The Vienna Prediction Model for identifying patients at low risk of recurrent venous thromboembolism: a prospective cohort study.

BACKGROUND AND AIMS: Patients with unprovoked venous thromboembolism (VTE) have a high recurrence risk, and guidelines suggest extended-phase anticoagulation. Many patients never experience recurrence but are exposed to bleeding. The aim of this study was to assess the performance of the Vienna Prediction Model (VPM) and to evaluate if the VPM accurately identifies these patients. METHODS: In patients with unprovoked VTE, the VPM was performed 3 weeks after anticoagulation withdrawal. Those with a predicted 1-year recurrence risk of ≤5.5% were prospectively followed. Study endpoint was recurrent VTE over 2 years. RESULTS: A total of 818 patients received anticoagulation for a median of 3.9 months. 520 patients (65%) had a predicted annual recurrence risk of ≤5.5%. During a median time of 23.9 months, 52 patients had non-fatal recurrence. The recurrence risk was 5.2% [95% confidence interval (CI) 3.2-7.2] at 1 year and 11.2% (95% CI 8.3-14) at 2 years. Model calibration was adequate after 1 year. The VPM underestimated the recurrence risk of patients with a 2-year recurrence rate of >5%. In a post-hoc analysis, the VPM's baseline hazard was recalibrated. Bootstrap validation confirmed an ideal ratio of observed and expected recurrence events. The recurrence risk was highest in men with proximal deep-vein thrombosis or pulmonary embolism and lower in women regardless of the site of incident VTE. CONCLUSIONS: In this prospective evaluation of the performance of the VPM, the 1-year rate of recurrence in patients with unprovoked VTE was 5.2%. Recalibration improved identification of patients at low recurrence risk and stratification into distinct low-risk categories.

Interval cancer after colonoscopy in the Austrian National Screening Programme: influence of physician and patient factors.

OBJECTIVE: Postscreening colorectal cancer (PSCRC) after screening colonoscopy is associated with endoscopists' performance and characteristics of resected lesions. Prior studies have shown that adenoma detection rate (ADR) is a decisive factor for PSCRC, but correlations with other parameters need further analysis and ADR may change over time. DESIGN: Cohort study including individuals undergoing screening colonoscopy between 1/2008 and 12/2019 performed by physicians participating in a quality assurance programme in Austria. Data were linked with hospitalisation data for the diagnosis of PSCRC (defined as CRC diagnosis >6 months after colonoscopy). ADR was defined dynamically in relation to the time point of subsequent colonoscopies; high-risk groups of patients were those with an adenoma ≥10 mm, or with high-grade dysplasia, or villous or tubulovillous histology, or a serrated lesion ≥10 mm or with dysplasia, or colonoscopies with ≥3 lesions. Main outcome was PSCRC for each risk group (negative colonoscopy, hyperplastic polyps, low-risk and high-risk group of patients) after colonoscopy by endoscopists with an ADR <20% compared with endoscopists with an ADR ≥20%. RESULTS: 352 685 individuals were included in the study (51.0% women, median age 60 years) of which 10.5% were classified as high-risk group. During a median follow-up of 55.4 months, 241 (0.06%) PSCRC were identified; of 387 participating physicians, 19.6% had at least one PSCRC (8.4% two or more). While higher endoscopist ADR decreased PSCRC incidence (HR per 1% increase 0.97, 95% CI 0.95 to 0.98), affiliation to the high-risk group of patients was also associated with higher PSCRC incidence (HR 3.27, 95% CI 2.36 to 4.00). Similar correlations were seen with regards to high-risk, and advanced adenomas. The risk for PSCRC was significantly higher after colonoscopy by an endoscopist with an ADR <20% as compared with an endoscopist with an ADR ≥20% in patients after negative colonoscopy (HR 2.01, 95% CI 1.35 to 3.0, p<0.001) and for the high-risk group of patients (HR 2.51, 95% CI 1.49 to 4.22, p<0.001). CONCLUSION: A dynamic calculation of the ADR takes into account changes over time but confirms the correlation of ADR and interval cancer. Both lesion characteristics and endoscopists ADR may play a similar role for the risk of PSCRC. This should be considered in deciding about appropriate surveillance intervals in the future.

