In-hospital thromboprophylaxis variation and the risk of venous thromboembolism after lung cancer surgery: a nationwide cohort study.

OBJECTIVES: Venous thromboembolic event (VTE) is a severe complication in patients with lung cancer undergoing thoracic surgery. Nevertheless, because of insufficient evidence, there are no clear guidelines, and VTE prophylaxis practices vary widely. This nationwide cohort study was a comparative study investigating VTE risk in surgical departments that routinely administered in-hospital thromboprophylaxis with low-molecular-weight heparin compared to those that did not. METHODS: We identified all patients with non-small-cell lung cancer (NSCLC) who underwent surgery in Denmark during 2010-2021. Thoracic surgery was exclusively performed in the 4 university hospitals. Three hospitals implemented in-hospital thromboprophylaxis as standard care since 2000, while the fourth adopted this practice in September 2016. VTE events were assessed at 6-month follow-up according to hospital and study period, using an inverse probability of treatment weighting approach. RESULTS: We identified 9615 patients. During 6-month follow-up, a total of 190 VTE events were observed, resulting in a weighted rate of 4.5 events per 100 person-years and an absolute risk of 2.2%. There was no clear trend according to hospital site or use of in-hospital thromboprophylaxis with a 2.2% risk in the hospital not using thromboprophylaxis compared to 1.7-3.1% in those that did. CONCLUSIONS: Use of in-hospital thromboprophylaxis did not affect the risk of VTE after surgery for NSCLC, suggesting that relying solely on in-hospital thromboprophylaxis may be insufficient to mitigate VTE risk in these patients. Further research is warranted to investigate the potential benefits of extended thromboprophylaxis in reducing VTE risk in selected NSCLC surgical patients.

Risk of Venous Thromboembolism in Patients With Stage III and IV Non-Small-Cell Lung Cancer: Nationwide Descriptive Cohort Study.

BACKGROUND: Venous thromboembolism (VTE) is a common complication in patients starting cancer therapies for non-small-cell lung cancer (NSCLC). We examined the risk and timing of VTE in patients with stage IIIA, IIIB to C, and stage IV NSCLC according to received cancer treatments. MATERIALS AND METHODS: A nationwide registry-based cohort study of patients recorded in the Danish Lung Cancer Registry (2010-2021) followed for 1 year after entry into the registry to assess the incidence of VTE. The Aalen-Johansen estimator was used to calculate the risk of VTE after treatment commencement with chemotherapy, radiotherapy, chemoradiation, immunotherapy, and targeted therapy. RESULTS: Among the 3475 patients with stage IIIA, 4047 with stage IIIB to C, and 18,082 patients with stage IV cancer, the 1-year risk of VTE was highest in the first 6 months and varied markedly by cancer stage and cancer treatment. In stage IIIA, VTE risk was highest with chemotherapy (3.9%) and chemoradiation (4.1%). In stage IIIB to C, risks increased with chemotherapy (5.2%), immunotherapy (9.4%), and targeted therapy (6.0%). Stage IV NSCLC showed high risk with targeted therapy (12.5%) and immunotherapy (12.2%). The risk was consistently higher for pulmonary embolism than deep vein thrombosis. CONCLUSION: VTE risks vary substantially according to cancer treatments and cancer stages. The highest risk was observed in the initial 6 months of therapy initiation. These insights emphasize the need for tailored risk assessment and vigilance in managing VTE complications in patients with NSCLC. Further research is needed to optimize individual thromboprophylaxis strategies for patients with unresectable and metastatic NSCLC.

Comparative Safety and Effectiveness of Reduced Doses of Direct Acting Oral Anticoagulants for Stroke Prevention in Atrial Fibrillation.

