What mesaurment is uses to determine a persons level of impairment?

A common measurement used to determine a person's level of impairment is the International Classification of Functioning, Disability and Health (ICF), which evaluates various domains of health and disability. Another frequently used tool is the World Health Organization Disability Assessment Schedule (WHODAS), which assesses a person's functioning across different life areas. Additionally, assessments like the Barthel Index or the Functional Independence Measure (FIM) may be used in specific contexts to gauge functional abilities.