MUSCULOSKELETAL FUNCTION ASSESSMENT INSTRUMENT - CRITERION AND CONSTRUCT-VALIDITY

The Musculoskeletal Function Assessment (MFA) instrument, a health sta tus instrument with 100 self-reported health items, was designed for u se with the broad range of patients with musculoskeletal disorders of the extremities commonly seen in clinical practice. In this paper, we report on its criterion and construct validity. Criterion validity was tested against physicians' ratings of patient functioning (e.g., uppe r functioning, lower functioning, daily activities, recreational funct ioning, emotional adjustment, and overall functioning) and standard cl inical measures (e.g., grip strength, walking speed, fine motor skills , knee and elbow strength, and range of motion). Significant correlati ons (p less than or equal to 0.05) between its scores, physicians' rat ings, and clinical measures support the MFA's criterion validity. Cons truct validity was demonstrated against existing measures of health st atus (e.g., measures of lower and upper mobility, activity level and s atisfaction, health status, social support, pain. emotional status. an d quality of life), in accordance with clinical hypotheses about the e ffect of musculoskeletal disorders on functioning (e.g., type and numb er of problems, severity of illness or injury, and comorbidities) and by an analysis of demographic characteristics (e.g., sex, education, i ncome, health insurance, and employment) against the MFA scores. Discr iminant construct validity was supported in an analysis of MFA scores by patient disease groups (p less than or equal to 0.01).