Through a series of work packages, we have investigated a range of approaches that could improve the management and control of tuberculosis in socially excluded groups. In work package 1, we identified very high levels of latent tuberculosis infection and hepatitis C, HIV and hepatitis B in people experiencing homelessness in London and evidence of inadequate levels of hepatitis B vaccination. We have shown that, provided treatment uptake is > 50%, screening for latent tuberculosis infection among people experiencing homelessness would be cost-effective at a willingness-to-pay threshold of £20,000. This has led to NHS-funded commissioning of screening for latent tuberculosis in people experiencing homelessness alongside the Find&Treat service. The service is also screening for hepatitis C and offering influenza B vaccination, although at present this is largely funded through other research proposals and clear commissioning approaches need to be developed. In work package 2, we showed similar high rates of latent tuberculosis in prisoners but lower levels of blood-borne virus infection. Our evaluation of routine radiographic screening in a London prison demonstrated feasibility but showed that there are many barriers to implementing this approach in prisons. Within both homeless populations and prison populations, injecting drug users are a particularly high-risk group for tuberculosis and blood-borne viruses. In work package 3, we found that peer educators with experience of homelessness and tuberculosis were no better or worse than health-care workers at encouraging the uptake of screening. Peer educators continue to play an important role within the Find&Treat service, including encouraging the uptake of screening, engaging those identified with radiographs potentially indicating tuberculosis or other abnormal results and supporting the management of socially complex cases. In work package 4, we developed the capability to undertake rapid PCR-based investigation on the mobile radiographic unit to investigate those with radiographs potentially indicating tuberculosis. Although we were not able to deliver a RCT of effectiveness in this challenging high-throughput setting, the technology is now used selectively to support the work of the Find&Treat screening and outbreak investigation work. In work package 5, we undertook, to our knowledge, the world’s first RCT of smartphone-enabled VOT, showing it to be considerably more effective and cheaper in ensuring that treatment observation takes place over the course of treatment than the current standard of care for tuberculosis. This work has led to the service being commissioned across London and in some other parts of the UK. The work has also supported WHO to recommend the use of VOT as an alternative to DOT. In work package 6, we showed that VOT is cheaper to deliver than DOT.
We faced a series of difficulties in undertaking this research, which primarily involved challenges in recruiting socially excluded groups for consented research as well as logistical difficulties in conducting work outside mainstream NHS settings. These difficulties, to a large extent, mirror the challenges that socially excluded groups experience in accessing health services. Nevertheless, we were able to identify important approaches to improving management and control that have already influenced practice, demonstrating the value of funding research in these groups despite the challenges. Although focused in London, the results of our work are likely to be generalisable to other major urban settings where socially excluded groups, such as people experiencing homelessness, drug users and prisoners, have high levels of tuberculosis and poor outcomes. The VOT intervention also shows very wide potential applicability for improving adherence to tuberculosis treatment in settings across the world.
Recommendations for future research
- How can the uptake of treatment of latent tuberculosis infection be maximised in homeless populations?
- How can radiographic and latent tuberculosis infection screening programmes in prisons best be operationalised?
- How can identification and treatment of homeless populations, prisoners and drug users for hepatitis C best be maximised?
- How can prison and community tuberculosis care best be integrated to reduce loss to follow-up and treatment interruption?
- What is the effectiveness of VOT in high-incidence countries?
- Can VOT be used to support adherence in other conditions in socially complex groups (e.g. hepatitis C and mental health management)?