Evidence for using point-of-care diagnostics in the management of respiratory tract infections in primary care: a scoping review protocol

Introduction

Antimicrobial resistance (AmR) is predicted to be the next global health pandemic and is expected to become the leading cause of death by 2050¹. It has been projected by the Organisation for Economic Co-operation and Development (OECD) that over the next 30 years, 2.4 million people throughout Europe, North America and Australia will die because of AmR, and that this will cost up to USD 3.5 billion annually². One of the main causative but modifiable risk factors associated with AmR is inappropriate antimicrobial use³. The majority (80–90%) of human antimicrobial medicines prescribing takes place in primary care, prescribed by general practitioners (GPs) and dispensed by community pharmacists (CPs). However, up to 50% of this prescribing is deemed inappropriate^3–5. The inappropriate management (i.e. diagnosis and treatment) of respiratory tract infections (RTIs) is particularly problematic, with large variations reported between what is prescribed and what should be prescribed, when the viral aetiologies and self-limiting nature of most RTIs are considered⁶.

Improving the diagnostic certainly of RTIs in antimicrobial interventions is achieved by the use of point-of-care diagnostic tests (i.e. testing of patients at the time and place of care)⁷.

Point-of-care tests therefore help to ensure antimicrobials are only prescribed for those who have a bacterial infection, according to the outcomes of the test. Several point-of-care diagnostic tests can be used in the diagnosis of RTIs. Rapid antigen detection tests (RADT) can be used to detect group A Streptococcus, and report good sensitivity (86%; 95% CI 83–88) and specificity (96%; CI 94–97)^8,9. A Cochrane review by Cohen and colleagues noted that their use in the management of sore throats in primary care results in reductions (25%) in antibiotic prescribing when compared to clinical management alone¹⁰. Point-of-care diagnostic tests involving the detection of inflammatory markers such as C-reactive protein (CRP) and procalcitonin are used in the diagnosis of lower RTI and sepsis, respectively^11,12. A Cochrane review by Tonkin-Crine et al. found that point-of-care diagnostics using CRP testing and procalcitonin-guided management significantly reduced antibiotic prescribing for acute RTIs in primary care (RR 0.78 95% CI 0.66–0.92 and OR 0.1 95% CI 0.07–0.14, respectively)¹³.

The value of using these tests in general practice has also been assessed in health economic evaluations. For example, a study published in 2022 on the cost-effectiveness of CRP point-of-care testing in primary care examined the use of the tests by GPs to guide antibiotic prescribing and found that such prescribing was reduced¹⁴. Using a decision-analytic model and data from published studies, CRP POCT was compared to the usual practice of managing patients with RTI symptoms without CRP POCT over five years. The authors reported that CRP point-of-care testing helped to reduce antibiotic prescribing but that healthcare costs were greater, mainly due to the cost of CRP tests. However, they commented that further analysis of a potential CRP point-of-care testing programme over a longer time would be necessary to assess its clinical and cost-effectiveness impact.

Using point-of-care diagnostic tests in the management of RTIs could also have a positive impact on the workload of some primary care healthcare professionals. For example, a United Kingdom (UK) based service was provided by community pharmacists in Wales to test (using RADT to detect group A Streptococcus) and treat sore throats¹⁵. In total, 11,304 consultations were completed in pharmacies and 8256 (73.0%) of these met the threshold for RADT after a scoring system for sore throat symptoms was applied (FeverPAIN or Centor). Of the patients undertaking a RADT, 2449 (29.6%) tested positive and 2354 (28.5%) were given antibiotics. A total of 410 patients (3.6%) were given a RADT even though they did not meet the scoring criteria, and of these 54 (13.2%) tested positive and 52 (12.7%) were given antibiotics. The authors reported that, had this service not been available in pharmacies, 96% of the service users would have presented to their GP or the emergency setting. Overall, 2406/11,303 (21.3%) patients received antibiotics. This was lower than figures observed from consultations with GPs where rapid antigen detecting is not commonly used (90% of practices prescribe antibiotics for between 35% and 83% of sore throat consultations)¹⁶.

Point-of-care diagnostic testing has been found to be accurate. A recent systematic review identified studies which tested the accuracy of a biomarker among patients with acute cough or suspected community acquired pneumonia (CAP) and found that CRP was the most accurate for distinguishing CAP from other causes of lower RTI¹⁷. Further, in a cluster randomised controlled trial designed to assess whether point-of-care procalcitonin could reduce antibiotic prescribing in patients with lower RTIs in 60 Swiss general practices, the test was found to result in a 26% absolute reduction in the probability of prescription¹⁸.

Despite favourable evidence in support of their use, and the knowledge that point-of-care diagnostic tests are commonly used by patients themselves (e.g. to test for COVID-19), they are not routinely used by GPs or CPs in the management of RTIs in primary care. However, more research is needed to ascertain how such testing should be implemented. This was highlighted by a recent randomised controlled trial which tested the potential for point-of-care CRP testing in respiratory infections in a primary care setting in Vietnam¹⁹. The intervention group (24 health centres, n=18,621 patients) received point-of-care CRP testing plus routine care, while the control group (24 health centres, n=21,235) received routine care only. Intention to treat analysis showed that the proportion of patients prescribed antibiotics in the intervention group (93.1%) was lower than the control group (98.2%) (adjusted RR 0·83 [95% CI 0.66–0.93]. While only 2606 patients (14%) in the intervention group had undergone CRP testing, prescriptions were shown to have reduced further in the per-protocol analysis with 1859 patients (73.1%) receiving an antibiotic prescription (adjusted RR vs control 0.64 [95% CI 0.60–0.70]). The authors noted that barriers to implementation of CRP testing should be explored and suggested that challenges include difficulties in patients accessing the test (because they were treated remotely), as patients often assumed and expected that they would be prescribed an antibiotic and many were uncertain about having the CRP test.

