₂ DS₂ -VASc (congestive heart failure, hypertension, age ≥75 years, diabetes, previous stroke/TIA [transient ischemic attack]/systemic embolism (2 points), vascular disease, age 65-74 years, and female sex) score and the risk of stroke, thromboembolism, and all-cause mortality in patients with hip fracture with or without atrial fibrillation (AF).

DESIGN

Nationwide prospective cohort study.

SETTING

Danish hospitals.

PARTICIPANTS

Subjects were all incident hip fracture patients in Denmark age 65 years and older with surgical repair procedures between 2004 and 2016 (n = 78,096). Participants were identified using the Danish Multidisciplinary Hip Fracture Registry.

MEASUREMENTS

We calculated incidence rates, cumulative incidences, and hazard ratios (HRs) with 95% confidence intervals (CIs) by CHA₂ DS₂ -VASc score, stratified on AF history.

RESULTS

The cumulative incidence of ischemic stroke 1 year after hip fracture increased with ascending CHA₂ DS₂ -VASc score, and it was 1.9% for patients with a score of 1 and 8.6% for patients with a score above 5 in the AF group. Corresponding incidences in the non-AF group were 1.6% and 7.6%. Compared with a CHA₂ DS₂ -VASc score of 1, adjusted HRs were 5.53 (95% CI = 1.37-22.24) among AF patients and 4.91 (95% CI = 3.40-7.10) among non-AF patients with a score above 5. A dose-response-like association was observed for all cardiovascular outcomes. All-cause mortality risks and HRs were substantially higher for all CHA₂ DS₂ -VASc scores above 1 in both the AF group and the non-AF group.

CONCLUSION

Among patients with hip fracture, a higher CHA₂ DS₂ -VASc score was associated with increased risk of stroke, thromboembolism, and death. This finding applied both to patients with and without AF. Patients with high CHA₂ DS₂ -VASc scores had almost similar absolute risks for cardiovascular outcomes, irrespective of AF. J Am Geriatr Soc 68:1698-1705, 2020.

Cohort profile: the Funen Diabetes Database-a population-based cohort of patients with diabetes in Denmark

PURPOSE

Detailed population-based data are essential to understanding the epidemiology of diabetes and its clinical course. This article describes the Funen Diabetes Database (FDDB). The purpose of the FDDB was to serve as a shared electronic medical record system for healthcare professionals treating patients with diabetes. The cohort can also be used for research.

PARTICIPANTS

The FDDB covers a geographical area of almost 500 000 Danish inhabitants. It currently includes 3691 patients with type 1 diabetes, 19 085 patients with type 2 diabetes, 292 patients with other types of diabetes and 5992 patients with an unknown type of diabetes. Patients have been continuously enrolled from general practitioners and endocrinology departments in the Funen area in Denmark since 2003. Patients undergo a clinical work-up at their first diabetes contact and during follow-up visits. The information collected includes type of diabetes contact, blood pressure, height, weight, lifestyle factors (smoking, exercise), laboratory records (eg, haemoglobin A1c and cholesterol levels), results from foot examinations (eg, pulse, cutaneous sensitivity and ankle brachial index), results from eye examinations (eg, degree of retinopathy assessed by retinal photo and eye examination), glucose-lowering drugs and diabetic complications.

FINDINGS TO DATE

The FDDB cohort was followed for a total of 212 234 person-years up to 2016. A cross-sectional study described the prevalence of diabetic retinopathy and its associated risk factors. The clinical outcomes of patients with type 1 diabetes, type 2 diabetes and latent autoimmune diabetes in adults have been assessed. Linkage to population-based medical registries with complete follow-up has enabled the collection of extensive continuous data on general practice contacts, diagnoses and procedures from hospital contacts, medication use and mortality.

FUTURE PLANS

The FDDB serves as a strong data resource that will be used in future studies of diabetes epidemiology with focus on occurrence, risk factors, treatment, complications and prognosis.

Trends in preadmission oral anticoagulant use and clinical outcome in atrial fibrillation patients admitted with acute stroke in Denmark

AIMS

Use of oral anticoagulation (OAC) therapy has increased in recent years among patients with atrial fibrillation (AF). However, it remains uncertain whether this translates into improved clinical outcomes. We aimed to examine time trends in preadmission OAC use and clinical outcomes among AF patients admitted with stroke.

METHODS AND RESULTS

We used nationwide registries to perform a follow-up study of 14 999 patients with AF who were admitted with acute stroke to a Danish hospital between 2008 and 2016. The proportion of AF-related stroke was 16.1% in 2008 and 17.6% in 2016. Among patients with AF-related stroke, the overall proportion of preadmission OAC users increased from 22.6% in 2008 to 41.5% in 2016. Between 2008 and 2016, the proportion of patients with AF admitted with severe stroke declined from 32.4% to 27.4% [adjusted odds ratio (OR) = 0.78, 95% confidence interval (CI): 0.75-0.81], the median length of hospital stay (LOS) decreased from 12 to 8 days (adjusted hazard ratio of discharge = 1.32, 95% CI: 1.30-1.34) and 30-day mortality decreased from 19.2% to 13.7% (adjusted OR = 0.72, 95% CI: 0.68-0.75).

CONCLUSION

The incidence of AF-related strokes remains high although preadmission use of OAC has increased substantially in recent years. Despite the proportion of OAC users almost doubled from 2008 to 2016, a sizeable proportion of AF patients is still without OAC when admitted with stroke. The increased use of OAC has been accompanied by a lower proportion of patients with severe stroke, shorter LOS, and lower mortality.

Impact of risk minimisation measures on the use of strontium ranelate in Europe: a multi-national cohort study in 5 EU countries by the EU-ADR Alliance

INTRODUCTION

In May 2013 and March 2014, the European Medicines Agency (EMA) issued two decisions restricting the use of strontium ranelate (SR). These risk minimisation measures (RMM) introduced new contraindications and limited the indications of SR therapy. The EMA required an assessment of the impact of RMMs on the use of SR in Europe. Methods design: multi-national, multi-database cohort Setting: electronic medical record databases based on hospital (Denmark) and primary care provenance (Italy, Spain, the Netherlands, UK).

PARTICIPANTS

the database source populations were included for population-based analyses, and SR users for patient-level analyses.

INTERVENTION

New RMMs included contraindications (ischaemic heart disease, peripheral arterial disease, cerebrovascular disease, uncontrolled hypertension) and restricted SR indication to severe osteoporosis with initiation by experienced physician and not as first line anti-osteoporosis therapy.

METHODS

Prevalence and incidence rates of SR use in the population; prevalence of contraindications and restricted indications in SR users, plus 1-year therapy persistence. Drug use measures were calculated in three periods for comparison: reference (2004 to May 2013), transition (June 2013 to March 2014) and assessment (from April 2014 to end 2016).

RESULTS

The study population included 143 million person-years(PY) of follow-up and 76,141 incident episodes of SR treatment. Average monthly prevalence rates of SR use dropped by 86.4% from 62.6/10,000 PY (95 CI 62.4-62.9) in the reference to 8.5 (8.5-8.6) in the assessment period. Similarly, the incidence rate of SR use fell by 97.3% from 7.4/10,000 PY (7.4-7.4) to 0.2 (0.2-0.2) between the reference and assessment period. The prevalence of any contraindication decreased, whilst the prevalence of restricted indications increased in these periods. One-year persistence decreased in the assessment compared with reference period.

CONCLUSIONS

Our study demonstrates a substantial impact of the regulatory action to restrict use of SR in Europe: SR utilisation overall decreased strongly. The proportion of patients fulfilling the restricted indications, without contraindications, increased after the proposed RMMs.

