The predictive value of ICD-10 diagnostic coding used to assess Charlson comorbidity index conditions in the population-based Danish National Registry of Patients

Intensive care at the end of life in patients dying due to non-cancer chronic diseases versus cancer: a nationwide study in Denmark

Introduction

It is unknown to what extent use of palliative care and focus on proactive planning of end-of-life (EOL) care among cancer patients is also reflected by less use of intensive care. We aimed to examine the use of intensive care in the EOL in patients dying as a result of non-cancer diseases compared with patients dying due to cancer.

Methods

We conducted a nationwide follow-up study among 240,757 adults dying as a result of either non-cancer chronic disease or cancer in Denmark between 2005 and 2011. Using the Danish Intensive Care Database, we identified all admissions and treatments in intensive care units (ICU) during the patients’ last 6 months before death. We used prevalence ratios (aPRs) adjusted for age, sex, comorbidity, marital status and residential region to compare the 6-month prevalence of ICU admissions as well as treatment with invasive mechanical ventilation (MV), non-invasive ventilation (NIV), renal replacement therapy (RRT) and inotropes and/or vasopressors. In addition, length of ICU stay and death during ICU admission were compared among non-cancer and cancer patients dying between 2009 and 2011.

Results

Overall 12.3 % of non-cancer patients were admitted to an ICU within their last 6 months of life, compared with 8.7 % of cancer patients. The overall aPR for ICU admission was 2.11 [95 % confidence interval (CI) 1.98–2.24] for non-cancer patients compared with cancer patients and varied widely within the non-cancer patients (patients with dementia, aPR 0.19, 95 % CI 0.17–0.21; patients with chronic obstructive lung disease, aPR 3.19, 95 % CI 2.97–3.41). The overall aPRs for treatment among non-cancer patients compared with cancer patients were 1.40 (95 % CI 1.35–1.46) for MV, 1.62 (95 % CI 1.50–1.76) for NIV, 1.19 (95 % CI 1.07–1.31) for RRT and 1.05 (95 % CI 0.87–1.28) for inotropes and/or vasopressors. No difference in admission length was observed. Non-cancer patients had an increased risk of dying in an ICU (aPR 1.23, 95 % CI 0.99–1.54) compared with cancer patients.

Conclusions

Overall, patients dying as a result of non-cancer diseases were twice as likely to be admitted to ICUs at the EOL as patients dying due to cancer. Further studies are warranted to explore whether this difference in use of intensive care reflects an unmet need of palliative care, poor communication about the EOL or lack of prognostic tools for terminally ill non-cancer patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-1124-1) contains supplementary material, which is available to authorized users.

The Danish National Patient Registry: a review of content, data quality, and research potential

Background

The Danish National Patient Registry (DNPR) is one of the world’s oldest nationwide hospital registries and is used extensively for research. Many studies have validated algorithms for identifying health events in the DNPR, but the reports are fragmented and no overview exists.

Objectives

To review the content, data quality, and research potential of the DNPR.

Methods

We examined the setting, history, aims, content, and classification systems of the DNPR. We searched PubMed and the Danish Medical Journal to create a bibliography of validation studies. We included also studies that were referenced in retrieved papers or known to us beforehand. Methodological considerations related to DNPR data were reviewed.

Results

During 1977–2012, the DNPR registered 8,085,603 persons, accounting for 7,268,857 inpatient, 5,953,405 outpatient, and 5,097,300 emergency department contacts. The DNPR provides nationwide longitudinal registration of detailed administrative and clinical data. It has recorded information on all patients discharged from Danish nonpsychiatric hospitals since 1977 and on psychiatric inpatients and emergency department and outpatient specialty clinic contacts since 1995. For each patient contact, one primary and optional secondary diagnoses are recorded according to the International Classification of Diseases. The DNPR provides a data source to identify diseases, examinations, certain in-hospital medical treatments, and surgical procedures. Long-term temporal trends in hospitalization and treatment rates can be studied. The positive predictive values of diseases and treatments vary widely (<15%–100%). The DNPR data are linkable at the patient level with data from other Danish administrative registries, clinical registries, randomized controlled trials, population surveys, and epidemiologic field studies – enabling researchers to reconstruct individual life and health trajectories for an entire population.

Conclusion

The DNPR is a valuable tool for epidemiological research. However, both its strengths and limitations must be considered when interpreting research results, and continuous validation of its clinical data is essential.

Long-term prognosis and causes of death after spondylodiscitis: A Danish nationwide cohort study

BACKGROUND

Data on long-term prognosis after spondylodiscitis are scarce. The purpose of this study was to determine long-term mortality and the causes of death after spondylodiscitis.

METHODS

A nationwide, population-based cohort study using national registries of patients diagnosed with non-post-operative pyogenic spondylodiscitis from 1994-2009, alive 1 year after diagnosis (n = 1505). A comparison cohort from the background population individually matched for sex and age was identified (n = 7525). Kaplan-Meier survival curves were constructed and Poisson regression analyses used to estimate mortality rate ratios (MRR).

RESULTS

Three hundred and sixty-five patients (24%) and 1115 individuals from the comparison cohort (15%) died. Unadjusted MRR for spondylodiscitis patients was 1.76 (95% CI = 1.57-1.98) and 1.47 (95% CI = 1.30-1.66) after adjustment for comorbidity. No deaths were observed in 128 patients under the age of 16 years. Siblings of patients did not have increased long-term mortality compared with siblings of the individuals from the comparison cohort. This study observed increased mortality due to infections (MRR = 2.57), neoplasms (MRR = 1.40), endocrine (MRR = 3.72), cardiovascular (MRR = 1.62), respiratory (MRR = 1.71), gastrointestinal (MRR = 3.35), musculoskeletal (MRR = 5.39) and genitourinary diseases (MRR = 3.37), but also due to trauma, poisoning and external causes (MRR = 2.78), alcohol abuse-related diseases (MRR = 5.59) and drug abuse-related diseases (6 vs 0 deaths, MRR not calculable).

CONCLUSIONS

Patients diagnosed with spondylodiscitis have increased long-term mortality, mainly due to comorbidities, particularly substance abuse.

Venous thromboembolism and subsequent risk of cancer in patients with liver disease: a population-based cohort study

Objective

Venous thromboembolism (VTE) may be a marker of occult cancer in the general population. While liver disease is known to increase the risk of VTE and cancer, it is unclear whether VTE in patients with liver disease is also a marker of occult cancer.

Design

A population-based cohort study.

Setting

Denmark.

Participants

We used population-based health registries to identify all patients with liver disease in Denmark with a first-time diagnosis of VTE (including superficial or deep venous thrombosis and pulmonary embolism) during 1980–2010. Patients with non-cirrhotic liver disease and patients with liver cirrhosis were followed as two separate cohorts from the date of their VTE.

Measures

For each cohort, we computed the absolute and relative risk (standardised incidence ratio; SIR) of cancer after VTE.

Results

During the study period, 1867 patients with non-cirrhotic liver disease and 888 with liver cirrhosis were diagnosed with incident VTE. In the first year following VTE, the absolute risk of cancer was 2.7% among patients with non-cirrhotic liver disease and 4.3% among those with liver cirrhosis. The SIR for the first 90 days of follow-up was 9.96 (95% CI 6.85 to 13.99) among patients with non-cirrhotic liver disease and 13.11 (95% CI 8.31 to 19.67) among patients with liver cirrhosis. After 1 year of follow-up, SIRs declined, but remained elevated in patients with non-cirrhotic liver disease (SIR=1.50, 95% CI 1.23 to 1.81) and patients with liver cirrhosis (SIR=1.95, 95% CI 1.45 to 2.57).

Conclusions

VTE may be a marker of occult cancer in patients with liver disease.

Substantial differences in initiation of oral anticoagulant therapy and clinical outcome among non-valvular atrial fibrillation patients treated in inpatient and outpatient settings

AIMS

Patients with atrial fibrillation (AF) are encountered and treated in different healthcare settings, which may affect the quality of care. We investigated the use of oral anticoagulant (OAC) therapy and the risk of thrombo-embolism (TE) and bleeding, according to the healthcare setting.

METHODS AND RESULTS

Using national Danish registers, we categorized non-valvular AF patients (2002-11) according to the setting of their first-time AF contact: hospitalization (inpatients), ambulatory (outpatients), or emergency department (ED). Event rates and hazard ratios (HRs), calculated using Cox regression analysis, were estimated for outcomes of TE and bleeding. We included 116 051 non-valvular AF patients [mean age 71.9 years (standard deviation 14.1), 51.3% males], of whom 55.2% were inpatients, 41.9% outpatients, and 2.9% ED patients. OAC therapy 180 days after AF diagnosis among patients with a CHADS2 ≥ 2 was 42.1, 63.0, and 32.4%, respectively. Initiation of OAC therapy was only modestly influenced by CHADS2 and HAS-BLED scores, regardless of the healthcare setting. The rate of TE was 4.30 [95% confidence interval (CI) 4.21-4.40] per 100 person-years for inpatients, 2.28 (95% CI 2.22-2.36) for outpatients, and 2.30 (95% CI 2.05-2.59) for ED patients. The adjusted HR of TE, with inpatients as reference, was 0.74 (95% CI 0.71-0.77) for outpatients and 0.89 (95% CI 0.79-1.01) for ED patients.