To tune or not to tune, a case study of ridge logistic regression in small or sparse datasets.

BACKGROUND: For finite samples with binary outcomes penalized logistic regression such as ridge logistic regression has the potential of achieving smaller mean squared errors (MSE) of coefficients and predictions than maximum likelihood estimation. There is evidence, however, that ridge logistic regression can result in highly variable calibration slopes in small or sparse data situations. METHODS: In this paper, we elaborate this issue further by performing a comprehensive simulation study, investigating the performance of ridge logistic regression in terms of coefficients and predictions and comparing it to Firth's correction that has been shown to perform well in low-dimensional settings. In addition to tuned ridge regression where the penalty strength is estimated from the data by minimizing some measure of the out-of-sample prediction error or information criterion, we also considered ridge regression with pre-specified degree of shrinkage. We included 'oracle' models in the simulation study in which the complexity parameter was chosen based on the true event probabilities (prediction oracle) or regression coefficients (explanation oracle) to demonstrate the capability of ridge regression if truth was known. RESULTS: Performance of ridge regression strongly depends on the choice of complexity parameter. As shown in our simulation and illustrated by a data example, values optimized in small or sparse datasets are negatively correlated with optimal values and suffer from substantial variability which translates into large MSE of coefficients and large variability of calibration slopes. In contrast, in our simulations pre-specifying the degree of shrinkage prior to fitting led to accurate coefficients and predictions even in non-ideal settings such as encountered in the context of rare outcomes or sparse predictors. CONCLUSIONS: Applying tuned ridge regression in small or sparse datasets is problematic as it results in unstable coefficients and predictions. In contrast, determining the degree of shrinkage according to some meaningful prior assumptions about true effects has the potential to reduce bias and stabilize the estimates.

Utilization of potentially inappropriate medication and risk of adverse drug events among older adults with chronic renal insufficiency: a population-wide cohort study.

BACKGROUND: The use of potentially inappropriate medication (PIM) in population of older adults may result in adverse drug events (ADE) already after short term exposure, especially when it is prescribed to patients with chronic kidney disease (CKD). In order to limit ADE in the treatment of older adults PIM lists have been constructed as a source of information for healthcare professionals. The aim of this study was to estimate the utilization of PIM and incidence of ADE in older adults (≥70 years) with CKD. METHODS: We conducted a retrospective population-wide cohort study including patients from Lower Austria who were 70 years or older and diagnosed with CKD in the period from 2008 to 2011. Utilization of PIM was estimated from prescriptions filled by target population. We estimated risks of hospitalization due to ADE within 30 days after incident PIM prescription and compared them to a PIM-free control group by using marginal structural models (MSM). RESULTS: We identified 11,547 patients (women: 50.6%, median age in 2008: 78 years) who fulfilled the inclusion criteria. In total 24.7 and 8.1% of all prescriptions from that period contained a medication with a substance listed in the EU (7)-PIM and AT-PIM list, respectively. Proton pump inhibitors and Ginkgo biloba were the most often prescribed PIMs in this population. 94.6 and 79.3% patients filled at least one EU(7)-PIM and AT-PIM prescription, respectively. Despite the relatively high utilization of PIM there was only a low incidence of clinically relevant ADE. No event type exceeded the threshold level of 1% in the analysis of risks of ADE after filling a prescription for PIM. Nevertheless, MSM analysis showed an increased risk for 11 drugs and reduced risk for 4 drugs. CONCLUSIONS: PIM prescription was common among older adults with CKD, however, only a small number of these drugs eventually led to hospitalization due to ADE within 30 days after incident PIM was filled. In the absence of a clinically important PIM-related increase in risk, an assessment of potential ADE severity to a PIM list by using a warning score system seems prudent.

Circumstances of provoked recurrent venous thromboembolism: the Austrian study on recurrent venous thromboembolism.