No Evidence of Off-label Use of Olodaterol and Indacaterol in Denmark, France, and the Netherlands: A Drug Utilization Study

To characterize the use of olodaterol and indacaterol in clinical practice and to quantify the off-label use in asthma. Drug utilization study of new users of olodaterol or indacaterol between 2014 and 2017 in the PHARMO Database Network in the Netherlands, the Danish population registers, and the IMS Real-World Evidence Longitudinal Patient Database panels in France. On-label use was defined as use among adults with a recorded diagnosis of COPD. Off-label use was defined as use among adults with a recorded diagnosis of asthma without a recorded diagnosis of COPD or as use among patients aged ≤18 years. Potential off-label use was defined as no recorded diagnosis of either COPD or asthma. The study included 4,158 new users of olodaterol and 9,966 new users of indacaterol. Prevalence of off-label use ranged from 3.5% for both drugs to 12.4% for olodaterol and 11.9% for indacaterol. Prevalence of on-label use ranged from 47.8% to 77.7% for olodaterol and from 28.7% to 70.1% for indacaterol. The remaining new users of olodaterol and indacaterol were classified as potential off-label users, with prevalence ranging from 17.3% to 48.6% for olodaterol and from 20.5% to 66.6% for indacaterol. This study provides no evidence of a major concern in Europe for olodaterol or indacaterol for off-label use in asthma or for pediatric use.

Exploring Functional Impairment in Light of Prolonged Grief Disorder: A Prospective, Population-Based Cohort Study

Background: Functional impairment is essential in the diagnostic criteria for prolonged grief disorder (PGD) in the ICD-11. It refers to the negative impact on everyday life, including inability to maintain the usual level of functioning. We aimed to assess the extent of functional impairment, emotion-related role limitation, and impaired social functioning before and after bereavement, and to explore associations with PGD, as measured by the 13-item Prolonged Grief Scale (PGD_PG13). Method: Relatives of terminally ill patients (n = 1,622) completed a questionnaire before and after bereavement. The questionnaire assessed "overall functional impairment" (PG-13 item) and "aspects of functional impairment" measured by mean scores of the 36-item Short Form Survey (SF-36) subscales emotional role and social functioning (0: worst; 100: best). We analyzed associations between PGD_PG13 and functional impairment prior to bereavement using logistic regression models adjusted for age, gender, personal relation, education, time interval to patient's death, and pre-loss grief. Results: In total, 51% reported overall functional impairment before bereavement, 27% reported functional impairment at 6 months after bereavement, and 19% reported functional impairment at 3 years after bereavement. The mean emotional role score was 47.5 (95%CI: 45.4-49.7) before bereavement, increasing to 77.4 (95%CI: 75.7-79.0) at 3 years after bereavement, compared to 85.1 (95%CI: 77.6-92.6) in a reference sample. Mean social functioning score increased gradually reaching the mean of the reference sample at 3 years after bereavement. PGD_PG13 was present in 26% of those with overall functional impairment at 6 months after bereavement, decreasing to 11% at 3 years after bereavement. Pre-bereavement measures of emotional role and social functioning were associated with PGD_PG13at 6 months and 3 years after bereavement. Discussion: Overall functional impairment was prevalent as reflected in low scores on daily activities and social functioning compared to a reference sample. Functioning may be an important factor during caregiving and bereavement and pre-bereavement functional impairment was associated with PGD_PG13. Future studies should investigate if maintaining daily activities and social functioning before bereavement could be key in early supportive care. Moreover, the role of functional impairment in bereavement interventions should be explored.

Factors influencing harmonized health data collection, sharing and linkage in Denmark and Switzerland: A systematic review

Introduction

The digitalization of medicine has led to a considerable growth of heterogeneous health datasets, which could improve healthcare research if integrated into the clinical life cycle. This process requires, amongst other things, the harmonization of these datasets, which is a prerequisite to improve their quality, re-usability and interoperability. However, there is a wide range of factors that either hinder or favor the harmonized collection, sharing and linkage of health data.

Objective

This systematic review aims to identify barriers and facilitators to health data harmonization—including data sharing and linkage—by a comparative analysis of studies from Denmark and Switzerland.

Methods

Publications from PubMed, Web of Science, EMBASE and CINAHL involving cross-institutional or cross-border collection, sharing or linkage of health data from Denmark or Switzerland were searched to identify the reported barriers and facilitators to data harmonization.

Results

Of the 345 projects included, 240 were single-country and 105 were multinational studies. Regarding national projects, a Swiss study reported on average more barriers and facilitators than a Danish study. Barriers and facilitators of a technical nature were most frequently reported.

Conclusion

This systematic review gathered evidence from Denmark and Switzerland on barriers and facilitators concerning data harmonization, sharing and linkage. Barriers and facilitators were strictly interrelated with the national context where projects were carried out. Structural changes, such as legislation implemented at the national level, were mirrored in the projects. This underlines the impact of national strategies in the field of health data. Our findings also suggest that more openness and clarity in the reporting of both barriers and facilitators to data harmonization constitute a key element to promote the successful management of new projects using health data and the implementation of proper policies in this field. Our study findings are thus meaningful beyond these two countries.

A positive Helicobacter pylori test is associated with low spondylarthritis incidence in a Danish historical cohort study

Ankylosing spondylitis (AS) and undifferentiated spondylarthritis (uSpA) are related inflammatory diseases affecting the spine and joints with infections among possible etiological factors. Helicobacter pylori (H. pylori) may affect the development of inflammatory diseases. Thus, we hypothesized that H. pylori infection affects AS and uSpA development. This cohort study was performed in Denmark with 56,000 patients from primary health care centers who were enrolled when a UBT was performed. They were followed for a median time of 8 years. From nationwide administrative registries, we extracted personal, diagnostic, and treatment information. Prevalence at time of UBT was studied on enrollment using logistic regression and incidence in the follow-up time of 8 years after UBT was studied using Cox regression, comparing H. pylori positive and H. pylori negative patients and adjusting for confounding variables. The prevalence of AS at the time of the UBT was higher among H. pylori positive individuals (OR = 2.00, CI 1.17-3.41), but likely to be linked to confounding as trends disappeared when stratifying for country of birth. The incidence of AS after UBT was lower for individuals who were previously H. pylori positive (OR = 0.23, CI 0.06-0.93). A similar phenomenon was observed for uSpA. As a novel finding, after UBT, the previously H. pylori infected individuals had lower risk of developing AS and uSpA compared to non-infected. This finding may be caused by etiological effects of previous H. pylori infection or unknown confounders. This suggests that H. pylori may somehow be positively involved in the pathogenesis of AS and uSpA.

Risk factors of post-discharge under-five mortality among Danish children 1997-2016: A register-based study

Objectives

Estimating associations between somatic and socioeconomic risk factors and post-discharge under-five mortality.

Design

Register-based national cohort study using multiple Cox regression.

Participants

The population of 1,263,795 Danish children live-born 1997–2016 who survived until date of first discharge to the home after birth was followed from that date until death, emigration, 5 years of age or 31 December 2016.

Main outcome measures

(A) Mortality hazard ratios (HRs) among all children, (B) mortality HRs among children without severe chronic disease, and (C) mortality HRs among children without severe chronic disease or asthma.

Main results

In the total population (1,947 deaths) severe chronic disease was associated with mortality HR = 15.28 (95% CI: 13.77–16.95). In children without severe chronic-disease (719 deaths) other somatic risk factors were immature birth HR = 3.40 (1.92–6.02), maternal smoking HR = 1.84 (1.55–2.18) and low birth weight HR = 1.74 (1.21–2.51). Socioeconomic risk factors for mortality included: maternal age < 25 years HR = 1.91 (1.38–2.64) compared to > 35 years (similar for 30–35 years and 25–29 years), lowest vs. highest family income tertile HR = 1.76 (1.23–2.51), not living with both parents HR = 1.63 (1.25–2.13), maternal unemployment HR = 1.54 (1.12–2.12), presence of siblings HR = 1.44 (1.20–1.71) and secondary vs. tertiary parental education HR = 1.33 (1.07–1.65) for fathers and HR = 1.23 (1.01–1.52) for mothers. Factors not found to be associated with child mortality in this population included presence of asthma HR = 1.29 (0.83–1.98) and non-Danish ethnicity HR = 0.98 (0.70–1.37).

