Exploring clinical heterogeneity and outcome-associated factors through cluster analysis in older adults with rifampicin-sensitive pulmonary tuberculosis: a retrospective cohort study

To identify factors associated with adverse outcomes in older adults(≥ 60 years) with rifampicin-sensitive pulmonary tuberculosis (PTB) and characterize clinical heterogeneity within this population. A retrospective cohort study included 861 older adults with rifampicin-sensitive PTB.Multivariate logistic regression identified independent risk factors, and systematic cluster analysis of baseline characteristics defined phenotypic subgroups, followed by subgroup-specific analyses. The overall incidence of adverse outcomes was 39.6%. In the multivariable analysis, adverse outcomes were associated with treatment plan modification (OR = 16.28), pseudomembranous enteritis (OR = 6.84), pulmonary cavity count ≥ 5 (OR = 3.35), and comorbidity count (OR = 1.29). Cluster analysis revealed four distinct clinical phenotypes: Severe Cavitary ( n = 354), Mild Localized ( n = 300), High ADR Incidence ( n = 144), and Comorbidity-Dominant ( n = 63). Adverse outcome rates varied substantially across these subgroups (41.8%, 26.0%, 50.0%, and 63.8%, respectively). Subgroup analyses identified different combinations of factors associated with adverse outcomes, including cavity severity, age, ADR grade, and specific comorbidities. Older adults with rifampicin-sensitive PTB showed substantial clinical heterogeneity, and factors associated with adverse treatment outcomes varied across the identified clinical subgroups.These findings provide a basis for further research on subgroup-oriented management strategies in older adults with PTB.