BACKGROUND: This Nordic observational cohort study aims to assess the effectiveness and safety of reduced-dose direct-acting oral anticoagulants (DOACs) dabigatran, rivaroxaban, and apixaban compared to standard warfarin for stroke prevention in nonvalvular atrial fibrillation. METHODS: The study, utilizing nationwide administrative databases from Denmark, Sweden, Norway, and Finland, spanned from January 1, 2011 to December 31, 2018 (2017 for Sweden). The cohort included 26,883 patients initiating reduced-dose DOACs and 108,014 comparable warfarin patients. Effectiveness was measured by the composite endpoint of ischemic stroke and systemic embolism, while safety was assessed through intracranial hemorrhage. RESULTS: The meta-analysis across countries revealed similar or lower incidences of ischemic stroke and systemic embolism in patients on reduced-dose DOACs compared to standard warfarin (rivaroxaban: HR 0.93, dabigatran: HR 0.88, apixaban: HR 0.79). Incidences within warfarin groups ranged from 2.16 to 3.71 per 100 person-years, comparable to DOAC recipients. Intracranial hemorrhage rates were generally low, ranging from 0.16 to 1.85 per 100 person-years. In comparison with warfarin patients, meta-analyses yielded HRs for rivaroxaban (1.41), dabigatran (0.35), and apixaban (0.72). CONCLUSIONS: In this study, atrial fibrillation patients initiating reduced-dose rivaroxaban and dabigatran exhibited incidences of ischemic stroke and systemic embolism similar to warfarin, and for apixaban, even lower. Rates of intracranial hemorrhage were comparable to or lower for patients on DOACs compared to warfarin.

Risk and Timing of Venous Thromboembolism After Surgery for Lung Cancer: A Nationwide Cohort Study.

BACKGROUND: Venous thromboembolism (VTE) is a potentially preventable serious complication in patients with lung cancer undergoing thoracic operation. We examined the risk and timing of VTE after surgery for primary non-small cell lung cancer (NSCLC). METHODS: All patients undergoing operation for NSCLC in Denmark between 2003 and 2021 were identified in the Danish Lung Cancer Registry. VTE events in the year after operation were assessed by stage, patient characteristics, and surgical procedure. RESULTS: We identified 13,197 patients who underwent operation for NSCLC in 2003 to 2021 (mean age, 67.6 years; 50% female); 10,524 (79.7%) had stage I-II NSCLC, and 2673 (20.3%) had stage III-IV. During 1-year follow-up, there were 335 VTE events, yielding a rate of 2.87 events/100 person-years and an absolute risk of 3.3% (95% CI, 2.3-4.0). VTE risk increased with advancing cancer stage (1.8% for stage I vs 3.9% for stage IV) but varied little by pathologic type, sex, and comorbidity level. Bilobectomy was associated with highest VTE risk (4.8%; 95% CI, 3.2-6.9), followed by pneumonectomy (3.5%; 95% CI, 2.3-5.0). The hazard of VTE was highest during the first 3 months after operation, after which it declined. For stage IV cancer, hazards increased again after 6 months. At 1 year, all-cause death was 12.6% (95% CI, 12.0%-13.1%). CONCLUSIONS: VTE developed in 3.3% of patients undergoing operation for NSCLC, most commonly within 3 months postoperatively. Prolonged thromboprophylaxis could be considered, particularly in those with advanced cancer stage and undergoing extended resections.

External Validation of the OAC3-PAD Bleeding Score in a Nationwide Population of Patients Undergoing Invasive Treatment for Peripheral Arterial Disease.

OBJECTIVE: The OAC3-PAD score was developed to predict bleeding risk in patients with lower extremity peripheral arterial disease (PAD), but its performance in concomitant international cohorts is largely unknown. This study aimed to validate the OAC3-PAD score in an unselected nationwide population of patients undergoing invasive treatment for symptomatic PAD. METHODS: This was a nationwide cohort study including all patients who underwent a first revascularisation procedure or major amputation for symptomatic PAD in Denmark from 2000 - 2021. The study population was stratified based on OAC3-PAD score, and the one year risk of major bleeding was assessed, accounting for the competing risk of death. The score performance was evaluated using calibration plots, C statistic, Brier score, and the index of prediction accuracy (IPA). RESULTS: A total of 52 016 patients were included (mean age 71 years, 43.8% female). The one year risk of major bleeding increased with higher OAC3-PAD score, ranging from 1.6% (95% confidence interval [CI] 1.4 - 1.8%) to 2.3% (95% CI 2.0 - 2.5%), 3.5% (95% CI 3.2 - 3.8%), and 5.2% (95% CI 4.8 - 5.6%) for patients with low, low moderate, moderate high, and high score, respectively. Using patients with low risk as reference, the OAC3-PAD score effectively categorised patients, demonstrating statistically significant differences in bleeding risk across strata. However, the score showed modest discriminative performance, with a C statistic of 65% (95% CI 63 - 66%) and a Brier score of 2.6% (95% CI 2.5 - 2.7%). Nevertheless, it performed significantly better than the null model, as indicated by an IPA of 3.1%. CONCLUSION: Among patients who underwent invasive treatment for symptomatic PAD in routine care, the OAC3-PAD score was associated with greater risk of major bleeding with increasing score level. However, its discriminatory ability was modest, and the clinical utility remains to be determined.