Conclusions

Childhood death after discharge to the home after birth and before 5 years of age is a very rare event in Denmark. This ‘post-discharge’ mortality was heavily associated with severe chronic disease. In children without severe chronic disease, immature birth, maternal smoking and certain socioeconomic characteristics were noticeable risk factors. Mortality may possibly be decreased by focusing on vulnerable groups.

Renin-angiotensin system blocker use and the risk of acute kidney injury after colorectal cancer surgery: a population-based cohort study

OBJECTIVES

It is unknown whether preoperative use of ACE inhibitors (ACE-I) or angiotensin receptor blockers (ARBs) affects the risk of acute kidney injury (AKI) after colorectal cancer (CRC) surgery. We assessed the impact of preoperative ACE-I/ARB use on risk of AKI after CRC surgery.

DESIGN

Observational cohort study. Patients were divided into three exposure groups-current, former and non-users-through reimbursed prescriptions within 365 days before the surgery. AKI within 7 days after surgery was defined according to the current Kidney Disease Improving Global Outcome consensus criteria.

SETTING

Population-based Danish medical databases.

PARTICIPANTS

A total of 9932 patients undergoing incident CRC surgery during 2005-2014 in northern Denmark were included through the Danish Colorectal Cancer Group Database.

OUTCOME MEASURE

We computed cumulative incidence proportions (risk) of AKI with 95% CIs for current, former and non-users of ACE-I/ARB, including death as a competing risk. We compared current and former users with non-users by computing adjusted risk ratios (aRRs) using log-binomial regression adjusted for demographics, comorbidities and CRC-related characteristics. We stratified the analyses of ACE-I/ARB users to address any difference in impact within relevant subgroups.

RESULTS

Twenty-one per cent were ACE-I/ARB current users, 6.4% former users and 72.3% non-users. The 7-day postoperative AKI risk for current, former and non-users was 26.4% (95% CI 24.6% to 28.3%), 25.2% (21.9% to 28.6%) and 17.8% (17.0% to 18.7%), respectively. The aRRs of AKI were 1.20 (1.09 to 1.32) and 1.16 (1.01 to 1.34) for current and former users, compared with non-users. The relative risk of AKI in current compared with non-users was consistent in all subgroups, except for higher aRR in patients with a history of hypertension.

CONCLUSIONS

Being a current or former user of ACE-I/ARBs is associated with an increased risk of postoperative AKI compared with non-users. Although it may not be a drug effect, users of ACE-I/ARBs should be considered a risk group for postoperative AKI.

Diabetes Mellitus Is Associated With Increased Risk of Ischemic Stroke in Patients With and Without Coronary Artery Disease

Background and Purpose- Diabetes mellitus (DM) and non-DM patients without coronary artery disease (CAD) have a similar low risk of myocardial infarction after coronary angiography. The risk of ischemic stroke in DM patients dependent on CAD status is less explored. We examined whether DM patients without CAD have a risk of ischemic stroke similar to that in patients with neither DM nor CAD. Methods- We conducted a cohort study of patients who underwent coronary angiography between 2004 and 2012 in Western Denmark. Patients diagnosed with previous ischemic stroke or transient ischemic attack were excluded. Patients were stratified according to the presence of DM and CAD. Follow-up started 30 days after coronary angiography. We computed event rates and adjusted incidence rate ratios using patients without DM or CAD as reference. We examined the trend between CAD extent and ischemic stroke in patients with DM. Results- A total of 81 909 patients were included. Median follow-up was 3.8 years. Patients with both DM and CAD were at the highest risk of ischemic stroke (1.32 events per 100 person-years; adjusted incidence rate ratio, 2.00 [95% CI, 1.72-2.32]). Patients with CAD alone (0.77 events per 100 person-years; adjusted incidence rate ratio, 1.27 [95% CI, 1.12-1.44]) or DM alone (0.95 events per 100 person-years; adjusted incidence rate ratio, 1.74 [95% CI, 1.42-2.15]) were at intermediate risk, whereas patients with neither DM nor CAD (0.52 events per 100 person-years) were at the lowest risk. Among patients with DM, extent of CAD was further predictive of risk (P_trend<0.001). Conclusions- Not only CAD but also DM are associated with the risk of ischemic stroke after coronary angiography. Their combination further increases the risk of ischemic stroke depending on the extent of CAD.

Trend of antidepressants before, during, and after pregnancy across two decades-A population-based study

INTRODUCTION

Factors that influence antidepressant (AD) prescription and use during pregnancy are multiple including, in particular, the balance between the potential risk of untreated depression and the potential risk of AD treatment. Surveillance of temporal trends of AD use might identify areas requiring further research. We studied the use of ADs before, during, and after pregnancy using national data across two decades in Denmark.

METHODS

We included 1,232,233 pregnancies leading to live birth in Denmark between 1 January 1997 and 31 December 2016. Information on redemption of AD prescriptions was obtained from the Danish National Prescription Register.

RESULTS

We identified 29,504 (2.4%) pregnancies having at least one AD prescription (96,232 AD prescriptions) during pregnancy. The majority redeemed more than one prescription (69.7%) often for a single kind of AD (83.5%), and in 94% of the AD-exposed pregnancies, the estimated duration of treatment was 1 month or longer. Prescription of ADs during pregnancy increased steadily from 0.4% in 1997 to 4.6% in 2011, but decreased thereafter to 3.1% in 2016. The proportion of pregnancies with ADs in 2011 was 6.05-fold higher than that in 1997. The temporal trends in AD prescription in the years before and after pregnancy were similar to the trend during pregnancy. The decreasing use of ADs during pregnancy after 2011 was mainly driven by a decrease in the use of selective serotonin reuptake inhibitors (SSRIs), especially citalopram, the main type of SSRIs used in Denmark.

CONCLUSION

Prescription of ADs during pregnancy in Denmark increased steadily from 1997 to 2011 but decreased sharply thereafter. More research is needed to show whether the same trend exists in other populations, like women of reproductive age, men of reproductive age, and old people, and other countries. We also need to find explanation for the decreasing trend in recent years and potential risk for untreated depression.

Dermatology nurses view on factors related to Danish psoriasis patients' adherence to topical drugs: a focus group study

BACKGROUND

Topical medications are first-line treatment for mild-to-moderate psoriasis, but adherence is low, which negatively affects patients' outcomes and quality of life. Nurses can play a central role in patient care, particularly in improving adherence.

OBJECTIVES

To explore the experience of dermatology nurses with psoriasis patients' adherence to topical drugs.

METHODS

We conducted a semi-structured focus group study with 6 dermatology nurses and 2 dermatology nursing students. Participants were recruited from a dermatology hospital outpatient clinic. Data were analyzed by a systematic text condensation method with a phenomenological-hermeneutic approach.

RESULTS

Nurses experienced that factors such as social inequality, patient-centered nursing, and patients' quality of life can have an influence on adherence.

CONCLUSION

Optimal adherence to topical treatments is a complex exercise and is influenced by many different factors. Involving nurses when prescribing topical treatments may be beneficial since they are one of the most trustworthy professions and have a holistic view on psoriasis severity, patient preferences, health care resources available and socioeconomic factors.

Too much? Mortality and health service utilisation among Danish children 1999-2016: A register-based study

OBJECTIVES

To describe the temporal development of mortality and health service utilisation defined as in- and outpatient hospital contacts, contacts with general practitioner and specialists, and prescribed dispensed medication among Danish children 0-5 years of age from 1999 to 2016.

DESIGN

Register-based descriptive study.

PARTICIPANTS

All children born in Denmark in the period 1994-2016 followed until 5 years of age.

MAIN OUTCOME MEASURES

Annual incidence rates of mortality and health service utilisation outcomes, and incidence rate ratios compared to the reference calendar year 1999. The new measure of post-discharge mortality is presented.

