Accuracy of physicians' intuitive risk estimation in the diagnostic management of pulmonary embolism: an individual patient data meta-analysis.

BACKGROUND: In patients clinically suspected of having pulmonary embolism (PE), physicians often rely on intuitive estimation ("gestalt") of PE presence. Although shown to be predictive, gestalt is criticized for its assumed variation across physicians and lack of standardization. OBJECTIVES: To assess the diagnostic accuracy of gestalt in the diagnosis of PE and gain insight into its possible variation. METHODS: We performed an individual patient data meta-analysis including patients suspected of having PE. The primary outcome was diagnostic accuracy of gestalt for the diagnosis of PE, quantified as risk ratio (RR) between gestalt and PE based on 2-stage random-effect log-binomial meta-analysis regression as well as gestalts' sensitivity and specificity. The variability of these measures was explored across different health care settings, publication period, PE prevalence, patient subgroups (sex, heart failure, chronic lung disease, and items of the Wells score other than gestalt), and age. RESULTS: We analyzed 20 770 patients suspected of having PE from 16 original studies. The prevalence of PE in patients with and without a positive gestalt was 28.8% vs 9.1%, respectively. The overall RR was 3.02 (95% CI, 2.35-3.87), and the overall sensitivity and specificity were 74% (95% CI, 68%-79%) and 61% (95% CI, 53%-68%), respectively. Although variation was observed across individual studies (I2, 90.63%), the diagnostic accuracy was consistent across all subgroups and health care settings. CONCLUSION: A positive gestalt was associated with a 3-fold increased risk of PE in suspected patients. Although variation was observed across studies, the RR of gestalt was similar across prespecified subgroups and health care settings, exemplifying its diagnostic value for all patients suspected of having PE.

Clinical consequences of off-label reduced dosing of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation: a systematic review and meta-analysis.

OBJECTIVE: Postmarketing observational studies report that a substantial percentage of patients with atrial fibrillation (AF) receive a reduced non-vitamin K antagonist oral anticoagulant (NOAC) dose without a clear indication. Recently, increasing evidence has become available to explore the clinical consequences of such off-label reduced dosing (OLRD). This study aims to systematically review and meta-analyse observational studies that report clinical outcomes associated with OLRD of NOACs compared with on-label non-reduced dosing (OLNRD) of NOACs in patients with AF. METHODS AND ANALYSIS: We performed a systematic literature review and meta-analysis of observational studies reporting clinical outcomes in AF patients with OLRD of an NOAC compared with AF patients with OLNRD of an NOAC. Using random effects meta-analyses, we estimated the risk of stroke/thromboembolism, bleeding and all-cause mortality. RESULTS: We included 19 studies with a total of 170 394 NOAC users. In these studies, the percentage of OLRD among patients with an indication for an on-label non-reduced NOAC dose ranged between 9% and 53%. 7 of these 19 studies met the predefined criteria for meta-analysis (n=80 725 patients). The pooled HR associated with OLRD of NOACs was 1.04 (95% CI 0.83 to 1.29; 95% prediction interval (PI) 0.60 to 1.79) for stroke/thromboembolism, 1.10 (95% CI 0.95 to 1.29; 95% PI 0.81 to 1.50) for bleeding and 1.22 (95% CI 0.81 to 1.84; 95% PI 0.55 to 2.70) for all-cause mortality. CONCLUSION: This meta-analysis shows no statistically significant increased risk of stroke/thromboembolism, nor a decreased bleeding risk, nor a difference in risk of all-cause mortality in patients with OLRD of NOACs. Future research may focus on differences between NOACs.

Real-life impact of clinical prediction rules for venous thromboembolism in primary care: a cross-sectional cohort study.

OBJECTIVE: Clinical prediction rules (CPRs) followed by D-dimer testing were shown to safely rule out venous thromboembolism (VTE) in about half of all suspected patients in controlled and experienced study settings. Yet, its real-life impact in primary care is unknown. The aim of this study was to determine the real-life impact of CPRs for suspected VTE in primary care. DESIGN: Cross-sectional cohort study. SETTING: Primary care in the Netherlands. PARTICIPANTS: Patients with suspected deep venous thrombosis (n=993) and suspected pulmonary embolism (n=484). INTERVENTIONS: General practitioners received an educational instruction on how to use CPRs in suspected VTE. We did not rectify incorrect application of the CPR in order to mimic daily clinical care. MAIN OUTCOME MEASURES: Primary outcomes were the diagnostic failure rate, defined as the 3-month incidence of VTE in the non-referred group, and the efficiency, defined as the proportion of non-referred patients in the total study population. Secondary outcomes were determinants for and consequences of incorrect application of the CPRs. RESULTS: In 267 of the included 1477 patients, VTE was confirmed. When CPRs were correctly applied, the failure rate was 1.51% (95% CI 0.77 to 2.86), and the efficiency was 58.1% (95% CI 55.2 to 61.0). However, the CPRs were incorrectly applied in 339 patients, which resulted in an increased failure rate of 3.31% (95% CI 1.07 to 8.76) and a decreased efficiency of 35.7% (95% CI 30.6 to 41.1). The presence of concurrent heart failure increased the likelihood of incorrect application (adjusted OR 3.26; 95% CI 1.47 to 7.21). CONCLUSIONS: Correct application of CPRs for VTE in primary care is associated with an acceptable low failure rate at a high efficiency. Importantly, in nearly a quarter of patients, the CPRs were incorrectly applied that resulted in a higher failure rate and a considerably lower efficiency.

Validation and impact of a simplified clinical decision rule for diagnosing pulmonary embolism in primary care: design of the PECAN prospective diagnostic cohort management study.

INTRODUCTION: Combined with patient history and physical examination, a negative D-dimer can safely rule-out pulmonary embolism (PE). However, the D-dimer test is frequently false positive, leading to many (with hindsight) 'unneeded' referrals to secondary care. Recently, the novel YEARS algorithm, incorporating flexible D-dimer thresholds depending on pretest risk, was developed and validated, showing its ability to safely exclude PE in the hospital environment. Importantly, this was accompanied with 14% fewer computed tomographic pulmonary angiography than the standard, fixed D-dimer threshold. Although promising, in primary care this algorithm has not been validated yet. METHODS AND ANALYSIS: The PECAN (Diagnosing Pulmonary Embolism in the context of Common Alternative diagNoses in primary care) study is a prospective diagnostic study performed in Dutch primary care. Included patients with suspected acute PE will be managed by their general practitioner according to the YEARS diagnostic algorithm and followed up in primary care for 3 months to establish the final diagnosis. To study the impact of the use of the YEARS algorithm, the primary endpoints are the safety and efficiency of the YEARS algorithm in primary care. Safety is defined as the proportion of false-negative test results in those not referred. Efficiency denotes the proportion of patients classified in this non-referred category. Additionally, we quantify whether C reactive protein measurement has added diagnostic value to the YEARS algorithm, using multivariable logistic and polytomous regression modelling. Furthermore, we will investigate which factors contribute to the subjective YEARS item 'PE most likely diagnosis'. ETHICS AND DISSEMINATION: The study protocol was approved by the Medical Ethical Committee Utrecht, the Netherlands. Patients eligible for inclusion will be asked for their consent. Results will be disseminated by publication in peer-reviewed journals and presented at (inter)national meetings and congresses. TRIAL REGISTRATION: NTR 7431.