Patients with unprovoked deep-vein thrombosis (DVT) of the leg or pulmonary embolism (PE) have a high recurrence risk. How often these recurrences are provoked by a temporary risk condition is unknown. In a cohort of patients with unprovoked venous thromboembolism (VTE), we evaluated the clinical circumstances of recurrence. We studied patients with DVT of the leg and/or PE. End point was recurrence of objectively verified symptomatic VTE. Provoked recurrence was defined according to guidance criteria. 1188 patients were followed for a median of 8.9 years after withdrawal of oral anticoagulants. 312 patients had recurrent VTE, which was provoked in 42 (13%). Recurrence was related to a major risk factor in 19, to a minor risk factor in 22, and to a persistent risk factor in one patient(s). 14 recurrences occurred after major surgery and 5 during hospitalization. Ten recurrences occurred after minor surgery, eight after trauma and three during female hormone intake. Four recurrences occurred during heparin prophylaxis. The incidence of provoked VTE recurrence appears to be low. VTE can recur when prevention is stopped or even during thromboprophylaxis. Surgery and trauma are frequent risk factors.

Development of Cross-Sector Health Care Quality Indicators Based on Claims Data.

Quality indicators serve as a tool to measure and improve evidence-based health care. Often the transition from inpatient to outpatient care is not sufficiently included. The focus of this work was to develop and to evaluate methods to define relevant cross-sector quality indicators based on Austrian claims data, using myocardial infarction as tracer.

Adherence to Secondary Prevention Measures after Acute Myocardial Infarction and Its Impact on Patient Outcome-A Nationwide Perspective.

Objectives: Secondary prevention is crucial for reducing morbidity and mortality in patients following acute myocardial infraction (MI). However, adherence to cardiac rehabilitation (CR) and pharmacotherapy remains suboptimal despite strong guideline recommendations. This study investigated the adherence to CR, dual antiplatelet therapy (DAPT), and statins following acute MI and evaluated their impact on patient outcomes from a nationwide perspective in Austria. Methods: In this national observational study, all patients diagnosed with acute MI, defined as STEMI or NSTEMI, between April 2011 and August 2015 in Austria were included. Patient characteristics and comorbidities were derived from the Austrian national health insurance system using ICD-10 codes. Adherence to CR, high-intensity statins, and DAPT was assessed based on health insurance records and pharmacy prescription submissions. Cox Regression hazard analysis was used to explore the impact of non-adherence to CR on mortality. Results: Among 16,518 acute MI patients, only 13.4% adhered to the recommended CR programs, which was associated with a significantly lower risk of mortality (adjusted hazard ratio [HR] 0.73; 95% CI: 0.54-0.98; p = 0.036). In contrast, 66.4% of 23,240 patients did not comply with high-intensity statin therapy, correlating with an increased mortality risk (adjusted HR 1.16; 95% CI: 1.06-1.25; p < 0.001). Furthermore, among 22,331 patients analyzed for DAPT adherence, only 29.3% followed the guidelines, yet this adherence was linked to a 21% reduction in mortality over the observation period (adjusted HR 0.79; 95% CI: 0.72-0.88; p < 0.001). Conclusions: This nationwide study reveals alarmingly low adherence to CR and secondary preventive medications among acute MI patients, which is significantly linked to higher mortality rates. Enhanced efforts to promote awareness and adherence are crucial, involving structured referrals and personalized follow-ups to improve patient outcomes. Addressing these gaps through comprehensive healthcare strategies could substantially enhance cardiovascular health.

Extracellular Vesicles and Citrullinated Histone H3 in Coronavirus Disease 2019 Patients.