RESULTS

Post-discharge mortality decreased from 1999 to 2016, IRR2016 = 0.49 (95% CI: 0.36 to 0.66). Total contacts did not change much over time, IRR2016 = 1.02 (1.02 to 1.03), but increased among neonates, IRR2016 = 3.69 (3.63 to 3.75), and decreased among children with chronic disease IRR2016 = 0.94 (0.93 to 0.94). In- and out-patient hospitalisations increased, IRR2016 = 1.26 (1.24-1.27) resp. IRR2016 = 1.62 (1.60-1.63), contacts with medical specialists increased, IRR2016 = 1.43 (1.42 to 1.43), whilst contacts with general practitioner decreased, IRR2016 = 0.91 (0.91 to 0.91). Medication use decreased, IRR2016 = 0.82 (0.82 to 0.82).

CONCLUSIONS

Our measure of post-discharge mortality was halved during the study period indicating improved health. Overall health service utilisation did not change much, but the type of utilisation changed, and the development over time differed between subgroups defined by age and chronic disease status. Our findings call for considerations about the benefit of increased specialisation and increased use of health services among 'healthy' children not suffering from chronic disease.

Prevalence of lifestyle characteristics in glucocorticoid users and non-users: a Danish population-based cross-sectional study

OBJECTIVES

Lifestyle may affect observed associations between glucocorticoid use and adverse events. This study aimed to investigate whether lifestyle differ according to use of systemic glucocorticoids.

DESIGN

Population-based cross-sectional study.

SETTING

The Central Denmark Region.

PARTICIPANTS

30 245 adults (≥25 years of age) who participated in a questionnaire-based public health survey in 2010.

OUTCOME MEASURES

Systemic glucocorticoid use was categorised as never use, current use (prescription redemption ≤90 days before completing the questionnaire), recent use (prescription redemption 91-365 days before completing the questionnaire), former use (prescription redemption >365 days before completing the questionnaire) and according to cumulative dose expressed in prednisolone equivalents (<100, 100-499, 500-999, 1000-1999, 2000-4999, ≥5000 mg). We computed the prevalence of lifestyle factors (body mass index, smoking, alcohol intake, physical activity and dietary habits) according to glucocorticoid use. We then estimated age-adjusted prevalence ratios (aPRs) and 95% CIs, comparing the categories of glucocorticoid users versus never users. All analyses were stratified by sex.

RESULTS

Of the 30 245 participants (53% women, median age 53 years), 563 (1.9%) were current users, 885 (2.9%) were recent users, 3054 (10%) were former users and 25 743 (85%) were never users. Ever users of glucocorticoids had a slightly higher prevalence of obesity than never users (18% vs 14%, aPR=1.4, 95% CI 1.2 to 1.5 in women and 17% vs 15%, aPR=1.2, 95% CI 1.1 to 1.4 in men). In women, ever users of glucocorticoids had a slightly lower prevalence of high-risk alcohol consumption compared with never users (17% vs 20%, aPR=0.8, 95% CI 0.7 to 1.0). Smoking, diet and physical activity did not differ substantially according to use of glucocorticoids.

CONCLUSION

Our study provides a framework for quantifying potential uncontrolled confounding by lifestyle factors in studies of systemic glucocorticoids.

Increased risk of mortality after postoperative infection in hip fracture patients

BACKGROUND

Postoperative infection is a common complication in hip fracture patients and the risk appears to have increased during the last decade. However, the impact of infection on mortality after hip fracture surgery remains unclear.

PURPOSE

We aimed to examine the association between infection (any, as well as specific infections), with all-cause mortality following hip fracture surgery.

METHODS

Using Danish nationwide registries, we conducted a population-based cohort study on 74,771 hip fracture patients ≥65 years old operated from 2005 to 2016. We included hospital-treated infection as a time-varying exposure, and calculated 30-days mortality rate per 1000 person-years (PY). We used time-varying Cox Proportional Hazard Regression to compute 30-days adjusted hazards ratios (aHRs) with 95% confidence interval (CI) comparing the mortality of hip fracture patients with and without infections. We adjusted for sex, age, comorbidities, medication use, and marital status.

RESULTS

Within 30 days of surgery, 9592 (12.8%) patients developed a hospital-treated infection. Among these, 30-days mortality was 8.43 per 1000 PY compared with 3.34 among patients without infection (aHR = 2.72, 95% CI: 2.56-2.88). For patients who developed pneumonia, aHR was 4.18 (95% CI: 3.91-4.48), whereas the aHR was 8.86 (95% CI: 7.88-9.95) for patients who developed systemic sepsis. For patients who sustained reoperation due to infection, aHR was 2.95 (95%CI: 1.88-4.64). The mortality was higher in infected vs. non-infected patients irrespective of patients' age, sex and comorbidity.

CONCLUSION

Infection within 30 days of hip fracture surgery is associated with substantially increased mortality risk. Further research should improve our knowledge about patients at increased risk and prevention measures for specific infections.

Use of anti-osteoporosis medication dispensing by patients with hip fracture: could we do better?

Although Scandinavian countries have the highest incidence of hip fracture in the world, trends in anti-osteoporosis medication use have not been studied. We found less than one-third of Danish hip fracture patients had dispensing of anti-osteoporosis medication over a 10-year period using routinely collected data from population-based registries.

INTRODUCTION

To examine trend in dispensing of anti-osteoporosis medication before and after hip fracture surgery in Denmark over a 10-year period using routinely collected data from population-based registries.

METHODS

From the Danish Multidisciplinary Hip Fracture Registry, we included 65,011 patients aged 65 years or older with an incident hip fracture in 2005-2015. We calculated, for each calendar year of hip fracture diagnosis, the prevalence of use of anti-osteoporosis medication (at least one dispensing of bisphosphonates, strontium ranelate, denosumab, selective estrogen receptor modulators, or teriparatide) in the year before and in the year following hip fracture diagnosis. Among those without a dispensing in the year before hip fracture, we computed 1-year cumulative incidence of use following hip fracture. We treated death as a competing risk and stratified the analysis on sex, age, and comorbidity.

RESULTS

The prevalence of use before hip fracture varied between 7 and 12%, increasing slightly from 2005 to 2015. The cumulative incidence of use following hip fracture decreased from 16% in 2005 to 13% in 2010, whereupon it increased to 20%. A similar pattern was seen with each stratum of sex, age groups, and comorbidity. The overall prevalence of use after hip fracture was below 22% in all calendar years.

CONCLUSIONS

Less than one-third of hip fracture patients had dispensing of anti-osteoporosis medication up to 1 year after hip fracture. We observed only a slight increase in dispensing after hip fracture over the study period, irrespective of patient sex, age, and comorbidity at the time of hip fracture.

Does a mandatory non-medical switch from originator to biosimilar etanercept lead to increase in healthcare use and costs? A Danish register-based study of patients with inflammatory arthritis

Objectives

In year 2016, Danish national guidelines included a mandatory switch of patients with inflammatory rheumatic diseases treated with originator etanercept (ETA) to biosimilar SB4 in routine care. We aimed to explore if switching lead to increased healthcare utilisation and costs.

Methods

Observational cohort study. Adult patients who switched from ETA to SB4 were identified in the Danish nationwide DANBIO registry. In the National Patient Registry, we identified health utilisation (hospital admissions/hospital days/outpatient visits/prescription medication use) and comorbidities. Estimation of health utilisation included average use and costs 1 year before/after switch, changes after the switch, and whether patient characteristics affected changes. Analyses were by adjusted two-step gamma distributed regression models, and for changes over time a generalized estimation equations (GEE) model was applied. Impact of comorbidities was explored as interaction terms in the model. Medication costs of ETA and SB4 were not included in model.

Results

1620 patients were included (mean age 55 years (SD 14.7), 40% male). Costs before and after switching were mainly driven by outpatient visits (67%/72% of all costs). Monthly fluctuations of costs were similar before/after switch. After switching, use (8%) and costs (7%) of outpatient services increased, whereas costs of admissions (55%) and medication (5%) decreased. Patients with longer ETA treatment duration had an increase in use and costs of healthcare resources, whereas gender and comorbidities had no impact. Higher age was associated with an increase in costs of inpatient services.

Conclusion

We demonstrated no obvious changes in overall use and costs of healthcare services following switch from originator to biosimilar etanercept.

