The added diagnostic value of five different C-reactive protein point-of-care test devices in detecting pneumonia in primary care: A nested case-control study

C-reactive protein point-of-care testing to guide antibiotic prescribing for respiratory tract infections

INTRODUCTION

Antimicrobial resistance is strongly correlated with the volume of antibiotics used. Most antibiotics are prescribed in primary care, mostly for respiratory tract infections (RTIs), and are often unneeded.

AREAS COVERED

The current knowledge regarding the use of C-reactive protein (CRP) rapid testing in primary care is outlined. A comprehensive literature search and narrative review of the evidence on CRP rapid testing for patients presenting with symptoms of RTIs was conducted to develop a holistic perspective on the subject. Relevant studies were identified through a PubMed search up to April 2025.

EXPERT OPINION

CRP testing is an effective, cost-efficient tool to reduce unnecessary antibiotic use for lower RTIs in primary care. This test should be included in guidelines and implemented when a clinician is uncertain about the prognosis of an infection. It should complement history taking and clinical examination before deciding to prescribe antibiotics, primarily to rule out serious infections, but should never be used as a standalone test. To tackle antimicrobial resistance, the reduction of unnecessary antibiotic use in acute RTIs is optimized with clear guidance, advanced communication training for clinicians, and delayed antibiotic prescribing strategies when applicable.

Current Diagnostic Techniques for Pneumonia: A Scoping Review

Community-acquired pneumonia is one of the most lethal infectious diseases, especially for infants and the elderly. Given the variety of causative agents, the accurate early detection of pneumonia is an active research area. To the best of our knowledge, scoping reviews on diagnostic techniques for pneumonia are lacking. In this scoping review, three major electronic databases were searched and the resulting research was screened. We categorized these diagnostic techniques into four classes (i.e., lab-based methods, imaging-based techniques, acoustic-based techniques, and physiological-measurement-based techniques) and summarized their recent applications. Major research has been skewed towards imaging-based techniques, especially after COVID-19. Currently, chest X-rays and blood tests are the most common tools in the clinical setting to establish a diagnosis; however, there is a need to look for safe, non-invasive, and more rapid techniques for diagnosis. Recently, some non-invasive techniques based on wearable sensors achieved reasonable diagnostic accuracy that could open a new chapter for future applications. Consequently, further research and technology development are still needed for pneumonia diagnosis using non-invasive physiological parameters to attain a better point of care for pneumonia patients.

Analytical performance and user-friendliness of four commercially available point-of-care devices for C-reactive protein

INTRODUCTION

Proper implementation of Point-of-Care testing (POCT) for C-reactive protein (CRP) in primary care can decrease the inappropriate use of antibiotics, thereby tackling the problem of growing antimicrobial resistance.

OBJECTIVE

The analytical performance and user-friendliness of four POCT-CRP assays were evaluated: QuikRead go easy, LumiraDx, cobas b 101 and Afinion 2.

MATERIALS AND METHODS

Imprecision was evaluated using plasma pools in addition to manufacturer-specific control material. Trueness was assessed by verification of traceability to ERM-DA474/IFCC in parallel to method comparison towards the central laboratory CRP method (cobas c 503) using i) retrospectively selected plasma samples (n = 100) and ii) prospectively collected capillary whole blood samples (n = 50). User-friendliness was examined using a questionnaire.

RESULTS

Between-day imprecision on plasma pools varied from 4.5 % (LumiraDx) to 11.5 % (QuikRead). Traceability verification revealed no significant difference between cobas c 503 CRP results and the ERM-DA474/IFCC certified value. cobas b 101 and Afinion achieved the best agreement with the central laboratory method. LumiraDx and QuikRead revealed a negative mean difference, with LumiraDx violating the criterion of > 95 % of POCT-CRP-results within ± 20 % of the comparison method. Regarding user-friendliness, Afinion obtained the highest Likert-scores.

CONCLUSION

The analytical performance and user-friendliness of POCT-CRP devices varies among manufacturers, emphasizing the need for quality assurance supervised by a central laboratory.

