To compare the effectiveness and cost-effectiveness of a CAD-only tuberculosis screening strategy versus a CAD-plus-CRP strategy.
Approach:
Study Design: A pragmatic community trial involving over 20,000 adults in Lesotho and South Africa, comparing two screening algorithms within the same participants.
Participants: 20,023 participants aged 18 years or older, enrolled from Sept. 26, 2022, to Sept. 4, 2024.
Screening Strategies: Participants underwent digital chest x-rays analyzed with CAD4TBv7 software; CAD-only strategy versus CAD plus CRP testing.
Outcome Measures: Primary outcome was tuberculosis detection; cost analysis was performed due to noninferiority not being demonstrated.
Key Findings:
CAD-only detected tuberculosis in 94.5% of cases compared to 82.2% with CAD plus CRP.
CAD plus CRP was 37% more expensive per case detected ($7,486 vs $5,454).
46% of participants with confirmed tuberculosis had no main symptoms.
Interpretation:
The CAD-plus-CRP strategy was more costly and did not demonstrate noninferiority in tuberculosis detection compared to CAD alone.
Limitations:
Site-specific adjustments to CAD thresholds due to x-ray equipment issues.
Missing outcomes for some participants.
Cost estimates based on trial conditions rather than routine implementation.
Conclusion:
CAD alone is an effective and economically viable tuberculosis screening strategy in high-burden areas.