Post-authorisation Safety Study of Pioglitazone Use and Safety Endpoints of Interest in Denmark After Direct Healthcare Professional Communication

INTRODUCTION

A Direct Healthcare Professional Communication (DHPC) sent in Denmark on 11 August 2011 provided information on new pioglitazone labelling and guidance on monitoring treatment effectiveness. We describe pioglitazone use in Denmark after the DHPC, estimate the incidence of heart failure (HF), quantify pioglitazone cessation following a diagnosis of bladder cancer (BC) or uninvestigated macroscopic haematuria, and describe glycated haemoglobin (HbA1c) values.

METHODS

This was a cohort study. From Danish population-based registries, cohorts of type 2 diabetes mellitus incident or prevalent users of pioglitazone or insulin in 2011-2015 were created. Patient characteristics, treatment patterns, laboratory results (available for a regional subset of the population), and incidence rates of HF and BC were estimated.

RESULTS

There were 80 pioglitazone and 17,699 insulin incident users, 140 pioglitazone and 13,183 insulin prevalent users. There were no new BC cases among incident pioglitazone users, and < 5 new BC cases among prevalent pioglitazone users. Pioglitazone was rarely the first-line treatment. History of haematuria was documented in < 5 incident and 11 prevalent pioglitazone users. During follow-up, there were < 5 HF cases among 77 incident pioglitazone users and < 5 among 133 prevalent pioglitazone users without a history of HF. Median HbA1c at index date was 7.8% and 8.8% in incident pioglitazone and insulin cohorts, and 7.5% and 7.6% in prevalent pioglitazone and insulin cohorts, respectively. During follow-up of up to 4.4 years, 28.8% incident and 20.7% prevalent pioglitazone users discontinued pioglitazone.

CONCLUSIONS

Numbers of pioglitazone users in Denmark were low and decreased over time. Risks of BC or HF were low and risk estimates imprecise.

Optimal duration of anticoagulant thromboprophylaxis in total hip arthroplasty: new evidence in 55,540 patients with osteoarthritis from the Nordic Arthroplasty Register Association (NARA) group

Background and purpose - The recommended optimal duration of the thromboprophylaxis treatment in total hip arthroplasty (THA) patients has been a matter of debate for years. We examined the association between short (1-5 days), standard (6-14 days), and extended (≥ 15 days) duration of thromboprophylaxis, with regards to the risk of venous thromboembolism (VTE), major bleeding, and death in unselected THA patients. Patients and methods - We performed a cohort study using prospectively collected data from the population-based hip arthroplasty registries, prescription databases, and patient administrative registries in Denmark and Norway. We included 55,540 primary THA patients with osteoarthritis Results - The 90-day cumulative incidence of VTE was 1.0% for patients with standard treatment (reference), 1.1% for those with short-term treatment (adjusted hazard ratio [aHR] of 1.1, 95% confidence interval (CI) 0.8-1.5) and 1.0% for those with extended treatment (aHR of 0.9, CI 0.8-1.2). The aHRs for major bleeding were 1.1 (CI 0.8-1.6) for short and 0.8 (CI 0.6-1.1) for extended vs. standard treatment. In addition, patients with short and extended treatment had aHRs for death of 1.2 (CI 0.8-1.8) and 0.8 (CI 0.5-1.1) vs. standard treatment, respectively. Patients who started short treatment postoperatively had an aHR for death of 1.8 (CI 1.1-3.1) and absolute risk difference of 0.2%, whereas patients who started short treatment preoperatively had an aHR for death of 0.5 (CI 0.2-1.2) and absolute risk difference of 0.3% compared with patients who had standard treatment with post- and preoperative start, respectively. Interpretation - In routine clinical practice, we observed no overall clinically relevant difference in the risks of VTE and major bleeding within 90 days of THA with respect to thromboprophylaxis duration. However, our data indicate that short-term thromboprophylaxis started postoperatively is associated with increased 90-day mortality. The significance of these data should be explored further.

Risk of thromboembolic and bleeding outcomes following hematological cancers: A Danish population-based cohort study

BACKGROUND

Therapeutic advances have improved survival after hematological cancers. In turn, patients may be at increased risk of thromboembolic and bleeding events.

OBJECTIVES

To examine the risks of myocardial infarction (MI), ischemic stroke, venous thromboembolism (VTE), and bleeding requiring hospital contact in patients with hematological cancers.

METHODS

We conducted a Danish population-based cohort study (2000-2013). We identified all adult hematological cancer patients and sampled a general population comparison cohort in a 1:5 ratio matched by age, sex, previous thromboembolic events, bleeding, and solid cancer. Ten-year absolute risks of thromboembolism and bleeding were calculated and hazard ratios (HRs) were computed, controlling for matching factors.

RESULTS

Among 32 141 hematological cancer patients, the 10-year absolute risk of any thromboembolic or bleeding complication following hematological cancer was 19%: 3.3% for MI, 3.5% for ischemic stroke, 5.2% for VTE, and 8.5% for bleeding. Except among patients with myeloid leukemia, acute lymphoid leukemia, or myelodysplastic syndrome, the risk of thromboembolic events surpassed that of bleeding. The hematological cancer cohort overall was at increased risk for MI [HR = 1.36, 95% confidence interval (CI): 1.25-1.49], ischemic stroke (HR = 1.22, 95% CI: 1.12-1.33), VTE (HR = 3.37, 95% CI: 3.13-3.64), and bleeding (HR = 2.39, 95% CI: 2.26-2.53) compared with the general population.

CONCLUSIONS

Approximately 2 of 10 hematological cancer patients experienced MI, ischemic stroke, VTE, or bleeding requiring hospital contact within 10 years. The hematological cancer cohort had higher hazards of MI, ischemic stroke, VTE, and bleeding requiring hospital contact than a general population comparison cohort.

Antidepressant use during pregnancy and risk of congenital heart defects: A case-time-control study

PURPOSE

We estimated the association between maternal antidepressant (AD) use in early pregnancy and risk of congenital heart defects.

METHODS

We applied a case-time-control design with the aim of controlling for confounding from time-invariant factors and compared the results of the design to results from a cohort design in a population of 792 685 singletons born alive in Denmark during 1995-2008. In the case-time-control design, we identified children diagnosed with a congenital heart defect in the first 5 years of life (cases) and compared maternal AD use in the risk period (the first 3 months of pregnancy) and the reference period (gestational months 5-7). A nondiseased control group was included to adjust for time trends of exposure. In the cohort design, we identified children whose mothers redeemed at least one AD prescription in the first 3 months of pregnancy (the exposed) and two other groups including the unexposed children with maternal AD prescriptions in the 12 months before pregnancy. We applied conditional logistic regression and logistic regression to compute odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

The case-time-control OR for any congenital heart defect was 1.03 (95% CI, 0.61-1.73), which was similar to the OR (1.09, 95% CI, 0.88-1.35) from the cohort design when we compared the exposed children with the unexposed children with maternal AD use before pregnancy.

CONCLUSIONS

The case-time-control design provided results similar to the cohort design when the cohort design had a better confounder control strategy. We discussed the strengths and drawbacks of case-time-control design.

Use of Opioids and Other Analgesics Before and After Primary Surgery for Adult Spinal Deformity: A 10-Year Nationwide Study

Objective

To report the 1-year pre and postoperative analgesic use in patients undergoing primary surgery for adult spinal deformity (ASD) and assess risk factors for chronic postoperative opioid use.

Methods

Patients > 18 years undergoing primary instrumented surgery for ASD in Denmark between 2006 and 2016 were identified in the Danish National Patient Registry. Information on analgesic use were obtained from the Danish National Health Service Prescription Database. Use of analgesics was calculated one year before and after surgery for each patient, per quarter (-Q4 to -Q1 before and Q1 to Q4 after). Users were defined as patient with one or more prescriptions in the given quarter.

