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

Objective To 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). Design Systematic review. Study selection Ten 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 synthesis Data 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. Results Of 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. Conclusions PPM 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 registration PROSPERO CRD42021289509. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement CHORUS funded by UK Aid, from the UK Government, Grant 301132 ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data analysed during this study are included in this published article and its supplementary information files.