Performance of the Wells score in predicting deep vein thrombosis in medical and surgical hospitalized patients with or without thromboprophylaxis: The R-WITT study.

The Wells score had shown weak performance to determine pre-test probability of deep vein thrombosis (DVT) for inpatients. So, we evaluated the impact of thromboprophylaxis on the utility of the Wells score for risk stratification of inpatients with suspected DVT. This bicentric cross-sectional study from February 1, 2018 to January 31, 2019 included consecutive medical and surgical inpatients who underwent lower limb ultrasound study for suspected DVT. Wells score clinical predictors were assessed by both ordering and vascular physicians within 24 h after clinical suspicion of DVT. Primary outcome was the Wells score's accuracy for pre-test risk stratification of suspected DVT, accounting for anticoagulation (AC) treatment (thromboprophylaxis for ⩾ 72 hours or long-term anticoagulation). We compared prevalence of proximal DVT among the low, moderate and high pre-test probability groups. The discrimination accuracy was defined as area under the receiver operating characteristics (ROC) curve. Of the 415 included patients, 30 (7.2%) had proximal DVT. Prevalence of proximal DVT was lower than expected in all pre-test probability groups. The prevalence in low, moderate and high pre-test probability groups was 0.0%, 3.1% and 8.2% (p = 0.22) and 1.7%, 4.2% and 25.8% (p < 0.001) for inpatients with or without AC, respectively. Area under ROC curves for discriminatory accuracy of the Wells score, for risk of proximal DVT with or without AC, was 0.72 and 0.88, respectively. The Wells score performed poorly for discrimination of risk for proximal DVT in hospitalized patients with AC but performed reasonably well among patients without AC; and showed low inter-rater reliability between physicians. ClinicalTrials.gov Identifier: NCT03784937.

Seasonal variations do not affect the superiority of fecal immunochemical tests over guaiac tests for colorectal cancer screening.

The aim of this study was to compare the seasonal variation in performance of a faecal immunochemical test for haemoglobin (FIT) and a guaiac test (gFOBT) for colorectal cancer screening. From June 2009 to May 2011, 18,290 screening participants (50-74 years old) performed OC-SENSOR quantitative FIT (1 sample) and Hemoccult II gFOBT (3 stool samples with 2 spots/sample). Referral for colonoscopy required a minimum of one positive spot (gFOBT), or a positive FIT [cut-off 150 ng haemoglobin/mL buffer (i.e. 30 µg haemoglobin/g feces)]. The performance of tests for detection of advanced neoplasia was compared according to seasons using Receiver Operating Characteristics (ROC) curves, at various FIT cut-off values. The positivity rate of FIT was significantly lower in the summer compared with other seasons (2.3% versus 3.0%, p = 0.03), whilst the positivity rate of gFOBT increased in the autumn (1.8% versus 1.5%, p = 0.11). FIT was clinically more effective than gFOBT over the four season-specific ROC curves. At the cut-off concentration used in the study, the season-specific FIT/gFOBT ratios for true positive rates were: 2.8 (Autumn), 2.5 (Winter), 3.0 (Spring), 3.7 (Summer), and for false positive rates: 1.2 (Autumn), 1.5 (Winter), 1.8 (Spring), 0.9 (Summer). Therefore, in this study with this cut-off concentration and in spite of lower positivity rate in summer, the seasonal variations of performance of OC-SENSOR FIT led to improved gain in specificity in the summer, without a decrease in gain in sensitivity compared with gFOBT.