Adoption of C-reactive protein point-of-care tests for the management of acute childhood infections in primary care in the Netherlands and England: a comparative health systems analysis

BACKGROUND

The use of point of care (POC) tests varies across Europe, but research into what drives this variability is lacking. Focusing on CRP POC tests, we aimed to understand what factors contribute to high versus low adoption of the tests, and also to explore whether they are used in children.

METHODS

We used a comparative qualitative case study approach to explore the implementation of CRP POC tests in the Netherlands and England. These countries were selected because although they have similar primary healthcare systems, the availability of CRP POC tests in General Practices is very different, being very high in the former and rare in the latter. The study design and analysis were informed by the non-adoption, abandonment, spread, scale-up and sustainability (NASSS) framework. Data were collected through a review of documents and interviews with stakeholders. Documents were identified through a scoping literature review, search of websites, and stakeholder recommendation. Stakeholders were selected purposively initially, and then by snowballing. Data were analysed thematically.

RESULTS

Sixty-five documents were reviewed and 21 interviews were conducted. The difference in the availability of CRP POC tests is mainly because of differences at the wider national context level. In the two countries, early adopters of the tests advocated for their implementation through the generation of robust evidence and by engaging with all relevant stakeholders. This led to the inclusion of CRP POC tests in clinical guidelines in both countries. In the Netherlands, this mandated their reimbursement in accordance with Dutch regulations. Moreover, the prevailing better integration of health services enabled operational support from laboratories to GP practices. In England, the funding constraints of the National Health Service and the prioritization of alternative and less expensive antimicrobial stewardship interventions prevented the development of a reimbursement scheme. In addition, the lack of integration between health services limits the operational support to GP practices. In both countries, the availability of CRP POC tests for the management of children is a by-product of the test being available for adults. The tests are less used in children mainly because of concerns regarding their accuracy in this age-group.

CONCLUSIONS

The engagement of early adopters combined with a more favourable and receptive macro level environment, including the role of clinical guidelines and their developers in determining which interventions are reimbursed and the operational support from laboratories to GP practices, led to the greater adoption of the tests in the Netherlands. In both countries, CRP POC tests, when available, are less used less in children. Organisations considering introducing POC tests into primary care settings need to consider how their implementation fits into the wider health system context to ensure achievable plans.

Machine learning-assisted prediction of pneumonia based on non-invasive measures

Background

Pneumonia is an infection of the lungs that is characterized by high morbidity and mortality. The use of machine learning systems to detect respiratory diseases via non-invasive measures such as physical and laboratory parameters is gaining momentum and has been proposed to decrease diagnostic uncertainty associated with bacterial pneumonia. Herein, this study conducted several experiments using eight machine learning models to predict pneumonia based on biomarkers, laboratory parameters, and physical features.

Methods

We perform machine-learning analysis on 535 different patients, each with 45 features. Data normalization to rescale all real-valued features was performed. Since it is a binary problem, we categorized each patient into one class at a time. We designed three experiments to evaluate the models: (1) feature selection techniques to select appropriate features for the models, (2) experiments on the imbalanced original dataset, and (3) experiments on the SMOTE data. We then compared eight machine learning models to evaluate their effectiveness in predicting pneumonia

Results

Biomarkers such as C-reactive protein and procalcitonin demonstrated the most significant discriminating power. Ensemble machine learning models such as RF (accuracy = 92.0%, precision = 91.3%, recall = 96.0%, f1-Score = 93.6%) and XGBoost (accuracy = 90.8%, precision = 92.6%, recall = 92.3%, f1-score = 92.4%) achieved the highest performance accuracy on the original dataset with AUCs of 0.96 and 0.97, respectively. On the SMOTE dataset, RF and XGBoost achieved the highest prediction results with f1-scores of 92.0 and 91.2%, respectively. Also, AUC of 0.97 was achieved for both RF and XGBoost models.

Conclusions

Our models showed that in the diagnosis of pneumonia, individual clinical history, laboratory indicators, and symptoms do not have adequate discriminatory power. We can also conclude that the ensemble ML models performed better in this study.

Implementation factor mapping of a pilot study of point-of-care C-reactive protein testing for respiratory tract infections in community pharmacy

Background

Explicit consideration of implementation factors in community pharmacy service development may facilitate widespread implementation and sustainability.

