2.1. Step 1: Identifying the Research Question

These questions were deemed sufficiently broad to capture the current state of knowledge while maintaining a manageable scope for the review. A preliminary search of the literature confirmed that a scoping review on this topic had not been previously conducted and that there was sufficient literature to warrant the review.

2.2. Step 2: Identifying Relevant Studies

We collaborated with a medical librarian to develop a comprehensive search strategy, including keywords, Medical Subject Headings (MeSH), and databases. The search strategy was designed to balance breadth and specificity, ensuring that all relevant studies were captured while minimizing the inclusion of irrelevant papers. The following databases were searched in March 2023: MEDLINE (Ovid), CINAHL, Embase, Web of Science, Cochrane Library, and Google Scholar. The search terms included variations of “point of care testing,” “primary care,” “adult patients,” and general types of POC devices (e.g., rapid tests, biomarker indicators, and bedside tests). The complete search strategy is available in the (Supporting Information, eTable 1).

Inclusion criteria were defined as primary, secondary, and gray literature written in English, available in full text, involving adult human participants, POC devices, and specified patient medical conditions. In addition, as previously mentioned, to build on Lingervelder et al.’s systematic review [10] and to ensure the currency of results particularly which relate to the POC devices and technologies, the literature was limited to papers published between 2018 and 2023. Exclusion criteria were studies not aligned with the conceptual framework, using laboratory or in-hospital POC devices, using self-test POC devices, providing general summaries of POC devices, or lacking actual application of the POC device. Editorials, protocols, and letters were also excluded. For studies that included both adult and pediatric populations, only data pertaining to adults were extracted when possible.

2.3. Step 3: Selecting Studies to be Included in the Review

We used EndNote Version 20 [22] for reference management and duplicate removal. To identify potentially relevant studies from the initial search results, we constructed and validated a high-performance machine learning classifier based on the bidirectional encoder representations from transformers’ (BERTs) architecture following the guidance of Marshall and Wallace [23]. The training process involved two reviewers (AA and RF) independently screening a random sample of 10% of the papers for inclusion, discussing discrepancies until a high level of agreement (≥ 90%) was achieved, and annotating titles and abstract records from the database. We assessed the model’s performance against our classification using precision, recall, specificity, and accuracy metrics. Following the validation, we employed the algorithm to analyze the titles and abstracts of the remaining publications, generating predictions for inclusion or exclusion. The inclusion criteria were then applied to the remaining papers, with one reviewer (AA) conducting the screening and the second reviewer (RF) verifying a random sample of 20% of the papers to ensure consistency. Disagreements were resolved through discussion; if not, disagreements were reconciled by a third reviewer (OU). The screening process involved reading both the title and abstract of each paper. If an abstract was not available, a full-text review was conducted. Screening papers by title alone was deemed insufficient, as the contents of a paper are not always well reflected in the title. The reasons for excluded articles will be highlighted in a PRISMA flowchart [24].

2.4. Step 4: Charting the Data

A data extraction form was collaboratively developed by the team, including items such as study type, clinical setting, study location, name and type of POC device, and disease type (Supporting Information, eTable 2). Additional categories were included to capture data specific to the research questions, such as the diagnostic accuracy of the POC devices and the impact on patient outcomes. An overview of the extracted data items is included in the Supporting Information. Data extraction for the included full-text articles was conducted using a bespoke online form on the Airtable website [25]. The extraction form was tested on 10% of the included articles. As the primary focus of this review is to map the evidence regarding POC devices used in primary care and following the JBI recommendations, we did not conduct a critical appraisal.

2.5. Step 5: Collating, Summarizing, and Reporting the Results

We conducted both numerical and thematic analyses of the extracted data. Numerical findings, such as the frequency of different types of POC devices and diseases, were presented in tables and charts to highlight the most salient aspects of the review. Descriptive statistics were used to summarize the characteristics of the included studies, such as study design, sample size, and geographical location. Thematic analysis was conducted using an inductive approach, following the six-phase process described by Braun and Clarke [26]. This involved familiarization with the data, generating initial codes, searching for themes, reviewing themes, defining and naming themes, and producing the report. Two reviewers independently (AA and OU) coded a subset of the extracted data, meeting regularly to discuss and refine the codebook. The entire dataset was then coded using the agreed-upon codebook, with the reviewers meeting to discuss any new codes or themes that emerged.

In this study, POC devices will be classified based on two primary criteria: their technological function and the specific disease conditions they were used to diagnose or monitor. This classification approach was designed to provide a comprehensive understanding of the diverse applications and roles of these devices in various clinical settings in primary care. The results of the scoping review were reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA–ScR) checklist [27] (Supporting Information, eTable 3). This included a flow diagram depicting the study selection process, a summary of the characteristics of the included studies, and a narrative synthesis of the key findings organized by themes.

