Developing Validated Tools to Identify Pulmonary Embolism in Electronic Databases: Rationale and Design of the PE-EHR+ Study

Validating International Classification of Diseases Code 10th Revision algorithms for accurate identification of pulmonary embolism

BACKGROUND

Many research investigations for pulmonary embolism (PE) rely on the International Classification of Diseases 10th Revision (ICD-10) codes for analyses of electronic databases. The validity of ICD-10 codes in identifying PE remains uncertain.

OBJECTIVES

The objective of this study was to validate an algorithm to efficiently identify pulmonary embolism using ICD-10 codes.

METHODS

Using a prespecified protocol, patients in the Mass General-Brigham hospitals (2016-2021) with ICD-10 principal discharge codes for PE, those with secondary codes for PE, and those without PE codes were identified (n = 578 from each group). Weighting was applied to represent each group proportionate to their true prevalence. The accuracy of ICD-10 codes for identifying PE was compared with adjudication by independent physicians. The F1 score, which incorporates sensitivity and positive predictive value (PPV), was assessed. Subset validation was performed at Yale-New Haven Health System.

RESULTS

A total of 1712 patients were included (age: 60.6 years; 52.3% female). ICD-10 PE codes in the principal discharge position had sensitivity and PPV of 58.3% and 92.1%, respectively. Adding secondary discharge codes to the principal discharge codes improved the sensitivity to 83.2%, but the PPV was reduced to 79.1%. Using a combination of ICD-10 PE principal discharge codes or secondary codes plus imaging codes for PE led to sensitivity and PPV of 81.6% and 84.7%, respectively, and the highest F1 score (83.1%; P < .001 compared with other methods). Validation yielded largely similar results.

CONCLUSION

Although the principal discharge codes for PE show excellent PPV, they miss 40% of acute PEs. A combination of principal discharge codes and secondary codes plus PE imaging codes led to improved sensitivity without severe reduction in PPV.

Isolated subsegmental pulmonary embolism identification based on international classification of diseases (ICD)-10 codes and imaging reports

BACKGROUND

Isolated subsegmental pulmonary embolism (issPE) is a commonly encountered diagnosis. Although the International Classification of Diseases (ICD)-10 codes are used for research, their validity for identifying issPE is unknown. Moreover, issPE diagnosis is challenging, and the findings from radiology reports may conflict with those from expert radiologists.

METHODS

Based on prespecified criteria, 1734 medical records of adult patients hospitalized within the Mass General Brigham health system (2016-2021) were selected in three equal groups: (1) patients with principal discharge diagnosis codes for PE, (2) patients with secondary discharge diagnosis codes for PE, and (3) patients with no PE codes. The accuracy of ICD-10 codes for issPE was verified by two independent physicians and weighted by total hospitalizations. In a randomly selected sample of 70 patients, the accuracy of initial radiology reports was determined through a blinded re-evaluation by two expert radiologists.

RESULTS

In weighted estimates, ICD-10 codes in primary or secondary discharge positions, compared with chart reviews, showed a low sensitivity (7.0 %) and positive predictive value (25.2 %). Evaluation by two expert radiologists noted that initial radiology reports were sensitive (97.1 %) for issPE but had a low specificity (40.0 %). Two (3.6 %) out of 55 patients with initial issPE reports did not have PE, while 19 (34.5 %) had more proximal PE.

CONCLUSIONS

ICD-10 codes for issPE have poor sensitivity and positive predictive value and should not be used for research or quality improvement. Radiology reports for issPE may be inaccurate regarding the location or, less often, the presence of PE.

Sex differences in treatment strategies for pulmonary embolism in older adults: The SERIOUS-PE study of RIETE participants and US Medicare beneficiaries

INTRODUCTION

Sex differences exist in risk factors and comorbidities of older adults (aged ⩾ 65 years) with pulmonary embolism (PE). Clinically relevant sex-based treatment disparities for PE have not been adequately addressed. The few existing show conflicting results due to small sample size (type II error) and suboptimal methods (overreliance on p-value, which may detect differences of small clinical relevance).

METHODS

We assessed sex differences in anticoagulation and advanced therapies for PE in older adults, utilizing data from Registro Informatizado Enfermedad TromboEmbolica (RIETE), a large PE registry with predominant participation from Europe, and data from US Medicare beneficiaries. We prespecified a standardized difference (SRD) > 10% as clinically relevant. RIETE included 33,462 (57.7% female) and Medicare included 102,391 (55.0% female) older adults with PE.