Objectives

This study involved mapping the methodology for the pilot study of point-of-care C-reactive protein (CRP) testing to support pharmacists' management of respiratory tract infections in Western Australian pharmacies against an implementation factor framework, focussing on the resources and training program provided to participating pharmacy staff.

Methods

Phase 1 involved post hoc mapping of the pilot study methodology against the framework previously described by Garcia-Cardenas et al.; phase 2 was an a priori evaluation of the resources and training program, involving pre-training, post-training, and post-pilot questionnaires administered to pharmacists and pharmacy assistants/interns. A mixed model analysis compared pharmacists' responses at the three time points.

Results

Employment of comprehensive strategies to optimise service feasibility and sustainability was demonstrated across the five domains of ‘professional service’, ‘pharmacy staff’, ‘pharmacy’, ‘local environment’ and ‘system’; further consideration of ‘consumer’ or ‘patient’ factors is needed to address issues such as patient refusal. Study pharmacists (n = 10) and pharmacy assistants/interns (n = 5) reported high levels of satisfaction with the training (100% ‘good’/‘excellent’). Pharmacists reported significantly improved attitudes towards, confidence in, and knowledge about CRP testing and service provision from pre- to post-training (p < 0.05). Positive perceptions were maintained at the post-pilot time point.

Conclusions

Post hoc mapping of implementation factors highlighted potential strengths and deficiencies of the current service model. Systematic, prospective mapping, coupled with strategies to explicitly emphasise the patient perspective, may have value in optimising service implementation or modifying future service delivery models.

Does availability of point of care C-reactive protein measurement affect provision of antibiotics in a community respiratory service?

Antibiotic resistance presents a growing threat to health systems and patients at a global scale. Point of care (POC) C-reactive protein (CRP) measurement, as an adjunct to exacerbation assessment, has been studied in primary and secondary care and may represent a useful tool for community teams. A retrospective service review was conducted to determine the effect of CRP measurement on antibiotic provision in a community respiratory setting, with chronic obstructive pulmonary disease (COPD) and bronchiectasis exacerbations. This review compared antibiotic provision for COPD and bronchiectasis patients for those where CRP was measured versus those where it was not. It was found that antibiotic provision dropped by almost 25% points for COPD exacerbations, and almost 59% in bronchiectasis, when a CRP measurement was taken as a component of a respiratory assessment. Antibiotics were also provided at a greater amount based on symptom presentation. Therefore, it is concluded that CRP measurement correlates with a reduction in antibiotic provision, highlighting its use alongside symptom assessment in future work.

Point-of-care C-reactive protein testing service for respiratory tract infections in community pharmacy: a qualitative study of service uptake and experience of pharmacists

Background Targeted interventions in community pharmacies, such as point-of-care C-reactive protein testing, could reduce inappropriate antimicrobial consumption in patients presenting with symptoms of respiratory tract infections, although data regarding Australian pharmacists’ perspectives on its provision are limited. Aim To explore pharmacists’ experiences and perspectives of point-of-care C-reactive protein testing, including barriers and facilitators, influencing service provision and uptake. Method A point-of-care C-reactive protein testing service for patients presenting with respiratory tract infection symptoms was trialled in five purposively selected community pharmacies in metropolitan Western Australia. Two pharmacists from each pharmacy participated in one-to-one semi-structured telephone interviews, regarding pharmacist demographics, pharmacy characteristics, experience with the point-of-care C-reactive protein service and training/resources. Interviews were audio-recorded and transcribed. Data were imported into NVivo for thematic analysis. Results Interview durations ranged from 28.2 to 60.2 min (mean: 50.7 ± 10.2 min). Of the five themes which emerged, participants reported the point-of-care C-reactive protein testing was simple, fast, reliable and accurate, assisted their clinical decision-making and contributed to antimicrobial stewardship. A major factor facilitating service provision and uptake by consumers was the accessibility and credibility of pharmacists. Barriers included time constraints and heavy documentation. Participants believed there was a public demand for the service. Conclusion Given the global antimicrobial resistance crisis, pharmacists have an important role in minimising the inappropriate use of antimicrobials. The point-of-care C-reactive protein service was readily accepted by the public when offered. However, ensuring efficient service delivery and adequate remuneration are essential for its successful implementation.