CONCLUSION

In a nationwide cohort of non-valvular AF patients, outpatients were much more likely to receive OAC therapy and had a significantly lower risk of stroke/TE compared with inpatients and ED patients. However, across all settings investigated, OAC therapy was far from optimal.

Association between the diagnosis of atrial fibrillation and aspects of health status: a Danish cross-sectional study

BACKGROUND

Caring for patients living with atrial fibrillation (AF) is expected to be an increasing challenge for the healthcare sector in the future. Inconclusive results on self-reported health-related quality of life and health status in patients living with AF have previously been reported, ranging from being similar to those observed in patients who have sustained and survived a myocardial infarction to not being different from those of healthy subjects. In these studies, gender differences were not taken into account.

AIM AND OBJECTIVE

To investigate the association between the diagnosis of atrial fibrillation and self-reported health status.

DESIGN

An observational, cross-sectional study was conducted using data from the Danish Diet, Cancer and Health cohort. Information on health status was obtained using the Danish version of the Short Form 36 version 2 questionnaire. The analyses were stratified on gender. In adjusted analysis, we considered potential confounding from comorbidity expressed by the Charlson Comorbidity Index and effect modification by age.

ETHICAL APPROVAL

The local ethical committees of Copenhagen and Frederiksberg municipalities (Approval no.: (KF) 01-345/93) approved the study.

RESULTS

We included 42 598 participants of whom 873 had a diagnosis of AF and/or atrial flutter. We found a lower adjusted physical component score among AF patients. No systematic differences in the mental component score (MCS) were observed.

CONCLUSION

Participants diagnosed with AF report a clinically and statistically significantly lower physical health component score. No systematic differences in the MCS were found when comparing with the remaining participants in the cohort. As healthcare professionals caring for patients living with AF are not always expecting patients living with AF to experience a burden from their disease, the individual patients' experience of their situation, feelings, preferences, symptoms and needs leading to physical limitations should always be articulated.

Short-term mortality risk of serum potassium levels in acute heart failure following myocardial infarction

AIMS

Diuretic treatment is often needed in acute heart failure following myocardial infarction (MI) and carries a risk of abnormal potassium levels. We examined the relation between different levels of potassium and mortality.

METHODS AND RESULTS

From Danish national registries we identified 2596 patients treated with loop diuretics after their first MI episode where potassium measurement was available within 3 months. All-cause mortality was examined according to seven predefined potassium levels: hypokalaemia <3.5 mmol/L, low normal potassium 3.5-3.8 mmol/L, normal potassium 3.9-4.2 mmol/L, normal potassium 4.3-4.5 mmol/L, high normal potassium 4.6-5.0 mmol/L, mild hyperkalaemia 5.1-5.5 mmol/L, and severe hyperkalaemia: >5.5 mmol/L. Follow-up was 90 days and using normal potassium 3.9-4.2 mmol/L as a reference, we estimated the risk of death with a multivariable-adjusted Cox proportional hazard model. After 90 days, the mortality rates in the seven potassium intervals were 15.7, 13.6, 7.3, 8.1, 10.6, 15.5, and 38.3%, respectively. Multivariable-adjusted risk for death was statistically significant for patients with hypokalaemia [hazard ratio (HR): 1.91, confidence interval (95%CI): 1.14-3.19], and mild and severe hyperkalaemia (HR: 2, CI: 1.25-3.18 and HR: 5.6, CI: 3.38-9.29, respectively). Low and high normal potassium were also associated with increased mortality (HR: 1.84, CI: 1.23-2.76 and HR: 1.55, CI: 1.09-2.22, respectively).

CONCLUSION

Potassium levels outside the interval 3.9-4.5 mmol/L were associated with a substantial risk of death in patients requiring diuretic treatment after an MI.

Preadmission glucocorticoid use and anastomotic leakage after colon and rectal cancer resections: a Danish cohort study

OBJECTIVE

To examine whether preadmission glucocorticoid use increases the risk of anastomotic leakage after colon and rectal cancer resections.

DESIGN

A population-based cohort study.

SETTING

Denmark (2001-2011).

PARTICIPANTS

We identified patients who had undergone a primary anastomosis after a colorectal cancer resection by linking medical registries. Participants who filled their most recent glucocorticoid prescription ≤90, 91-365 and >365 days before their surgery date were categorised as current, recent and former users, respectively.

MAIN OUTCOME MEASURES

We calculated 30-day absolute risk of anastomotic leakage and computed ORs using logistic regression models with adjustment for potential confounders.

RESULTS

Of the 18,190 patients with colon cancer, anastomotic leakage occurred in 1184 (6.5%). Glucocorticoid use overall was not associated with an increased risk of leakage (6.4% vs 6.9% among never-users; OR 1.05; 95% CI 0.89 to 1.23). Categories of oral, inhaled or intestinal-acting glucocorticoids did not greatly affect risk of leakage. Anastomotic leakage occurred in 695 (13.2%) of 5284 patients with rectal cancer. Glucocorticoid use overall slightly increased risk of leakage (14.6% vs 12.8% among never-users; OR 1.36, 95% CI 1.08 to 1.72). Results did not differ significantly within glucocorticoid categories.

CONCLUSIONS

Preadmission glucocorticoids modestly increased the risk of anastomotic leakage mainly after rectal cancer resection. However, absolute risk differences were small and the clinical impact of glucocorticoid use may therefore be limited.

Risk of Cancer in Patients with Insomnia, Parasomnia, and Obstructive Sleep Apnea: A Nationwide Nested Case-Control Study

Purpose: Insomnia, parasomnia, and obstructive sleep apnea have been associated with a number of disease pathologies, but little is known about the relationship of these sleep disorders and cancer. The study explored the risk of sleep disorder (SD)-induced cancer using nationwide population data. Two million data from the National Health Insurance system of Taiwan was used to assess for the relationship.

Patients and Methods: Patients with cancer as our cases and patients without cancer as our control group in 2001-20011. The study patients were traced back to seek the exposure risk factor of sleep disorders, which was divided into three categories: insomnia, obstructive sleep apnea (OSA) and parasomnia. Patients were selected excluding patients who had cancer prior to presenting with the sleep disorder and the person-year is less than 2 years. Each case was randomly matched with two cases with the same age, gender, and index year.

Results: There were significantly increased risks of breast cancer in the patients with insomnia (AHR=1.73; 95% CI: 1.57-1.90), patients with parasomnia (AHR=2.76; 95% CI: 1.53-5.00), and patients with OSA (AHR=2.10; 95% CI: 1.16-3.80). Moreover, patients with parasomnia had significantly higher risk of developing oral cancer (AHR=2.71; 95% CI: 1.02-7.24) compared with patients without parasomnia. The risk of suffering from nasal cancer (AHR=5.96, 95% CI: 2.96-11.99) and prostate cancer (AHR=3.69, 95% CI: 1.98- 6.89) in patients with OSA was significantly higher than that of patients without OSA.

Conclusions: Our findings provided the evidence that people diagnosed with insomnia, parasomnia and OSA are at a higher risk of developing cancers to remind people to improve sleep quality.

Metformin initiation and renal impairment: a cohort study in Denmark and the UK

OBJECTIVES

To estimate prevalence of renal impairment, rate of decline in kidney function and changes in metformin use after decline in kidney function, in metformin initiators.

DESIGN, SETTING AND PARTICIPANTS

We conducted this 2-country cohort study using routine data from northern Denmark and the UK during 2000-2011. We included metformin initiators among patients aged ≥30 years with medically treated diabetes.

MAIN OUTCOME MEASURES

We described patients' demographics, comorbidity, co-medications and their estimated glomerular filtration rates (eGFR). Furthermore, we described the patients' characteristics according to eGFR level. Finally, we examined the rate of any decline in eGFR and changes in metformin use within 90 days after first decline in eGFR during follow-up.

RESULTS

We included 124,720 metformin initiators in the 2 countries. Prevalence of eGFR <60 mL/min/1.73 m(2) among metformin initiators was 9.0% in Denmark and 25.2% in the UK. In contrast, prevalence of eGFR values <30 mL/min/1.73 m(2) among metformin initiators was 0.3% in Denmark and 0.4% in the UK. Patients with renal impairment were older and more likely to have received cardiovascular drugs. Incidence rate of decline in renal function was 4.92 per 100 person-years (95% CI 4.76 to 5.09) in Denmark and 7.48 per 100 person-years (95% CI 7.39 to 7.57) in the UK. The proportion of patients continuing metformin use, even after a first decline brought the eGFR below 30 mL/min/1.73 m(2), was 44% in Denmark and 62% in the UK. There was no clinically significant dose reduction with decreasing baseline eGFR level discernible from the data.

CONCLUSIONS

Mild to moderate renal impairment was common among metformin initiators, while severe renal impairment was uncommon. Patients with severe renal impairment frequently continued receiving/redeeming metformin prescriptions even 90 days after eGFR decline.