RESULTS

In RIETE, there were no overall sex differences in the use of anticoagulation (median: 181 vs 180 days, SRD < 1%), fibrinolysis (SRD < 3%), thrombectomy (SRD < 2%), or inferior vena cava (IVC) filters (SRD: 4.4%). However, fibrinolytic therapy (systemic or catheter-based) was less often used in female than male patients with intermediate-risk PE (8.0% vs 12.1%, SRD: 13.6%). No sex differences were noted with advanced PE therapies in Medicare beneficiaries. In unadjusted analyses, fibrinolysis and IVC filter placement were more frequent in Medicare than RIETE participants regardless of sex (p < 0.001).

CONCLUSION

In a predominantly European PE registry and a US study of older adults, there were no overall sex differences in anticoagulation patterns or advanced therapy utilization. Future studies should determine if sex disparities in fibrinolytic therapy for intermediate-risk PE and greater use of advanced therapies in US older adults correlate with clinical outcomes.

Innovation in Catheter-Directed Therapy for Intermediate-High-Risk and High-Risk Pulmonary Embolism

Although anticoagulation remains the cornerstone treatment for patients with acute pulmonary embolism (PE), catheter-directed therapy (CDT) has generated great interest as an adjunctive option for those presenting with hemodynamic decompensation or high risk for deterioration and in whom systemic thrombolysis has failed or is contraindicated. However, randomized controlled data supporting the efficacy and safety of CDT in addition to antithrombotic therapy in patients with high-risk and intermediate- to high-risk PE compared with anticoagulation and systemic thrombolysis alone are lacking. This paucity of high-quality data hampers guideline recommendations regarding the optimal therapeutic approach in such patients with PE. The aim of the present paper is to critically appraise the current evidence for CDT in patients with high-risk and intermediate- to high-risk PE and to highlight major areas of innovation in the recent literature. In addition, the authors describe unmet clinical and research needs, potential strategies to resolve these knowledge gaps, and pathways for device selection.

Derivation and external validation of a portable method to identify patients with pulmonary embolism from radiology reports: The READ-PE algorithm

BACKGROUND

Identification of pulmonary embolism (PE) across a cohort currently requires burdensome manual review. Previous approaches to automate capture of PE diagnosis have either been too complex for widespread use or have lacked external validation. We sought to develop and validate the Regular Expression Aided Determination of PE (READ-PE) algorithm, which uses a portable text-matching approach to identify PE in reports from computed tomography with angiography (CTA).

METHODS

We identified derivation and validation cohorts of final radiology reports for CTAs obtained on adults (≥ 18 years) at two independent, quaternary academic emergency departments (EDs) in the United States. All reports were in the English language. We manually reviewed CTA reports for PE as a reference standard. In the derivation cohort, we developed the READ-PE algorithm by iteratively combining regular expressions to identify PE. We validated the READ-PE algorithm in an independent cohort, and compared performance against three prior algorithms with sensitivity, specificity, positive-predictive-value (PPV), negative-predictive-value (NPV), and the F1 score.

RESULTS

Among 2948 CTAs in the derivation cohort 10.8 % had PE and the READ-PE algorithm reached 93 % sensitivity, 99 % specificity, 94 % PPV, 99 % NPV, and 0.93 F1 score, compared to F1 scores ranging from 0.50 to 0.85 for three prior algorithms. Among 1206 CTAs in the validation cohort 9.2 % had PE and the algorithm had 98 % sensitivity, 98 % specificity, 85 % PPV, 100 % NPV, and 0.91 F1 score.

CONCLUSIONS

The externally validated READ-PE algorithm identifies PE in English-language reports from CTAs obtained in the ED with high accuracy. This algorithm may be used in the electronic health record to accurately identify PE for research or surveillance. If implemented at other EDs, it should first undergo local validation and may require maintenance over time.

Early predictors of clinical deterioration in intermediate-high risk pulmonary embolism: clinical needs, research imperatives, and pathways forward

A subset of intermediate-high risk pulmonary embolism (PE) patients will suffer clinical deterioration in the early hours following the acute event. Current evidence-based guidelines for the management of acute PE have provided limited direction for identification of which intermediate-high risk PE patients will go on to develop haemodynamic decompensation. Furthermore, a paucity of data further hampers guideline recommendations regarding the optimal approach and duration of intensive monitoring, best methods to assess the early response to anticoagulation, and the ideal window for reperfusion therapy, if decompensation threatens. The aim of the present article is to identify the current unmet needs related to the early identification of intermediate-high risk PE patients at higher risk of clinical deterioration and mortality during the early hours after the acute cardiovascular event and suggest some potential strategies to further explore gaps in the literature.