The International Cardiac Arrest Research Consortium Electroencephalography Database

OBJECTIVES

To develop the International Cardiac Arrest Research (I-CARE), a harmonized multicenter clinical and electroencephalography database for acute hypoxic-ischemic brain injury research involving patients with cardiac arrest.

DESIGN

Multicenter cohort, partly prospective and partly retrospective.

SETTING

Seven academic or teaching hospitals from the United States and Europe.

PATIENTS

Individuals 16 years old or older who were comatose after return of spontaneous circulation following a cardiac arrest who had continuous electroencephalography monitoring were included.

INTERVENTIONS

Not applicable.

MEASUREMENTS AND MAIN RESULTS

Clinical and electroencephalography data were harmonized and stored in a common Waveform Database-compatible format. Automated spike frequency, background continuity, and artifact detection on electroencephalography were calculated with 10-second resolution and summarized hourly. Neurologic outcome was determined at 3-6 months using the best Cerebral Performance Category (CPC) scale. This database includes clinical data and 56,676 hours (3.9 terabytes) of continuous electroencephalography data for 1,020 patients. Most patients died ( n = 603, 59%), 48 (5%) had severe neurologic disability (CPC 3 or 4), and 369 (36%) had good functional recovery (CPC 1-2). There is significant variability in mean electroencephalography recording duration depending on the neurologic outcome (range, 53-102 hr for CPC 1 and CPC 4, respectively). Epileptiform activity averaging 1 Hz or more in frequency for at least 1 hour was seen in 258 patients (25%) (19% for CPC 1-2 and 29% for CPC 3-5). Burst suppression was observed for at least 1 hour in 207 (56%) and 635 (97%) patients with CPC 1-2 and CPC 3-5, respectively.

CONCLUSIONS

The I-CARE consortium electroencephalography database provides a comprehensive real-world clinical and electroencephalography dataset for neurophysiology research of comatose patients after cardiac arrest. This dataset covers the spectrum of abnormal electroencephalography patterns after cardiac arrest, including epileptiform patterns and those in the ictal-interictal continuum.

The International Cardiac Arrest Research (I-CARE) Consortium Electroencephalography Database

Objective

To develop a harmonized multicenter clinical and electroencephalography (EEG) database for acute hypoxic-ischemic brain injury research involving patients with cardiac arrest.

Design

Multicenter cohort, partly prospective and partly retrospective.

Setting

Seven academic or teaching hospitals from the U.S. and Europe.

Patients

Individuals aged 16 or older who were comatose after return of spontaneous circulation following a cardiac arrest who had continuous EEG monitoring were included.

Interventions

not applicable.

Measurements and Main Results

Clinical and EEG data were harmonized and stored in a common Waveform Database (WFDB)-compatible format. Automated spike frequency, background continuity, and artifact detection on EEG were calculated with 10 second resolution and summarized hourly. Neurological outcome was determined at 3-6 months using the best Cerebral Performance Category (CPC) scale. This database includes clinical and 56,676 hours (3.9 TB) of continuous EEG data for 1,020 patients. Most patients died (N=603, 59%), 48 (5%) had severe neurological disability (CPC 3 or 4), and 369 (36%) had good functional recovery (CPC 1-2). There is significant variability in mean EEG recording duration depending on the neurological outcome (range 53-102h for CPC 1 and CPC 4, respectively). Epileptiform activity averaging 1 Hz or more in frequency for at least one hour was seen in 258 (25%) patients (19% for CPC 1-2 and 29% for CPC 3-5). Burst suppression was observed for at least one hour in 207 (56%) and 635 (97%) patients with CPC 1-2 and CPC 3-5, respectively.

Conclusions

The International Cardiac Arrest Research (I-CARE) consortium database provides a comprehensive real-world clinical and EEG dataset for neurophysiology research of comatose patients after cardiac arrest. This dataset covers the spectrum of abnormal EEG patterns after cardiac arrest, including epileptiform patterns and those in the ictal-interictal continuum.