OBJECTIVES: Pulmonary thrombus formation is a hallmark of coronavirus disease 2019 (COVID-19). A dysregulated immune response culminating in thromboinflammation has been described, but the pathomechanisms remain unclear. METHODS: We studied 41 adult COVID-19 patients with positive results on reverse-transcriptase polymerase-chain-reaction assays and 37 sex- and age-matched healthy controls. Number and surface characteristics of extracellular vesicles (EVs) and citrullinated histone H3 levels were determined in plasma upon inclusion by flow cytometry and immunoassay. RESULTS: In total, 20 patients had severe and 21 nonsevere disease. The number of EV (median [25th, 75th percentile]) was significantly higher in patients compared with controls (658.8 [353.2, 876.6] vs. 435.5 [332.5, 585.3], geometric mean ratio [95% confidence intervals]: 2.6 [1.9, 3.6]; p < 0.001). Patients exhibited significantly higher numbers of EVs derived from platelets, endothelial cells, leukocytes, or neutrophils than controls. EVs from alveolar-macrophages and alveolar-epithelial cells were detectable in plasma and were significantly higher in patients. Intercellular adhesion molecule-1-positive EV levels were higher in patients, while no difference between tissue factor-positive and angiotensin-converting enzyme-positive EV was seen between both groups. Levels of EV did not differ between patients with severe and nonsevere COVID-19. Citrullinated histone H3 levels (ng/mL, median [25th, 75th percentile]) were higher in patients than in controls (1.42 [0.6, 3.4] vs. 0.31 [0.1, 0.6], geometric mean ratio: 4.44 [2.6, 7.7]; p < 0.001), and were significantly lower in patients with nonsevere disease compared with those with severe disease. CONCLUSION: EV and citrullinated histone H3 are associated with COVID-19 and could provide information regarding pathophysiology of the disease.

D-dimer levels over time after anticoagulation and the association with recurrent venous thromboembolism.

INTRODUCTION: D-dimer measured shortly after discontinuation of anticoagulation by an immunoturbidimetric assay predicts the risk of recurrent venous thromboembolism (VTE). We assessed the performance of this assay over time and its association with recurrent VTE. MATERIALS AND METHODS: We followed 556 patients with a first VTE for a median of 9.6 years. The study end point was recurrent VTE. D-dimer was measured 3 weeks, and 3, 9, and 15 months after discontinuation of anticoagulation in plasma using an immunoturbidimetric assay (INNOVANCE D-Dimer). To estimate the effect of longitudinal D-dimer on the recurrence risk, we used a dynamic prediction Cox model with landmark times (3 weeks, and 3, 9, 15 months) as a stratification factor. RESULTS: 135 patients had recurrent VTE. D-dimer levels varied between patients but without a consistent pattern. Levels increased slightly over time [0.7% increase (95% CI: 0.5-0.9; p < 0.001)/month]. D-dimer levels were positively correlated with body mass index (BMI) [2% (95% CI: 1.1-2.9; p < 0.001) increase/1 unit BMI increase], and were 14.8% (95% CI: 5.1-25.3; p = 0.002) higher in women than in men. The recurrence risk with doubling D-dimer levels was higher after 3 weeks, 3, 9 and 15 months [hazard ratios 1.4 (1.06-1.84), 1.37 (1.06-1.77), 1.31 (1.04-1.65) and 1.26 (1.01-1.57), respectively]. CONCLUSIONS: In patients with a first VTE, immunoturbidimetric D-dimer levels are associated with the risk of recurrence at multiple times points from 3 weeks up to 15 months after discontinuation of oral anticoagulation.

A randomized controlled trial comparing the effectiveness of individual versus household treatment for Scabies in Lambaréné, Gabon.

BACKGROUND: It is unclear whether individual treatment of scabies is similarly effective compared to household treatment. This study compared these two treatment strategies with topical benzyl benzoate for treating scabies in Lambaréné, Gabon. METHODS: Participants presenting with uncomplicated scabies were randomized into either the Individual Treatment group, where only the affected participants received treatment, or the Household Treatment group, where all family members were treated in parallel to the affected participants regardless of signs and symptoms. The primary endpoint was clinical cure after 28 days; the secondary endpoint was the proportion of affected household members per household after 28 days. RESULTS: After 28 days, from a total of 79 participants assessed, 67% (n = 53) were clinically cured; 59% (20/34) in the Individual Treatment group and 73% (33/45) in the Household Treatment group. Participants in the Household Treatment group had about twice the odds of being cured (odds ratio 1.9, 95% confidence interval: 0.8-4.9; p = 0.17). For the secondary outcome, an effect of similar size was observed. CONCLUSIONS: Our findings show that treating close contacts of persons affected by scabies may be beneficial to patients and contacts, however, the benefit was less pronounced than anticipated and further research is needed to definitively answer this question.

