This qualitative descriptive study sought to explore the implementation of the PPM model and the provision of health insurance for tuberculosis care. The study design allowed for an in-depth understanding of the facilitators and barriers encountered by three stakeholder groups: tuberculosis patients, health workers/volunteers, and sub-metro TB coordinators. Data were collected through semi-structured interviews and focus group discussions (FGDs). By triangulating information across the different stakeholder groups, the validity of the findings was enhanced. The analysis followed the guidelines of the Consolidated Framework for Implementation Research (CFIR), which facilitated the interpretation of the findings within the relevant implementation contexts. The CFIR is a conceptual framework developed to guide the systematic assessment of different implementation contexts to identify key factors that may influence the implementation and effectiveness of a given intervention (20).

The PPM model was implemented in five sub-metropolitan (sub-metros) assemblies in Accra and four in Kumasi, the two major cities in Ghana from October 2018 to March 2020. These specific sub-metros have been selected based on the features of high-burden TB communities and low case detection rates. Despite having all the features of high-burden TB settings, the selected intervention metros in Accra and Kumasi carry 14% of the national population but reported only 9.8% of TB notification in 2017.

The PPM model intervention was implemented in 72 private health facilities, 69 pharmacies and Over-The-Counter Medicines Shops (OTCMS), and slum communities by the Aurum Institute Ghana (AIG) in collaboration with two local NGO partners – Ghana TB Voice Network (TBVN) and Afro Global Alliance (AGA). Key interventions involving public and private healthcare providers areas focused on: (1) intensified case finding in private health facilities, (2) intensified case finding in community pharmacies and over-the-counter medicine sellers (OTCMS), (3) community active case search in urban slums, and (4) contact tracing among index TB cases. The details, yield, and impact of each intervention have been previously described (21); however, we provide a brief overview of the interventions’ screening outcomes in Figure 1.

Health workers in private facilities were trained and supported to screen for TB at their Outpatient Departments (OPDs). Through the launch of “Know Your Lung” campaigns in all the sub-metros, trained community volunteers increased TB awareness and generated traffic to accredited private health clinics and community pharmacies as entry points for TB screening and case finding. Presumed patients were screened, tested, and those diagnosed with TB were enrolled in free TB treatment and NHIS to cover review consultations in private clinics. The community volunteers were also assigned to clinics, pharmacies, and the communities to refer presumptive TB cases for testing, transport samples, conduct home visits, and contact investigations.

Participants were purposively sampled to reflect the perspectives of three key stakeholder groups: (1) TB patients identified through the PPM intervention, (2) health workers and community volunteers engaged in the PPM interventions, and (3) sub-metro and facility-level TB coordinators in the PPM intervention areas.

Patients were recruited if they were currently on TB treatment or had recently completed treatment at one of the participating private healthcare facilities. Eligibility was verified using TB treatment cards and patient folders. Health workers and volunteers were selected from facilities and communities actively involved in screening, referral, and treatment activities. Implementers, comprising all sub-metro TB coordinators and facility-level TB coordinators in the intervention sites, were also approached to participate, given their direct involvement in project oversight and delivery.

Data collection took place from October 2019 to November 2022 at intervention facilities and communities involved. Semi-structured interview guides with open-ended questions were developed for each stakeholder group through a review of relevant literature on PPM and ACF implementation, informed by the study's conceptual framework and implementation outcomes of interest, and further refined through expert input. The guides were piloted and adjusted before data collection. The patient interview guide explored experiences with TB screening, diagnosis, treatment, and NHIS enrolment. The interview guides for health workers, volunteers, and coordinators explored various factors that influenced the implementation of the interventions and their outcomes, including intervention characteristics, acceptability, adoption, processes, sustainability, successes, challenges, and areas for improvement. Interview guides were translated into local languages (Twi and Ga) and back-translated into English to ensure accuracy and cultural relevance. To strengthen trustworthiness, triangulation was applied by drawing information from different stakeholder groups and validating patient inclusion through treatment cards and facility records.

A team of four qualified research assistants with at least a bachelor's or master's degree in public health were recruited. They received intensive training in qualitative research methods, interviewing techniques, and ethical conduct during a two-day preparatory workshop. Mock interviews were conducted during training to standardize approaches. Research assistants explained the study purpose to participants before interviews, emphasizing that the aim was to capture their lived experiences rather than test their knowledge.

All interviews and FGDs were conducted face-to-face in private spaces such as health facility offices, pharmacies, or homes, based on convenience and confidentiality. No invited participants declined; some requested rescheduling due to other commitments, which were accommodated. Interviews lasted 15–30 min, FGDs lasted 60–90 min.

All interviews were audio-recorded with the participants’ consent and were supplemented by field notes taken immediately afterward. These field notes included contextual information and observations that were important for data interpretation. Data collection was conducted iteratively, with interviews and FGDs continuing until no new information or themes emerged, confirming saturation. In total, we conducted 54 exit interviews with TB patients and key informant interviews with seven sub-metro TB coordinators and 44 facility-level TB coordinators. Additionally, we organized four FGDs with health workers (n = 53) and two with volunteers (n = 18), taking place in both Accra and Kumasi to capture shared experiences and group dynamics. The overview of the study participants interviewed is presented in Table 1.