Results

We identified 892 patients. Preoperatively, 28% (n = 246) of patients were opioid users in -Q4 and 33% (n = 295) in -Q1. Postoperatively, 85% (n = 756) of patients were opioid users in Q1 and 31% (n = 280) in Q4. Proportions of users of other analgesics (paracetamol, antidepressants, and anticonvulsants) were stable before and after surgery. Use of nonsteroidal anti-inflammatory drug decreased postoperatively by 40% (-Q1 vs. Q4). 26% of patients had chronic preoperative opioid use (one or more prescriptions in each -Q2 and -Q1) and 24% had chronic postoperative use (prescription each of Q1–Q4). Multivariate logistic regression analysis showed age increment per 10 years and preoperative chronic opioid use as risk factors for chronic postoperative opioid use.

Conclusion

One year after ASD surgery, opioid use was not reduced compared to preoperative usage.

The Danish health care system and epidemiological research: from health care contacts to database records

Denmark has a large network of population-based medical databases, which routinely collect high-quality data as a by-product of health care provision. The Danish medical databases include administrative, health, and clinical quality databases. Understanding the full research potential of these data sources requires insight into the underlying health care system. This review describes key elements of the Danish health care system from planning and delivery to record generation. First, it presents the history of the health care system, its overall organization and financing. Second, it details delivery of primary, hospital, psychiatric, and elderly care. Third, the path from a health care contact to a database record is followed. Finally, an overview of the available data sources is presented. This review discusses the data quality of each type of medical database and describes the relative technical ease and cost-effectiveness of exact individual-level linkage among them. It is shown, from an epidemiological point of view, how Denmark’s population represents an open dynamic cohort with complete long-term follow-up, censored only at emigration or death. It is concluded that Denmark’s constellation of universal health care, long-standing routine registration of most health and life events, and the possibility of exact individual-level data linkage provides unlimited possibilities for epidemiological research.

Association between anti-diabetes treatments and cardiovascular risk in diabetes patients with and without coronary artery disease

OBJECTIVE

We examined the risk of myocardial infarction associated with glucose-lowering therapy among diabetes patients with and without obstructive coronary artery disease.

METHODS

A cohort of patients with type 1 or type 2 diabetes (n = 12,030), who underwent coronary angiography from 2004 to 2012, were stratified by presence of obstructive (any stenosis ⩾50%) coronary artery disease and by type of diabetes treatment: diet, non-insulin treatment and insulin (±oral anti-diabetics). The primary endpoint was myocardial infarction. Adjusted hazard ratios were calculated using diet-treated patients without coronary artery disease as reference.

RESULTS

In patients without coronary artery disease, risk of myocardial infarction was similar in patients treated with non-insulin medication (adjusted hazard ratio 0.70, 95% confidence interval 0.27-1.81) and insulin (adjusted hazard ratio 0.76, 95% confidence interval 0.27-2.08) as compared to diet only. In patients with coronary artery disease, the risk of myocardial infarction was higher than in the reference group and an incremental risk was observed being lowest in patients treated with diet (adjusted hazard ratio 3.79, 95% confidence interval 1.61-8.88), followed by non-insulin medication (adjusted hazard ratio 5.42, 95% confidence interval 2.40-12.22), and highest in insulin-treated patients (adjusted hazard ratio 7.91, 95% confidence interval 3.51-17.82).

CONCLUSION

The presence of obstructive coronary artery disease defines the risk of myocardial infarction in diabetes patients. Glucose-lowering therapy, in particular insulin, was associated with risk of myocardial infarction only in the presence of coronary artery disease.

Influenza vaccination and 1-year risk of myocardial infarction, stroke, heart failure, pneumonia, and mortality among intensive care unit survivors aged 65 years or older: a nationwide population-based cohort study

PURPOSE

We examined whether influenza vaccination affects 1-year risk of myocardial infarction, stroke, heart failure, pneumonia, and death among intensive care unit (ICU) survivors aged ≥ 65 years.

METHODS

Danish Intensive Care Database data on all elderly ( ≥ 65 years) patients hospitalized in Danish ICUs in the period 2005-2015, and subsequently discharged, were linked with data from other medical registries, including data on uptake of the seasonal influenza vaccine. We computed these patients' 1-year risk of hospitalization for myocardial infarction, stroke, heart failure, or pneumonia, and their 1-year risk of all-cause mortality. Hazard ratios (HRs) with 95% confidence intervals (CIs) were computed using Cox proportional hazards regression, with adjustment and propensity score matching applied to handle confounding.

RESULTS

The study included 89,818 ICU survivors. The influenza vaccinated patients (n = 34,871, 39%) were older, had more chronic diseases, and used more prescription medications than the unvaccinated patients. Adjusted 1-year mortality was decreased among the vaccinated versus the unvaccinated patients (19.3% versus 18.8%; adjusted HR, 0.92; 95% CI 0.89-0.95). Influenza vaccination was also associated with a decreased risk of stroke (adjusted HR, 0.84; 95% CI 0.78-0.92), but only a small, non-significantly decreased risk of myocardial infarction (adjusted HR, 0.93; 95% CI 0.83-1.03). There was no association between vaccination and subsequent hospitalization for heart failure or pneumonia. Propensity score matched analyses confirmed these findings.

CONCLUSIONS

Compared with the unvaccinated ICU survivors, the influenza vaccinated ICU survivors had a lower 1-year risk of stroke and a lower 1-year risk of death, whereas no substantial association was observed for the risk of hospitalization for myocardial infarction, heart failure, or pneumonia. Our findings support influenza vaccination of individuals aged ≥ 65 years.

Preadmission use of antidepressants and risk of complications and death after colorectal cancer surgery: a nationwide population-based cohort study

AIM

Few studies have evaluated how preadmission use of antidepressants affects outcomes in colorectal cancer (CRC) patients after they have undergone surgery. Therefore, our aim is to examine whether preadmission use of antidepressants increased the risk of complications and death in patients who underwent CRC surgery.

METHOD

Using the Danish Colorectal Cancer Group Database we identified patients who underwent CRC surgery in Denmark from 2005 to 2012. We identified prescriptions for antidepressants redeemed within 1 year prior to surgery and categorized patients as current users (≤ 90 days), former users (91-365 days) and nonusers. All patients were followed from surgery to 30 days thereafter or to death. We calculated 30-day rates of complications, intensive care unit (ICU) admission and mortality and compared these between users and nonusers using logistic and Cox regression adjusting for potential confounders.

RESULTS

Of 27 374 patients, 8.9% were current users and 3.0% were former users. Antidepressant users were older and had more comorbidity but a similar cancer stage. Compared with nonusers, current users had a higher risk of postoperative reoperation [adjusted odds ratio (aORs) = 1.15 (95% CI 1.02-1.30)], medical complications [aORs = 1.41 (95% CI 1.25-1.60)] and increased ICU admission rate [adjusted hazard ratio (aHR) = 1.32 (95% CI 1.21-1.45)]. The 30-day mortality was 11.4% for current users, 9.1% for former users and 6.2% for nonusers [aHR = 1.34 (95% CI 1.17-1.53) for current vs nonusers].

CONCLUSION

Patients with preadmission use of antidepressants had a higher risk of complications and ICU admission, and higher 30-day mortality following CRC surgery than nonusers.

Predicting stroke in patients without atrial fibrillation

BACKGROUND

Only few studies in selected cohorts have examined whether the CHA₂ DS₂ -VASc score can predict the risk of atrial fibrillation and thromboembolic events in patients without atrial fibrillation.

MATERIALS AND METHODS

Patients with coronary angiography performed between 2004 and 2012 were grouped according to CHA₂ DS₂ -VASc score. We excluded patients with atrial fibrillation, anticoagulant therapy and follow-up <30 days. The endpoints were atrial fibrillation and a composite of ischaemic stroke, transient ischaemic attack and systemic embolism. Event rates per 100 person-years were estimated for each CHA₂ DS₂ -VASc score (0, 1, 2, 3, 4, and >4). Incidence rate ratios were calculated using low-risk patients (CHA₂ DS₂ -VASc score 0 in males or 1 in females) as reference.

