Is language an issue? Accuracy of the German computerized diagnostic decision support system ISABEL and cross-validation with the English counterpart.

OBJECTIVES Existing computerized diagnostic decision support tools (CDDS) accurately return possible differential diagnoses (DDx) based on the clinical information provided. The German versions of the CDDS tools for clinicians (Isabel Pro) and patients (Isabel Symptom Checker) from ISABEL Healthcare have not been validated yet. METHODS We entered clinical features of 50 patient vignettes taken from an emergency medical text book and 50 real cases with a confirmed diagnosis derived from the electronic health record (EHR) of a large academic Swiss emergency room into the German versions of Isabel Pro and Isabel Symptom Checker. We analysed the proportion of DDx lists that included the correct diagnosis. RESULTS Isabel Pro and Symptom Checker provided the correct diagnosis in 82 and 71 % of the cases, respectively. Overall, the correct diagnosis was ranked in 71 , 61 and 37 % of the cases within the top 20, 10 and 3 of the provided DDx when using Isabel Pro. In general, accuracy was higher with vignettes than ED cases, i.e. listed the correct diagnosis more often (non-significant) and ranked the diagnosis significantly more often within the top 20, 10 and 3. On average, 38 ± 4.5 DDx were provided by Isabel Pro and Symptom Checker. CONCLUSIONS The German versions of Isabel achieved a somewhat lower accuracy compared to previous studies of the English version. The accuracy decreases substantially when the position in the suggested DDx list is taken into account. Whether Isabel Pro is accurate enough to improve diagnostic quality in clinical ED routine needs further investigation

Thrombophilia and outcomes of venous thromboembolism in older patients.

BACKGROUND Limited data exist on thrombophilic risk factors and clinical outcomes in the elderly with venous thromboembolism (VTE). OBJECTIVES To describe the prevalence of laboratory thrombophilic risk factors and their association with VTE recurrence or death in a cohort of elderly people with VTE. METHODS In 240 patients aged ≥65 years with acute VTE without active cancer or an indication for extended anticoagulation, we performed laboratory thrombophilia testing 1 year after the index VTE. Recurrence or death was assessed during the 2-year follow-up. RESULTS A total of 78% of patients had ≥1 laboratory thrombophilic risk factor(s). Elevated levels of von Willebrand factor, homocysteine, coagulant activity of factor VIII (FVIII:C), fibrinogen, FIX:C, and low antithrombin activity were the most prevalent risk factors (43%, 30%, 15%, 14%, 13%, and 11%, respectively). Additionally, 16.2% of patients experienced VTE recurrence and 5.8% of patients died. Patients with a von Willebrand factor of >182%, FVIII:C level >200%, homocysteine level >15μmol/L, or lupus anticoagulant had a significantly higher rate of recurrence than those without these risk factors (15.0 vs. 6.1 [P = .006], 23.5 vs. 8.2 [P = .01], 17.0 vs. 6.8 [P = .006], and 89.5 vs. 9.2 [P = .02] events per 100 patient-years, respectively). Furthermore, patients with a high fibrinogen level or hyperhomocysteinemia with a homocysteine level ≥30 μmol/L had significantly higher mortality than patients with normal levels (18.5 vs. 2.8 [P = .049] and 13.6 vs. 2 [P = .002] deaths per 100 patient-years, respectively). After adjustments for relevant confounders, these associations remained unchanged. CONCLUSION Laboratory thrombophilic risk factors are common in elderly people with VTE and allow for the identification of a population at the risk of worse clinical outcomes

D-dimer and mortality in COVID-19: a self-fulfilling prophecy or a pathophysiological clue?

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as a global phenomenon has presented clinicians around the world with multiple challenges. Thromboembolic events are recognised complications of viral infection, but the diagnosis of an acute pulmonary thrombotic complication in the context of coronavirus disease 2019 (COVID-19) can be challenging because of the similarities of presentation, logistical considerations of diagnosis in a patient isolated for infection control reasons and the effects of cognitive errors in diagnostic reasoning. We present the case of a patient who was diagnosed with a pulmonary thrombotic complication during inpatient care for COVID-19. The haemostasis parameters we observed, including increased levels of von Willebrand factor and factor VIII, point towards a relevant involvement of endothelial cells in patients with severe COVID-19. We suggest that it is possible to hypothesise a spectrum of secondarily acquired, prothrombotic coagulopathy mediated by the endothelial interaction with SARS-CoV-2 as a cause of mortality in a subset of patients with a complicated clinical course of COVID-19. We support the recommendation of thromboembolic chemoprophylaxis for inpatients with COVID-19 as a very minimum in the absence of strict contraindications, while recognising that pulmonary thrombotic complications can occur under standard thromboprophylaxis. We suggest that higher, possibly therapeutic levels of anticoagulation might be mandatory for a further subset of patients with COVID-19 where a discrepant evolution of C-reactive protein and D-dimer is observed. Therapeutic levels of anticoagulation are obligatory where new evidence of a macrovascular thrombotic complication has been documented. More research to delineate the macro- and microvascular thrombotic complications of COVID-19, and the therapeutic implications for this patient group is required