Background: Tuberculosis (TB) treatment initiation is a critical transition in the care cascade, yet subnational geographic and temporal patterns may be obscured by aggregated estimates. This study characterized patterns of documented TB treatment initiation in Lampung Province, Indonesia.

Methods: We conducted a retrospective observational study using routine TB surveillance data from January to December 2025. All patients residing in Lampung Province with documented treatment initiation were included. Demographic characteristics and monthly and district/city distributions were described. Geographic and temporal variation in treatment initiation counts across 15 districts/cities was assessed using negative binomial regression, with adjusted count ratios (CRs) and 95% confidence intervals (CIs).

Results: Among 20,314 patients, the median age was 46 years (IQR 26–60), 60.5% were male, and 33.7% were aged 45–64 years. Treatment initiations varied substantially geographically, with the highest proportion recorded in Bandar Lampung (15.9%), followed by Lampung Selatan (13.5%) and Lampung Tengah (11.6%). Geographic variation remained significant after adjustment for calendar month (p<0.001). Compared with Bandar Lampung, adjusted treatment initiation counts were lowest in Pesisir Barat (CR 0.11; 95% CI 0.09–0.13), Metro (0.12; 0.10–0.14), and Mesuji (0.13; 0.11–0.16). Temporal variation was also significant (p<0.001), with December showing the largest reduction relative to January (CR 0.68; 95% CI 0.58–0.78).

Conclusions: TB treatment initiation in Lampung showed marked geographic and temporal heterogeneity. These findings represent variation in recorded treatment volumes rather than treatment coverage. Linking surveillance records with diagnostic denominators, population data, and multi-year observations could strengthen subnational monitoring and guide locally targeted TB control strategies.