Health system barriers to implementation of TB preventive strategies in South African primary care facilities

BACKGROUND: Isoniazid preventive therapy (IPT) is a key component of TB/HIV control, but few countries achieve high IPT coverage. METHODS: Using a behavioural COM-B design approach, the intervention consisted of a training on IPT guidelines and tuberculin skin testing (TST), identification of the optimal IPT implementation strategy by the health care workers (HCWs) of 3 primary care clinics, and a 2-month mentoring period. Using routine register data, TST and IPT uptake was determined 3 months before and 5 months after the intervention. Records were reviewed to identify factors associated with IPT initiation and HCW fidelity to the guidelines. A survey among HCWs was conducted to determine barriers to IPT. RESULTS: Two clinics implemented TST-guided IPT for all clients receiving HIV care, one clinic decided against use of TST. According to routine register data, the proportion of clients initiating IPT increased substantially at the clinic not opting for TST (6% vs 36%), but minimally (34% vs 37% and 0.7% vs 3%) in the two other clinics. TST uptake did not increase (0 vs 0% and 0.5%). In addition to poor IPT uptake, HCW fidelity to investigation for TB and timing of IPT initiation was poor, with only 68% of symptomatic patients investigated and IPT initiation delayed to a median of 374 days post-ART initiation. In multivariate analysis, pregnancy (aOR 18.62, 95% CI 6.99–53.46), recent HIV diagnosis (aOR 3.65, 95% CI 1.73–7.41), being on ART (aOR 9.44, 95% CI 3.05–36.17), and CD4 <500 cells/mm(3) (aOR 2.19, 95% CI 1.22–4.18) were associated with IPT initiation. Time needed to perform a TST, motivating patients to return for TST reading, and low IPT patient awareness were the main barriers to IPT implementation. CONCLUSION: Despite using a behavioural intervention framework including training and participatory development of the clinic IPT strategy, HCW fidelity to the guidelines was poor, resulting in low TST coverage and low IPT uptake under primary care conditions. To achieve the benefits of IPT, health system level approaches including TST-free guidelines and sensitization are needed.