Proxy subjective health status or evaluation measures refer to the use of a third party’s opinion, assessment, or interpretation to determine the state of physical and mental health in an individual who cannot adequately express themselves. This is often done for children and individuals with disabilities, as well as those with language barriers. While proxy measures can be useful for determining an individual’s overall health in these populations, there are certain underlying assumptions and potential ramifications which should be considered before their use.

The first assumption that must be made when using proxy subjective health status measures is that the third-party evaluator is knowledgeable about and has accurate insights into the individual being assessed. This means they must have had contact with them over a period of time while observing their behaviour and interactions; otherwise they may not possess enough knowledge to accurately judge how well the person’s physical and mental condition aligns with what would generally be considered healthy in most cases.