Cost-effectiveness and budget impact of decentralising childhood tuberculosis diagnosis in six high tuberculosis incidence countries: a mathematical modelling study

Abstract

Background: The burden of childhood tuberculosis remains high globally, largely due to under-diagnosis. Decentralising childhood tuberculosis diagnosis services to lower health system levels could improve case detection, but there is little empirically based evidence on cost-effectiveness or budget impact.

Methods: In this mathematical modelling study, we assessed the cost-effectiveness and budget impact of decentralising a comprehensive diagnosis package for childhood tuberculosis to district hospitals (DH-focused) or primary health centres (PHC-focused) compared to standard of care (SOC). The project was conducted in Cambodia, Cameroon, Côte d'Ivoire, Mozambique, Sierra Leone, and Uganda between August 1st, 2018 and September 30th, 2021. A mathematical model was developed to assess the health and economic outcomes of the intervention from a health system perspective. Estimated outcomes were tuberculosis cases, deaths, disability-adjusted life years (DALYs) and incremental cost-effectiveness ratios (ICERs). We also calculated the budget impact of nationwide implementation. The TB-Speed Decentralization study is registered with ClinicalTrials.gov, NCT04038632.

Findings: For the DH-focused strategy versus SOC, ICERs ranged between $263 (Cambodia) and $342 (Côte d'Ivoire) per DALY averted. For the PHC-focused strategy versus SOC, ICERs ranged between $477 (Cambodia) and $599 (Côte d'Ivoire) per DALY averted. Results were sensitive to TB prevalence and the discount rate used. The additional costs of implementing the DH-focused strategy ranged between $12.8 M (range 10.8-16.4) (Cambodia) and $50.4 M (36.5-74.4) (Mozambique), and between $13.9 M (12.6-15.6) (Sierra Leone) and $134.6 M (127.1-143.0) (Uganda) for the PHC-focused strategy.

Interpretation: The DH-focused strategy may be cost-effective in some countries, depending on the cost-effectiveness threshold used for policy making. Either intervention would require substantial early investment.

Funding: Unitaid.

Keywords: Decentralisation; Diagnosis; Economic evaluation; Low- and middle-income countries; Paediatric tuberculosis.

Fig. 1

Simplified patient care pathways for the diagnosis and treatment of tuberculosis in children ∗Clinical exam, and, for a proportion of patients, Xpert on sputum or gastric aspirate, smear microscopy and CXR (in DH). “Xpert” in the DH-focused and PHC-focused strategies means “Xpert Ultra on NPA & stool”. We define “non-systematic assessment” as a step in the patient care pathway where a child presenting to the health facility may receive consideration for the possibility of having TB, depending on the clinician and patient. This screening may contain some of the components of our systematic screening and/or some form of clinical examination, but it would not be expected to follow the precise protocols that define the “systematic screening” and “clinical examination” in our intervention arms. TB, tuberculosis; DH, district hospital; PHC, primary health centre; CXR, chest X-ray.

Fig. 2

Screening to diagnosis cascade during the intervention period by decentralisation approach Percentages are bar height both with respect to the previous step (italic parentheses below bar), and also overall (normal font atop the bar).

Fig. 3

Cost-effectiveness acceptability curves by country for the district hospital-focused and primary health centre-focused strategies, each compared to the standard of care (in US$ per DALY averted). DALY, disability-adjusted life year.