Electronic clinical outcome assessment (eCOA) is software that collects how each patient in a clinical trial is doing, on a phone or a tablet. It includes the questionnaires and diaries that patients fill in themselves. An outcome assessment is a measure of how a patient feels or functions, such as pain, itching, sleep or the ability to walk.
There are three main kinds. A patient-reported outcome is filled in by the patient, for example a daily pain score. A clinician-reported outcome is filled in by the trial doctor, for example a score for how much of the skin is affected. An observer-reported outcome is filled in by someone else, such as a parent reporting a young child's coughing.
Imagine a trial of a new migraine medicine. A patient in Guwahati gets the trial's app on her phone, in Assamese. Every evening at 9 p.m., the app reminds her to fill in her headache diary. Did she have a headache today? How bad was it, from 0 to 10? Did she take any other painkiller? Each answer is saved with the exact time she gave it. If she misses a day, the app does not let her fill it in a week later. It only marks the day as missing.
Why does this matter? Trials once used paper diaries. Studies found that some patients filled in a whole week of entries just before their hospital visit, from memory. Those entries looked complete but were unreliable. With eCOA, every entry is time-stamped, so a late entry is visible.
The questions themselves are fixed. A questionnaire used in a trial must be tested to show that it measures what it claims to measure. Each translation, such as the Assamese one, must be checked as well, so that a score of 7 means the same in every language. eCOA companies maintain these approved translations.
Each entry is recorded with an audit trail, as GxP rules require. The entries go to the clinical trial data platform, and some scores also appear in the hospital's electronic data capture (EDC) forms. In a decentralised trial, where patients take part from home, eCOA is often the main way patients report. Readings from devices worn at home are collected separately, as described in remote patient monitoring.
How is eCOA different from EDC? EDC records what the hospital measures. eCOA records what the patient reports, in the patient's own words and numbers.