Multilevel Determinants of Traditional Korean Medicine Rehabilitation Use after Total Knee Arthroplasty among Older Adults in Korea: An Empirical Analysis Using National Health Insurance Claims Data

Objectives This study aimed to examine multilevel determinants of traditional Korean medicine rehabilitation (TKMR) use after total knee arthroplasty among older adults in Korea using a multilevel analysis framework.It sought to identify individual, hospital, and district-level factors that contribute to unmet needs for post-discharge rehabilitation.Methods This study analyzed customized National Health Insurance Service claims data linked with district-level indicators.The study population included adults aged 65 years or older who underwent total knee arthroplasty in 2019 (M13, M17, M19, M24, M25).Patients with surgery for the same condition in 2018 or those who died within six months after discharge were excluded, resulting in a final sample of 17,765 individuals.Multilevel logistic regression was conducted to incorporate individual, index hospital, and district-level variables.Results Among 17,765 patients, 3,143 (17.69%) used TKMR within six months after discharge.In the multilevel models, TKMR use was significantly more likely among women, medical aid beneficiaries, and those with a higher Charlson comorbidity index or longer length of stay.At the index hospital level, private ownership was associated with higher use.At the district level, a higher proportion of older residents, a greater number of TKMR hospitals, and a higher share of welfare-related budget were positively associated with TKMR use, whereas the number of TKMR clinics was not significant.Conclusions Post-discharge TKMR use is a multilevel phenomenon shaped by individual needs, hospital characteristics, and district-level contexts.These findings suggest that addressing regional capacity imbalances and strengthening discharge planning are essential to reduce disparities in post-surgical rehabilitation utilization. (