Recorded comorbidities, tuberculosis coding patterns, neoplasm coding, inpatient discharge status, and costs in Indonesian Health Insurance Claims

Background Administrative claims can characterize tuberculosis (TB)-related care, but incomplete diagnostic histories and coding practices complicate interpretation of comorbidities and neoplasm codes. Evidence on these claims-recording patterns and associated inpatient and cost outcomes in Indonesia remains limited. Aim To examine whether recorded pre-index comorbidities were associated with pulmonary or extrapulmonary TB coding patterns and whether TB coding patterns and recorded comorbidities were associated with first observed malignant or benign neoplasm codes, inpatient discharge-coded death, and verified claim costs. Methods We analyzed a BPJS Kesehatan contextual sample with available claims from 2015 to 2024 and included patients whose first observed TB-coded claim occurred in 2024. Claim-level source files were linked and cleaned before derivation of a one-row-per-patient analytic file. The first observed TB code was not assumed to be the first clinical diagnosis. Pre-index conditions were identified in available records before the index date. Follow-up extended from the index date through 31 December 2024 and therefore varied by index date. Exploratory regression models assessed extrapulmonary coding, first observed neoplasm codes on or after index, discharge-coded death among inpatients, and verified claim costs. Results Among 10,770 patients, 4,365 (40.5%) had an extrapulmonary TB code. Pre-index malignancy was associated with an extrapulmonary TB coding pattern (adjusted odds ratio [aOR] 2.96, 95% confidence interval [CI] 2.07–4.24), whereas diabetes showed an inverse association (aOR 0.57, 95% CI 0.44–0.75). An extrapulmonary coding pattern was associated with first recorded malignant (aOR 2.55, 95% CI 1.88–3.45) and benign neoplasm codes (aOR 3.89, 95% CI 3.08–4.90). Because TB coding pattern incorporated all observed 2024 codes, its chronological relationship to neoplasm coding and other outcomes was indeterminate. Among 5,179 inpatients, 315 (6.1%) had discharge coded as death; pre-index malignancy was associated with this outcome (aOR 2.61, 95% CI 1.39–4.91) and with higher conditional verified costs among patients with positive costs (cost ratio 1.86, 95% CI 1.31–2.66). Conclusion Recorded comorbidities, TB coding patterns, neoplasm codes, inpatient discharge status, and verified costs co-occurred within this administrative dataset. These findings describe documentation and healthcare-use patterns, not chronological clinical sequences, disease incidence, or causal effects. Unequal observation time, surveillance intensity, and sparse comorbidity subgroups further limit interpretation.