This exploratory approach allowed for diverse perspectives to be documented, ensuring a deeper understanding of both patient experiences and implementation dynamics within the PPM model.

The interviews and discussions were audio-recorded and transcribed verbatim by the research assistants and imported into NVivo qualitative data analysis software. Field notes were taken after every FGD and used in the analysis. To ensure anonymity and confidentiality, interviewees were coded by as numbers, and identifiers were removed. Thematic content data analysis of the transcripts was conducted by the any two of the authors HKM, DAB, BOA, MAO and cross-checked by EK to resolve any difference. To ensure all themes were identified, we used an inductive approach for thematic analysis. The authors discussed the final themes and categorized them into main themes and sub-themes based on their relevance to the research question posed by the study.

Following a thematic content analysis based on the final themes reported by participants in this study, we identified the CFIR as the most suitable model to provide a theoretical basis for interpreting the findings (21). The CFIR was chosen because it provides a comprehensive, multi-domain framework that is especially useful for evaluating complex public–private implementation models like the PPM intervention. Its ability to incorporate multiple stakeholder perspectives and systematically identify barriers and facilitators at the intervention, organizational, and individual levels made it the most suitable framework for understanding the implementation dynamics observed in this study. The CFIR consists of five major domains that may affect implementation including: (1) intervention characteristics; (2) outer setting; (3) inner setting; (4) characteristics of individuals; and (5) the implementation process. Definitions of the five domains and their subconstructs are further detailed in Supplementary Table S1. Within each domain, we assessed key factors or constructs of the intervention that influence implementation.

The research team acknowledges that our backgrounds and training may have influenced the study's design, data collection, and interpretation. The lead author is a public health researcher with experience in implementing health interventions. While this expertise enhanced the analysis, it also may pose a risk of bias. To mitigate this, five of the authors, who are mainly from diverse disciplines, participated in coding and validating findings. We held regular team discussions to ensure interpretations reflected participants’ perspectives, and field research assistants, not involved in TB service delivery, conducted most interviews to reduce social desirability bias.

Written informed consent was obtained from all study participants. Ethical clearance was obtained from the GHS Ethics Review Committee (GHS-ERC 00s/01/19) and an ethical vote from Ludwig-Maximilians-University Munich, Germany (23–0484). The interventions and operational research were funded by the TB REACH initiative of the Stop TB Partnership Wave 6. The sponsor had no role in the study design or data collection. The sponsor was involved in monitoring overall project performance through quarterly reports but was not involved in analysis, decision to publish, or preparation of the manuscript.

The successful implementation of the innovation (PPM model intervention) can be attributed to its key characteristics and the collaborative design that involved multiple stakeholders. Within the innovation characteristics domain, three constructs: origin, adaptability, and relative advantage, were particularly critical to successful implementation. The specific characteristics of the PPM model related to these constructs are discussed below.

The implementation of the PPM model for TB case detection and health insurance access was significantly influenced by external contextual factors. Participants described a combination of facilitators and barriers that affected collaboration, funding, and service delivery within the broader health system.

Participants emphasized that effective implementation of the interventions relied on the availability of resources, accessible knowledge and information, and clear communication. Conversely, they noted barriers such as inadequate incentives for workers despite a heavier workload, delayed communication from lead implementers to volunteers, and negative attitudes from some volunteers.

The individuals involved in implementing the PPM model, including project coordinators, TB officers, private healthcare providers, community volunteers, NHIS officers, and patients, played a crucial role in shaping how the intervention was delivered. Their motivation, engagement, and capacity either facilitated or constrained the effectiveness of the model.

The implementation process captures how the PPM intervention was planned, executed, and evaluated across private healthcare facilities and communities. Participants described several processes that facilitated effective implementation, as well as barriers that limited the smooth rollout and sustainability of the intervention.

This study adds value by presenting specific insights into identifying barriers and leveraging facilitators while suggesting ways to address barriers. A key strength lies in involving various stakeholder groups, including community volunteers, who are engaged in the PPM model throughout its design and implementation. The four multifaceted interventions proved easily adaptable by private healthcare providers. Capacity-building initiatives and access to diagnostic tools, such as GeneXpert machines and screening instruments, enabled early detection of TB cases. Collaboration with skilled data collectors, familiar with qualitative research, contributed to the production of high-quality, contextualized data for our study. Data triangulation and thorough discussions among research team members helped us gain a clearer understanding of the reliability, accuracy, and comprehensiveness of the data collected.

In terms of study limitations, it is worth noting that the capacity building, public engagement, and diagnostic components of the PPM model were externally funded, which affects its scalability and long-term sustainability. Mobilizing national resources to support all aspects of the PPM model interventions would be advantageous. Another limitation was the time gap between the project's conclusion and the study's duration, potentially introducing recall bias. To reduce this risk, interviewers employed probing techniques and cross-verified responses among participant groups to improve accuracy and ensure that accounts were as detailed and consistent as possible. Although issues with enrolling patients into the NHIS were a major barrier, we were unable to interview any NHIS personnel to understand this setback.