Classification of older pulmonary tuberculosis patients based on symptom clusters and differences in medication adherence: a latent class analysis

To explore the symptom experience subtypes of older pulmonary tuberculosis (PTB) patients during the intensive phase of treatment and to examine the association between different symptom subtypes and patient medication adherence. This study was a prospective, multicenter, observational cohort study conducted between September 1, 2025, and December 31, 2025. A total of 300 newly diagnosed older patients with pulmonary tuberculosis were consecutively recruited from 4 tuberculosis wards at Nantong Sixth People's Hospital and Nanjing Gaochun People's Hospital. At the end of the first month of anti-tuberculosis treatment, the burden of 17 symptoms was assessed using the Pulmonary Tuberculosis Patient Symptom Cluster Assessment Scale, and Latent Class Analysis (LCA) was employed to identify symptom experience subtypes. In the third month of treatment, treatment adherence was assessed for the 285 patients who completed follow-up using the self-developed and validated Treatment Adherence Scale for Tuberculosis (TAS-TB), with a score > 36 points defined as "good adherence". Univariate and multivariate logistic regression analyses were used to examine the association between symptom subtypes and the status of "good adherence". LCA identified three symptom subtypes: Class 1: Low Symptom Burden (42.7%, n=128); Class 2: High Psychogastrointestinal Symptoms (30.7%, n=92), characterized by the co-occurrence and high burden of symptoms such as depression, anxiety, nausea, and vomiting; Class 3: High Respiratory Symptoms-Dominant (26.6%, n=80). At the third month of treatment, patients in the "High Psychogastrointestinal Symptoms" subtype had the lowest rate of good adherence (45.7%), which was significantly lower than that of the "Low Burden" subtype (77.3%) and the "High Respiratory" subtype (60.0%) (P<0.001). Multivariate analysis showed that, after controlling for confounding factors, the "High Psychogastrointestinal Symptoms" subtype was the factor most strongly associated with poor adherence (aOR = 0.24, 95% CI: 0.13–0.45, P<0.001). Compared to patients in the "Low Burden" subtype, those in this subtype had significantly lower odds of achieving good adherence (adjusted odds ratio 0.24). Co-morbid diabetes mellitus was another independently associated factor (aOR=0.52, 95% CI: 0.28–0.97, P=0.037). In the present study sample, a specific subtype characterized by the co-occurrence of psychological and gastrointestinal symptoms was identified among older patients with pulmonary tuberculosis. This subtype was closely associated with poor treatment adherence. Early identification of this symptomatic phenotype may serve as a reference for stratified adherence management interventions.