Effectiveness and safety of direct oral anticoagulation vs. warfarin in frail patients with atrial fibrillation.

AIMS: Although frail patients with atrial fibrillation (AF) carry a high risk of stroke and treatment-related bleeding complications, evidence for the safety and effectiveness of anticoagulation remains sparse. This study investigated the effectiveness and safety of direct oral anticoagulant (DOAC) vs. warfarin in frail AF patients. METHODS AND RESULTS: Nationwide registry-based cohort study including 32 048 anticoagulation naïve frail patients (median age 80 years, 53% female) with incident AF during 2012-20. Frailty was assessed using the hospital frailty risk score. To address baseline confounding, we applied inverse probability of treatment weighting (IPTW) and marginal structural models with weighted pooled regression to compute weighted hazard ratios (wHRs) and risk differences for thromboembolism and major bleeding comparing specific DOAC doses with warfarin. After AF diagnosis, 6747 (21.1%) initiated warfarin, 17 076 (50.3%) initiated standard-dose DOAC, and 9179 (28.6%) initiated reduced-dose DOAC. Comparative effectiveness analyses in the IPTW pseudo-populations revealed similar thromboembolism risk between standard-dose DOAC and warfarin [wHR 0.95, 95% confidence interval (CI) 0.80-1.13] and between reduced-dose DOAC and warfarin (wHR 0.97, 95% CI 0.77-1.23). The 1-year thromboembolic event-free survival difference was -0.2% for DOAC, regardless of dosing, vs. warfarin. Major bleeding risk was significantly lower with standard-dose DOAC (wHR 0.69, 95% CI 0.59-0.87) and reduced-dose DOAC (wHR 0.67, 95% CI 0.55-0.81) vs. warfarin. The 1-year bleeding risk difference with DOAC ranged from -1.3% to -3.0%. CONCLUSION: Our findings indicate comparable thromboembolism risk and significantly lower bleeding risk with both standard and reduced DOAC regimens compared with warfarin in frail AF patients in routine care.

Epidemiological Trends and Projections of Incidence, Prevalence, and Disease Related Mortality Associated With Peripheral Arterial Disease: Observations Using Nationwide Danish Data.

OBJECTIVE: Peripheral arterial disease (PAD) trends remain unclear because contemporary data are sparse and conflicting. This nationwide cohort study quantified changes in PAD incidence, prevalence, and all cause mortality, and projected prevalence development through to 2040. METHODS: Population based registries covering the entire Danish population aged ≥ 40 years from 2000 to 2018 were linked to assess trends in PAD incidence, prevalence, and all cause mortality, overall and by sex and age groups. Based on observed trends in incidence and mortality, and estimated future annual age distribution and population mortality, the PAD prevalence through to 2040 was projected. RESULTS: The Danish population aged 40 - 99 years in 2000 - 2018 included 4 811 281 individuals, among whom 145 870 incident PAD diagnoses were identified. The age and sex standardised PAD incidence decreased from 2.26 per 1 000 person years in 2000 to 1.65 in 2018 (incidence RR 0.74, 95% CI 0.72 - 0.77). The incidence was approximately 20% higher in men than women but declined similarly over time. Concurrently, PAD prevalence in the Danish adult population increased from 1.3% to 1.6% (prevalence ratio 1.28, 95% CI 1.26 - 1.30). Among patients aged ≥ 80 years, the prevalence reached 5.7% in women and 7.9% in men. The age and sex standardised annual mortality among patients with PAD decreased from 9.8% in 2000 to 7.2% in 2018 (mortality ratio 0.75, 95% CI 0.72 - 0.78). Projections of PAD prevalence demonstrated that the rising PAD prevalence will continue until around 2030, followed by a decline towards 2040. Among individuals aged ≥ 80 years, the prevalence was projected to plateau at 8.9% for men and 6.2% for women before declining. CONCLUSION: Within an unselected nationwide population, the incidence and all cause mortality of PAD have declined over the last two decades. Concurrently, prevalence increased and is projected to increase further over the coming decade, emphasising the growing burden of this common atherosclerotic disease in ageing populations.