Comorbidities in Patients With Anterior Cruciate Ligament Reconstruction Compared With Matched Controls Without Anterior Cruciate Ligament Injury From Danish Registries

PURPOSE

To describe and compare comorbidity among anterior cruciate ligament (ACL)-reconstructed patients and a gender- and age-matched group without ACL injury. Furthermore, we sought to evaluate the impact of comorbid diseases on the risk of ACL revision surgery.

METHODS

This case-control study included 13,443 unilateral primary ACL-reconstructed patients from the Danish Knee Ligament Reconstruction Register matched on gender and age with a comparison group without ACL injury. Information on medical comorbid conditions was obtained from the Danish National Registry of Patients. The prevalence of all comorbid conditions was described for ACL-reconstructed patients and the comparison group in terms of (1) the Charlson Comorbidity Index (CCI); (2) International Classification of Diseases, Tenth Revision disease chapters; and (3) more common chronic diseases in a younger population. Finally, we assessed the risk of ACL revision surgery according to the more common chronic diseases in a younger population, using Cox regression analysis.

RESULTS

Although we found a large variety of diseases present among ACL-reconstructed patients, the percentage of patients with a CCI equal to 0 was high in both groups. ACL-reconstructed patients generally had a slightly lower prevalence of almost all International Classification of Diseases, Tenth Revision-classified comorbid disease groups compared with the comparison group without ACL injury. As expected, the prevalence of most diseases increased slightly with rising age. Furthermore, we found that having back pain or diseases of the back did alter the risk of revision surgery.

CONCLUSIONS

ACL-reconstructed patients are found to be generally healthy individuals with a low prevalence of serious and chronic diseases compared with an age- and gender-matched control group from the general population. A large variety of diseases are present in the ACL-reconstructed group but with very low prevalence rates and low CCIs, indicating that the severity of their illness is limited.

LEVEL OF EVIDENCE

Level III, case-control study.

Trauma, comorbidity, and mortality following diagnoses of severe stress and adjustment disorders: a nationwide cohort study

Longitudinal outcomes following stress or trauma diagnoses are receiving attention, yet population-based studies are few. The aims of the present cohort study were to examine the cumulative incidence of traumatic events and psychiatric diagnoses following diagnoses of severe stress and adjustment disorders categorized using International Classification of Diseases, Tenth Revision, codes and to examine associations of these diagnoses with all-cause mortality and suicide. Data came from a longitudinal cohort of all Danes who received a diagnosis of reaction to severe stress or adjustment disorders (International Classification of Diseases, Tenth Revision, code F43.x) between 1995 and 2011, and they were compared with data from a general-population cohort. Cumulative incidence curves were plotted to examine traumatic experiences and psychiatric diagnoses during the study period. A Cox proportional hazards regression model was used to examine the associations of the disorders with mortality and suicide. Participants with stress diagnoses had a higher incidence of traumatic events and psychiatric diagnoses than did the comparison group. Each disorder was associated with a higher rate of all-cause mortality than that seen in the comparison cohort, and strong associations with suicide were found after adjustment. This study provides a comprehensive assessment of the associations of stress disorders with a variety of outcomes, and we found that stress diagnoses may have long-lasting and potentially severe consequences.

Association of Selected Antipsychotic Agents With Major Adverse Cardiovascular Events and Noncardiovascular Mortality in Elderly Persons

BACKGROUND

Data from observational studies have raised concerns about the safety of treatment with antipsychotic agents (APs) in elderly patients with dementia, but this area has been insufficiently investigated. We performed a head-to-head comparison of the risk of major adverse cardiovascular events and noncardiovascular mortality associated with individual APs (ziprasidone, olanzapine, risperidone, quetiapine, levomepromazine, chlorprothixen, flupentixol, and haloperidol) in Danish treatment-naïve patients aged ≥70 years.

METHODS AND RESULTS

We followed all treatment-naïve Danish citizens aged ≥70 years that initiated treatment with APs for the first time between 1997 and 2011 (n=91 774, mean age 82±7 years, 35 474 [39%] were men). Incidence rate ratios associated with use of different APs were assessed by multivariable time-dependent Poisson regression models. For the first 30 days of treatment, compared with risperidone, incidence rate ratios of major adverse cardiovascular events were higher with use of levomepromazine (3.80, 95% CI 3.43 to 4.21) and haloperidol (1.85, 95% CI 1.67 to 2.05) and lower for treatment with flupentixol (0.54, 95% CI 0.45 to 0.66), ziprasidone (0.31, 95% CI 0.10 to 0.97), chlorprothixen (0.76, 95% CI 0.61 to 0.95), and quetiapine (0.68, 95% CI 0.58 to 0.80). Relationships were generally similar for long-term treatment. The majority of agents were associated with higher risks among patients with cardiovascular disease compared with patients without cardiovascular disease (P for interaction <0.0001). Similar results were observed for noncardiovascular mortality, although differences in associations between patients with and without cardiovascular disease were small.

CONCLUSIONS

Our study suggested some diversity in risks associated with individual APs but no systematic difference between first- and second-generation APs. Randomized placebo-controlled studies are warranted to confirm our findings and to identify the safest agents.

Low-Dose Aspirin or Nonsteroidal Anti-inflammatory Drug Use and Colorectal Cancer Risk: A Population-Based, Case-Control Study

BACKGROUND

A recent comprehensive review concluded that additional research is needed to determine the optimal use of aspirin for cancer prevention.

OBJECTIVE

To assess associations between the use of low-dose aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) and colorectal cancer risk.

DESIGN

Population-based, case-control study.

SETTING

Northern Denmark.

PATIENTS

Patients with first-time colorectal cancer in northern Denmark between 1994 and 2011. Population control participants were selected by risk set sampling.

MEASUREMENTS

Data on drug use, comorbid conditions, and history of colonoscopy were obtained from prescription and patient registries. Use of low-dose aspirin (75 to 150 mg) and nonaspirin NSAIDs was defined according to type, estimated dose, duration, and consistency of use.

RESULTS

Among 10 280 case patients and 102 800 control participants, the adjusted odds ratios (ORs) for colorectal cancer associated with ever use (≥2 prescriptions) of low-dose aspirin and nonaspirin NSAIDs were 1.03 (95% CI, 0.98 to 1.09) and 0.94 (CI, 0.90 to 0.98), respectively. Continuous long-term use (≥5 years) of low-dose aspirin was associated with a 27% reduction in colorectal cancer risk (OR, 0.73 [CI, 0.54 to 0.99]), whereas the overall OR for cumulative long-term use (continuous or noncontinuous) was close to unity. Nonaspirin NSAID use was associated with a substantial reduction in colorectal cancer risk, particularly for long-term, high-intensity use (average defined daily dose ≥0.3) of agents with high cyclooxygenase-2 selectivity (OR, 0.57 [CI, 0.44 to 0.74]).

LIMITATIONS

Data were unavailable on over-the-counter purchases of high-dose aspirin and low-dose ibuprofen or NSAID dosing schedules, there were several comparisons, and the authors were unable to adjust for confounding by some risk factors.

CONCLUSION

Long-term, continuous use of low-dose aspirin and long-term use of nonaspirin NSAIDs were associated with reduced colorectal cancer risk. Persons who continuously used low-dose aspirin comprised only a small proportion of the low-dose aspirin users.

PRIMARY FUNDING SOURCE

Danish Cancer Society, Aarhus University Research Foundation.

Epidemiology and Clinical Significance of Secondary and Therapy-Related Acute Myeloid Leukemia: A National Population-Based Cohort Study

PURPOSE

Secondary and therapy-related acute myeloid leukemia (sAML and tAML, respectively) remain therapeutic challenges. Still, it is unclear whether their inferior outcome compared with de novo acute myeloid leukemia (AML) varies as a result of previous hematologic disease or can be explained by differences in karyotype and/or age.

PATIENTS AND METHODS

In a Danish national population-based study of 3,055 unselected patients with AML diagnosed from 2000 to 2013, we compared the frequencies and characteristics of tAML, myelodysplastic syndrome (MDS) -sAML, and non-MDS-sAML (chronic myelomonocytic leukemia and myeloproliferative neoplasia) versus de novo AML. Limited to intensive therapy patients, we compared chance of complete remission by logistic regression analysis and used a pseudo-value approach to compare relative risk (RR) of death at 90 days, 1 year, and 3 years, overall and stratified by age and karyotype. Results were given crude and adjusted with 95% CIs.

