Background:
South Africa's protracted battle with the dual epidemic of HIV and TB is well-documented. TB patients who smoke tobacco are often faced by low socio-economic status and alcohol dependence, with poor TB treatment outcomes. This paper reports on findings that inform the feasibility of scaling an intervention based on motivational interviewing and mhealth, delivered by lay health workers (LHWs), towards achieving tobacco and alcohol cessation and improving TB and HIV treatment adherence.

Methods:
A theory-driven, qualitative feasibility study was conducted in the Free State, North-West and Gauteng provinces of South Africa. Thirteen semi-structured interviews were conducted with district, provincial and national TB managers, and nine focus group discussions were conducted with LHWs and TB patients at the study sites. Transcribed data was thematically analysed in NVivo 11 and guided by Normalisation Process Theory.

Results:
The intervention package and its importance were generally understood among participants, though some had difficulty differentiating it from past and current government initiatives (Coherence). The intervention package does not require extensive re-alignment in terms of work roles, and participants were well-aligned to the introduction of LHWs in existing work spaces (Cognitive Participation). Little difficulties were foreseen in different stakeholders working together in adopting new practices, and the intervention was perceived to align well with government policies. It was noted that the LHWs would require extensive training and support (Collective Action). Measuring the effects post-intervention was perceived to possibly be hampered by fragmented health information systems (Reflexive Monitoring).

Conclusions:
The intervention package was suggested to have a fairly high level of feasibility, being well-supported by stakeholders and aligning well with key health system elements. The findings also illustrate the precarious nature of the challenge under focus, and suggest the necessity of a fair amount of sustained support, dynamism and flexibility in different sites for intervention success.