Project Details

Tuberculosis (TB) remains a leading infectious disease killer globally despite the availability of robust diagnostics, effective prevention, and treatment. Poor implementation of comprehensive TB programs and HIV infection remain drivers of ongoing high TB rates in high burden countries such as South Africa. In South Africa there are many losses in the TB care cascade; an estimated 95% of individuals with TB access testing, yet only 82% are diagnosed, 70% initiate treatment, and 53% successfully complete treatment. However, it is also imperative to screen and treat subclinical TB infection to lessen the vast reservoir of people at risk of progressing to TB disease, especially recent contacts of TB patients and people living with HIV (PLH). Using implementation science methods and building on the success of the improvements in the HIV care cascade “90-90-90” targets, our team has recently piloted two TB care cascades for drug-resistant and drug-sensitive TB and a TB prevention program in which 922 household contacts of patients with TB were screened.

This R01 award will adapt the Systems Analysis and Improvement Approach (SAIA), an evidence-based implementation strategy combining systems engineering tools into a clinic-level package for TB (SAIA-TB), expanding upon successful SAIA models trialed across a range of clinical settings in sub-Saharan Africa and the USA, and leverage the PI’s preliminary TB cascade analysis data in this setting. SAIA-TB will evaluate five comprehensive TB indicators (screening, diagnosis, linkage to care, treatment, and TB-free survival) to aid frontline healthcare workers and managers to optimize cascade performance through the use of a cascade analysis tool, process flow mapping, and continuous quality improvement cycles.

Our specific aims are to:

1. Evaluate the effectiveness of SAIA-TB on cascade optimization for patients with TB and high-risk contacts, specifically people living with HIV. We will use a stepped-wedge crossover trial to evaluate the impact of SAIA-TB on comprehensive TB care in 16 rural clinics. We hypothesize that SAIA-TB implementation will lead to a 20% increase in both screening and TB preventive treatment or TB disease treatment initiation during the 3-year intervention period.
2. Determine the drivers of SAIA-TB implementation variability across clinics. The implementation process will be evaluated using focus group discussions and key informant interviews with clinic staff and analyzed using the consolidated framework for implementation research, with additional data gathered from study logs to describe fidelity to SAIA-TB.
3. Assess the acceptability of comprehensive TB care among patients accessing care at clinics implementing SAIA-TB at each step of the cascade. We will use the theoretical framework for acceptability and the socioecological model to define acceptability and compare individual-, family- and systems-level barriers and facilitators to completing TB cascade steps among patients with and without HIV infection.

Methodology

We aim to assess the effectiveness of the SAIA-TB implementation strategy on TB cascade optimization, including screening, and successful TB preventive treatment and TB disease treatment initiation. This study includes all individuals screened for TB at rural clinics during the study period. The stepped-wedge crossover trial design assigns clinics as clusters, with randomization determining the sequence of intervention exposure (SAIA-TB). Data on TB care, including screening and treatment outcomes, will be collected from Ministry of Health forms and entered into our study REDCap database by study staff. The primary outcome is TB screening completion, TPT initiation, and TB treatment. Statistical analysis will include generalized linear mixed modeling, controlling for patient and clinic-level covariates.

Additionally, to determine drivers of success among clinics, we will hold focus groups and in-depth interviews (IDIs) will assess the implementation of SAIA-TB, using the CFIR framework to identify drivers of variability. Data will also be gathered from study logs and process mapping to identify system bottlenecks. Continuous quality improvement will be employed to prioritize and test micro-interventions. The analysis will test inter-rater reliability and readiness profiles at the clinic level.

Key Findings

From baseline data, in 2023 – 283,711 patients (77.9%) were screened for TB (range 58.1-100%) out of those registered at participating clinics. This screening rate improved at 6 of 16 clinics in 2023.

Yet, there is significant heterogeneity in TB case rates per facility. Between 2022 and 2023, screening declined, symptom reporting declined, diagnosis declined, and successful completion declined. However, testing and treatment initiation improved. Understanding reporting variation prior to intervention is critical. Overall trends in cascade performance are slightly better in 2022 than 2023.