Risk of recurrent cancer-associated venous thromboembolism: A Danish nationwide cohort study.

BACKGROUND: Predictive factors for recurrent cancer-associated venous thromboembolism have been inconsistent across previous studies. To provide data for improved risk stratification, we described the risk of recurrent venous thromboembolism overall and across age, sex, calendar period, cancer type, Ottawa risk score, cancer stage, and cancer treatment in a nationwide cohort of patients with active cancer. METHODS: Using Danish administrative registries, we identified a cohort of all adult patients with active cancer and a first-time diagnosis of venous thromboembolism during 2003-2018. We accounted for the competing risk of death and calculated absolute risks of recurrent venous thromboembolism at six months. RESULTS: The population included 34,072 patients with active cancer and venous thromboembolism. Recurrence risks at six months were higher for patients with genitourinary cancer (6.5%), lung cancer (6.1%), gastrointestinal cancer (5.6%), brain cancer (5.2%), and hematological cancer (5.1%) than for patients with gynecological cancer (4.7%), breast cancer (4.1%), and other cancer types (4.8%). Recurrence risks were similar for men (5.2%) and women (4.9%), with and without chemotherapy (5.1%), across Ottawa risk score group (low: 5.0%; high: 5.1%) and across calendar periods but increased with increasing cancer stage. The overall six-month all-cause mortality risk was 26%, and highest for patients with lung cancer (49%) and lowest among breast cancer patients (4.1%). CONCLUSIONS: Six-month recurrence risk after first-time cancer-associated venous thromboembolism was high and varied by cancer type and patient characteristics. Refining risk stratification for recurrence may improve decision-making regarding treatment duration after cancer-associated thromboembolism.

Positive Prediction Value of Retinal Artery Occlusion Diagnoses in the Danish National Patient Registry: A Validation Study.

PURPOSE: The hospital registration of retinal artery occlusions in the Danish National Patient Registry has not previously been validated. In this study, the diagnosis codes were validated to ensure the diagnoses had an acceptable validity for research. The validation was performed both for the overall diagnosis population and at the subtype diagnosis level. METHODS: The medical records for all patients with retinal artery occlusion with an incident hospital record in the years 2017-2019 in Northern Jutland (Denmark) were assessed in this population-based validation study. Furthermore, fundus images and two-person verification were assessed for the included patients when available. The positive prediction values for the overall diagnosis of retinal artery occlusion, as well as for the central or branch subtypes, were calculated. RESULTS: A total of 102 medical records were available for review. The overall positive prediction value for a retinal artery occlusion diagnosis was 79.4% (95% CI: 70.6-86.1%), while the overall positive prediction value at the subtype diagnosis level was 69.6% (95% CI: 60.1-77.7%), with 73.3% (95% CI: 58.1-85.4%) for branch retinal artery occlusion and 71.2% (95% CI: 56.9-82.9%) for central retinal artery occlusion. For the stratified analyses at the subtype diagnosis, age, sex, diagnosis year, and primary or secondary diagnosis, the positive prediction values ranged from 73.5 to 91.7%. In the stratified analyses at the subtype level, the positive prediction values ranged from 63.3 to 83.3%. The differences among the positive prediction values of the individual strata of both analyses were not statistically significant. CONCLUSIONS: the validities of the retinal artery occlusion and subtype level diagnoses are comparable to other validated diagnoses and considered acceptable for use in research.

Pregnancy-Related Complications and Incidence of Atrial Fibrillation: A Systematic Review.

