Severe pre-treatment attrition in the care cascade: clinical outcomes and risk factors among older MDR/RR-TB patients in China

Background The rising global burden of multidrug- and rifampicin-resistant tuberculosis (MDR/RR-TB) coincides with rapid population aging. Older patients face unique challenges, yet age-stratified analyses of the MDR/RR-TB care cascade are lacking, obscuring the specific barriers they encounter. Objective This study aimed to characterize the treatment cascade and identify factors associated with attrition among older MDR/RR-TB patients in China. Methods We conducted a retrospective cohort study of 667 MDR/RR-TB patients aged ≥65 years in Guangdong Province, southern China (2010–2022). Using data from the national Tuberculosis Information Management System (TIMS), we constructed a care cascade to quantify attrition across four stages (diagnosis, treatment initiation, retention at 6 months, and treatment success) and three inter-stage gaps (attrition between successive stages). Separate multivariable logistic regression models identified factors associated with failure to initiate treatment and with poor outcomes. Results Of the 667 diagnosed patients (median age 70), 500 (74.96%) initiated treatment, 406 (60.87% of diagnosed cases, 81.2% of treated cases) were retained at 6 months, and only 268 (40.18% of diagnosed cases, 53.6% of treated cases) achieved treatment success. Multivariable analysis showed that workers/farmers ( a OR = 1.87, 95% CI: 1.24–2.84), diagnosis by conventional DST ( a OR = 9.34, 95% CI: 4.52–21.64), diagnosis before 2016 ( a OR = 1.91, 95% CI: 1.18–3.08), and older age ( a OR = 1.05 per year, 95% CI: 1.01–1.08) were independently associated with failure to initiate treatment; prior TB treatment history was protective ( a OR = 0.42, 95% CI: 0.25–0.72). Among treatment initiators, older age ( a OR = 1.06 per year, 95% CI: 1.02–1.09) and diagnosis before 2016 ( a OR = 1.88, 95% CI: 1.06–3.39) were independent risk factors for poor outcomes. Conclusion The MDR/RR-TB care cascade for older patients in China is marked by severe pre-treatment attrition. Targeted interventions, including scaling up rapid molecular testing, providing targeted support (e.g., financial subsidies, home-based care, and flexible treatment schedules) for high-risk workers, and implementing geriatric-adapted follow-up, and expanding active case finding, are urgently needed to protect this vulnerable population and to close this equity gap.