RESULTS

In total, 78 233 patients were included with group sizes varying between 8299 (CHA₂ DS₂ -VASc >4) and 19 882 (CHA₂ DS₂ -VASc 2). An increasing CHA₂ DS₂ -VASc score was significantly associated with a future diagnosis of atrial fibrillation (P for trend <0.0001) and an incremental risk of ischaemic stroke, transient ischaemic attack, systemic embolism (P for trend <0.0001) and all-cause death (P for trend <0.0001). Patients with a CHA₂ DS₂ -VASc score of 3 had a rate of ischaemic stroke/transient ischaemic attack/systemic embolism of 1.30 per 100 person-years.

CONCLUSIONS

Among patients undergoing coronary angiography, the CHA₂ DS₂ -VASc score predicted a future diagnosis of atrial fibrillation and the composite risk of ischaemic stroke, transient ischaemic attack or systemic embolism in patients without atrial fibrillation. A CHA₂ DS₂ -VASc score of 3 was associated with a risk that would justify prophylactic oral anticoagulation treatment in a patient with atrial fibrillation.

Cardiovascular Outcomes and All-cause Mortality Following Measurement of Endogenous Testosterone Levels

Although reduced testosterone levels are common in aging populations, the clinical consequences remain to be further explored. We examined whether low total testosterone levels are associated with stroke (ischemic and hemorrhagic), myocardial infarction (MI), venous thromboembolism (VTE), and all-cause mortality in adult men. We conducted a cohort study in the Central Denmark Region (2000 to 2015). We included all men with a first-ever laboratory testosterone result and computed the 5-year risks of cardiovascular outcomes and all-cause mortality. Propensity score-weighted hazard ratios were computed, comparing persons with normal versus low testosterone levels. Individuals were censored at testosterone treatment during follow-up (3%). We identified 4,771 men with low testosterone levels and 13,467 with normal levels. Persons with low testosterone levels were older (median ages, 55 years vs 50 years) and had more co-morbidities than men with normal testosterone levels. Persons with low testosterone had higher 5-year risks of stroke (2.4% vs 1.5%), MI (1.5% vs 1.2%), VTE (1.4% vs 0.9%), and all-cause mortality (17.8% vs 6.8%) than persons with normal testosterone levels. After propensity score-weighting, the associations with cardiovascular outcomes reached unity. The 5-year hazard ratios were 1.14 (95% confidence intervals [CIs] 0.87 to 1.49) for stroke, 0.95 (95% CI 0.70 to 1.30) for MI, 1.10 (95% CI 0.78 to 1.55) for VTE, whereas it was 1.48 (95% CI 1.32 to 1.64) for all-cause mortality. In conclusion, low testosterone level was a strong predictor for cardiovascular outcomes and all-cause mortality in unadjusted models, however only the association between low testosterone and all-cause mortality persisted after adjustment for age and co-morbidity.

Extent of coronary artery disease is associated with myocardial infarction and mortality in patients with diabetes mellitus

Purpose: We examined risk of myocardial infarction and all-cause death associated with the extent of coronary artery disease ascertained by coronary angiography in patients with diabetes mellitus. We hypothesized that risks of myocardial infarction and death were associated with extent of coronary artery disease in diabetes patients.

Patients and methods: We conducted a cohort study of patients with type 1 and type 2 diabetes, who underwent coronary angiography from 2004 to 2012. Patients were stratified according to extent of coronary artery disease: 0-, 1-, 2- or 3-vessel disease or diffuse vessel disease. Endpoints were myocardial infarction, all-cause death, and major adverse cardiovascular events (MACE), defined as the composite of myocardial infarction, cardiac death, or ischemic stroke. Adjusted incidence and mortality rate ratios (IRRs_adj) were calculated using patients with 0-vessel disease as the reference group. Median follow-up was 3 years for a total of 45,164 person-years.

Results: The study included 12,594 diabetes patients. Of these, 3,147 (25.0%) had 0-vessel disease, 1,195 (9.5%) had diffuse vessel disease, 3,001 (23.8%) had 1-vessel disease, 2,220 (17.6%) had 2-vessel disease, and 3,031 (24.1%) had 3-vessel disease. The myocardial infarction rate was 0.4 per 100 person-years (95% CI: 0.3–0.5) in patients with 0-vessel disease. Using patients with 0-vessel disease as reference, the risk of myocardial infarction increased according to the number of diseased vessels (diffuse vessel disease: 1.4 per 100 person-years, IRR_adj 3.87, 95% CI: 2.41–6.23; 1-vessel disease: 1.9 per 100 person-years, IRR_adj 4.99, 95% CI: 3.33–7.46; 2-vessel disease: 2.7 per 100 person-years, IRR_adj 7.14, 95% CI: 4.78–10.65; and 3-vessel disease: 4.3 per 100 person-years, IRR_adj 11.42, 95% CI: 7.76–16.82; p_trend<0.001). Similar associations were observed for all-cause death and MACE.

Conclusion: The extent of coronary artery disease is a major risk factor for myocardial infarction and death in patients with diabetes mellitus.

Delay in surgery, risk of hospital-treated infections and the prognostic impact of comorbidity in hip fracture patients. A Danish nationwide cohort study, 2005-2016

Purpose: We examined the association between delay in surgery and hospital-treated infections in hip fracture patients with and without known comorbidities.

Patients and methods: All hip fracture patients aged ≥65 years registered in the Danish Multidisciplinary Hip Fracture Registry from 2005 to 2016 were included (n=72,520). Delay in surgery was defined as the time in hours from admission to surgery and was divided into 3 groups (12, 24 and 48 hrs). The outcomes were hospital-treated pneumonia, urinary tract infection and reoperation due to infection 0–30 days after surgery. As a measure of comorbidity, we used the Charlson Comorbidity Index (CCI): none (no registered comorbidities prior to the fracture), medium (1–2 points) and high (≥3 points).

Results: Overall, there was an association between a delay of 12 hrs and pneumonia. A delay of 12 hrs was associated with an increased risk of pneumonia in patients with no comorbidities (adjusted hazard ratio (HR) 1.20, confidence interval (CI) 1.03–1.40) and a delay of 24 hrs was associated with an increased risk of pneumonia in patients with a medium level of comorbidity (HR 1.12, CI (1.02–1.23)). Overall, delay was associated with reoperation due to infection, particularly among patients with comorbidities, although the confidence intervals of some of the estimates were wide. A delay of 48 hrs was associated with an increased risk of reoperation due to infection in patients with a high level of comorbidity (HR 2.36, CI 1.19–4.69).

Conclusion: Delay in surgery was associated with an increased risk of hospital-treated pneumonia and reoperations due to infection within 30 days of surgery. The number of postoperative hospital-treated infections within 30 days may be reduced by continuously targeting pre-, per- and postoperative optimization not only for patients with high level of comorbidity but also for hip fracture patients without known comorbidities prior to surgery.

Pregnancy, Birth, Neonatal, and Postnatal Neurological Outcomes After Pregnancy With Migraine

BACKGROUND

Prevalence of migraine is high during the reproductive age. Although migraine often improves during pregnancy, the risk of adverse pregnancy, birth, neonatal, and neurological outcomes in mother and offspring remains poorly understood.

OBJECTIVE

To investigate the associations between maternal migraine and risks of adverse pregnancy outcomes in the mother, and birth, neonatal and postnatal outcomes in the offspring.

METHODS

We used Danish population registries to assemble a cohort of pregnancies among women with migraine and an age- and conception year-matched comparison cohort of pregnancies among women without migraine. The study period was 2005-2012. We computed adjusted prevalence ratios (aPRs) for pregnancy and birth outcomes and adjusted risk ratios (aRRs) for neonatal and postnatal outcomes, adjusting for age, preconception medical history, and preconception reproductive history.

