Effect of case detection strategies on the prognosis of tuberculosis patients in the state of São Paulo, Brazil, 2010-19: A retrospective cohort study.

Background: Despite existing recommendations, there is still a scarcity of evidence on the impact of active case finding strategies versus passive case finding strategies, especially with regard to the mortality of tuberculosis patients. Therefore, our aim was to estimate the effect of case detection strategies on the prognosis of tuberculosis patients.

Methods: We conducted a retrospective cohort study of 160,384 new cases of tuberculosis patients diagnosed between 1 January 2010 and 31 August 2019 in the state of São Paulo, Brazil. We classified exposure into: passive case finding (emergency room, outpatient clinics or hospital settings) and active case finding (institutions, community or contact investigation). The primary outcome was all-cause mortality, and the secondary outcome was a composite outcome with treatment outcomes. We investigated associations using logistic regression, allowing for municipality-level random effects.

Results: Compared with outpatient passive case finding, passive case finding in the emergency room and in the hospital showed higher odds of death (adjusted odds ratio [OR] 3.69; 95% CI: 3.47-3.93 and 4.47; 95% CI: 4.22-4.74, respectively) and unfavourable treatment outcomes (1.92; 95% CI: 1.84-1.99 and 2.06; 95% CI: 1.98-2.14, respectively). By contrast, patients detected through community-based active case finding and contact investigation showed lower odds of death (0.77; 95% CI: 0.61-0.97 and 0.71; 95% CI: 0.54-0.92, respectively) and unfavourable treatment outcomes (0.85; 95% CI: 0.77-0.95 and 0.82; 95% CI: 0.74-0.91, respectively).

Conclusion: Community-based active case finding and contact investigation were associated with better prognosis than passive strategies in tuberculosis patients. Our results highlight the importance of strengthening active case finding as a fundamental part of mitigating the disease burden and controlling tuberculosis.