Observer-reported or Proxy-reported: Is One Better than the Other?

By Aimee Lee Russell, Programs Associate

On February 24, the National Health Coucil held a webinar to discuss differences between caregiver-reported and proxy-reported outcomes, which are not are not the same. The speakers provided clarity on the use of these terms, and pointed out there are critical differences between them to the FDA and those working with FDA. The webinar featured:

• Laurie Burke, MPH, founder of the LORA Group, LLC. and Former Director, Study Endpoints and Labelling Development at the Food and Drug Administration (FDA),
• Grace Whiting, President and CEO of the National Alliance for Caregiving; and
• Ryan Fischer, Senior Vice President of Community Engagement at Parent Project Muscular Dystrophy

Ms. Burke provided definitons for the terms, described the differences between them, and discussed how those differences are important, especially to regulators (see Table). She emphasized that in instances where it is impossible to collect valid and reliable self-report data from the patient (using a patient-reported outcome (PRO) measure), an ObsRO instrument shoud be used, a proxy-reported measure should not be used.

Observer-reported outcomes (ObsROs)

A measurement based on a report of observable signs, events or behaviors related to a patient’s health condition by someone other than the patient or a health professional. Generally, ObsROs are reported by a parent, caregiver, or someone who observes the patient in daily life and are particularly useful for patients who cannot report for themselves (e.g., infants or individuals who are cognitively impaired).

Proxy-reported outcome

A report by someone other than the patient, who reports on patient experiences as if he or she is the patient. Importantly, proxy-reported outcomes are discouraged when measuring concepts that are only known by the patient (e.g., symptoms).

Ms. Whiting described how among patients with chronic conditions, the patient voice and the caregiver voice are often thought to be interchangeable. But, patient and caregiver perspectives can be very different. She described research demonstrating that if the caregiving relationship is strained, a caregiver may overstate the amount of pain a patient is facing. So there is a clear need for a more nuanced approach to identify where caregivers can help and to what degree their voice should be included in data collection.

She highlighted how the caregiver role evolves over time. For example, among young patients who may be unable to self-report, the caregiver voice may be more prominent. But, as the patient matures, they may be able to report on their own signs and symptoms, indicating that at that point a patient-reported outcome should be used. Similarly, among patients with dementia, the patient has a more prominent voice in the beginning. But, as the disease progresses, their ability to report decreases, and a caregiver may need to step in on their behalf.

Mr. Fischer described Parent Project Muscular Dystrophy (PPMD)’s journey collecting outcome data through its patient registry. He described how measures often used in their patient population, such as the Pediatric Outcomes Data Collection Instrument (PODCI), include questions appropriate for caregivers to report upon (e.g., get in and out of bed), but also questions that are inappropriate for caregivers to report upon (e.g., pain). He emphasized that the patient and researcher communities are all in the process of learning the new vernacular reflected in FDA Guidance – as described by Ms. Burke. To ensure outcomes are accurately captured, PPMD is investing in and supporting efforts to develop better fit-for-purpose measures for both patients and caregivers.

Please click here to listen to the full webinar.