3.1. Overview of the Included Studies

The number of published articles increased in 2020 and 2021, followed by a decline in the following years (Figure 2). The methodologies used in the articles were quantitative for 155 (92.6%) articles, qualitative for 7 (3.8%) articles, and 5 (3.6%) were mixed method studies. The top five countries with the highest publications were the United States (n = 17, 10.18%), the United Kingdom (n = 17, 10.18%), South Africa (n = 13, 7.78%), Spain (n = 12, 7.19%), and Australia (n = 9, 5.39%). The publications from high-income countries were (n = 108, 65.01%), compared to (n = 29, 18.93%) in upper-middle-income countries, (n = 20, 11.20%) in LMICs, and (n = 10, 4.86%) in low-income countries. Most of the studies were conducted in urban settings (n = 128, 79.7%), followed by rural settings (n = 18, 10.9%), both rural and urban settings (n = 20, 9.3%), and not mentioned (n = 1, 0.1%). A descriptive summary of the articles’ characteristics is mentioned in Table 1.

3.2. Overall Results

To answer the review questions, the 167 identified studies were categorized into two groups (i.e., types of POC devices and types of diseases) with multiple subcategories. The percentage and count of each subcategory are provided in Table 2. In addition, a list of POCTs’ names and manufacturers was added to the Supporting Information (eTable 4).

3.3. Types of POC Devices

3.4. Types of Diseases

As shown in Table 2, most of the studies (n = 78, 46.7%) targeted communicable diseases, followed by NCDs (n = 66, 39.5%) and others (n = 23, 13.8%).

4.1. Main Findings

This scoping review provides a comprehensive overview of the current landscape of POCT devices used in primary care settings. Our findings highlight the diverse range of POCT devices available, including biomarker tests, antibody tests, antigen tests, molecular tests, and emerging technologies such as microfluidic devices and biosensors. These devices are used for a wide spectrum of clinical applications, ranging from communicable to NCDs. Based on our review, we identified several key practice and research implications. First, there is a need to expand the use of POCT devices for NCDs in LMICs, where the burden of these diseases is rapidly growing and difficulties in accessing healthcare (e.g., cost and travel) are more prominent. In addition, integrating POCT devices with digital health technologies, such as electronic health records, telemedicine, and mobile health applications, could enhance the efficiency and effectiveness of primary care delivery. Furthermore, research is required to evaluate the clinical and cost-effectiveness of specific POCT devices in real-world primary care settings, as well as to develop and validate novel POCT technologies that are affordable, reliable, and user-friendly. Lastly, implementing POCT in primary care requires addressing various organizational, financial, and regulatory challenges, requiring collaborative efforts among researchers, clinicians, policymakers, and industry partners.

This scoping review highlighted the current practices and mapped the evidence regarding POC devices in primary care. One hundred sixty-seven studies met the inclusion criteria and were synthesized to answer the review questions. The number of publications related to POC devices increased in 2020 and 2021, commensurating with the rapid need to diagnose patients suspected of having coronavirus [200]. In addition, aligned with the global trend [15], many POC devices utilizing information technology were identified in this review (i.e., 9.2% of the included articles). Our findings show that POC devices are mainly used for communicable diseases, particularly for LMICs and mostly in urban healthcare settings. Moreover, unlike LMIC countries, POC devices used in high-income countries are targeting NCDS in mostly urban healthcare settings.

Our findings build on Tenorio-Mucha et al.’s [13] recent scoping review focused on POCT devices for cardiometabolic diseases. They found a substantial gap in evidence regarding POCT device application in LMIC. In their review, they found that more research had examined the application of POCT devices for communicable diseases than cardiometabolic conditions [13]. Moreover, despite the increasing morbidity and mortality of NCDs [201], Tenorio-Mucha et al. argue that POCT utilization for NCDs in limited-resource settings is at an “early stage.” In contrast to Tenorio-Mucha et al.’s review, the scope of our review was broader, and we did not focus on a particular disease. Their findings could be attributed to the increasing prevalence of infectious diseases in LMIC [202] with the poor availability and accessibility of the necessary diagnostics [203].

One of the Sustainable Development Goals (SDGs) targeted by the United Nations is Goal 3.4, which aims to reduce premature death caused by NCDs by one-third through prevention and treatment [204]. Our review findings show that 8.4% (n = 14) of all articles are focused on cardiovascular disease compared with 10% (n = 17) on diabetes. The number of publications is insufficient, considering that cardiovascular diseases are the leading cause of death globally [205]. This is concordant with Sohn et al. [206], Cals et al. [207], and Howick et al.’s [7] studies, and they found that diabetes mellitus was the most diagnosed condition by primary care doctors utilizing POCT. However, this does not reflect the current clinical needs for POCTs that allow primary healthcare providers to take immediate actions (e.g., treatment decisions or urgent referrals) [7, 208]. Studies conducted in the United Kingdom [208], the Netherlands [207], and an international survey on five high-income countries [7] found that primary care providers want to use POCTs to diagnose and reduce unnecessary referrals of patients with acute cardiac diseases. This might be linked to the increasing epidemic of Type 2 diabetes and obesity faced by primary care providers [206] and the fact that there are concerns regarding cardiovascular POCT accuracy [209].

