Predictors of Sarcopenia Among Vietnamese Elderly Outpatients with Chronic Musculoskeletal Disorders: A Cross-Sectional Study

Objectives: Sarcopenia impairs physical function and increases healthcare burden among older adults with chronic musculoskeletal disorders. This study estimated the prevalence of sarcopenia and explored factors associated with sarcopenia among Vietnamese elderly outpatients. Methods: A hospital-based cross-sectional study was conducted among 88 outpatients aged 60 years or older with knee osteoarthritis and/or chronic spinal pain at a tertiary hospital in Northern Vietnam from May 2024 to October 2025. Sarcopenia and severe sarcopenia were defined according to the Asian Working Group for Sarcopenia 2019 criteria. Muscle mass, muscle strength, and physical performance were assessed using bioelectrical impedance analysis, handgrip dynamometry, and usual gait speed, respectively. Multivariable logistic regression and an exploratory chi-square automatic interaction detection decision tree were applied. Results: The prevalence of sarcopenia was 40.9%, including 23.9% with sarcopenia and 17.0% with severe sarcopenia. Age >70 years (adjusted odds ratio [AOR] 9.00, 95% confidence interval [CI] 2.40-33.60), history of falls (AOR 6.33, 95% CI 2.77-14.45), low educational attainment (AOR 2.86, 95% CI 1.46-5.61), and poor sleep quality (AOR 1.16, 95% CI 1.02-1.32) were independently associated with sarcopenia. Conclusions: Sarcopenia was common in this outpatient population. Routine case-finding may be particularly relevant in older patients with falls, lower educational attainment, and poor sleep quality. The decision-tree findings should be interpreted as exploratory because of the cross-sectional, single-center design and modest sample size.