Public Private Mix (PPM) for Tuberculosis (TB) in Urban Health Systems in Least Developed, Low Income and Lower Middle Income Countries and Territories: A Systematic Review

ObjectiveTo assess the impact of Public-Private Mix (PPM) models for Tuberculosis (TB) diagnosis and treatment on health, process, and system outcomes within urban contexts of least developed, low Income, and lower-middle-income countries and territories (LMICs). DesignSystematic review. Study selectionTen electronic databases and research repositories, covering published and grey literature were searched on 15 August 2022. All primary studies on PPM models delivering TB services in urban health sectors of eligible countries were included. There were no restrictions applied by type of outcome measurement, publication date, or language. Data extraction and synthesisData were extracted on COVIDENCE and quality appraisals were carried out using the Mixed Methods Appraisal Tool (MMAT). Narrative synthesis was carried out by tabulating studies according to PPM model types (direct or interface), and assessing their performance on TB health, process (including cost-effectiveness) and system outcomes. ResultsOf the 55 included studies, covering quantitative (n=41), qualitative (n=5), and mixed-method (n=9) designs, the majority were from South-East Asia (n=36). PPM models had overall positive results on TB treatment outcomes, access and coverage, and value for money. They also promoted and improved TB health workers skills and service delivery. Most outcomes tended to favour interface models, albeit with considerable heterogeneity. Inconsistent implementation of NTP guidelines, uncoordinated referrals, and lack of trust among partners were identified as areas of improvement. Evidence was lacking on involvement of informal providers within PPM models. ConclusionsPPM models can be effective and cost-effective for TB care in urban LMIC contexts, particularly when levels of mistrust between public and private sectors are addressed through principles of equal partnership. The evidence indicates that this may be more achievable when an interface organisation manages the partnership. Study registrationPROSPERO CRD42021289509. Key messagesWhat is already known on this topic? -Although previous reviews have concluded overall improvements in Tuberculosis (TB) service outcomes with Public-Private Mix (PPM) implementation, they did not explicitly focus on urban contexts. Given the rate of urbanisation in low-and middle-income countries (LMICs) and the proliferation of PPs in urban areas, an up-to-date synthesis of the urban-specific evidence is needed for policy makers to design effective PPMs. What this study adds -Following recommended guidelines for conducting systematic reviews, we have narratively synthesised the evidence on the impact of TB-PPM models across health, process, and system outcomes within urban contexts of LMICs. -The implemented models appear cost-effective form the societal perspective and contribute to better TB treatment outcomes, and increased access and coverage. They also consistently promote TB health workers skills and service delivery. Mistrust between public and private sectors can be addressed through regular communications built on principles of equal partnership. -Although most results tend to favour models managed by interface organisations, the high heterogeneity and poor quality-scores of reporting studies must be considered. How this study might affect research, practice, or policy -This context-specific mixed-methods systematic review supports the implementation of PPM models for TB care in cities in LMICs. Providing decision-makers with evidence on the best design of PPM models is, however, less straightforward. -Our review supports the need for more studies assessing different PPM model types, as well as clearer and more standard reporting of models and their performances. -Very few studies mentioned the inclusion of informal providers in PPM-TB models. These providers have an important role in providing healthcare for vulnerable urban populations in the LMIC contexts. This gap must be addressed in future discussions and planning of TB-PPM models.