Piloting new interventions for tuberculosis control in Indonesia

Yodi Mahendradhata

Proefschrift voorgelegd aan de Faculteit Geneeskunde en Gezondheidswetenschappen tot het verkrijgen van de graad van Doctor in de Medische Wetenschappen

Gent, 15 december 2009

Promotor:

Prof. Dr. Patrick Van der Stuyft

Vakgroep Maatschappelijke Gezondheidkunde, Universiteit Gent, Departement Volksgezondheid, Eenheid Epidemiologie en Ziektebestrijding, Instituut voor Tropische Geneeskunde Antwerpen

Co-Promotor:

Prof. Dr. Marleen BoelaertDepartement Volksgezondheid, Eenheid Epidemiologie en Ziektebestrijding, Instituut voor Tropische Geneeskunde Antwerpen

 

 

SummaryWorldwide, there were 9.27 million new tuberculosis (TB) cases (139 per 100,000 population) in 2007, including 1.37 million (14.8%) HIV-positive cases. In the same year, there were 1.3 million deaths among HIV-negative TB cases, and additionally 456,000 deaths occurred among HIV-positive TB cases. This makes TB a leading cause of death from an infectious disease, especially in Africa and Asia. The most populous countries of Asia harbor the largest absolute number of all TB cases: India, China, and Indonesia rank first

to third respectively. Beyond the African region, most HIV-positive TB cases (11%) are in South-East Asia.

Global TB control relies on the six-point stop TB strategy recommended by WHO: (1) pursue high-quality DOTS (Directly Observed Treatment, Short-course) expansion and enhancement; (2) address TB-HIV, multi-drug resistant TB (MDR-TB) and other challenges; (3) contribute to health system strengthening; (4) engage all care providers; (5) empower people with TB, and communities; and (6) enable and promote research. However, the supporting evidence for some of these recommendations could still be augmented, and the know-how gap remains wide.

We aimed to contribute to addressing these important challenges for TB control in a resources constrained setting. We conducted operational research on the feasibility of HIV testing among TB patients and the effectiveness and cost-effectiveness of engaging private practitioners (PPs) for TB case detection and treatment in Indonesia.

With regard to the challenge of addressing the threats of an emerging TB-HIV dual epidemic in Indonesia, our specific objectives were: (1) to determine the HIV prevalence among TB patients in Jogjakarta province; (2) to pilot Voluntary Counseling and Testing (VCT) among TB patients and assess the uptake; and (3) to document the barriers for VCT uptake in our study population.

As for engaging private practitioners, our specific objectives were: (1) to appraise the available evidence for effectiveness of Public-Private Mix (PPM) DOTS; (2) to assess the current and potential role of private practitioners in TB control in Jogjakarta province; (3) to model the effects of involving private practitioners in TB control compared to developing community interventions to increase case detection; and (4) to set up an intervention to engage private practitioners for TB case detection and treatment, and assess the actual effectiveness and costeffectiveness.

To attain the first set of objectives, we piloted an unlinked (without personal identifiers) anonymous HIV testing strategy among TB patients in Jogjakarta province and, additionally, provided access to linked (personal identifiers obtained and recorded) confidential testing through VCT. HIV prevalence among TB patients in the province was 1.9% (95% CI 1.6-2.2%), i.e. three times higher than the national estimate for that period. HIV infections were less frequently diagnosed among TB patients who attended public health centres than public hospital (OR 0.15; 95% CI 0.03-0.70). Of all the TB patients whom were offered unlinked anonymous testing, 77.9% (95% CI 75.6-80.1%) accepted. In contrast, of all the TB patients whom were offered linked confidential testing, only 4.1% (95% CI 3.1-5.3%).actually reached the VCT centre. An important underlying factor was providers’ poor knowledge regarding HIV. We also showed that the main barriers perceived by patients were the inconvenience for accessing VCT (e.g. opportunity cost of taking time to travel to VCT centres and the nuisance of undergoing the lengthy procedures) and fear of knowing the test result. Stigma did exist, but apparently did not play much role in VCT uptake.