Implementation and Use of Point-of-Care C-Reactive Protein Testing in Nursing Homes

OBJECTIVES

This study evaluated logistics, process data, and barriers/facilitators for the implementation and use of C-reactive protein point-of-care testing (CRP POCT) for suspected lower respiratory tract infections (LRTIs) in nursing home (NH) residents.

DESIGN

This process evaluation was performed alongside a cluster randomized, controlled trial (UPCARE study) to evaluate the effect of CRP POCT on antibiotic prescribing for suspected LRTIs in NH residents.

SETTING AND PARTICIPANTS

Eleven NHs in the Netherlands.

METHODS

Data sources for process data regarding intervention quality included a questionnaire among NH staff, logs, reports, and CRP POCT-analyzer records. Barriers and facilitators for implementation were assessed in focus group interviews with physicians and nurses from 3 NHs.

RESULTS

Correct patient selection for CRP POCT and generally continued CRP POCT use indicated good fidelity. The initial training and training of new employees seemed to fit the need, but some POCT-user group sizes had increased over time, which could have impeded frequent use. Users were generally satisfied with CRP POCT and perceived its use feasible and relevant. Facilitators for implementation were initial commitment and active initiation, followed by continued attention and enthusiasm for building routine practice and trust. Short lines of communication between staff, short distance to the POCT-analyzer, 24/7 coverage of staff, and a clear task division facilitated continued attention and routine practice.

CONCLUSIONS AND IMPLICATIONS

This process evaluation showed sufficient quality of providing CRP POCT in Dutch NHs. We processed findings of intervention quality and implementation knowledge into key recommendations for CRP POCT implementation in this setting. Future research could focus on CRP POCT use in countries with different organization of care in NHs.

Point-of-care C-reactive protein testing to support the management of respiratory tract infections in community pharmacy: A feasibility study

BACKGROUND

Point-of-care (POC) C-reactive protein (CRP) testing is employed in European primary care settings to differentiate viral from bacterial respiratory tract infections (RTIs) the latter, requiring referral for antibiotics. This service has yet to be trialled in Australian community pharmacy to support over-the-counter RTI management.

OBJECTIVES

To evaluate the feasibility, based on clinical and operational outcomes, of POC CRP testing to support Western Australian community pharmacists' management of RTIs.

METHODS

Patients with RTI signs and symptoms were recruited from June-August 2019 at 5 community pharmacies. Trained pharmacists made recommendations based on participants' POC CRP levels and routine clinical assessment. Participants completed questionnaires and telephone follow-ups on Days 3 (by pharmacists) and 5 (by researchers) post-testing. Service provision and uptake were assessed in 3 separate weekly tally sheets.

RESULTS

Clinical outcomes: CRP levels among the 131 participants recruited were: < 5 mg/L (bacterial infection unlikely; n = 60; 45.8%); 5-19 mg/L (bacterial infection possible if suggestive routine assessment; n = 52; 39.7%) and 20-100 mg/L (bacterial infection likely if suggestive routine assessment; n = 19; 14.5%). Pharmacists' management included over-the-counter medicines (131, 100%), self-care advice (125, 95.4%) and immediate general practitioner (GP) referral (15, 11.5%). Sixty-five percent (76/117) of participants had recovered by Day 5. Operational outcomes: The services was provided in 21.2% of eligible RTI presentations, representing a service uptake rate of 28.1%. Post-CRP testing, 50.9% (58/114) of participants had changed perceptions regarding their need for antibiotics, with 14.3% (16/112) subsequently intending to seek a GP prescription. Consumer satisfaction was high (100%) and most participants (93.4%, 123/131) would utilise the service again.

CONCLUSIONS

POC CRP testing was a feasible and well-accepted strategy to facilitate community pharmacy as a triage point for RTI. Consumer confidence in the pharmacists' advice, supported by CRP testing, potentially reduced unnecessary GP visits and antibiotic prescribing.

C-reactive protein influences the doctor's degree of suspicion of pneumonia in primary care: a prospective observational study

BACKGROUND

In primary care, the diagnosis of pneumonia is often based on history and clinical examination alone. However, a previous study showed that the general practitioner's degree of suspicion correlates well with findings on chest X-ray, when the C-reactive protein (CRP) value is known.