RESULTS

Overall, frequencies of sAML and tAML were 19.8% and 6.6%, respectively. sAML, but not tAML, was associated with low likelihood of receiving intensive treatment. Among intensive therapy patients (n = 1,567), antecedent myeloid disorder or prior cytotoxic exposure was associated with decreased complete remission rates and inferior survival (3-year adjusted RR for MDS-sAML, non-MDS-sAML, and tAML: RR, 1.14; 95% CI, 1.02 to 1.32; RR, 1.27; 95% CI, 1.16 to 1.34; and RR, 1.16; 95% CI, 1.03 to 1.32, respectively) compared with de novo AML. Among patients ≥ 60 years old and patients with adverse karyotype, previous MDS or tAML did not impact overall outcomes, whereas non-MDS-sAML was associated with inferior survival across age and cytogenetic risk groups (adverse risk cytogenetics: 1-year adjusted RR, 1.47; 95% CI, 1.23 to 1.76; patients ≥ 60 years old: 1-year adjusted RR, 1.31; 95% CI, 1.06 to 1.61).

CONCLUSION

Our results support that de novo AML, sAML, and tAML are biologically and prognostically distinct subtypes of AML. Patients with non-MDS-sAML have dismal outcomes, independent of age and cytogenetics. Previous myeloid disorder, age, and cytogenetics are crucial determinants of outcomes and should be integrated in treatment recommendations for these patients.

Pre-existing atrial fibrillation and risk of arterial thromboembolism and death in intensive care unit patients: a population-based cohort study

INTRODUCTION

Pre-existing atrial fibrillation (AF) may worsen prognosis in patients admitted to the intensive care unit (ICU).

METHODS

In a cohort study (2005-2011) including all patients with first-time ICU admissions in Denmark (n=57,110), we compared patients with and without pre-existing AF and estimated absolute risks and relative risks (RRs) of arterial thromboembolism and death within 30 days and 365 days following admission, using Kaplan-Meier methods and multivariate regression analyses. We analysed the prognostic impact of AF within strata of patient age, sex, coexisting cardiac diseases, and ICU therapies.

RESULTS

Among ICU patients, 5065 (9%) had pre-existing AF. Compared with patients without AF, those with AF were older (median age 75 vs. 62 years) and had more comorbidity. The risk of arterial thromboembolism was 2.8% in patients with AF and 2.0% in non-AF patients at 30 days, and 4.3% and 2.9%, respectively, at 365 days. Corresponding RRs were 1.41 crude and 1.14 (95% confidence interval [CI] 0.93-1.40) adjusted at 30 days, and 1.50 crude and 1.20 (95% CI 1.02-1.41) adjusted at 365 days. Thirty-day mortality was 27% in patients with pre-existing AF and 16% in non-AF patients (crude RR 1.67, adjusted RR 1.04, 95% CI 0.99-1.10). Corresponding mortality estimates at 365 days were 40.9% and 25.4%, respectively (crude RR 1.61, adjusted RR 1.03, 95% CI 1.00-1.07). In stratified analyses, pre-existing AF increased mortality in ICU patients aged <55 years (adjusted RR at 30 days 1.73, 95% CI 1.29-2.32; adjusted RR at 365 days 1.34, 95% CI 1.06-1.69) and in ICU patients treated with mechanical ventilation (adjusted RR at 30 days 1.12, 95% CI 1.05-1.20, adjusted RR at 365 days 1.09, 95% CI: 1.04-1.15). Analyses stratified by sex and coexisting cardiac diseases yielded adjusted RRs close to 1.

CONCLUSIONS

In ICU patients, pre-existing AF was associated with modestly increased risk of arterial thromboembolism when adjusted for the substantially higher age and comorbidity levels in patients with AF, whereas there was no overall association with mortality. In ICU patients aged <55 years and in those treated with mechanical ventilation, AF predicted increased mortality.

Impact of preoperative serum albumin on 30-day mortality following surgery for colorectal cancer: a population-based cohort study

Objective

Surgery is the only potentially curable treatment for colorectal cancer (CRC), but it is hampered by high mortality. Human serum albumin (HSA) below 35 g/L is associated with poor overall prognosis in patients with CRC, but evidence regarding the impact on postoperative mortality is sparse.

Methods

We performed a population-based cohort study including patients undergoing CRC surgery in North and Central Denmark (1997–2011). We categorised patients according to HSA concentration measured 1–30 days prior to surgery date. We used the Kaplan-Meier method to compute 30-day mortality and Cox regression model to compute HRs as measures of the relative risk of death, controlling for potential confounders. We further stratified patients by preoperative conditions, including cancer stage, comorbidity level, and C reactive protein concentration.

Results

Of the 9339 patients undergoing first-time CRC surgery with preoperative HSA measurement, 26.4% (n=2464) had HSA below 35 g/L. 30-day mortality increased from 4.9% among patients with HSA 36–40 g/L to 26.9% among patients with HSA equal to or below 25 g/L, compared with 2.0% among patients with HSA above 40 g/L. The corresponding adjusted HRs increased from 1.75 (95% CI 1.25 to 2.45) among patients with HSA 36–40 g/L to 7.59 (95% CI 4.95 to 11.64) among patients with HSA equal to or below 25 g/L, compared with patients with HSA above 40 g/L. The negative impact associated with a decrement of HSA was found in all subgroups.

Conclusions

A decrement in preoperative HSA concentration was associated with substantial concentration-dependent increased 30-day mortality following CRC surgery.

Geographical variation in use of intensive care: a nationwide study

PURPOSE

To examine whether there is geographical variation in the use of intensive care resources in Denmark concerning both intensive care unit (ICU) admission and use of specific interventions. Substantial variation in use of intensive care has been reported between countries and within the US, however, data on geographical variation in use within more homogenous tax-supported health care systems are sparse.

METHODS

We conducted a population-based cross-sectional study based on linkage of national medical registries including all Danish residents between 2008 and 2012 using population statistics from Statistics Denmark. Data on ICU admissions and interventions, including mechanical ventilation, noninvasive ventilation, acute renal replacement therapy, and treatment with inotropes/vasopressors, were obtained from the Danish Intensive Care Database. Data on patients' residence at the time of admission were obtained from the Danish National Registry of Patients.

RESULTS

The overall age- and gender standardized number of ICU patients per 1000 person-years for the 5-year period was 4.3 patients (95 % CI, 4.2; 4.3) ranging from 3.7 (95 % CI, 3.6; 3.7) to 5.1 patients per 1000 person-years (95 % CI, 5.0; 5.2) in the five regions of Denmark and from 2.8 (95 % CI, 2.8; 3.0) to 23.1 patients per 1000 person-years (95 % CI, 13.0; 33.1) in the 98 municipalities. The age-, gender-, and comorbidity standardized proportion of use of interventions among ICU patients also differed across regions and municipalities.

CONCLUSIONS

There was only minimal geographical variation in the use of intensive care admissions and interventions at the regional level in Denmark, but more pronounced variation at the municipality level.

Breast cancer risk in hyperprolactinemia: a population-based cohort study and meta-analysis of the literature

OBJECTIVE

To enhance the precision of the risk estimate for breast cancer in hyperprolactinemia patients by collecting more data and pooling our results with available data from former studies in a meta-analysis.

DESIGN

Population-based cohort study and meta-analysis of the literature.

METHODS

Using nationwide registries, we identified all patients with a first-time diagnosis of hyperprolactinemia during 1994-2012 including those with a new breast cancer diagnoses after the start of follow-up. We calculated standardised incidence ratios (SIRs) as a measure of relative risk (RR) using national cancer incidence rates. We performed a meta-analysis, combining data from our study with data in the existing literature.

RESULTS

We identified 2457 patients with hyperprolactinemia and 20 breast cancer cases during 19,411 person-years of follow-up, yielding a SIR of 0.99 (95% CI 0.60-1.52). Data from two additional cohort studies were retrieved and analyzed. When the three risk estimates were pooled, the combined RR was 1.04 (95% CI 0.75-1.43).

CONCLUSIONS

We found no increased risk of breast cancer among patients with hyperprolactinemia.

Early glycaemic control among patients with type 2 diabetes and initial glucose-lowering treatment: a 13-year population-based cohort study

AIM

To examine real-life time trends in early glycaemic control in patients with type 2 diabetes between 2000 and 2012.

METHODS

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.

RESULTS

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 <7% (<53 mmol/mol) in 2010-2012 than in 2000-2003 [80 vs 60%, adjusted relative risk (aRR) 1.10, 95% confidence interval (CI) 1.08-1.13], and more achieved an HbA1c target of <6.5% [(<48 mmol/mol) 53 vs 37%, aRR 1.07 95% CI 1.03-1.11)], with similar success rates observed among patients aged <65 years without comorbidities. Achieved HbA1c levels were similar for different initiation therapies, with reductions of 0.8% (from 7.3 to 6.5%) on metformin, 1.5% (from 8.1 to 6.6%) on sulphonylurea, 4.0% (from 10.4 to 6.4%) on non-insulin combination therapies, and 3.8% (from 10.3 to 6.5%) on insulin monotherapy.

CONCLUSIONS

Pretreatment HbA1c levels in patients with incident type 2 diabetes have decreased substantially, which is probably related to earlier detection and treatment in accordance with changing guidelines. Achievement of glycaemic control has improved, but 20% of patients still do not attain an HbA1c level of <7% within the first 6 months of initial treatment.

