Effects of conditional cash transfers and pre-test and post-test tuberculosis counselling on patient outcomes and loss to follow-up across the continuum of care in South Africa: a randomised controlled trial.

BACKGROUND: Economic and behavioural factors lead to poor outcomes in patients with tuberculosis. We investigated the effects of a package of interventions consisting of pre-test and post-test tuberculosis counselling with conditional cash transfers on patient outcomes in adults undergoing investigation for pulmonary tuberculosis.

METHODS: This pragmatic, open-label, individual randomised controlled trial was done in nine clinics in Johannesburg, South Africa. Participants (aged ≥18 years) undergoing investigation for tuberculosis were randomly assigned (1:1) to the intervention group or control group (standard of care) via permuted block randomisation, stratified by clinic; group assignment was concealed using opaque envelopes. The intervention group received pre-test and post-test tuberculosis counselling, and for participants diagnosed with rifampicin-susceptible tuberculosis, a digital payment (R150; approximately US$10) at treatment initiation and each monthly treatment visit. Payments were contingent on timely attendance: 14 days from initial sputum sample collection and within 7 days on either side of their scheduled monthly appointment. The primary endpoint was successful patient outcome (patients who were cured or completed treatment) or unsuccessful patient outcome (pretreatment loss-to-follow-up, on-treatment loss-to-follow-up, development of rifampicin-resistant tuberculosis while on treatment, treatment failure [ie, smear or culture positive at 5 months or later after commencing treatment], or death). The primary outcome was analysed in the modified intention-to-treat population, defined as all randomly assigned participants with rifampicin-susceptible tuberculosis confirmed before the commencement of tuberculosis treatment. Weighted outcome prevalence, relative risks (RRs), and risk differences were calculated using a multivariable Poisson model with robust standard errors. This trial is registered with the Pan African Clinical Trials Registry (PACTR202410708311054) and is completed.

FINDINGS: Between Oct 25, 2018, and Dec 9, 2019, 4110 participants were enrolled and randomly assigned, 2059 to the intervention group and 2051 to the control group. 381 (9·3%) participants had microbiologically confirmed rifampicin-susceptible pulmonary tuberculosis (195 [9·5%] of 2059 in the intervention group vs 186 [9·1%] of 2051 in the control group; median age 37 years [IQR 30 to 45], 257 [67·5%] male, 124 [32·5%] female). At study closure, primary outcome data were available for 128 (65·6%) of 195 participants in the intervention group and 139 (74·7%) of 186 participants in the control group. 105 (82·0%) of 128 participants in the intervention group and 93 (66·9%) of 139 participants in the control group had a successful patient outcome; 23 (18·0%) of 128 participants in the intervention group and 46 (33·1%) of 139 participants in the control group had an unsuccessful patient outcome. The weighted regression analysis showed a substantial reduction in the risk of unsuccessful patient outcomes in the intervention group compared with the control group (weighted prevalence 15·9% vs 28·6%; RR in weighted population 0·52, 95% CI 0·33 to 0·82; risk difference in weighted population -14·1 percentage points, 95% CI -23·3 to -4·8). Pretreatment loss to follow-up was lower in the intervention group than in the control group (unweighted population: five [3·9%] of 128 participants vs 22 [15·8%] of 139 participants; risk difference in weighted population -9·6 percentage points, 95% CI -14·9 to -4·2).

INTERPRETATION: The package of interventions consisting of pre-test and post-test tuberculosis counselling with conditional cash transfers significantly reduced the risk of unsuccessful tuberculosis patient outcomes, bringing one of the 90-90-90 targets within reach (ie, achieving 90% tuberculosis treatment success). Furthermore, reduction in pretreatment loss to follow-up is expected to reduce transmission and lower incidence of the disease over time.

FUNDING: South African Medical Research Council, UK Medical Research Council, and Newton Fund.