Utilizing visualization to qualitatively evaluate electronic health record-derived database limitations

317

Background: Electronic health record (EHR) databases are a promising platform for clinical research using real-world data. However, information on potential limitations of these data sources is lacking. We sought to understand how data visualization might be used to identify data inconsistencies and the applicability of previously validated claims-based algorithms used to identify patients with metastatic breast cancer (MBC). Methods: This retrospective study utilized ASCO’s CancerLinQ Discovery database derived from EHR data. Subjects included women ≥18 years treated for MBC diagnosed ≥1980. Subjects with MBC were identified using two billing codes for metastasis on separate dates following primary breast cancer diagnosis. Treatment course sequences were visualized. Patients were represented by a horizontal bar on the Y-axis. Treatments were displayed using colored bars (blue: chemotherapy, red: endocrine therapy, green: HER2 targeted, orange: novel therapy) with time of treatment on the X-axis. Visualizations were qualitatively evaluated, and treatment patterns inconsistent with clinical practice were identified. Results: We identified 4,760 women treated for MBC using billing codes for primary breast cancer diagnosis and distant metastasis. Most patients (96%) had a primary breast cancer diagnosed in 2000 later. Treatment patterns inconsistent with clinical practice identified using the visualization technique included: 1% of patients received adjuvant chemotherapy continuously for ≥1.5 years, suggesting missed coding for metastatic disease; 5% of patients did not receive any treatment in the year following metastasis, suggesting the billing code may have been used in workup and not for confirmed metastatic disease. Among patients with MBC, 50% identified as HR+ across all records had not received hormone therapy, while 39% identified as HR- across all records received hormone therapy. Conclusions: Because previously validated algorithms may not translate well to EHR databases, quality auditing should always be performed. The proposed data visualization can be used for improving algorithms, qualitatively identifying errors, and avoiding biased or inaccurate results.

Visualizing treatment patterns and survival in metastatic breast cancer

316

Background: Optimal treatment sequencing (i.e., the order in which drugs are given) for metastatic breast cancer (MBC) is unknown. We aimed to develop an approach to visualize treatment patterns and survival in MBC. Methods: This retrospective study utilized ASCO’s CancerLinQ Discovery® database generated from electronic health records. Subjects included 3,312 women aged ≥18 years who were diagnosed with and received treatment for MBC after 1980. Hormone receptor (HR) status was determined by concordant diagnosis and treatment records. Human epidermal growth factor (HER2) status was determined by delivery of HER2-targeted therapy. Ordered and administered treatments were included. We created spatiotemporal plots of treatment patterns for HR+/HER2-, HER2+, and triple negative (TN) MBC. Individuals were represented on the Y-axis, and time on the X-axis with development of MBC aligned at time 0. Treatment classes were identified by colors: hormone therapies in shades of red, chemotherapies in shades of blue, HER2-targeted therapies in shades of green, and novel therapies in shades of orange. Concurrent treatments were represented by split bars. An overlaid Kaplan-Meier curve allowed for observations about the relationship between survival and treatment. Results: We developed a novel visualization approach to simultaneously display heterogeneous, longitudinal treatments and survival. Median survival after first documentation of MBC was 3.1 (IQR 1.4-7.2), 1.3 (IQR 0.6-2.8), and 2.6 (IQR 1.0-5.2) years for HR+/HER2-, TN, and HER2+ MBC, respectively. Patients with longer survival often had long duration of initial therapy, suggesting a more indolent or responsive disease. Substantial heterogeneity in treatment sequencing was observed for HR+HER2- and TN cohorts. In the HER2+ cohort, HER2-targeted therapy was commonly administered for the duration of treatment with more homogeneous sequencing. Conclusions: This novel visualization approach allows for observing the relationship between treatment patterns and survival, which is challenging to demonstrate with traditional quantitative methods. This approach can generate hypotheses regarding impact of treatment patterns on survival.