Integrating tuberculosis and noncommunicable diseases care in low- and middle-income countries (LMICs): A systematic review.

Background: Low- and middle-income countries (LMICs) are facing a combined affliction from both tuberculosis (TB) and noncommunicable diseases (NCDs), which threatens population health and further strains the already stressed health systems. Integrating services for TB and NCDs is advantageous in tackling this joint burden of diseases effectively. Therefore, this systematic review explores the mechanisms for service integration for TB and NCDs and elucidates the facilitators and barriers for implementing integrated service models in LMIC settings.

Methods and findings: A systematic search was conducted in the Cochrane Library, MEDLINE, Embase, PubMed, Bibliography of Asian Studies, and the Global Index Medicus from database inception to November 4, 2021. For our search strategy, the terms "tuberculosis" AND "NCDs" (and their synonyms) AND ("delivery of healthcare, integrated" OR a range of other terms representing integration) were used. Articles were included if they were descriptions or evaluations of a management or organisational change strategy made within LMICs, which aim to increase integration between TB and NCD management at the service delivery level. We performed a comparative analysis of key themes from these studies and organised the themes based on integration of service delivery options for TB and NCD services. Subsequently, these themes were used to reconfigure and update an existing framework for integration of TB and HIV services by Legido-Quigley and colleagues, which categorises the levels of integration according to types of services and location where services were offered. Additionally, we developed themes on the facilitators and barriers facing integrated service delivery models and mapped them to the World Health Organization's (WHO) health systems framework, which comprises the building blocks of service delivery, human resources, medical products, sustainable financing and social protection, information, and leadership and governance. A total of 22 articles published between 2011 and 2021 were used, out of which 13 were cross-sectional studies, 3 cohort studies, 1 case-control study, 1 prospective interventional study, and 4 were mixed methods studies. The studies were conducted in 15 LMICs in Asia, Africa, and the Americas. Our synthesised framework explicates the different levels of service integration of TB and NCD services. We categorised them into 3 levels with entry into the health system based on either TB or NCDs, with level 1 integration offering only testing services for either TB or NCDs, level 2 integration offering testing and referral services to linked care, and level 3 integration providing testing and treatment services at one location. Some facilitators of integrated service include improved accessibility to integrated services, motivated and engaged providers, and low to no cost for additional services for patients. A few barriers identified were poor public awareness of the diseases leading to poor uptake of services, lack of programmatic budget and resources, and additional stress on providers due to increased workload. The limitations include the dearth of data that explores the experiences of patients and providers and evaluates programme effectiveness.

Conclusions: Integration of TB and NCD services encourages the improvement of health service delivery across disease conditions and levels of care to address the combined burden of diseases in LMICs. This review not only offers recommendations for policy implementation and improvements for similar integrated programmes but also highlights the need for more high-quality TB-NCD research.