Pregnancy-related complications are associated with a higher risk of various incident cardiovascular diseases, but their specific potential relationship with incident atrial fibrillation (AF) is less clear. This systematic review summarises the available evidence from observational studies which have examined associations between pregnancy-related complications and the risk of AF. MEDLINE and EMBASE (Ovid) were searched for studies between 1990 to 10 February 2022. Pregnancy-related complications examined included hypertensive disorders of pregnancy (HDP), gestational diabetes, placental abruption, preterm birth, small-for-gestational-age and stillbirth. Study selection, data extraction and quality assessment were completed independently by two reviewers. Narrative synthesis was used to evaluate the results of the included studies. Nine observational studies were included, with eight eligible for narrative synthesis. Sample sizes ranged from 1839 to 2,359,386. Median follow-up ranged from 2 to 36 years. Six studies reported that pregnancy-related complications were associated with a significantly increased risk of incident AF. Hazard ratios (HRs) (95% confidence intervals) for the four studies that evaluated HDP ranged from 1.1 (0.8-1.6) to 1.9 (1.4-2.7). For the four studies that evaluated pre-eclampsia, HRs ranged from 1.2 (0.9-1.6) to 1.9 (1.7-2.2). Current evidence from observational studies suggests pregnancy-related complications are associated with a significantly higher risk of incident AF. However, only a small number of studies examining each pregnancy-related complication were identified, and considerable statistical heterogeneity was observed. Further large-scale prospective studies are required to confirm the association between pregnancy-related complications and incident AF.

Similarities and differences in systemic risk factors for retinal artery occlusion and retinal vein occlusion: A nationwide case-control study.

BACKGROUND: To investigate the relationship between risk factors for retinal artery occlusion (RAO) and retinal vein occlusion (RVO) and thereby identify similarities and differences between the two types of retinal vascular occlusions. METHODS: In this case-control study, 5708 patients with RAO were included and matched with three patients with RVO each. The patients with RVO were matched on sex and age at index date. All patients, personal information, diagnoses, and prescriptions were obtained from the Danish nationwide registries. Adjusted conditional logistic regression was used to investigate the association of RAO and RVO with the included risk factors. RESULTS: RAO was stronger associated with arterial hypertension, heart failure, ischemic heart disease, peripheral artery disease, and stroke than RVO, with effect measures ranging from 1.10 to 2.21. RVO was associated with cataract and glaucoma with effect measures of 0.80 (95% CI 0.73-0.87) and 0.65 (95% CI 0.56-0.76), respectively. CONCLUSION: Differences in the level of associations with the included risk factors suggests differences in the pathophysiologies of the two diseases. The main pathophysiology associated with RAO was atherosclerosis, whereas the main pathophysiology associated with RVO was changes in the pressure gradients of the eyes.

Retinal Artery Occlusion as an Early Indicator of Macrovascular Complications in Diabetes.

BACKGROUND: A characteristic of the retinal circulation is that arterial occlusion is embolic or secondary to vasculitis but rarely or never due to in situ atherosclerosis. Therefore, retinal artery occlusion suggests the presence of cardiac or large-vessel disease outside the eye. This cohort study examined the general risk of macrovascular disease in individuals with diabetes, with or without retinal artery occlusion. METHODS: We retrieved data on 992 subjects with incident retinal artery occlusion and preexisting diabetes, registered in Denmark between January 1, 2000, and December 31, 2018. Each retinal artery occlusion subject was matched for age, sex, and diabetes duration, with 5 control subjects with diabetes but without retinal artery occlusion. We performed survival analyses to compare the risk of extraocular macrovascular disease between the 2 groups in a 5-year follow-up. RESULTS: After 1 year, the incidence of macrovascular disease in subjects with retinal artery occlusion was approximately 21 per 100 person-years (95% confidence interval [CI]: 18.11-24.29), compared to 6.25 per 100 patient-years (95% CI: 5.57-7.00) in those without retinal artery occlusion. After 5 years, the cumulative incidences of macrovascular disease were 51.2% (95% CI: 47.9-54.7%) and 29.4% (95% CI: 28.0-30.8%) in patients with diabetes with or without retinal artery occlusion, respectively. Hazard rate ratios were 3.36 (95% CI: 2.79-4.05) after 1 year and 2.27 (95% CI: 2.04-2.53) after 5 years. CONCLUSION: Among individuals with diabetes, those diagnosed with retinal artery occlusion had a higher general risk of macrovascular complications for at least 5 years after the occlusion event compared with those without retinal artery occlusion.

Validity of Algorithm for Classification of In- and Outpatient Hospital Contacts in the Danish National Patient Registry.