Bring More Data!-A Good Advice? Removing Separation in Logistic Regression by Increasing Sample Size.

The parameters of logistic regression models are usually obtained by the method of maximum likelihood (ML). However, in analyses of small data sets or data sets with unbalanced outcomes or exposures, ML parameter estimates may not exist. This situation has been termed 'separation' as the two outcome groups are separated by the values of a covariate or a linear combination of covariates. To overcome the problem of non-existing ML parameter estimates, applying Firth's correction (FC) was proposed. In practice, however, a principal investigator might be advised to 'bring more data' in order to solve a separation issue. We illustrate the problem by means of examples from colorectal cancer screening and ornithology. It is unclear if such an increasing sample size (ISS) strategy that keeps sampling new observations until separation is removed improves estimation compared to applying FC to the original data set. We performed an extensive simulation study where the main focus was to estimate the cost-adjusted relative efficiency of ML combined with ISS compared to FC. FC yielded reasonably small root mean squared errors and proved to be the more efficient estimator. Given our findings, we propose not to adapt the sample size when separation is encountered but to use FC as the default method of analysis whenever the number of observations or outcome events is critically low.

Factor XI and recurrent venous thrombosis: an observational cohort study.

Essentials Factor XI is a potential target for anticoagulation. The association between factor XI and venous thrombosis recurrence was tested in a cohort study. Low factor XI was associated with reduced risk of recurrent venous thrombosis. A sex-and age-adjusted linear association between D-Dimer and factor XI was found. SUMMARY: Background and objectives Low factor XI activity (FXIa) reduces the risk of venous thromboembolism (VTE), and FXI is regarded as a potential target for anticoagulation. Patients/methods We studied the relationship between FXIa and VTE in 851 patients with unprovoked VTE in whom anticoagulation had been stopped. Results Recurrent VTE was recorded in 265 patients. The sex-adjusted and age-adjusted hazard ratio (HR) of recurrence was 0.94 (95% confidence interval [CI] 0.89-0.99) for each decrease of 10 IU dL-1 in FXIa. The HRs of recurrence were 0.73 (95% CI 0.54-0.99) for patients with FXIa below the 34th percentile, and 1.05 (95% CI 0.79-1.39) for patients with FXIa between the 34th and 67th percentiles, as compared with patients with higher FXIa. The probability of recurrence was lower among patients with FXIa below the 34th percentile than in patients with higher FXIa (P = 0.029). At 10 years, the probabilities of recurrence were 31%, 43% and 41% among patients with FXIa below the 34th percentile, with FXIa between the 34th and 67th percentiles, or with higher FXIa, respectively. We found a significant sex-adjusted and age-adjusted linear association between D-dimer levels, measured 3 weeks after anticoagulation, and FXIa. When patients' age and sex are taken into account, a patient with 10 IU dL-1 lower FXIa is expected to have a 2.79% (95% CI 0.95-4.59%) lower D-dimer value (P = 0.003). Conclusions Our findings of a lower thrombosis risk and less pronounced hemostatic system activation among patients with low FXIa is in line with the concept that FXI is a promising target for anticoagulation.

Fixed and adaptive beamforming improves speech perception in noise in cochlear implant recipients equipped with the MED-EL SONNET audio processor.

OBJECTIVE: To determine the impact of the fixed and adaptive beamforming technology of the new MED-EL SONNET cochlear implant audio processor on speech perception in noise. METHODS: The study cohort comprises 18 postlingually deafened adult cochlear implant recipients with at least six months of experience. Speech reception thresholds were measured with the Oldenburg Sentence Test in continuous, speech-shaped noise. Target sentences were presented in front of the listener, with noise sources placed at -135° and 135°, respectively. Outcome measures were the differences in speech reception threshold using omnidirectional, fixed and adaptive beamformer microphone settings. RESULTS: The use of directional microphones significantly improved speech reception thresholds: fixed beamformer vs. omnidirectional: 4.3 dB (95%-CI [3.1; 5.5]), p<0.0001; adaptive beamformer vs. omnidirectional: 6.1 dB (95%-CI [4.9; 7.3]), p<0.0001; and adaptive beamformer vs. fixed beamformer: 1.8 dB (95%-CI [0.7; 3.0]), p = 0.001. CONCLUSION: This study confirms the previously reported improvements in speech perception in noise of the fixed beamformer microphone setting and is the first to report significant improvements in speech perception in noise when applying the adaptive beamformer microphone settings of the SONNET audio processor. Cochlear implant users may be able to benefit from improved hearing performance especially in difficult listening situations.

