Observer-reported outcome (ObsRO)

An observer-reported outcome (ObsRO) is a type of clinical outcome assessment based on a report of observable signs, events or behaviours related to a patient's health condition by someone other than the patient or a health professional, typically a parent, spouse or caregiver who observes the patient in daily life. The observer does not require professional training and reports what is observed, not the patient's internal experience, which distinguishes an ObsRO from both a patient-reported outcome and a clinician-reported outcome.

ObsROs are used where patients cannot reliably report for themselves: infants and young children, people with severe cognitive impairment or advanced dementia, and patients with communication disorders. Examples include caregiver-reported seizure diaries in paediatric epilepsy, observer-rated pain or crying scales in infants, and behavioural scales in autism or Alzheimer's disease. Regulators expect ObsRO instruments to be validated for the specific observer and context and, where possible, to be complemented by other COA types.

ObsRO data is health data about the patient and, at the same time, personal data about the observer, whose identity, relationship to the patient and sometimes own wellbeing (caregiver burden) are recorded. Caregivers therefore need their own information notice and, where they are also the legally designated representative, the two roles should be distinguished in the consent documentation. Electronic diaries used by caregivers raise the same eCOA questions about device data, hosting and transfers.