Background
: Knee osteoarthritis (OA) is a major cause of disability, particularly in the elderly. The factors determining disability remain unclear and have not been defined in Korea. The aim of this study was to assess the various aspects of the quality of life, and to define the determinant factors of disability in patients with knee OA.

Methods : The Korean version of AIMS2 (K-AIMS2) and CMCHS (Catholic Medical Center Health Survey) were administered to a cohort of 239 outpatients with symptomatic OA of the knee who attended 7 participating University Hospitals in Seoul, Ilsan and Taejon. The scores of K-AIMS2 12 subscales by demographic variables and body mass index were compared using Student t-test. And the determinant factors of the lower extremity disability were analysed by stepwise multiple regression method.

Results : The study subjects (n=239) were 61.6±9.1 years old, comprised of 197 (82.4%) females and 42 (17.6%) males, had been sick with knee osteoarthritis for 6.2±6.5 years, and had 24.7±3.1 kg/m² BMI. Among K-AIMS2 12 subscales 'Walking and bending' (5.82±2.17), 'Arthritis pain' (5.19±1.98), 'Social activities' (3.97±2.04), and 'Mobility level' (3.61±1.74) showed high scores, while subscales related with upper extremities function showed low scores, reflecting the costruct validity of K-AIMS2 in patients with symptomatic knee OA. After adjustment for the presence of sociodemographic variables, we found bodily pain (P＜0.001), age (P＜0.001), emotional function (P=0.033), and education level (P=0.099) as determinant factors of K-AIMS2 lower limb function.

Conclusion : It is recommendable that the knee OA patients should be treated properly in the emotional aspect as well as the bodily pain aspect. In addition, it is suggested that education level be considered as an important factor when teaching the OA patients about coping with knee disabilities.

Background
: The second version of the Arthritis Impact Measurement Scales (AIMS2) is an improvement on an evaluation instrument that was developed to measure patient outcome in the rheumatic diseases. The goal of this study was to validate a translated version of the revised and expanded Arthritis Impact Measurement Scales (AIMS2) to be used by Korean patients with osteoarthritis (OA) of the knee.

Methods : The AIMS2 was translated into Korean according to a recommended translation guideline. The Korean version of AIMS2 (K-AIMS2) was administered to a cohort of 239 outpatients with symptomatic OA of the knee who attended 7 participating University Hospitals in Seoul, Ilsan and Taejon. Forty eight patients readministered the K-AIMS2, 7 days after the first visit, to evaluate the instrument's test-retest reliability. After 6 weeks of NS AIDs therapy, 79 subjects were asked to complete a second survey of the questionnaire.

Results : The internal consistency reliability of each scale score, as estimated by Cronbach's alpha coefficient, was high and indicated that the components of the scale measured the same construct. The items were all correlated with each other, but there was no redundancy; this indicated that each domain addressed a somewhat different aspect of functional disability. The test-retest reliability equalled or exceeded 0.86 for 12 scales. Factor analysis provided a three-factor health status model explaining 58.2% of the variance. The upper limb function scales formed the first factor. Psycho-social scale were loaded on the second factor. Arthritis pain together with physical scales for mobility level and walking and bending were loaded on the third factor (the lower limb function). The scale for support from family and friends was not loaded on any factors. These results demonstrate that the physical health status scales of the K-AIMS2 are valid, as shown by the significant, moderate to high correlations between the K-AIMS2 subscales and the majority of the clinical measures.

Conclusion : Our data suggest that, like the original questionnaire, the Korean version of AIMS2 is a reliable, consistent and valid instrument for measuring health status and physical functioning in patients with OA of the knee.