Functional assessment system of lower-extremity dysfunction

Abstract: The Functional Assessment System (FAS) is a new instrument for evaluation of lower-extremity dysfunction. It consists of 20 variables, representing major lower--extremity functions related to daily life activities. The variables are divided into five groups: hip impairment, knee impairment, physical disability, social disability, and paiu variables. The grouping agrees fairly well with the WHO classification of impairment, disabilities and handicaps. Every variable is given a disability score on a five-point scale. The scores are plotted into a diagram, giving an individual functional profile. The profile can be used to document present functional status, for goal-setting, and for follow-up after treatment. It can also be used to design individual training programs.The aim of this thesis was:• to present the new Functional Assessment System (FAS)• to examine the metric properties of the FAS, and• to apply the FAS in some clinical situations.The FAS was applied on a series of patients with osteoarthritis of the hip or knee. Content validity was tested with factor analysis. The obtained factor structure agreed very well with the preliminary grouping of the variables. Concurrent validity was tested by comparison with measurements from the AIMS (Arthritis Impact Measurement Scales), the Rosser-Kind index (for evaluation of quality of life), and a radiographic scale for grading of osteoarthritis. There was a good agreement between the measurements of the FAS and the physical variables of the AIMS. There was also a good agreement between the FAS and the results obtained by the Rosser-Kind index. There was a low agreement between the FAS and the psychosocial variables of the AIMS. There was also a low correlation between the radiographic grading of osteoarthritis and the functional status recorded with the FAS. Inter-tester reliability was evaluated as correlation between the measurements performed by two independent physiotherapists. There was an almost perfect agreement between the two testers. The FAS was also tested for discriminatory power. It showed a good ability to differentiate between healthy subjects and patients with osteoarthritis. It also had a good power to discriminate between different degrees of the disease. The disability group of variables had better discriminstory power than the impairment group of variables. Most variables had a high specificity, whereas high sensitivity was mainly found in the disability group of variables and pain. The FAS was used to measure outcome after arthroplasty. A baseline functional status was recorded before surgery, and a goal profile was made. Six months later there was a striking improvement, especially in the disability variables and pain, and there was a high degree of goal achievement of most patients in most variables. Patients admitted for arthroplasty were examined for age-related diffirences in founctional status, Despite the fact that age was not included in the criteria for operation, old people had significantly lower functional status. This finding may indicate a hidden age criterion for referral of patients for arthroplasty. The age-related changes were mainly found in the disability group of variables. These findings may speak in favor of early surgery of patients with osteoarthritis.To summarize: The FAS had very good metric properties, such as validity, intertester reliability, discriminatory power, sensitivity and specificity. It was also a useful instrument in a clinical setting to record functional status, to set an individual treatment goal, and as an instrument for follow-up and outcome measurements. It was also sensitive in detecting age-related differences in patients admitted for arthroplasty. It can be used to communicate functional status to other health professionals, and to establish realistic goals for the patient.