Purpose: Following the implementation of the 3rd version of the Danish National Patient Register (DNPR-3), information on whether hospitalizations were inpatient, outpatient, or emergency room (ER) contacts was no longer readily available. This study examined the positive predictive values (PPV) of a common algorithm to characterize hospitalizations as inpatient, outpatient, or emergency room (ER) contacts in both DNPR-2 and DNPR-3. Patients and Methods: All hospital contacts in North Denmark Region were identified in the DNPR within a 1-year window of the implementation of DNPR-3 in early 2019. An algorithm based upon proportion of overnight (±50%) and elective (±50%) contacts for each hospital department was developed. Next, PPVs of these categorizations were computed using manual characterization of all departments and clinics by two experienced clinicians as reference. Second, the reliability of various time intervals to join department contacts and subsequent categorization of overnight hospital stays as proxies for inpatient contacts was explored. Results: The algorithm yielded PPVs of 91% and 89% for hospital units and related contacts categorized as inpatient in DNPR-2 and 100% for both parameters in DNPR-3. In outpatient units, the PPVs were 99% in both DNPR-2 and DNPR-3, whereas the corresponding PPVs were 99.6% and 99% on the contact level. In contrast, the PPV for ERs was 33% in DNPR-2 and 56% in DNPR-3, primarily due to misclassification of outpatient clinics. Still, the proportion of correctly categorized ER contacts was 87% in DNPR-2 and 85% in DNPR-3. Using time intervals from 0 to 12 hours to join department contacts showed that overnight hospitalizations comprised inpatient contacts in 97% in DNPR-2 and 98% in DNPR-3. However, the sensitivity was moderate at 76-78% for all inpatient hospitalizations in DNPR-2 and DNPR-3. Conclusion: This algorithm accurately categorized hospitalizations as inpatient, outpatient, or ER contacts in both DNPR-2 and DNPR-3.

The Khorana score and venous and arterial thrombosis in patients with cancer treated with immune checkpoint inhibitors: A Danish cohort study.

BACKGROUND: Thrombosis is common among patients with cancer. Primary thromboprophylaxis guided by the Khorana score is endorsed by guidelines but recommendations rely mainly on data from patients treated with chemotherapy. OBJECTIVES: To explore if the Khorana score could risk stratify patients with cancer treated with immune checkpoint inhibitors according to risk of venous and arterial thrombosis. PATIENTS/METHODS: The study population and Khorana score were defined using administrative Danish health registries. The primary outcome was 6-month risk of venous thromboembolism after initiation of checkpoint inhibitor treatment. Secondary outcomes were arterial thrombosis and any thromboembolic event. Death was considered a competing risk event. RESULTS: Among 3946 patients with cancer initiating checkpoint inhibitor treatment without other indications for anticoagulation, the overall 6-month incidence of venous thromboembolism was 2.6% (95% confidence interval [CI]: 2.1-3.1). Risks were 2.1% (95% CI: 1.5-3.0), 2.6% (95% CI: 2.0-3.4), and 3.7% (95% CI: 2.1-5.9) in low (score 0), intermediate (score 1-2), and high risk (score ≥3) Khorana categories, respectively. Among patients eligible for primary thromboprophylaxis according to guidelines (Khorana score ≥2), risk of venous thromboembolism was 4.1% (95% CI: 3.1-5.4). Higher Khorana risk category was also associated with higher 6-month risk of both arterial thrombosis and any thromboembolic events. CONCLUSIONS: The Khorana score was able to risk stratify patients with cancer treated with immune checkpoint inhibitors according to 6-month risk of thromboembolic events. Risks of venous thromboembolism were lower than in randomized thromboprophylaxis trials, thus questioning the absolute benefit of routine primary thromboprophylaxis in an unselected population of patients treated with immune checkpoint inhibitors.

A review of risk factors for retinal vein occlusions.

INTRODUCTION: Risk factors for retinal vein occlusion have been extensively studied, with varying population sizes. Smaller populations result in less certain measures of associations. The present review included studies with a relevant population size to identify clinically relevant risk factors for retinal vein occlusion. Understanding the risk factors of retinal vein occlusion is important for the management of these patients. AREAS COVERED: A comprehensive literature review was conducted through a systematic literature search in PubMed and Embase. Additional studies were selected from cross references in the assessed studies. Weighted effect measures were calculated for all included risk factors.Risk factors associated with retinal vein occlusion included cardiovascular diseases, eye diseases, systemic diseases, medical interventions, and sociodemographic factors. EXPERT OPINION: This review provided an extensive overview of a wide variety of risk factors increasing the risk of developing retinal vein occlusion. The severity of the identified risk factors indicated that these patients have been in contact with the health care system before their retinal vein occlusion event. Therefore, the clinical course for patients with retinal vein occlusion may benefit from a multidisciplinary collaboration between ophthalmologists and especially cardiologists.