RESULTS

We identified 22,841 pregnancies among women with migraine and 228,324 matched pregnancies among women without migraine. Migraine was associated with an increased risk of pregnancy-associated hypertension disorders (aPR: 1.50 [95% confidence interval (CI): 1.39-1.61]) and miscarriage (aPR: 1.10 [95% CI: 1.05-1.15]). Migraine was associated with an increased prevalence of low birth weight (aPR: 1.14 [95% CI: 1.06-1.23]), preterm birth (aPR: 1.21 [95% CI: 1.13-1.30]) and cesarean delivery (aPR: 1.20 [95% CI: 1.15-1.25]), but not of small for gestational age offspring (aPR: 0.94 [95% CI: 0.88-0.99]) and birth defects (aPR: 1.01 [95% CI: 0.93-1.09]). Offspring prenatally exposed to maternal migraine had elevated risks of several outcomes in the neonatal and postnatal period, including intensive care unit admission (aRR: 1.22 [95% CI: 1.03-1.45]), hospitalization (aRR: 1.12 [95% CI: 1.06-1.18]), dispensed prescriptions (aRR: 1.34 [95% CI: 1.24-1.45]), respiratory distress syndrome (aRR: 1.20 [95% CI: 1.02-1.42]), and febrile seizures (aRR: 1.27 [95% CI: 1.03-1.57), but not of death (aRR: 0.67 [95% CI: 0.43-1.04]) and cerebral palsy (aRR: 1.00 [95% CI: 0.51-1.94]).

CONCLUSIONS

Women with migraine and their offspring have greater risks of several adverse pregnancy outcomes than women without migraine.

Can diabetic polyneuropathy and foot ulcers in patients with type 2 diabetes be accurately identified based on ICD-10 hospital diagnoses and drug prescriptions?

Purpose: We examined whether diabetic polyneuropathy (DPN) and diabetic foot ulcers in type 2 diabetes can be accurately identified using International Classification of Diseases, 10th revision discharge diagnosis codes, surgery codes, and drug prescription codes.

Methods: We identified all type 2 diabetes patients in the Central Denmark region, 2009–2016, who had ≥1 primary/secondary diagnosis code of “diabetes with neurological complication” (E10.4-E14.4), “diabetic polyneuropathy” (G63.2), or “polyneuropathy, unspecified” (G62.9). Patients with potential painful DPN and non-painful DPN were identified based on prescription history for serotonin–norepinephrine reuptake inhibitors, tricyclic antidepressants, or gabapentinoids. Likewise, type 2 diabetes patients with potential foot ulcers were identified based on diagnosis or surgery codes. We used medical record review as the reference standard and calculated positive predictive values (PPVs).

Results: Of 53 randomly selected patients with potential painful DPN, 38 were classified as having DPN when validated against medical records; of these, 18 also had neuropathic pain, yielding a PPV of 72% (95% CI: 58–83%) for DPN and 34% (95% CI: 22–48%) for painful DPN. Likewise, among 54 randomly selected patients with potential non-painful DPN, 30 had DPN based on medical record data; of these, 27 had non-painful DPN, yielding PPVs of 56% (95% CI: 41–69%) and 50% (95% CI: 36–64%), respectively. Secondary E-chapter codes often denoted stroke or mononeuropathies, rather than DPN. Excluding secondary E-chapter codes from the algorithm increased the PPV for DPN to 78% (95% CI: 63–89%) for the painful DPN cohort and to 74% (95% CI: 56–87%) for the non-painful DPN cohort. Of 53 randomly selected patients with potential diabetic foot ulcer, only 18 diagnoses were confirmed; PPV=34% (95% CI: 22–48%).

Conclusion: G-chapter and primary E-chapter diagnosis codes can detect type 2 diabetes patients with hospital-diagnosed DPN, and may be useful in epidemiological research. In contrast, our diabetic foot ulcer algorithm did not perform well.

Decreasing trends, and geographical variation in outpatient antibiotic use: a population-based study in Central Denmark

Background

Antimicrobial overuse and misuse of broad-spectrum antibiotics increases the risk for antimicrobial resistance. Investigating unwarranted variation in antibiotic prescription has therefore gained global priority.

Methods

We examined recent time trends in the utilization of narrow- and broad-spectrum antibiotics as well as the variation in antibiotic use by sex, age, and municipality of residence. Complete individual-level data on all redeemed out-of hospital prescriptions for antibiotics in the entire adult population of Central Denmark (1.3 million inhabitants) was obtained for the period 2006–2015.

Results

Following an initial increase of 2% between 2006 and 2011, the overall rate of redeemed prescriptions for antibiotics per 1000 person years declined by 17% between 2011 and 2015. Among persons aged over 65 years, the decline in use began later (from 2013) and was less pronounced. Antibiotic use in 2015 remained substantially higher among females (289/1000 person-years) vs. males (182/1000 person-years) and among the very old (520/1000 person-years in >85y old) vs. middle-aged (204/1000 person-years in 45-65y old). A decreasing trend in antibiotic use over time was observed in all municipalities, mainly due to a decrease in narrow-spectrum antibiotics. However, a striking and unexplained 1.6-fold geographical variation in antibiotic use, including tetracyclines, macrolides and fluoroquinolones remained in 2015. Of concern, among females aged ≥65 years and males aged ≥85 years, a continuous increasing trend in broad-spectrum antibiotic use was observed.

Conclusions

Antibiotic use has decreased almost 20% in Central Denmark after 2011, possibly related to a nationwide antibiotic stewardship program in Denmark. However, substantial geographical variation in antibiotic prescription remains and the use of broad-spectrum antibiotics has increased in adults of older age. Continuous focus on avoiding unnecessary use of broad-spectrum antibiotics is requested.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-3964-9) contains supplementary material, which is available to authorized users.

Comparison of Risk of Osteoporotic Fracture in Denosumab vs Alendronate Treatment Within 3 Years of Initiation

IMPORTANCE

Head-to-head randomized clinical trials showed greater efficacy of denosumab vs alendronate in improving bone mineral density. Although there is an association of changes in bone mineral density with reductions in fracture risk, the magnitude of the association is not well established.

OBJECTIVE

To compare the risk of hip and any fracture in patients treated with denosumab and alendronate in routine practice settings.

DESIGN, SETTING, AND PARTICIPANTS

This Danish nationwide, population-based, historical cohort study of a population with universal access to health care used prospectively collected, individually linked data from Danish health registries with complete follow-up. Cohorts consisted of 92 355 individuals 50 years or older who were new users of denosumab (n = 4624) or alendronate (n = 87 731) from May 2010 to December 2017 after at least 1 year without an antiosteoporosis medication dispensing.

EXPOSURES

Initiation of denosumab or alendronate.

MAIN OUTCOMES AND MEASURES

The primary outcome was hospitalization for hip fracture, and the secondary outcome was hospitalization for any fracture. Inverse probability of treatment weights and the intention-to-treat approach were used to calculate cumulative incidences and adjusted hazard ratios (aHRs) with 95% CIs.

RESULTS

Of the 92 355 included patients, 75 046 (81.3%) were women, and the mean (SD) age was 71 (10) years. The denosumab cohort had a lower proportion of men than the alendronate cohort (12.7% [589] vs 19.0% [16 700]), while age distributions were similar in the 2 cohorts. Within 3 years of follow-up, initiation of denosumab or alendronate was associated with cumulative incidences of 3.7% and 3.1%, respectively, for hip fracture and 9.0% and 9.0%, respectively, for any fracture. Overall, the aHRs for denosumab vs alendronate were 1.08 (95% CI, 0.92-1.28) for hip fracture and 0.92 (95% CI, 0.83-1.02) for any fracture. The aHR of denosumab vs alendronate for hip fracture was 1.07 (95% CI, 0.85-1.34) among patients with a history of any fracture and 1.05 (95% CI, 0.83-1.32) among patients without history of fracture. The aHR for any fracture for denosumab vs alendronate was 0.84 (95% CI, 0.71-0.98) among patients with a history of any fracture and 0.77 (95% CI, 0.64-0.93) among patients with no history of fracture.

CONCLUSIONS AND RELEVANCE

Treatment with denosumab and alendronate was associated with similar risks of hip or any fracture over a 3-year period, regardless of fracture history.