OBJECTIVES

The present study aimed to investigate to what extent the physician's degree of suspicion is affected by the CRP level when community-acquired pneumonia is suspected in primary care.

METHODS

A prospective observational study was conducted at five primary health care centres in Sweden between October 2015 and December 2017. Adult patients (n = 266) consulting their health care centre with symptoms of lower respiratory tract infection, where the physician suspected pneumonia, were included consecutively. Anamnestic information and findings from clinical examination were documented in a case report form. All patients were tested for CRP. The physicians rated their degree of suspicion as 'unsure,' 'quite sure,' and 'sure' before and after the CRP result.

RESULTS

The degree of suspicion of pneumonia changed in 69% of the cases; most often to a lower degree (40%). In 28% of the cases, there was no longer any suspicion of pneumonia after CRP.

CONCLUSION

Our results indicate that CRP testing highly influences the physician's degree of suspicion of pneumonia in primary care and that it seems to be of most value when not sure of the diagnosis.

The diagnostic accuracy of lung auscultation in adult patients with acute pulmonary pathologies: a meta-analysis

The stethoscope is used as first line diagnostic tool in assessment of patients with pulmonary symptoms. However, there is much debate about the diagnostic accuracy of this instrument. This meta-analysis aims to evaluate the diagnostic accuracy of lung auscultation for the most common respiratory pathologies. Studies concerning adult patients with respiratory symptoms are included. Main outcomes are pooled estimates of sensitivity and specificity with 95% confidence intervals, likelihood ratios (LRs), area under the curve (AUC) of lung auscultation for different pulmonary pathologies and breath sounds. A meta-regression analysis is performed to reduce observed heterogeneity. For 34 studies the overall pooled sensitivity for lung auscultation is 37% and specificity 89%. LRs and AUC of auscultation for congestive heart failure, pneumonia and obstructive lung diseases are low, LR− and specificity are acceptable. Abnormal breath sounds are highly specific for (hemato)pneumothorax in patients with trauma. Results are limited by significant heterogeneity. Lung auscultation has a low sensitivity in different clinical settings and patient populations, thereby hampering its clinical utility. When better diagnostic modalities are available, they should replace lung auscultation. Only in resource limited settings, with a high prevalence of disease and in experienced hands, lung auscultation has still a role.

C-Reactive Protein Testing to Guide Antibiotic Prescribing for COPD Exacerbations

BACKGROUND

Point-of-care testing of C-reactive protein (CRP) may be a way to reduce unnecessary use of antibiotics without harming patients who have acute exacerbations of chronic obstructive pulmonary disease (COPD).

METHODS

We performed a multicenter, open-label, randomized, controlled trial involving patients with a diagnosis of COPD in their primary care clinical record who consulted a clinician at 1 of 86 general medical practices in England and Wales for an acute exacerbation of COPD. The patients were assigned to receive usual care guided by CRP point-of-care testing (CRP-guided group) or usual care alone (usual-care group). The primary outcomes were patient-reported use of antibiotics for acute exacerbations of COPD within 4 weeks after randomization (to show superiority) and COPD-related health status at 2 weeks after randomization, as measured by the Clinical COPD Questionnaire, a 10-item scale with scores ranging from 0 (very good COPD health status) to 6 (extremely poor COPD health status) (to show noninferiority).

RESULTS

A total of 653 patients underwent randomization. Fewer patients in the CRP-guided group reported antibiotic use than in the usual-care group (57.0% vs. 77.4%; adjusted odds ratio, 0.31; 95% confidence interval [CI], 0.20 to 0.47). The adjusted mean difference in the total score on the Clinical COPD Questionnaire at 2 weeks was -0.19 points (two-sided 90% CI, -0.33 to -0.05) in favor of the CRP-guided group. The antibiotic prescribing decisions made by clinicians at the initial consultation were ascertained for all but 1 patient, and antibiotic prescriptions issued over the first 4 weeks of follow-up were ascertained for 96.9% of the patients. A lower percentage of patients in the CRP-guided group than in the usual-care group received an antibiotic prescription at the initial consultation (47.7% vs. 69.7%, for a difference of 22.0 percentage points; adjusted odds ratio, 0.31; 95% CI, 0.21 to 0.45) and during the first 4 weeks of follow-up (59.1% vs. 79.7%, for a difference of 20.6 percentage points; adjusted odds ratio, 0.30; 95% CI, 0.20 to 0.46). Two patients in the usual-care group died within 4 weeks after randomization from causes considered by the investigators to be unrelated to trial participation.

