Correlation of Self-Reported Questionnaire (KOOS) with Some Objective Measures in Primary OA Knee Patients

Area of Science:

• Orthopedics
• Rehabilitation Medicine
• Biostatistics

Background:

• Osteoarthritis (OA) of the knee significantly impacts patient quality of life.
• Objective and subjective measures are crucial for assessing OA knee severity and treatment efficacy.
• The Knee Osteoarthritis Outcome Score (KOOS) is a patient-reported outcome measure, while the 6-minute walk test (6-MWT) provides objective functional data.

Purpose of the Study:

• To investigate the correlation between the subjectively measured KOOS questionnaire and objectively measured 6-minute walk test (6-MWT).
• To assess the relationship between KOOS scores and demographic/anthropometric factors including age, height, weight, and Body Mass Index (BMI).

Main Methods:

• 251 subjects with knee OA, diagnosed per American College of Rheumatology criteria, participated.
• Data collected included age, height, weight, BMI, KOOS questionnaire responses, and performance on the 6-MWT.
• Spearman rank correlation test was employed to analyze the relationships, with a significance level set at P < 0.05.

Main Results:

• The 6-MWT demonstrated a weak correlation with KOOS-ADL but strong to very strong correlations with KOOS-symptom, KOOS-pain, KOOS-sports, and KOOS-QOL.
• BMI showed strong correlations with KOOS-pain, KOOS-symptom, KOOS-ADL, KOOS-sports, and a very strong correlation with KOOS-QOL.
• Weight exhibited weak to strong correlations across different KOOS subscales, with all significant findings (P < 0.001).

Conclusions:

• The KOOS questionnaire is strongly positively correlated with 6-MWT performance, indicating good functional agreement.
• KOOS scores are negatively correlated with BMI, suggesting higher BMI is associated with poorer knee health outcomes.
• Correlation strength between KOOS and anthropometric measures varies, with weight showing a decreased correlation strength compared to BMI.