Body mass index and health-related quality of life of outpatients with knee osteoarthritis: evidence from a cross-sectional study.

Abstract

Purpose: To estimate the health-related quality of life (HRQoL) of knee osteoarthritis outpatients in China overall and by body mass index (BMI), and to explore the factors associated with knee osteoarthritis.

Method: This was a cross-sectional study in which outpatients with knee osteoarthritis were recruited from three tertiary hospitals in China from June 2020 to May 2021. The EuroQoL five-dimensional instrument was used to measure HRQoL. Descriptive analysis, one-way analysis of variance, and a Tobit regression model were performed.

Results: One thousand and eight questionnaires were distributed, and nine hundred and fifty-two participants were included. The mean age was 61.71 years, and 61.03% of the participants were female. The mean health utility was 0.751 (95% CI 0.737, 0.765). The health utility varied significantly according to BMI: underweight = 0.627 (95% CI 0.536, 0.719), normal = 0.764 (95% CI 0.744, 0.784), overweight = 0.755 (95% CI 0.733, 0.776), and obese = 0.728 (95%CI 0.681, 0.776). Additionally, outpatients with knee osteoarthritis who were younger, had received treatment in the past six months, and had a disease duration shorter than 2 years had significantly higher HRQoL scores.

Conclusion: The HRQoL of knee osteoarthritis outpatients was considerably impaired and was significantly associated with BMI. These findings emphasize the importance of weight examination and management in outpatients with knee osteoarthritis for healthcare providers. Supplementary data were provided for public health-related policies and health economics studies, contributing to the development of effective management strategies and increasing the breadth of knowledge of HRQoL in outpatients with knee osteoarthritis.