CONCLUSIONS

CRP-guided prescribing of antibiotics for exacerbations of COPD in primary care clinics resulted in a lower percentage of patients who reported antibiotic use and who received antibiotic prescriptions from clinicians, with no evidence of harm. (Funded by the National Institute for Health Research Health Technology Assessment Program; PACE Current Controlled Trials number, ISRCTN24346473.).

Development of practical recommendations for diagnostic accuracy studies in low-prevalence situations

OBJECTIVE

Low disease prevalence poses challenges for diagnostic accuracy studies because of the large sample sizes that are required to obtain sufficient precision. The aim is to collate and discuss designs of diagnostic accuracy studies suited for use in low-prevalence situations.

STUDY DESIGN AND SETTING

We conducted a literature search including backward citation tracking and expert consultation. Two reviewers independently selected studies on designs for estimating diagnostic accuracy in a low-prevalence situation. During a 1-day expert meeting, all designs were discussed and recommendations were formulated.

RESULTS

We identified six designs for diagnostic accuracy studies that are suitable in low-prevalence situations because they reduced the total sample size or the number of patients undergoing the index test or reference standard depending on which poses the highest burden. We described the advantages and limitations of these designs and evaluated efficiencies in sample sizes, risk of bias, and alignment with the clinical pathway for applicability in routine care.

CONCLUSION

Choosing a study design for diagnostic accuracy studies in low-prevalence situations should depend on whether the aim is to limit the number of patients undergoing the index test or reference standard, and the risk of bias associated with a particular design type.

Clinical features for diagnosis of pneumonia among adults in primary care setting: A systematic and meta-review

Pneumonia results in significant morbidity and mortality worldwide. However, chest radiography may not be accessible in primary care setting. We aimed to evaluate clinical features and its diagnostic value to identify pneumonia among adults in primary care settings. Three academic databases were searched and included studies that assessed clinical predictors of pneumonia, adults without serious illness, have CXR and have conducted in primary care settings. We calculated sensitivity, specificity, positive and negative likelihood ratios, diagnostic odds ratio of each index test and the pool estimates for index tests. We identified 2,397 articles, of which 13 articles were included. In our meta-analysis, clinical features with the best pooled positive likelihood ratios were respiratory rate ≥20 min⁻¹ (3.47; 1.46–7.23), temperature ≥38 °C (3.21; 2.36–4.23), pulse rate >100 min⁻¹ (2.79; 1.71–4.33), and crackles (2.42; 1.19–4.69). Laboratory testing showed highest pooled positive likelihood ratios with PCT >0.25 ng/ml (7.61; 3.28–15.1) and CRP > 20 mg/l (3.76; 2.3–5.91). Cough, pyrexia, tachycardia, tachypnea, and crackles are limited as a single predictor for diagnosis of radiographic pneumonia among adults. Development of clinical decision rule that combine these clinical features together with molecular biomarkers may further increase overall accuracy for diagnosis of radiographic pneumonia among adults in primary care setting.

C-reactive protein point of care testing in the management of acute respiratory infections in the Vietnamese primary healthcare setting - a cost benefit analysis

Aim

We assess the cost-benefit implications of C-reactive protein (CRP) testing in reducing antibiotic prescription for acute respiratory infection in Viet Nam by comparing the incremental costs of CRP testing with the economic costs of antimicrobial resistance averted due to lower antibiotic prescribing.

Findings

Patients in the CRP group and the controls incurred similar costs in managing their illness, excluding the costs of the quantitative CRP tests, provided free of charge in the trial context. Assuming a unit cost of $1 per test, the incremental cost of CRP testing was $0.93 per patient. Based on a previous modelling analysis, the 20 percentage point reduction in prescribing observed in the trial implies a societal benefit of $0.82 per patient. With the low levels of adherence to the test results observed in the trial, CRP testing would not be cost-beneficial. The sensitivity analyses showed, however, that with higher adherence to test results their use would be cost-beneficial.