Similarities and Differences in Systemic Risk Factors for Retinal Artery Occlusion and Stroke: A Nationwide Case-Control Study.

BACKGROUND: Retinal artery occlusion (RAO) has been considered a stroke equivalent. This study compares risk factor profiles for thromboembolism among patients with RAO and stroke, respectively. METHODS: This case-control study is based on 5683 RAO patients entered in the Danish National Patient Register between 1st of January 2000 and 31st of December 2018. Cases were matched on sex, year of birth, and age at event with 28,415 stroke patients. The Danish nationwide registries were used to collect information about age, sex, previous diagnoses, and drug prescriptions. Adjusted conditional logistic regression models were used to investigate the association between hypothesised risk factors and the patient outcome. RESULTS: For atrial fibrillation, a substantially stronger association to stroke was found, with an odds ratio (OR) of 0.52 (95% CI: 0.47-0.58) when comparing RAO patients with stroke patients. RAO was stronger associated with arterial hypertension, peripheral artery disease, retinal vein occlusion, cataract, and glaucoma with OR's ranging from 1.21-11.70. The identified effect measures reached equivalence or was close to equivalence for diabetes, heart failure, ischemic heart disease, and renal disease. CONCLUSION: The differences in risk factor profiles between RAO and stroke suggests differences in the pathophysiology of the two diseases. These variations in pathophysiologies between the two diseases may indicate that different interventions are needed to ensure the optimal long-term prognosis for the patients.

Effectiveness and Safety of Nonvitamin K Oral Anticoagulants Rivaroxaban and Apixaban in Patients with Venous Thromboembolism: A Meta-Analysis of Real-World Studies.

Background: Rivaroxaban and apixaban are the most widely used nonvitamin K oral anticoagulants (NOACs) in patients with venous thromboembolism (VTE). This meta-analysis evaluates the effectiveness and safety of both NOACs versus standard of care (SoC) in real-world practice. Methods: Real-world evidence (RWE) studies were identified through a systematic literature review conducted between January 2012 and July 2020, using Embase, MEDLINE, and the websites of cardiological, hematological, and oncological associations. Eligible RWE studies recruited adult patients with deep vein thrombosis and/or pulmonary embolism and presented a comparison between rivaroxaban and apixaban versus SoC, consisting either of vitamin K antagonists, heparins, or combinations thereof. Hazard ratios (HRs) for the comparison between NOACs and SoC were extracted from the relevant studies or estimated based on the reported binary data. The between-treatment contrasts were reported as HRs with associated 95% confidence intervals. Results: A total of 65 RWE studies were identified and considered relevant for the meta-analysis. Compared with SoC, both rivaroxaban and apixaban were associated with reduced risks of recurrent VTE and a lower rate of major bleeding events. Patients treated with rivaroxaban were at a lower risk of all-cause death compared with those receiving SoC (HR = 0.56 [0.39-0.80]), while evidence for apixaban from the identified studies was insufficient to demonstrate a statistically significant change in mortality (HR = 0.66 [0.30-1.47]). Conclusion: This analysis indicates that in real-world practice, rivaroxaban and apixaban are associated with a lower risk of recurrent VTE and major bleeding events compared with SoC. Survival benefit in patients treated with rivaroxaban was also observed.

Cost Effectiveness of Patient Self-Managed Warfarin Compared with Direct Oral Anticoagulants in Atrial Fibrillation: An Economic Evaluation in a Danish Healthcare Sector Setting.

