What is eCOA and how does it improve clinical trial data quality?
Kelly Dumais, PhD – Senior Scientific Advisor
What is eCOA?
Clinical Outcome Assessments (COAs) are measures that describe or reflect how a patient feels, functions, or survives. Electronic Clinical Outcome Assessment (eCOA) is a method of capturing COA data electronically. Data can be collected using various electronic methods, including handheld devices, tablet devices, or patients’ own devices or computers. Using eCOA in clinical trials can substantially increase study data quality while meeting regulatory requirements. Before we dig into how it does that, let’s review the different types of COA and eCOA.
- Clinician-reported outcome (ClinRo): Using their clinical judgment, physicians, nurses, or other site staff report patient health outcomes based on their observation of the participant’s health condition, a physical examination, or participant interview. When collected electronically, it is called an eClinRo.
- Patient-reported outcome (PRO): Health outcome reported directly by the patient, without interpretation by a clinician or anyone else. An example would be a symptom diary in which the participant records their level of pain every evening in a diary. When collected electronically, it is called an ePRO (also commonly called an eDiary).
- Observer-reported outcome (ObsRo): Health outcome reported by someone other than the patient (e.g., caregiver) based on observable signs, events, or behaviors. An example would be a caregiver reporting their child’s seizure episodes. When collected electronically, it is called an eObsRO.
- Performance outcome (PerfO): Measurement based on task(s) performed by a patient according to instructions administered by a healthcare professional; medical devices can collect and record objective measures such as motor, sensory, and cognition. When collected electronically, it is called an ePerfO.
How Does eCOA Improve Data Quality?
A growing majority of clinical trial stakeholders (including sponsors, CROs, and regulators) consider eCOA as the most effective way to capture high-quality and more reliable data than traditional, paper-based methods. Here’s how eCOA does this:
eCOA increases patient protocol compliance
Patients using ePRO demonstrate significantly higher protocol compliance — as high as 94% compared to 11% with paper1 (Figure1). Through the use of electronic reminders/alerts, animated compliance feedback, and dynamic, context-sensitive messaging, only ePRO captures data in real-time, delivering accurate, reliable information on patients’ experiences during a trial.
94%
Compliance with eCOA
11%
Compliance with paper
Figure 1. Patient protocol compliance increases with eCOA
eCOA prevents inconsistent or conflicting data
Electronic data collection uses branching and logic sequences to guide patients through the appropriate questionnaire in the order established by the study protocol. Using on-device edit checks, patients – or sites/observers ─ are prevented from skipping questions or entering inconsistent or conflicting data.
eCOA eliminates transcription errors
Paper diary studies require site personnel to manually transcribe data into the trial management system, leaving a greater opportunity for errors and other inconsistencies. When patients enter data electronically (using ePRO), those steps are automated, eliminating transcription errors. Inconsistencies, missing data, and other data quality issues are detected in real-time at data capture.
eCOA meets global regulatory standards
Regulatory bodies recommend that the COA data collection method ensures data are collected and reported according to protocol requirements. Unlike paper diaries, eCOA data meet regulatory quality guidelines, meaning they are Attributable, Legible, Contemporaneous, Original, and Accurate (ALCOA). By meeting these fundamental quality elements, regulators’ queries regarding the capture of eCOA data are virtually eliminated.
Patients prefer eCOA
Patients across indications, including asthma, oncology, diabetes, pain, and others, consistently prefer eCOA versus paper when reporting symptoms. Therefore, using eCOA provides better quality data and promotes patient-centered clinical trials.

“Regardless of their size, sponsors and CROs who continue to rely on outdated, error-prone paper assessments for capturing important COA data may be introducing unnecessary risks into their clinical trials. Those who turn to eCOA data capture benefit from improved data quality, regulatory compliance, and accelerated clinical development.”
Kelly Dumais, PhD – Senior Scientific Advisor
References
1 Stone, A. A., Shiffman, S., Schwartz, J.E., Broderick, J.E., Hufford, M.R. (2002). Patient non-compliance with paper diaries. British Medical Journal, 324, 1193 – 1194.
To discuss using electronic data capture for your next study, contact our Science Team or visit our Science page
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