A systematic evaluation of immunoassay point-of-care testing to define impact on patients' outcomes

Background Point-of-care testing has been developed to provide rapid test results. Most published studies focus on analytical performance, neglecting its impact on patient outcomes. Objective To review the analytical performance and accuracy of point-of-care testing specifically planned for immunoassay and to evaluate the impact of faster results on patient management. Methods A search of electronic databases for studies reporting immunoassay results obtained in both point-of-care testing and central laboratory scenarios was performed. Data were extracted concerning the study details, and the methodological quality was assessed. The analytical characteristics and diagnostic accuracy of six points-of-care testing: troponin, procalcitonin, parathyroid hormone, brain natriuretic peptide, C-reactive protein and neutrophil gelatinase-associated lipocalin were evaluated. Results A total of 116 scientific papers were analysed. Studies measuring procalcitonin, parathyroid hormone and neutrophil gelatinase-associated lipocalin reported a limited impact on diagnostic decisions. Seven studies measuring C-reactive protein claimed a significant reduction of antibiotic prescription. Several authors evaluated brain natriuretic peptide or troponin reporting faster decision-making without any improvement in clinical outcome. Forty-four per cent of studies reported analytical data, showing satisfactory correlations between results obtained through point-of-care testing and central laboratory setting. Half of studies defined the diagnostic accuracy of point-of-care testing as acceptable for troponin (median sensitivity and specificity: 74% and 94%, respectively), brain natriuretic peptide (median sensitivity and specificity: 82% and 88%, respectively) and C-reactive protein (median sensitivity and specificity 85%). Conclusions Point-of-care testing immunoassay results seem to be reliable and accurate for troponin, brain natriuretic peptide and C-reactive protein. The satisfactory analytical performance, together with an excellent practicability, suggests that it could be a consistent tool in clinical practice, but data are lacking regarding the patient outcomes.

Qualitative study of primary care clinicians' views on point-of-care testing for C-reactive protein for acute respiratory tract infections in family medicine

OBJECTIVE

To explore clinicians views of the barriers and facilitators to use of C-reactive protein (CRP) point-of-care tests (POCT) in US family medicine clinics for the management of acute respiratory tract infections (ARTIs) in adults.

SETTING

Five family medicine clinics across two US states.

PARTICIPANTS

30 clinicians including 18 physicians, 9 physician residents, 2 physician assistants and 1 nurse practitioner, took part in the study.

DESIGN

A qualitative study using a grounded theory approach to thematically analyse focus group interviews.

RESULTS

These clinicians had limited access to diagnostic tests for patients with ARTI, and very little knowledge of CRP POCT. Three major themes were identified and included the potential clinical role of CRP POCT, concerns related to implementing CRP POCT and evidence needed prior to wider adoption in family medicine. Clinicians believed CRP POCT could support decision-making for some presentations of ARTIs and patient populations when used in conjunction with clinical criteria. Clinicians had concerns about possible overuse and inaccuracy of CRP POCT which they believed might increase antibiotic prescribing rates. Other concerns identified included integration of the test with clinic workflows and cost-effectiveness.

CONCLUSIONS

Clinicians stand at the forefront of antibiotic stewardship efforts, but have few diagnostic tests to help them confidently manage ARTIs. CRP POCT may facilitate some aspects of clinical practice. Incorporating CRP POCT with clinical guidelines may strengthen utility of this test, when there is diagnostic uncertainty.

Effect of Participating in a Quality Improvement System over Time for Point-of-Care C-Reactive Protein, Glucose, and Hemoglobin Testing

BACKGROUND

Users of point-of-care testing (POCT) in Norway participate in a quality improvement system that includes education and guidance in safe laboratory management along with participation in external quality assurance schemes (EQAS).

The aim of this study was to identify the effect on the analytical performance of POCT C-reactive protein (CRP), glucose, and hemoglobin (Hb) with the use of a quality improvement system over time and to identify which factors are associated with good performance.

