Scaling up isoniazid preventive therapy in Zimbabwe: has operational research influenced policy and practice?

Setting: Following the operational research study conducted during the isoniazid preventive therapy (IPT) pilot phase in Zimbabwe, recommendations for improvement were adopted by the national antiretroviral therapy (ART) programme. Objectives: To compare before (January 2013-June 2014) and after the recommendations (July 2014-December 2015), the extent of IPT scale-up and IPT completion rates, and after the recommendations the risk factors for IPT non-completion, in 530 ART clinics. Design: Retrospective cohort study. Results: People living with the human immunodeficiency virus newly initiating IPT increased every quarter (Q), from 585 in Q 1, 2013 to 4246 in Q 4, 2015, with 5648 new IPT initiations in the 18 months before the recommendations compared to 20 513 in the 18 months after the recommendations were made. The number of ART clinics initiating IPT increased from 10 (2%) in Q 1, 2013 to 198 (37%) in Q 4, 2015. Overall IPT completion rates were 89% in the post-recommendation period compared with 81% in the pilot phase (P < 0.001). After adjusting for confounders, being lost to follow-up from clinic review visits 1 year prior to IPT initiation was associated with a higher risk of not completing IPT, while having synchronised IPT and ART resupplies was associated with a lower risk. Conclusions: Implementation of recommendations from the initial operational research study have improved IPT scale-up in Zimbabwe.