There is also considerable variation in the use of point-of-care testing and in antibiotic prescribing throughout Europe. A recently published prospective audit of the management of RTIs involving 18 European countries, reported that some countries (e.g. Croatia) did not use any point-of-care diagnostics in the management of RTIs and relied on clinical presentation and opinion alone, while other countries (e.g. Norway) tested for group A streptococcal and/or CRP at point-of-care³. The proportion of patients prescribed antibiotics ranged from 18% in Denmark and Belgium to >50% in Ireland and Hungary. While using point-of-care diagnostics was not associated with lower antibiotic prescribing in this study, the authors concluded that using point-of-care diagnostics may enhance the quality of prescribing decisions made based on clinical grounds alone.

A European expert panel recently published recommendations on the role of CRP point-of-care testing in combatting the overuse of antimicrobials. Recommendations endorse the use of CRP point-of-care testing as being a ‘key tool’ in addressing antimicrobial over-use, but identify that reimbursement structures and the lack of guidelines on the use of CRP point-of-care tests are major barriers to the use of CRP point-of-care testing at national and international levels²⁰. Indeed, there is a lack of guidance on how any point-of-care diagnostic test should be used in the diagnosis of RTIs and the subsequent treatment of patients, either symptomatically or with antibiotics.

This scoping review therefore aims to synthesise the available evidence on use of point-of-care diagnostics in the management of RTIs in the primary care context to inform the development of best practice guidance for using point-of-care diagnostics in the management (i.e. diagnosis and treatment) of RTIs in primary care.

Methods

A scoping review was deemed the most suitable methodological approach to ensure that all available evidence regarding the use of point-of-care diagnostics in the management of RTIs in primary care and the recommended treatment strategies based on the outcomes of the point-of-care diagnostic test is retrieved. The Joanna Briggs Institute’s (JBI) approach to conducting scoping reviews has been adopted to ensure methodological rigour²¹. This approach is based on the framework originally developed by Arskey and O’Malley²², which was further refined by Levac and colleagues²³. This framework proposes that the following nine steps should be employed: (1) defining and aligning the objective/s and question/s; (2) developing and aligning the inclusion criteria with the objective/s and question/s; (3) describing the planned approach to evidence searching, selection, data extraction, and presentation of the evidence; (4) searching for the evidence; (5) selecting the evidence; (6) extracting the evidence; (7) analysis of the evidence; (8) presentation of the results and (9) summarising the evidence in relation to the purpose of the review, making conclusions and noting any implications of findings. Steps 1–3 inclusive are described in detail in this protocol. Steps 4–9 will be followed in the reporting of the scoping review. The PRISMA-P checklist has been used in the reporting of this protocol²⁴. The reporting of the review will be guided by the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for Scoping Reviews (PRISMA-ScR) checklist²⁵.

Defining and aligning the objectives and research questions

The overall aim is to summarise the evidence to inform the development of best practice guidance for using point-of-care diagnostic tests in the management (i.e. diagnosis and treatment) of RTIs in primary care, i.e. by GPs and/or CPs.

The specific objectives are to:

Developing and aligning the inclusion criteria with the objective/s

The planned approach to evidence searching, selection, data extraction, and presentation of the evidence

Presentation of the evidence

The search results will be reported in the final scoping review and presented in a Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for scoping review (PRISMA-ScR) flow diagram (Figure 1). Key findings will be presented in tabular format, which will be developed and refined throughout the data extraction process. The findings will be synthesised in a narrative format according to scoping review guidelines. The narrative summaries will be presented along with the tables and provide an overview of the evidence for each point-of-care diagnostic test, the healthcare professional using the point-of-care diagnostic test and treatment strategies based on the outcomes of each test. Gaps in the research evidence will also be identified.

Figure 1. PRISMA flow diagram for scoping review: Evidence for using point-of-care diagnostics in the management of respiratory tract infections in primary care.

Study status

The scoping review is currently at the full-text screening stage. A total of 13,201 studies were sourced from database searches. Of these, 3161 duplicates were removed leaving 10,040 titles for screening. After 9824 studies were deemed irrelevant, 216 full-text articles were passed to the full-text screening stage and when this is completed data extraction will begin.

Discussion

Using point-of-care diagnostic tests in the management of RTIs could serve as an important antimicrobial stewardship strategy to improve the appropriate management of RTIs and encourage more prudent use of antimicrobials in primary care. The lack of guidance to support their use has been identified as one of the barriers to their widespread use²⁰.

The findings of this scoping review will be used to produce draft guidance on using point-of-care diagnostics tests in the management of RTIs in primary care. The content of the draft guidance will include details on what point-of-care diagnostic tests should be performed (depending on symptomatology), who should provide the test, i.e. GPs/CPs/both, where the test should be provided (general practice/community pharmacy/both) and how and when outcomes of tests should be communicated within the primary healthcare team, i.e. between GPs and CPs and with patients. Guidance on the appropriate management, including when antibiotics are indicated and guidance on patient self-management, will also be included. This initial draft guidance will undergo a Delphi validation²⁹ process, where experts in the field of RTIs, antimicrobial stewardship, point-of-care diagnostics and primary care, i.e. GPs and CPs, will be asked to agree on the content of the guidance. Following agreement, views of GPs, CPs and patients will be sought to establish the perceived barriers and facilitators to using point-of-care diagnostic tests in the management of RTIs.