With regard to Public-Private Mix DOTS, we first reviewed the key references on the effectiveness. We found that the effectiveness of this strategy has not been convincingly demonstrated: the literature showed mixed results. This may point to the importance of contextual factors. We investigated these factors through two surveys covering Jogjakarta province: one on care seeking behaviour in TB patients and one on TB case detection and management in private practitioners. A primary health centre was the first choice provider for most (38.7%) TB patients, followed closely by private practitioners (27.3%). The remaining patients opted for hospitals, chest clinics and traditional care providers.

Many private practitioners (45.2%) always relied on the National Tuberculosis control Programme (NTP) services for diagnosis. The majority (63.6%) always referred confirmed cases for treatment, mainly (71.4%) to the National TB control Programme services. Most private practitioners (72.7%) who treated TB patients themselves did not prescribe the National TB control Programme standard regimen. We further revealed that the TB case load per individual private practitioner in Jogjakarta province is low: 5 suspects per private practitioner per year (95% CI 3-20). This suggested that engaging private practitioners in our setting would only marginally improve the overall TB case detection rate. Notwithstanding, using mathematical modeling, we then demonstrated that an intervention that results in more referrals of TB suspects to DOTS facilities for both diagnosis and treatment could yield higher treatment success.

Subsequently, we set up an intervention to engage private practitioners to refer TB suspects to health centres for diagnosis and treatment between May 2004 and April 2005. Private practitioners referred 1064 TB suspects, of which 57.5% failed to reach a health centre. The smear-positive rate among patients reaching a health centre was 61.8%. In total, 280 out of 1306 (21.4%) new smear-positive cases enrolled in the National TB control Programme were detected through this private practitioner strategy. Per smear-positive case successfully treated, the average cost-effectiveness ratio (ACER) for the health centre strategy and the incremental costeffectiveness ratio (ICER) for the private practitioner strategy were USD 321.66 (95% CI 190.71-342.99) and USD 351.66 (95% CI 322.84-601.33) respectively. Using the estimated marginal cost for a successfully treated case in the National TB control Programme (USD 427.73) as a willingness-to-pay threshold, we estimate the probability that the private practitioner strategy is cost effective at 66.8%. This suggests that involvement of private practitioners can contribute to TB control and can be incrementally cost-effective, albeit under specific conditions.

In view of our results, we recommend routine implementation of unlinked anonymous HIV testing among TB patients in low HIV prevalence setting, where the incidence starts increasing. It is highly acceptable, feasible and would serve well surveillance purposes, but it will not facilitate access to HIV care. The uptake of linked confidential VCT among TB patients being disappointingly low in such a setting, introduction of this latter strategy must be preceded by improving its acceptability. Taking into account resource constraints, we suggest that it would constitute a reasonable way forward to concentrate linked confidential HIV testing for TB patients in hospitals with well functioning VCT and DOTS services. However, provider’s knowledge on HIV should be improved first, conditions for effective communication and patient-provider interaction must be created, and VCT services should provide test results on the same day.

The policy implications of our research on engaging private practitioners are possibly more clear cut. We demonstrated that the pre-condition for cost-effective Public-Private Mix DOTS, and for sustainable TB control, remains an effective and efficient public DOTS programme. There is still scope for efficiency gains in the public service in Indonesia and these must be realized before expanding DOTS to private providers. Also, before scaling up a strategy to engage private practitioners in TB suspect referral, which - as we demonstrated - is incrementally cost-effective, the National TB control Programme must also take into account the cost-effectiveness of alternative DOTS expansion policy options. A substantial load of TB cases are managed in hospitals and chest clinics, many of them public, which are not yet offering DOTS. Engaging these providers, that are closer to the National TB control Programme’s sphere of influence, could arguably be more fruitful.

Our results and recommendations may not be directly applicable to other settings where the TBHIV epidemiology, health system characteristics or socio-economic context differs. However, generalization can be considered at least qualitatively to other high TB burden settings, particularly in Asia, with a low-middle income economy, low HIV prevalence, substantial presence of private practitioners and relatively well functioning DOTS services in the public sector. Notwithstanding, the National TB control Programme need to ensure that internationally recommended TB control strategies and recommendations for their implementation are in line with local realities. Operational research and critical evidence-based reflection, planning and policy setting are necessary for effective, equitable and sustainable TB control, in any context.