Precision geospatial targeting for cost-effective tuberculosis case finding in Eastern Uganda: a quasi-experimental study.

BACKGROUND

Universal community-based tuberculosis (TB) screening in high-burden settings is resource-intensive and inefficient, frequently missing cases and leading to suboptimal resource allocation. Integrating routine surveillance data with geospatial analytics offers a promising approach to enhance the efficiency and cost-effectiveness of active case finding.

OBJECTIVE

To evaluate whether integrating Uganda's electronic Case-Based Surveillance System (eCBSS) data with geospatial hotspot analytics improves the efficiency, yield and cost-effectiveness of integrated TB case finding (CAST+) in Eastern Uganda.

DESIGN

We conducted a quasi-experimental before-and-after study comparing a universal community screening campaign (September 2022) with a geospatially targeted campaign (March 2024) in Eastern Uganda.

METHODS

We analysed routine eCBSS data from 166 diagnostic and treatment units using a sequential two-stage geospatial approach in Quantum Geographic Information System (QGIS). Statistically significant hotspot parishes were identified using the Getis-Ord Gi* statistic (p < 0.05), followed by the prioritisation of villages reporting > 2 bacteriologically confirmed TB cases (March 2023-February 2024). Comparative effectiveness was assessed with a cluster-adjusted chi-square test (Rao-Scott correction). Cost-effectiveness was evaluated from the provider perspective using inflation-adjusted 2024 USD costs, disability-adjusted life years (DALYs) averted, cost-effectiveness ratios (CERs) and incremental cost-effectiveness ratios (ICERs).

RESULTS

The targeted strategy screened 49,373 individuals across 313 villages, compared with 627,082 in 3252 villages under the universal campaign, representing a 92.1% reduction in screening volume. Despite this, TB yield increased by 10% (1.68%-1.85%; p < 0.001). Total inflation-adjusted costs declined by 90.9% (from USD 62,804 to USD 5704), unit cost per TB case fell by 55.2% (USD 82.20-USD 36.80), and cost per DALY averted decreased from USD 4.72 to USD 2.11 (ICER: USD 5.39 per DALY averted). All diagnosed TB cases were initiated on treatment.

CONCLUSION

eCBSS-guided geospatial targeting improved efficiency, precision and cost-effectiveness of TB screening, supporting a shift from universal to targeted TB case finding, and provides programmatic evidence for high-value public health interventions in resource-limited settings.