Survival and PSA-markers for mortality and metastasis in nonmetastatic prostate cancer treated with androgen deprivation therapy

BACKGROUND

Few studies have examined the risk of developing castration-resistant prostate cancer (CRPC), metastasis, and mortality among nonmetastatic prostate cancer (M0-PC) patients treated with androgen deprivation therapy (ADT). We estimated the incidence of these outcomes among M0-PC patients on ADT and identified prostate-specific antigen (PSA) based biomarkers for mortality and metastasis.

METHODS

This population-based cohort study included all nonmetastatic prostate cancer patients in Northern and Central Denmark Regions during 1997-2010, identified through registry data. Primary outcomes were metastasis, overall survival, and bone metastasis-free survival (BMFS). We estimated relative risks (RR) associated with PSA and PSA doubling-time (PSA-DT), measured as time-varying variables beginning at ADT treatment start.

RESULTS

We included 2494 M0-PC patients treated with ADT, of whom 1617 (80%) developed CRPC during follow-up. One-fourth of the patients developed metastases within 5 years; bone metastases (BM) accounted for 81% of all metastases. Median survival time was 4.4 years. Compared with PSA <8 ng/mL, PSA ≥8 ng/mL was associated with an adjusted RR of 14.0 (95% confidence interval [CI]: 10.2, 19.0) for BM, 4.4 (CI: 3.9, 5.0) for all-cause mortality, and RR of 4.8 (CI: 4.3, 5.4) for the inverse of BMFS. PSA-DT ≤6 months was associated with an adjusted RR of 7.6 (95% CI: 6.1, 9.5) for BM, RR of 5.9 (CI: 5.2, 6.6) for all-cause mortality, and RR 6.6 (CI: 5.9, 7.4) for the inverse of BMFS.

CONCLUSIONS

PSA ≥8 ng/mL and PSA-DT ≤6 months are strong predictors of mortality and bone metastasis. The poor prognosis observed in this study may reflect inclusion of patients with severe prostate cancer by requiring repeated PSA measurements.

Inflammation and depression: combined use of selective serotonin reuptake inhibitors and NSAIDs or paracetamol and psychiatric outcomes

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) and paracetamol have been shown to yield the potential of adjunctive antidepressant treatment effects to selective serotonin reuptake inhibitors (SSRIs); however, when investigating treatment effects of concomitant use, simultaneous evaluation of potential adverse events is important. The objective was thus to investigate treatment effectiveness and safety aspects of concomitant SSRI use with NSAIDs or paracetamol.

METHODS

Within a 25% random sample of the Danish population, we identified all incident SSRI users between 1997 and 2006 (N = 123,351). Effectiveness and safety measures were compared between periods of SSRI use only and periods of combined SSRI and NSAID or paracetamol use by applying Cox regression.

RESULTS

Among 123,351 SSRI users (follow-up: 53,697.8 person-years), 21,666 (17.5%) used NSAIDs and 10,232 (8.3%) paracetamol concomitantly. Concomitant NSAID use increased the risk of any psychiatric contact [Hazard rate ratio (95%-confidence interval): 1.22 (1.07; 1.38)] and with depression [1.31 (1.11; 1.55)]. Low-dose acetylsalicylic acid reduced the risk of psychiatric contact in general [0.74 (0.56; 0.98)] and with depression [0.71 (0.50; 1.01)]. Ibuprofen reduced the risk of psychiatric contacts [0.76 (0.60; 0.98)]. Concerning safety, paracetamol was associated with increased mortality [3.18 (2.83; 3.58)], especially cardiovascular [2.51 (1.93; 3.28)]. Diclofenac [1.77 (1.22; 2.55)] and the selective COX-2 inhibitors [1.75 (1.21; 2.53)] increased mortality risks.

CONCLUSIONS

Concomitant use of SSRIs and NSAIDs occurred frequently, and effectiveness and safety outcomes varied across individual NSAIDs. Especially low-dose acetylsalicylic acid may represent an adjunctive antidepressant treatment option. The increased mortality risk of concomitant use of paracetamol needs further investigation.

Duration of Diabetes Mellitus and Risk of Thromboembolism and Bleeding in Atrial Fibrillation: Nationwide Cohort Study

BACKGROUND AND PURPOSE

Guidelines advocate anticoagulant treatment to all patients with atrial fibrillation and concomitant diabetes mellitus. The potential refinement to thromboembolic risk stratification that may spring from subdividing diabetes mellitus is unexplored. The purpose was to investigate duration of diabetes mellitus as a predictor of thromboembolism and anticoagulant-related bleeding in patients with atrial fibrillation.

METHODS

Using nationwide Danish registries, we identified all patients discharged from hospital with an incident diagnosis of atrial fibrillation from 2000 to 2011. Hazard ratios with 95% confidence intervals for thromboembolism and bleeding according to years of diabetes mellitus duration in categories (0-4, 5-9, 10-14, and ≥15) and as a continuous variable using cubic splines were calculated by Cox regression.

RESULTS

The study population comprised 137 222 patients with atrial fibrillation, of which 12.4% had diabetes mellitus. Compared with patients without diabetes mellitus and after adjustment for anticoagulant treatment and CHA2DS2-VASc components (congestive heart failure, hypertension, age, previous stroke, vascular disease, and sex), the risk of thromboembolism was lowest in the 0 to 4 years duration category (hazard ratio, 1.11; 95% confidence interval, 1.03-1.20), and highest in the longest duration category of ≥15 years (hazard ratio, 1.48; 95% confidence interval, 1.29-1.70). When analyzed as a continuous variable, duration of diabetes mellitus was associated with risk of thromboembolism in a dose-response-dependent manner, but not with a higher risk of bleeding during anticoagulant treatment.

CONCLUSIONS

In patients with atrial fibrillation, longer duration of diabetes mellitus was associated with a higher risk of thromboembolism, but not with a higher risk of anticoagulant-related bleeding. Considering the critical balance between preventing thromboembolism and avoiding bleeding, longer duration of diabetes mellitus may favor initiation of anticoagulant therapy.

Prostate cancer, comorbidity, and the risk of venous thromboembolism: A cohort study of 44,035 Danish prostate cancer patients, 1995-2011

BACKGROUND

Venous thromboembolism (VTE) is a serious complication of cancer. It is unknown whether comorbidity interacts clinically with prostate cancer (PC) to increase the VTE rate beyond that explained by PC and comorbidity alone, for example, by delaying diagnosis or precluding treatment.

METHODS

A nationwide, registry-based cohort study of all 44,035 Danish patients diagnosed with PC from 1995 to 2011 and 213,810 men from the general population matched 5:1 on age, calendar time, and comorbidities. The authors calculated VTE rate ratios and the interaction contrast as a measure on the additive scale of the excess VTE rate explained by synergy between PC and comorbidity.

RESULTS

In total, 849 patients in the PC cohort and 2360 men from the general population had VTE during 5 years of follow-up, and their risk of VTE was 2.2% and 1.3%, respectively. The 1-year VTE standardized rate among PC patients who had high comorbidity levels was 15 per 1000 person-years (PYs) (95% confidence interval, 6.8-24 per 1000 PYs), and 29% of that rate was explained by an interaction between PC and comorbidity. The VTE risk was increased among older patients, those with metastases, those with high Gleason scores, those in the D'Amico high-risk group, and those who underwent surgery.

CONCLUSIONS

PC interacted clinically with high comorbidity levels and increased the VTE rate. Because of the large PC burden, reducing VTEs associated with comorbidities may have an impact on VTE risk and the potential to improve prognosis. Clinical interactions between high levels of comorbidity and PC on the risk of VTE were observed. Almost 30% of all episodes of VTE occurred among patients who had high levels of comorbidity.

Cirrhosis is Associated with an Increased 30-Day Mortality After Venous Thromboembolism

Objectives:

Patients with cirrhosis are at increased risk of venous thromboembolism (VTE), but the impact of cirrhosis on the clinical course following VTE is unclear. In a nationwide cohort study, we examined 30-day mortality among patients with cirrhosis and VTE.

Methods:

We used Danish population-based health-care databases (1994–2011) to identify patients with incident VTE, i.e., deep venous thrombosis (DVT), pulmonary embolism (PE), and portal vein thrombosis (PVT). Among these, we identified 745 patients with cirrhosis and 3647 patients without cirrhosis (matched on gender, year of birth, calendar year of VTE diagnosis and VTE type). We assessed the 30-day mortality risk among VTE patients with and without cirrhosis, and the mortality rate ratios (MRRs), using an adjusted Cox model with 95% confidence interval. We obtained information on immediate cause of death for patients who died within 30 days after VTE.

Results:

The 30-day mortality risk for DVT was 7% for patients with cirrhosis and 3% for patients without cirrhosis. Corresponding PE-related mortality risks were 35% and 16%, and PVT-related mortality risks were 19% and 15%, respectively. The adjusted 30-day MRRs were 2.17 (1.24–3.79) for DVT, 1.83 (1.30–2.56) for PE, and 1.30 (0.80–2.13) for PVT. Though overall mortality was higher in patients with cirrhosis than patients without cirrhosis, the proportions of deaths due to PE were similar among patients (25% and 24%, respectively).