METHODS

Participants' results from 19 EQAS for CRP, glucose, and Hb from 2006 to 2015 along with information on the instruments used and different practice characteristics were analyzed. Logistic regression analysis was used to evaluate the factors associated with good laboratory performance. An instrument evaluation and comparison for CRP determination was performed by using commutable EQA material.

RESULTS

The mean number of participants in each EQAS was 2134, 2357, and 2271 for CRP, glucose, and Hb, respectively. The percentage of good participant performances increased gradually whereas that of poor performances decreased with participation in a quality improvement system over 9 years for all 3 analytes. Independent factors associated with good performance were type of instrument, the number of times performing EQA, performing internal QC weekly, performing 10 or more tests weekly, and having laboratory-qualified personnel perform the tests. Considering CRP instrument performance, Afinion and QuikRead exhibited the lowest systematic deviation.

CONCLUSIONS

The analytical quality of CRP, glucose, and Hb testing is improved by systematic participation in a quality improvement system over time.

Point-of-care CRP testing in the diagnosis of pneumonia in adults

Respiratory tract infections (RTI) are among the most common acute conditions leading to GP consultations and to antibiotic prescribing in primary care, even though 70% are viral, and many others are minor self-limiting bacterial infections.^1-4 Between 0.5% and 1.1% of adults have community-acquired pneumonia every year in the UK, most of whom are managed in primary care.^4,5 The decision to prescribe antibiotics for an acute RTI in primary care is often based on clinical symptoms, which have low sensitivity and specificity, and high inter-observer variability.^2,4 In primary care, it is very difficult to differentiate between diagnoses without additional tests.⁶ Unnecessary antibiotic prescribing may not aid recovery, exposes patients to potential adverse effects, may encourage repeat attendance and contributes to antibiotic resistance.^2,7 One strategy aiming to reduce antibiotic prescribing in primary care is the use of biomarkers (e.g. C-reactive protein [CRP]).² In the correct clinical context (e.g. in previously healthy people, not those with chronic lung disease) and as an adjunct to clinical assessment, a biomarker may help in the management of an RTI.² In order to be used during the consultation, the results of a biomarker test must be rapidly available (e.g. 'point-of-care' [POC] testing).⁴ POC testing for CRP has recently been recommended as part of a national clinical guideline on the diagnosis and management of pneumonia.⁴ Here, we review the rationale for POC CRP testing and its advantages and disadvantages.

Point-of-care C reactive protein for the diagnosis of lower respiratory tract infection in NHS primary care: a qualitative study of barriers and facilitators to adoption

OBJECTIVES

Point-of-care (POC) C reactive protein (CRP) is incorporated in National Institute of Health and Care Excellence (NICE) guidelines for the diagnosis of pneumonia, reduces antibiotic prescribing and is cost effective.

AIM

To determine the barriers and facilitators to adoption of POC CRP testing in National Health Service (NHS) primary care for the diagnosis of lower respiratory tract infection.

DESIGN

The study followed a qualitative methodology based on grounded theory. The study was undertaken in 2 stages. Stage 1 consisted of semistructured interviews with 8 clinicians from Europe and the UK who use the test in routine practice, and focused on their subjective experience in the challenges of implementing POC CRP testing. Stage 2 was a multidisciplinary-facilitated workshop with NHS stakeholders to discuss barriers to adoption, impact of adoption and potential adoption scenarios. Emergent theme analysis was undertaken.

PARTICIPANTS

Participants included general practitioners (including those with commissioning experience), biochemists, pharmacists, clinical laboratory scientists and industry representatives from the UK and abroad.

RESULTS

Barriers to the implementation of POC CRP exist, but successful adoption has been demonstrated abroad. Analysis highlighted 7 themes: reimbursement and incentivisation, quality control and training, laboratory services, practitioner attitudes and experiences, effects on clinic flow and workload, use in pharmacy and gaps in evidence.

CONCLUSIONS

Successful adoption models from the UK and abroad demonstrate a distinctive pattern and involve collaboration with central laboratory services. Incorporating antimicrobial stewardship into quality improvement frameworks may incentivise adoption. Further research is needed to develop scaling-up strategies to address the resourcing, clinical governance and economic impact of widespread NHS implementation.