BACKGROUND: Patient self-managed anticoagulant treatment with warfarin (PSM) has been proposed as an alternative to direct oral anticoagulants (DOACs) in patients with non-valvular atrial fibrillation (NVAF); however, direct evidence on the cost effectiveness of PSM compared with DOACs is lacking. We aimed to evaluate the cost effectiveness of PSM versus DOACs for NVAF patients in the Danish healthcare setting using a model-based cost-utility analysis. METHODS: A cost-utility analysis was performed using a decision-analytic model including two treatment alternatives: continuous PSM and DOACs. The analysis was performed from an extended Danish healthcare sector perspective, including patient-paid costs of medication related to the anticoagulant treatment, with a lifetime horizon. Inputs for the model comprised of probabilities of events, costs in Danish estimates, when possible, and effect in utilities. The probabilities of events are primarily based on real-life data from a direct comparison of PSM and DOACs. The results are presented as the incremental cost-effectiveness ratio (ICER) with an assumed cost-effectiveness threshold of £20,000/quality-adjusted life-year (QALY). Both deterministic and probabilistic sensitivity analyses were performed to investigate the robustness of the results. RESULTS: The base-analysis showed that PSM was dominant, with a decreased cost of £8495 and an increased QALY accumulation of 0.23 per patient (ICER = -£36,935/QALY). All deterministic sensitivity analyses indicated that PSM was dominant or at least cost effective. The probabilistic sensitivity analysis showed that 95% of the iterations were cost effective. CONCLUSIONS: The present study found that PSM is dominant (i.e., both more effective and cost saving) compared with DOACs, adding to the scarce evidence of the comparative cost effectiveness of PSM and DOACs in NVAF.

Adverse Events and All-Cause Mortality in Danish Patients with Cerebral Venous Thrombosis: A Nationwide Cohort Study.

BACKGROUND: Cerebral venous thrombosis (CVT) is a rare manifestation of stroke and venous thromboembolism (VTE), compared with deep vein thrombosis (DVT) and pulmonary embolism (PE). We examined whether CVT was associated with adverse cardiovascular events. METHODS: A Danish cohort study with adult patients diagnosed with CVT (N = 1,015) between 1997 and 2017. We matched 10 patients with VTE (DVT and PE) to each patient with CVT for age, sex, and diagnosis year. We also matched 10 individuals from the general population to each patient with CVT. We computed cumulative incidence and estimated hazard ratios (HRs) with 95% confidence intervals (95% CIs) at 5 years for major bleeding, intracranial bleeding, ischemic stroke, and cardiovascular events. Death was examined separately. RESULTS: Major bleeding risks were 1.2% for CVT and 0.7% for VTE at 6 months; these risks increased to 2.7% and 2.6%, respectively, at 5 years. Although rare, intracranial bleeding risks were markedly higher for CVT (2.9%) than for VTE (0.4%) at 5 years (HR = 8.9, 95% CI: 5.3-15.1). Incidences of ischemic stroke were 5.9% for CVT and 0.3% for VTE, at 6 months; and 10.0% and 1.4%, respectively, at 5 years (HR = 9.5, 95% CI: 7.1-12.7). In contrast, incidence of cardiac events was lower for CVT that VTE (1.7% vs. 3.6% at 5 years). Mortality risk was higher after CVT compared with VTE, at 6 months (6.6% vs. 3.8%), but the risks differed little at 5 years (14.3% vs. 14.1%). CONCLUSION: Intracranial bleeding, ischemic stroke, and mortality risks were higher for patients with CVT than matched patients with VTE and the general population, particularly within 6 months after diagnosis.

Assigning diagnosis codes using medication history.

Diagnosis assignment is the process of assigning disease codes to patients. Automatic diagnosis assignment has the potential to validate code assignments, correct erroneous codes, and register completion. Previous methods build on text-based techniques utilizing medical notes but are inapplicable in the absence of these notes. We propose using patients' medication data to assign diagnosis codes. We present a proof-of-concept study using medical data from an American dataset (MIMIC-III) and Danish nationwide registers to train a machine-learning-based model that predicts an extensive collection of diagnosis codes for multiple levels of aggregation over a disease hierarchy. We further suggest a specialized loss function designed to utilize the innate hierarchical nature of the disease hierarchy. We evaluate the proposed method on a subset of 567 disease codes. Moreover, we investigate the technique's generalizability and transferability by (1) training and testing models on the same subsets of disease codes over the two medical datasets and (2) training models on the American dataset while evaluating them on the Danish dataset, respectively. Results demonstrate the proposed method can correctly assign diagnosis codes on multiple levels of aggregation from the disease hierarchy over the American dataset with recall 70.0% and precision 69.48% for top-10 assigned codes; thereby being comparable to text-based techniques. Furthermore, the specialized loss function performs consistently better than the non-hierarchical state-of-the-art version. Moreover, results suggest the proposed method is language and dataset-agnostic, with initial indications of transferability over subsets of disease codes.