Risk of venous thromboembolism during rehabilitation of patients with spinal cord injury.

BACKGROUND: Patients with spinal cord injury (SCI) are at risk of thrombosis and bleeding. Data on the risks during rehabilitation are inconsistent, and thromboprophylactic strategies are heterogeneous. We aimed to evaluate the thrombotic risk and bleeding events of SCI patients during rehabilitation. METHODS: We retrospectively collected hospital record data of 263 consecutive SCI patients admitted at a rehabilitation clinic. 78 patients with acute venous thromboembolism (VTE) at the primary center, without acute trauma or lower extremity paresis, less than one month rehabilitation, or reasons for long-term therapeutic anticoagulation, were excluded. All patients received pharmacologic thromboprophylaxis throughout rehabilitation. Primary endpoint was objectively diagnosed VTE; secondary endpoint was bleeding. RESULTS: Of 185 patients, 162 (88%) were men; mean age was 47.8 years. 94 patients were tetraplegic, 91 paraplegic. During a mean (±SD) time of 5.1±2.1 months, VTE was diagnosed in 8 patients. After excluding five patients with VTE detected within 2 days after admission, the probability of developing VTE after 6 months of rehabilitation was 2% (95% CI 0-4.4%). Only high D-Dimer upon admission was associated with risk of VTE (adjusted HR 2.3, 95% CI 1.4-4.1). Of 24 bleedings, 14 (64%) occurred at the heparin injection site. Two patients had major bleeding and five had clinically relevant non major bleeding. CONCLUSION: SCI patients are at risk of VTE and bleeding during rehabilitation. Strategies need to be developed to identify these patients in order to initiate adequate anticoagulation. Direct oral anticoagulants, which have a favourable risk-benefit profile and are convenient, should be explored.

A loop-mediated isothermal amplification (LAMP) assay for the rapid detection of Enterococcus spp. in water.

Faecal pollution of water and the resulting potential presence of human enteric pathogens is a predominant threat to public health. Microbiological water quality can be assessed by the detection of standard faecal indicator bacteria (SFIB) such as E. coli or certain Enterococcus species. In recent years, isothermal amplification methods have become a useful alternative to polymerase chain reaction (PCR), allowing molecular diagnostics with simple or no instrumentation. In this study, a novel screening method for the molecular detection of Enterococcus spp. by loop-mediated isothermal amplification (LAMP) is described. A set of six specific LAMP primers was designed to amplify a diagnostic fragment of the Enterococcus 23S rRNA gene, which is present in several enterococcal species targeted by quantitative PCR (qPCR), which is the standard technique recommended by the US Environmental Protection Agency. Sensitivity and specificity tests were performed using a set of 30 Enterococcus and non-target bacterial reference strains. It is shown that LAMP is equally sensitive and even more specific than the qPCR assay. A dilution series of Enterococcus faecalis DNA revealed that the LAMP method can reliably detect 130 DNA target copies per reaction within 45 min. Additionally, enterococci isolated from Austrian surface waterbodies, as well as a set of DNA extracts from environmental waters, were tested. Contingency analysis demonstrated a highly significant correlation between the results of the developed LAMP assay and the reference qPCR method. Furthermore, a simple staining procedure with a fluorescence dye demonstrated the identification of amplified products by eye. In conclusion, this method is an important component for the efficient screening and testing of water samples in low-resource settings lacking sophisticated laboratory equipment and highly trained personnel, requiring only a simple heating block.