Conclusions:

Cirrhosis is a predictor for increased short-term mortality following VTE, with PE as the most frequent cause of death.

Hyponatremia and mortality risk: a Danish cohort study of 279 508 acutely hospitalized patients

OBJECTIVE

We aimed to investigate the impact of hyponatremia severity on mortality risk and assess any evidence of a dose-response relation, utilizing prospectively collected data from population-based registries.

DESIGN

Cohort study of 279 ,508 first-time acute admissions to Departments of Internal Medicine in the North and Central Denmark Regions from 2006 to 2011.

METHODS

We used the Kaplan-Meier method (1 - survival function) to compute 30-day and 1-year mortality in patients with normonatremia and categories of increasing hyponatremia severity. Relative risks (RRs) with 95% CIs, adjusted for age, gender and previous morbidities, and stratified by clinical subgroups were estimated by the pseudo-value approach. The probability of death was estimated treating serum sodium as a continuous variable.

RESULTS

The prevalence of admission hyponatremia was 15% (41,803 patients). Thirty-day mortality was 3.6% in normonatremic patients compared to 7.3, 10.0, 10.4 and 9.6% in patients with serum sodium levels of 130-134.9, 125-129.9, 120-124.9 and <120 mmol/l, resulting in adjusted RRs of 1.4 (95% CI: 1.3-1.4), 1.7 (95% CI: 1.6-1.8), 1.7 (95% CI: 1.4-1.9) and 1.3 (95% CI: 1.1-1.5) respectively. Mortality risk was increased across virtually all clinical subgroups, and remained increased by 30-40% 1 year after admission. The probability of death increased when serum sodium decreased from 139 to 132  mmol/l. No clear increase in mortality was observed for lower concentrations.

CONCLUSIONS

Hyponatremia is highly prevalent among patients admitted to Departments of Internal Medicine and is associated with increased 30-day and 1-year mortality risk, regardless of underlying disease. This risk seems independent of hyponatremia severity.

Levothyroxine Substitution in Patients with Subclinical Hypothyroidism and the Risk of Myocardial Infarction and Mortality

Background

Subclinical hypothyroidism is associated with a number of cardiovascular risk factors, yet only limited data exist on long-term outcome of levothyroxine treatment of this condition with respect to hard end-points. The aim of this retrospective cohort study was to determine effects of levothyroxine treatment on myocardial infarction (MI), cardiovascular death and all-cause mortality, in patients with subclinical hypothyroidism.

Methods and Results

Primary care patients aged 18 years and older that underwent thyroid function tests between 2000 and 2009 were enrolled. Participants were identified by individual-level linkage of nationwide registers. Patients with subclinical hypothyroidism at baseline were included in the study. Exclusion criteria included a history of thyroid disease, related medication or medication affecting thyroid function. The total cohort comprised 628,953 patients of which 12,212 (1.9%) had subclinical hypothyroidism (mean age 55.2 [SD ± 18.8] years; 79.8% female). Within the first six months 2,483 (20.3%) patients claimed a prescription for levothyroxine. During a median follow-up of 5.0 (IQR: 5.2) years, 358 MI’s and 1,566 (12.8%) deaths were observed. Out of these, 766 of the deaths were cardiovascular related. No beneficial effects were found in levothyroxine treated patients on MI (IRR 1.08 [95% CI: 0.81 to 1.44]), cardiovascular death (IRR 1.02 [95% CI: 0.83 to 1.25]) or all-cause mortality (IRR 1.03 [95% CI: 0.90 to 1.19]), except in patients under the age of 65 years (IRR 0.63 [95% CI: 0.40 to 0.99]).

Conclusion

Levothyroxine substitution in subclinical hypothyroid patients does not indicate an association with lower mortality or decreased risk of MI.

Survival of patients with chronic myeloproliferative neoplasms and new primary cancers: a population-based cohort study

BACKGROUND

Patients with chronic myeloproliferative neoplasms are at increased risk of new solid or haematological cancers, but how prognosis is affected in patients with preceding myeloproliferative neoplasms is unclear.

METHODS

We used data from population-based medical databases in Denmark from 1980 to 2011 to compare survival between cancer patients with and without a preceding diagnosis of myeloproliferative neoplasm, matched for age, sex, year of diagnosis, and type of cancer. We assessed outcomes by cancer stage and comorbidities.

FINDINGS

Data were available for 1246 patients with a history of myeloproliferative neoplasms and we matched 5155 patients without a history of myeloproliferative neoplasm for comparison. Among patients with new localised solid cancers, 5-year survival was 49.8% (95% CI 39.1-59.6) for patients with preceding essential thrombocythaemia, 47·9% (42·1-53·4) for those with preceding polycythaemia vera, and 48.0% (34.1-60.7) for those with preceding chronic myeloid leukaemia. The values were 72.4% (68.4-76.0), 63.9% (61.5-66.2), and 74.3% (68.2-79.4), respectively, in matched patients without preceding myeloproliferative neoplasms. The risk of death among patients with a solid tumour and preceding myeloproliferative neoplasm was 1.21-2.28 times higher than in patients without myeloproliferative neoplasms. Excess mortality risk was observed irrespective of whether new cancers were diagnosed within 5 years or 5 years or more after myeloproliferative neoplasm.

INTERPRETATION

Preceding myeloproliferative neoplasm is a predictor for poor outlook in patients who develop new primary cancers.

FUNDING

Lundbeck and Novo Nordisk Foundation Programme for Clinical Research Infrastructure, Danish Cancer Society, and Aarhus University Research Foundation.

Radioiodine therapy increases the risk of cerebrovascular events in hyperthyroid and euthyroid patients

BACKGROUND AND OBJECTIVE

Hyperthyroid patients treated with radioiodine have increased morbidity and mortality from cerebrovascular events. This risk has until now has been attributed to the hyperthyroidism. However, radioiodine therapy of benign thyroid diseases exposes the carotid arteries to radiation and is capable of inducing atherosclerosis. The objective of the study was to elucidate whether ionizing radiation from radioiodine might contribute to cerebrovascular morbidity.

METHODS

In a retrospective register cohort study, 4000 hyperthyroid and 1022 euthyroid goitre patients treated with radioiodine between 1975 and 2008 were matched 1:4 on age and sex with random controls. The cohort was followed from the date of treatment until hospitalization due to cerebrovascular event, death, 20 years of follow-up or March 2013. Data were analyzed in competing risk models adjusting for age, sex, Charlson's comorbidity score, atrial fibrillation and previous cerebrovascular events.

RESULTS

Mean follow-up time was 11.5 years, mean age 61 years, with a total number of 3228 events. Comparing all radioiodine-treated patients with controls, the fully adjusted model showed increased risk of cerebrovascular events among all treated patients, hazard ratio (HR) 1.18 (95% CI 1.09-1.29). The risk was increased among hyperthyroid (HR 1.17; 95% CI 1.07-1.28) as well as euthyroid patients (HR 1.21; 95% CI 1.02-1.44).

CONCLUSIONS

We report an increased risk of cerebrovascular events in hyperthyroid as well as euthyroid patients treated with radioiodine for benign thyroid disorders. That these patient groups have similar risks suggests the possibility that radiation from radioiodine contributes to cerebrovascular morbidity via acceleration or initiation of atherosclerosis.

Coexisting liver disease is associated with increased mortality after surgery for diverticular disease

BACKGROUND

Coexistence of liver disease in patients undergoing surgery for diverticular disease (DD) may increase the risk of postoperative complications, but the evidence is limited.

AIM

To investigate the impact of liver disease on mortality and reoperation rates following surgery for DD.

METHODS

We performed a cohort study based on medical databases of all patients undergoing surgery for DD in Denmark during 1977-2011, categorizing them into three cohorts according to history of liver disease: patients with non-cirrhotic liver disease, those with liver cirrhosis, and those without liver disease (comparison cohort). Using the Kaplan-Meier method, we computed mortality in each cohort for 0-30, 31-60, and 61-90 days following surgery for DD. We used a Cox regression model to compute hazard ratios as measures of the relative risk (RR) of death, controlling for potential confounders, including other comorbidities. In addition, we assessed the reoperation rate within 30 days of initial surgery.

RESULTS

Of 14,408 patients undergoing surgery for DD, 233 (1.6 %) had non-cirrhotic liver disease and 91 (0.6 %) had liver cirrhosis. Thirty-day mortality was 9.9 % in patients without liver disease and 14.6 % in patients with non-cirrhotic liver disease [adjusted RR = 1.64 (95 % confidence interval [CI] 1.16-2.31)]. Among patients with liver cirrhosis, mortality was 24.2 % [adjusted RR = 2.70 (95 % CI 1.73-4.22)]. Liver cirrhosis had an impact on mortality up to 60 days after surgery for DD. The reoperation rate was approximately 10 % in each cohort.

CONCLUSION

Preexisting liver disease has a major impact on postoperative mortality following surgery for DD.

