ความน่าเชื่อถือในการวัดซ้ำของแบบประเมิน Modified Lower Extremity Functional Scale (Modified LEFS) ฉบับภาษาไทย และความสัมพันธ์กับ Knee Osteoarthritis Outcome Scores (KOOS) ฉบับภาษาไทย, Self-Pace Walk Test และ Timed Up and Go Test ในผู้ที่มีข้อเข่าเสื่อม

Abstract

Background: Six millions of elderly citizens in Thailand have been reported to have knee osteoarthritis (OA). Thai version of self-report functional measures could be benefit to evaluate functional level of knee OA.

Objective: To examine test-retest reliability and validity of Modified Lower Extremity Functional Scale (Modified Thai LEFS) to Thai version of Knee Osteoarthritis Outcome Score (KOOS) and to functional performance tests including 40m-Self Pace Walk Test (40m-SPWT) and Timed Up and Go test (TUG) in participants with knee OA.

Method: Thirty participants with knee OA (27 females, aged 65±8) were included in this study. Forward/backward translation and Indexes of Objective Congruence (IOC) were used with respect to original version. Each participant completed the Modified Thai LEFS at first visit and within one week for test-retest reliability. Concurrent validity of Modified Thai LEFS comparing to Thai version of Knee Osteoarthritis Outcome Score (KOOS; pain, activity daily living and sport and recreation), 40m-Self Pace Walking Test (40m-SPWT), and Timed Up and Go test (TUG) were investigated using Pearson correlation coefficient.

Result: Results showed that Modified Thai LEFS had high congruence (IOC=0.8). The study also found high test-retest reliability(ICC=0.83, p<.001) and medium to high concurrent validity as indicated by moderate correlations to KOOS daily living (r=0.59, p<.001), KOOS pain (r=0.4, p<.05), 40m-SPWT (r=-0.48, p<.001) and TUG (r=-0.46, p<.001) and strong correlation to KOOS sport and recreation(r=0.72, p<.001).

Conclusion: Modified Thai LEFS was found to be a highly reliable and moderately valid tool for self-reported functional level in participants with knee OA.