4.2. Implications for Practice and Research

The findings of this scoping review mapped the current evidence and highlighted gaps that should be prioritized in future POC device applications. Despite the increasing burden of NCDs in LMICs [210], our review found that POC devices are primarily used for communicable diseases in these settings. Implementing POC devices for NCDs in LMICs could improve access to care, reduce health disparities, and enhance patient outcomes [211]. Future studies should engage diverse stakeholders, including patients, communities, and healthcare providers, to codesign, deploy, and evaluate POC testing interventions that are culturally appropriate, socially acceptable, and economically viable [212, 213]. In addition, research is needed to build the evidence base on the role of POC devices in advancing health equity and social justice in primary care.

POC devices’ integration with digital health technologies could enhance the efficiency and effectiveness of primary care delivery. Our review identified several studies that used POC technologies, such as CDSSs, risk prediction models, and mobile health applications. Integrating these technologies with POC devices could enable real-time data analysis, facilitate remote monitoring and consultation, and support evidence-based decision-making. Future research should explore the potential of emerging POC technologies, such as microfluidic devices, biosensors, and lab-on-a-chip systems, in primary care. These technologies offer the promise of miniaturization, multiplexing, and automation, which could enable more comprehensive and efficient testing at the point of care [214]. Although their performance, usability, and cost-effectiveness in primary care settings remain largely untested, a proof-of-concept study by Wang et al. demonstrated the potential of a smartphone-based microfluidic device for rapid and accurate detection of multiple infectious diseases [215].

The evaluation of the clinical and cost-effectiveness of POC devices in real-world primary care settings could help inform decision-making and resource allocation. While our review identified several studies that reported on the diagnostic accuracy and operational benefits of POC devices, there was limited evidence of their impact on clinical decision-making, patient management, and long-term health outcomes. Future research should conduct pragmatic clinical trials and observational studies to assess the effectiveness and cost-effectiveness of POC devices in different primary care populations and settings [216]. For example, a cluster-randomized trial by Boere et al. found that using POC C-reactive protein testing to guide antibiotic prescribing for acute respiratory infections in primary care reduced antibiotic use without compromising patient safety [49]. Similar studies are needed for other types of POC devices and clinical conditions to inform evidence-based practice and policy.

The implementation of POC devices in primary care requires addressing various organizational, financial, and regulatory barriers. Several studies in our review reported challenges to implementing POC devices in primary care, related to training and support for healthcare providers, quality control and data management, reimbursement, and regulatory issues [217]. Overcoming these barriers requires collaborative efforts among policymakers, healthcare organizations, industry partners, and researchers [218]. In addition, applying implementation science frameworks and methods in evaluating barriers and enablers of POC device application will systematically facilitate effective and sustainable long-term adoption in different primary care contexts [219].

4.3. Study’s Strengths and Limitations

A key strength of this review is that we conducted a comprehensive search of multiple electronic databases and gray literature sources, using a broad range of search terms and a clear conceptual framework. This approach aimed to capture the breadth and depth of the available evidence on POC devices used in primary care settings. In addition, we followed a rigorous and transparent methodology based on the JBI guidance and the PRISMA–ScR checklist to systematically identify, select, and chart the relevant studies. This enhances the reproducibility and trustworthiness of our findings. Furthermore, we involved a multidisciplinary team of researchers, clinicians, and stakeholders throughout the review process to provide diverse perspectives and expertise on the topic.

This review has some limitations that should be acknowledged. Despite the comprehensiveness of our search strategy, we only included studies published in English, which may have excluded relevant research from non-English speaking countries. Given the global nature of the topic and the importance of POC testing in LMICs, this language restriction may limit the generalizability of our findings [220]. Second, we focused on studies published between 2018 and 2023 to provide an updated overview of the recent literature on POC devices in primary care. While this approach ensures the currency and relevance of our findings, it may have excluded earlier studies that could provide valuable insights into the historical development and adoption of POC testing in primary care. Third, a notable limitation of our review is that we were unable to access full texts for 265 papers (21% of potentially eligible studies) despite extensive efforts through institutional access and interlibrary loans. This relatively high proportion of inaccessible texts could potentially impact the comprehensiveness of our findings, particularly if these papers contained unique or contrasting evidence about POC device implementation in primary care settings. While our included sample of 167 papers still provided rich data and clear thematic patterns, suggesting adequate coverage of the topic, we cannot rule out the possibility that the inaccessible papers might have provided additional insights or alternative perspectives. Fourth, we only included studies that involved adult populations, which may have excluded relevant research on POC testing in pediatric primary care settings. While this population’s focus aligned with our research questions and the high burden of chronic diseases in adult populations, it may limit the applicability of our findings to children and adolescents. Lastly, we did not assess the methodological quality or risk of bias of the included studies, as this is not typically required for scoping reviews [221]. While we provide a descriptive overview of the study designs and methods used, we cannot draw conclusions about the internal validity or reliability of the individual studies. Despite these limitations, this scoping review provides a valuable and timely overview of the current landscape of POC devices used in primary care settings. The findings can inform future research, policy, and practice initiatives to optimize the implementation and impact of POC testing in primary care.