Impact of metabolic disorders on the relation between overweight/obesity and incident myocardial infarction and ischaemic stroke in fertile women: a nationwide cohort study

AIMS

Whether overweight is a risk factor for cardiovascular disease in the absence of metabolic disorders remains under debate and is largely unexamined in young women. We evaluated the risk of myocardial infarction and ischaemic stroke in fertile women conditional on time-dependent presence of metabolic disorders.

MATERIALS AND METHODS

From nationwide registers we identified all normal weight (body mass index [BMI] ≥ 18.5 to <25 kg m(-2) and overweight (BMI ≥ 25 kg m(-2)) Danish women giving birth from 2004 to 2009. Using multivariable Poisson regression models adjusted for age, calendar year and smoking, the risk of the composite outcome of myocardial infarction and ischaemic stroke was assessed with metabolic disorders (i.e. hypertensive conditions, abnormal glucose metabolism and/or dyslipidaemia) included as time-dependent variables.

RESULTS

The population comprised 261,489 women with median age of 30.5 years (interquartile range = [27.3, 33.8]). Median follow-up was 5.6 years (interquartile range = [4.0, 6.8]). Compared with normal weight women without metabolic disorders (with an incidence rate [IR] of 17.0 [95% confidence interval {CI} = 14.5-20.0] events per 100,000 person-years), overweight women without metabolic disorders had no significantly increased risk, IR 22.6 (CI = 18.3-27.8), adjusted incidence rate ratio (IRR), 1.26 (CI = 0.97-1.65). For women with metabolic disorders, IR was 30.2 (CI = 18.8-48.6) and adjusted IRR 1.77 (CI = 1.07-2.93) in normal weight, while IR was 87.1 (CI = 67.6-112.2) and IRR 4.24 (CI = 5 3.11-5.79) in overweight.

CONCLUSIONS

The risk of myocardial infarction and ischaemic stroke was more strongly associated with the presence of metabolic disorders than with overweight per se in fertile women. Targeting prevention of metabolic disorders might be beneficial to reduce cardiovascular disease in overweight/obese young women.

Time trends for risk of severe age-related diseases in individuals with and without HIV infection in Denmark: a nationwide population-based cohort study

BACKGROUND

Whether the reported high risk of age-related diseases in HIV-infected people is caused by biological ageing or HIV-associated risk factors such as chronic immune activation and low-grade inflammation is unknown. We assessed time trends in age-standardised and relative risks of nine serious age-related diseases in a nationwide cohort study of HIV-infected individuals and population controls.

METHODS

We identified all HIV-infected individuals in the Danish HIV Cohort Study who had received HIV care in Denmark between Jan 1, 1995, and June 1, 2014. Population controls were identified from the Danish Civil Registration System and individually matched in a ratio of nine to one to the HIV-infected individuals for year of birth, sex, and date of study inclusion. Individuals were included in the study if they had a Danish personal identification number, were aged 16 years or older, and were living in Denmark at the time of study inclusion. Data for study outcomes were obtained from the Danish National Hospital Registry and the Danish National Registry of Causes of Death and were cardiovascular diseases (myocardial infarction and stroke), cancers (virus associated, smoking related, and other), severe neurocognitive disease, chronic kidney disease, chronic liver disease, and osteoporotic fractures. We calculated excess and age-standardised incidence rates and adjusted incidence rate ratios of outcomes for time after HIV diagnosis, highly active antiretroviral therapy (ART) initiation, and calendar time. The regression analyses were adjusted for age, sex, calendar time, and origin.

FINDINGS

We identified 5897 HIV-infected individuals and 53,073 population controls; median age was 36·8 years (IQR 30·6-44·4), and 76% were men in both cohorts. Dependent on disease, the HIV cohort had 55,050-57,631 person-years of follow-up and the population controls had 638,204-659,237 person-years of follow-up. Compared with the population controls, people with HIV had high excess and relative risk of all age-related diseases except other cancers. Overall, the age-standardised and relative risks of cardiovascular diseases, cancers, and severe neurocognitive disease did not increase substantially with time after HIV diagnosis or ART initiation. Except for chronic kidney diseases, the age-standardised and relative risks of age-related diseases did not increase with calendar time.

INTERPRETATIONS

Severe age-related diseases are highly prevalent in people with HIV, and continued attention and strategies for risk reduction are needed. The findings from our study do not suggest that accelerated ageing is a major problem in the HIV-infected population.

FUNDING

Preben og Anna Simonsens Fond, Novo Nordisk Foundation, Danish AIDS Foundation, Augustinus Foundation, and Odense University Hospitals Frie Fonds Midler.

Employment and disability pension after central nervous system infections in adults

In this nationwide population-based cohort study using national Danish registries, in the period 1980-2008, our aim was to study employment and receipt of disability pension after central nervous system infections. All patients diagnosed between 20 and 55 years of age with meningococcal (n = 451), pneumococcal (n = 553), or viral (n = 1,433) meningitis or with herpes simplex encephalitis (n = 115), who were alive 1 year after diagnosis, were identified. Comparison cohorts were drawn from the general population, and their members were individually matched on age and sex to patients. Five years after diagnosis, the differences in probability of being employed as a former patient with pneumococcal meningitis or herpes simplex encephalitis versus being a member of the comparison cohorts were -19.9% (95% confidence interval (CI): -24.7, -15.1) and -21.1% (95% CI: -33.0, -9.3), respectively, and the corresponding differences in probability of receiving disability pension were 20.2% (95% CI: 13.7, 26.7) and 16.2% (95% CI: 6.2, 26.3). The differences in probability of being employed or receiving disability pension in former meningococcal or viral meningitis patients versus members of the comparison cohorts were small. In conclusion, pneumococcal meningitis and herpes simplex encephalitis were associated with substantially decreased employment and increased need for disability pension. These associations did not seem to apply to meningococcal meningitis or viral meningitis.

Return to Work in Out-of-Hospital Cardiac Arrest Survivors

Background—

Data on long-term function of out-of-hospital cardiac arrest survivors are sparse. We examined return to work as a proxy of preserved function without major neurologic deficits in survivors.

Methods and Results—

In Denmark, out-of-hospital cardiac arrests have been systematically reported to the Danish Cardiac Arrest Register since 2001. During 2001–2011, we identified 4354 patients employed before arrest among 12 332 working-age patients (18–65 years), of whom 796 survived to day 30. Among 796 survivors (median age, 53 years [quartile 1–3, 46–59 years]; 81.5% men), 610 (76.6%) returned to work in a median time of 4 months [quartile 1–3, 1–19 months], with a median time of 3 years spent back at work. A total of 74.6% (N=455) remained employed without using sick leave during the first 6 months after returning to work. This latter proportion of survivors returning to work increased over time (66.1% in 2001–2005 versus 78.1% in 2006–2011; P =0.002). In multivariable Cox regression analysis, factors associated with return to work with ≥6 months of sustainable employment were as follows: (1) arrest during 2006–2011 versus 2001–2005, hazard ratio (HR), 1.38 (95% CI, 1.05–1.82); (2) male sex, HR, 1.48 (95% CI, 1.06–2.07); (3) age of 18 to 49 versus 50 to 65 years, HR, 1.32 (95% CI, 1.02–1.68); (4) bystander-witnessed arrest, HR, 1.79 (95% CI, 1.17–2.76); and (5) bystander cardiopulmonary resuscitation, HR, 1.38 (95% CI, 1.02–1.87).

Conclusions—

Of 30-day survivors employed before arrest, 76.6% returned to work. The percentage of survivors returning to work increased significantly, along with improved survival during 2001–2011, suggesting an increase in the proportion of survivors with preserved function over time.

Thirteen-year nationwide trends in use of implantable cardioverter-defibrillators and subsequent long-term survival

BACKGROUND

Long-term trends in use of implantable cardioverter-defibrillators (ICDs) and outcomes are rare.

OBJECTIVE

We examined 13-year nationwide trends in ICD implantation and survival rates in Denmark.

METHODS

Using medical databases, we identified all first time ICD recipients in Denmark during 2000-2012 (N = 8460) and ascertained all-cause mortality. We computed standardized annual implantation rates and mortality rate ratios according to age, sex, comorbidity level, indication, and device type.

RESULTS

The standardized annual implantation rate increased from 42 per million persons in 2000 to 213 per million persons in 2012 (from 34 to 174 for men and from 8 to 39 for women). The increase was driven by secondary prophylactic ICDs until 2006 and primary prophylactic ICDs thereafter. The increase occurred particularly in older patients and those with a high level of comorbidity. Independent of indication, 76% of all patients with ICD were alive after 5 years. Men had a higher mortality rate compared with women (mortality rate ratio 1.28; 95% confidence interval 1.10-1.49). Compared with low comorbidity level, moderate, severe, and very severe comorbidity levels were associated with 1.6-, 2.5-, and 4.9-fold increased mortality rates, respectively. The most influential individual comorbidities were heart failure, diabetes, liver disease, and renal disease.

CONCLUSION

The annual implantation rate of ICDs increased 5-fold in Denmark between 2000 and 2012. The rate increase occurred for both men and women, but particularly in the elderly and patients with severe comorbidity. Five-year survival probability was high, but severe comorbidity and male sex were associated with shorter survival.

