Cost-effectiveness of integrating paediatric tuberculosis services into child healthcare services in Africa: a modelling analysis of a cluster-randomised trial

Abstract

Background: In 2021, over one million children developed tuberculosis, resulting in 214 000 deaths, largely due to inadequate diagnosis and treatment. The diagnosis and treatment of tuberculosis is limited in most high-burden countries because services are highly centralised at secondary/tertiary levels and are managed in a vertical, non-integrated way. To improve case detection and treatment among children, the World Health Organisation (WHO) recommends decentralised and integrated tuberculosis care models. The Integrating Paediatric TB Services Into Child Healthcare Services in Africa (INPUT) stepped-wedge cluster-randomised trial evaluated the impact of integrating tuberculosis services into healthcare for children under five in Cameroon and Kenya, compared with usual care, finding a 10-fold increase in tuberculosis case detection in Cameroon but no effect in Kenya.

Methods: We estimated intervention impact on healthcare outcomes, resource use, health system costs and cost-effectiveness relative to the standard of care (SoC) using a decision tree analytical approach and data from the INPUT trial. INPUT trial data on cascades, resource use and intervention diagnostic rate ratios were used to parametrise the decision tree model. Health outcomes following tuberculosis treatment were modelled in terms of mortality and disability-adjusted life-years (DALYs).

Findings: For every 100 children starting antituberculosis treatment under SoC, an additional 876 (95% uncertainty interval (UI) -76 to 5518) in Cameroon and -6 (95% UI -61 to 96) in Kenya would start treatment under the intervention. Treatment success would increase by 5% in Cameroon and 9% in Kenya under the intervention compared with SoC. An estimated 350 (95% UI -31 to 2204) and 3 (95% UI -22 to 48) deaths would be prevented in Cameroon and Kenya, respectively. The incremental cost-effectiveness ratio for the intervention compared with SoC was US$506 and US$1299 per DALY averted in Cameroon and Kenya, respectively.

Interpretation: Although likely to be effective, the cost-effectiveness of integrating tuberculosis services into child healthcare services depends on baseline service coverage, tuberculosis detection and treatment outcomes.

Keywords: Health economics; Mathematical modelling; Paediatrics; Treatment; Tuberculosis.

Figure 1. Conceptual diagram of the model used to estimate the impact and cost-effectiveness of integrating paediatric tuberculosis services into child healthcare services in Cameroon and Kenya. (a) The use of risk ratio estimates to model changes in tuberculosis diagnosis under the intervention. (b) The impact of the intervention on the case fatality rate. (c) The care cascade for tuberculosis modelled. The red lines describe changes in case detection activities under intervention. The green arrows show changes in mortality under the intervention. ATT, antituberculosis treatment; CFR, case fatality rate; RR, risk ratio; TB, tuberculosis.

Figure 2. The cascade of care for initial care-seeking, TB symptom screening and diagnosis for children attending healthcare facilities in the INPUT study by country, age and model of care. Data are presented per 10 000 children seeking care at healthcare facilities. The red cross indicate the number of children tested on Xpert. The green plus sign indicate the number of children successfully treated. DS-TB, drug-susceptible tuberculosis; INPUT, Integrating Paediatric TB Services Into Child Healthcare Services in Africa; TB, tuberculosis.

Figure 3. Cost-effectiveness acceptability curves for the intervention in comparison to the standard of care. The figure shows the probability that an intervention is cost-effective (y-axis) in each country, based on the proportion of simulations in which the comparison of the intervention to the standard of care falls below the cost-effectiveness threshold (y-axis). DALY, disability-adjusted life-year.