Risk factors for hospitalization due to community-acquired sepsis - a population-based case-control study

Background

The aim of the study was to estimate risk factors for hospitalization due to sepsis and to determine whether these risk factors vary by age and gender.

Methods

We performed a population-based case-control study of all adult patients admitted to a medical ED from September 2010 to August 2011. Controls were sampled within the hospital catchment-area. All potential cases were manually validated using a structured protocol. Vital signs and laboratory values measured at arrival were registered to define systemic inflammatory response syndrome and organ dysfunction. Multivariable logistic regression was used to elucidate which predefined risk factors were associated with an increased or decreased risk hospitalization due to sepsis.

Results

A total of 1713 patients were admitted with sepsis of any severity. The median age was 72 years (interquartile range: 57–81 years) and 793 (46.3%) were male. 621 (36.3%) patients were admitted with sepsis, 1071 (62.5%) with severe sepsis and 21 (1.2%) with septic shock. Episodes with sepsis of any severity were associated with older age (85+ years adjusted OR 6.02 [95%CI: 5.09–7.12]), immunosuppression (4.41 [3.83–5.09]), alcoholism-related conditions (2.90 [2.41–3.50]), and certain comorbidities: psychotic disorder (1.90 [1.58–2.27]), neurological (1.98 [1.73–2.26]), respiratory (3.58 [3.16–4.06]), cardiovascular (1.62 [1.41–1.85]), diabetes (1.82 [1.57–2.12]), cancer (1.44 [1.22–1.68]), gastrointestinal (1.71 [1.44–2.05]) and renal (1.46 [1.13–1.89]). The strength of the observed associations for comorbid factors was strongest among younger individuals.

Conclusions

Hospitalization due to sepsis of any severity was associated with several independent risk factors, including age and comorbid factors.

Risk of psychiatric disorders in patients with chronic insomnia and sedative-hypnotic prescription: a nationwide population-based follow-up study

STUDY OBJECTIVES

Previous epidemiological studies have established insomnia as a major risk factor for mood, anxiety, and substance use disorders. However, the associations between insomnia with sedative-hypnotic prescriptions and various psychiatric disorders have not been thoroughly examined. The current study involved evaluating the risk of psychiatric disorders, namely schizophrenia, mood, anxiety, somatoform, and substance-related disorders, over a 6-y follow-up period in three groups: patients with insomnia and sedative-hypnotic prescriptions (Inso-Hyp), those with insomnia and without sedative-hypnotic prescriptions (Inso-NonHyp), and those with neither insomnia nor sedative-hypnotic prescriptions (NonInso-NonHyp).

METHODS

We used a historical cohort study design to compare the risk of psychiatric disorders among the three groups. Data regarding these patients were derived from reimbursement claims recorded in Taiwan's National Health Insurance Research Database. Cox proportional hazards regression was used to compare the 6-y risk of subsequent psychiatric disorders among the Inso-Hyp, Inso-NonHyp, and NonInso-NonHyp groups.

RESULTS

Compared with the Inso-NonHyp and NonInso-NonHyp group patients, the Inso-Hyp group patients exhibited a higher risk of psychiatric disorders, particularly bipolar disorders (adjusted hazard ratio [AHR]: 7.60; 95% confidence interval [CI]: 5.31-10.89 and AHR: 14.69; 95% CI: 11.11-19.43, respectively). Moreover, among the Inso-Hyp patient group, insomnia prescribed with benzodiazepine, a longer duration of sedative-hypnotic action, and higher doses of sedativehypnotics were significantly associated with a higher risk of depressive and anxiety disorders.

CONCLUSION

The Inso-Hyp group exhibited a higher risk of developing psychiatric disorders than did the Inso-NonHyp and NonInso-NonHyp groups. The results regarding patients with insomnia and sedative-hypnotic prescriptions associated with the risk of psychiatric disorders can serve as a reference for care providers when managing sleep disturbances.

Systolic blood pressure and short-term mortality in the emergency department and prehospital setting: a hospital-based cohort study

Introduction

Systolic blood pressure is a widely used tool to assess circulatory function in acutely ill patients. The systolic blood pressure limit where a given patient should be considered hypotensive is the subject of debate and recent studies have advocated higher systolic blood pressure thresholds than the traditional 90 mmHg. The aim of this study was to identify the best performing systolic blood pressure thresholds with regards to predicting 7-day mortality and to evaluate the applicability of these in the emergency department as well as in the prehospital setting.

Methods

A retrospective, hospital-based cohort study was performed at Odense University Hospital that included all adult patients in the emergency department between 1995 and 2011, all patients transported to the emergency department in ambulances in the period 2012 to 2013, and all patients serviced by the physician-staffed mobile emergency care unit (MECU) in Odense between 2007 and 2013. We used the first recorded systolic blood pressure and the main outcome was 7-day mortality. Best performing thresholds were identified with methods based on receiver operating characteristics (ROC) and multivariate regression. The performance of systolic blood pressure thresholds was evaluated with standard summary statistics for diagnostic tests.

Results

Seven-day mortality rates varied from 1.8 % (95 % CI (1.7, 1.9)) of 112,727 patients in the emergency department to 2.2 % (95 % CI (2.0, 2.5)) of 15,862 patients in the ambulance and 5.7 % (95 % CI (5.3, 6.2)) of 12,270 patients in the mobile emergency care units. Best performing thresholds ranged from 95 to 119 mmHg in the emergency department, 103 to 120 mmHg in the ambulance, and 101 to 115 mmHg in the MECU but area under the ROC curve indicated poor overall discriminatory performance of SBP thresholds in all cohorts.

Conclusions

Systolic blood pressure alone is not sufficient to identify patients at risk regardless of the defined threshold for hypotension. If, however, a threshold is to be defined, a systolic blood pressure threshold of 100 to 110 mmHg is probably more relevant than the traditional 90 mmHg.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-0884-y) contains supplementary material, which is available to authorized users.

The mortality after surgery in primary lung cancer: results from the Danish Lung Cancer Registry

OBJECTIVES

The study has been performed to investigate the mortality within the first year after resection in patients with primary lung cancer, together with associated prognostic factors including gender, age, tumour stage, comorbidity, alcohol abuse, type of surgery and post-surgical complications.

METHODS

All patients (n = 3363) from the nationwide Danish Lung Cancer Registry with first resection performed between 1 January 2007 and 31 December 2011 were analysed by Kaplan-Meier techniques and Cox-regression analysis concerning death within the first year after resection. Covariates included gender, age, comorbidity (Charlson comorbidity index), perioperative stage, type of resection, registered complications to surgery and alcohol abuse.

RESULTS

The cumulative deaths after 30 days, 90 days, 180 days and 360 days were 72 (2.1%), 154 (4.6%), 239 (7.1%) and 478 (14.2%), respectively. Low stage, female gender, young age, no comorbidity, no postoperative complications, no alcohol abuse and lobectomy as type of resection were favourable for survival.

CONCLUSIONS

Our results demonstrate that resection in primary lung cancer impacts mortality far beyond the initial 30 days after resection, which is conventionally considered a time window of relevance for the adverse outcome of surgery. Increased efforts should be made for optimizing the selection of patients suited for resection and for identifying patients at increased risk of death after resection. Furthermore, patients should be monitored more closely and more frequently, in particular those patients with high risk of death after resection.

Time-dependent effect of preinfarction angina pectoris and intermittent claudication on mortality following myocardial infarction: A Danish nationwide cohort study

BACKGROUND

As proxies for local and remote ischemic preconditioning, we examined whether preinfarction angina pectoris and intermittent claudication influenced mortality following myocardial infarction.

METHODS

Using medical registries, we conducted a nationwide population-based cohort study of all first-time myocardial infarction patients in Denmark during 2004-2012 (n=70,458). We computed all-cause and coronary mortality rate ratios (MRRs). We categorized time between angina/claudication presentation and subsequent myocardial infarction as 0-14, 15-30, 31-90, and > 90 days. We adjusted for age, sex, coronary intervention, comorbidities, and medication use.

RESULTS

Among all myocardial infarction patients, 18.4% had prior angina and 3.8% had prior intermittent claudication. Compared to patients without prior angina, the adjusted 30-day coronary MRR was 0.85 (95% confidence interval (CI): 0.80-0.92) for stable and 0.68 (95% CI: 0.58-0.79) for unstable angina patients. The mortality reduction increased when angina presented close to myocardial infarction and was higher for unstable than for stable angina. Thus, the 30-day coronary MRR was 0.72 (95% CI: 0.51-1.02) for stable angina and 0.35 (95% CI: 0.17-0.73) for unstable angina presenting within 14 days before MI. The results were robust for all-cause mortality and in numerous subgroups, including women, diabetics, patients treated with PCI, and patients treated with and without cardioprotective drugs. Preinfarction intermittent claudication was associated with higher short- and long-term mortality compared to patients without intermittent claudication.

CONCLUSIONS

Preinfarction angina reduced 30-day mortality, particularly when unstable angina closely preceded MI. Preinfarction intermittent claudication was associated with increased short- and long-term mortality.