Effects of primary care C-reactive protein point-of-care testing on antibiotic prescribing by general practice staff: pragmatic randomised controlled trial, England, 2016 and 2017

Evaluation of utilisation and consequences of CRP point-of-care-testing in primary care practices: qualitative interviews with GPs from Germany

BACKGROUND

The use and advantages of point-of-care tests (POCTs) for C-reactive protein (CRP) in general practice, especially for upper respiratory tract infections (uRTIs), have been studied extensively. However, there is limited knowledge about test indications, prerequisites, and integration of these tests into everyday practice.

AIM

To investigate the attitudes and experiences of GPs in Germany regarding the use of semi-quantitative C-reactive protein point-of-care tests (CRP-POCTs). The study places special emphasis on implementation in routine care, including testing procedures, feasibility, opportunities, and barriers for specific consultation scenarios, as well as test indications and their impact on GP-patient communication.

DESIGN & SETTING

Qualitative interview study with 10 GPs (May 2023-August 2023) in Germany.

METHOD

Ten German GPs who participated in an observational study on CRP-POCT use in general practices were interviewed using semi-structured interviews. Audio-recordings were transcribed and content analysis was performed.

RESULTS

Interviewed GPs stated that CRP-POCTs offer several advantages for various treatment cases. The tests improve diagnostic confidence and certainty of GPs' therapeutic decisions, and offer a broad spectrum of indications and application scenarios. Additionally, the tests have a positive impact on GP-patient communication, and their ease of use enables rapid implementation into existing workflows. On the other hand, CRP-POCTs increase the time required for test performance and patient consultation.

CONCLUSION

Owing to the numerous benefits of semi-quantitative CRP-POCTs, interviewed GPs have a favourable attitude towards their regular integration into everyday practice. Implementation barriers include increased time and personnel expenses for testing and inadequate reimbursement by German statutory health insurance.

Predicting abnormal C-reactive protein level for improving utilization by deep neural network model

BACKGROUND

C-reactive protein (CRP) is an inflammatory biomarker frequently used in clinical practice. However, insufficient evidence-based ordering inevitably results in its overuse or underuse. This study aims to predict its normal and abnormal levels using the deep neural network (DNN) models, helping clinicians order this item more appropriately and intelligently.

METHODS

We considered complete blood count (CBC) parameters as feature vectors and 10 mg/L as a cutoff value for CRP. Several models, including linear support vector classification, logistic regression, decision trees, random forests, and DNN, were developed based on a dataset of 53834 medical records to predict binary output. We externally validated DNN models on independent 20723 samples through discrimination, calibration curve, and decision curve analysis.

RESULTS

DNN models has the best area under the receiver operating characteristic curves (AUC). Learning curves revealed that models' AUC, balanced accuracy, and F1 score do not significantly and continuously improve following increasing data volume. In internal validation, the AUC, balanced accuracy, and the F1 score of 10 models were 0.818 (0.95 CI: 0.812-0.824), 0.741 (0.95 CI: 0.736-0.747), and 0.649 (0.95 CI: 0.643-0.656), respectively. These metrics were 0.817 (0.95 CI: 0.816-0.817), 0.741 (0.95 CI: 0.740-0.742), and 0.641 (0.95 CI: 0.640-0.642), respectively, in external validation. AUC and balanced accuracy shown no significant difference (P-values were 0.106 and 0.339). CRP10-C2 model has the lowest Brier score of 0.154, AUC of 0.818, and calibration curve formula of y=1.001x-0.010, which was identified as a target model to deploy in the app.

CONCLUSIONS

DNN models obtained moderate performance, surpassing baseline indices in distinguishing binary CRP levels. They are good generalizations and well-calibrated. The CRP-C2 model can enhance CRP utilization by informing the orders appropriately and can contribute to inflammatory diagnostics in primary health care where CBC is available, but the CRP test is inaccessible.

A systematic review of national interventions and policies to optimize antibiotic use in healthcare settings in England

OBJECTIVES

To identify and assess the effectiveness of national antibiotic optimization interventions in primary and secondary care in England (2013-2022).

METHODS

A systematic scoping review was conducted. Literature databases (Embase and Medline) were used to identify interventions and evaluations. Reports included the UK AMR Strategy (2013-2018), National Action Plan (2019-2024) and English Surveillance Programme for Antimicrobial Utilisation and Resistance (ESPAUR) reports (2014-2022). The design, focus and quality of evaluations and the interventions' effectiveness were extracted.

FINDINGS

Four hundred and seventy-seven peer-reviewed studies and 13 reports were screened. One hundred and three studies were included for review, identifying 109 interventions in eight categories: policy and commissioning (n = 9); classifications (n = 1); guidance and toolkits (n = 22); monitoring and feedback (n = 17); professional engagement and training (n = 19); prescriber tools (n = 12); public awareness (n = 17); workforce and governance (n = 12).Most interventions lack high-quality effectiveness evidence. Evaluations mainly focused on clinical, microbiological or antibiotic use outcomes, or intervention implementation, often assessing how interventions were perceived to affect behaviour. Only 16 interventions had studies that quantified effects on prescribing, of which six reported reductions. The largest reduction was reported with structural-level interventions and attributed to a policy and commissioning intervention (primary care financial incentives). Behavioural interventions (guidance and toolkits) reported the greatest impact in hospitals.

CONCLUSIONS

Many interventions have targeted antibiotic use, each pulling different levers across the health system simultaneously. On the basis of these studies, structural-level interventions may have the greatest impact. Collectively, the combination of interventions may explain England's decline in prescribing but direct evidence of causality is unavailable.

Cost-effectiveness of point-of-care diagnostics for AMR: a systematic review

BACKGROUND

Antimicrobial resistance (AMR) is a major threat to global health. By 2050, it is forecast that AMR will cause 10 million deaths and cost 100 trillion USD annually. Point-of-care tests (POCTs) may represent a cost-effective approach to reduce AMR.

OBJECTIVES

We systematically reviewed which POCTs addressing AMR have undergone economic evaluation in primary and secondary healthcare globally, how these POCTs have been economically evaluated, and which are cost-effective in reducing antimicrobial prescribing or the burden of AMR. Clinical cost-effectiveness was additionally addressed.

METHODS

This systematic review, accordant with PRISMA guidelines, was pre-registered on PROSPERO (CRD42022315192). MEDLINE, PubMed, Embase, Cochrane Library, and Google Scholar were searched from 2000 to 2023 for relevant publications. Quality assessment was performed using the Consensus of Health Economic Criteria.

RESULTS

The search strategy identified 1421 studies, of which 20 met the inclusion criteria. The most common POCTs assessed were for respiratory infections (n = 10), STIs (n = 3), and febrile patients in low- and middle-income countries (n = 3). All studies assessed costs from a healthcare provider perspective; five additionally considered the societal cost of AMR.Eighteen studies identified POCT strategies that reduced antimicrobial prescribing. Of these, 10 identified POCTs that would be considered cost-effective at a willingness-to-pay (WTP) threshold of £33.80 per antibiotic prescription avoided. Most POCT strategies improved clinical outcomes (n = 14); the remainder were clinically neutral.

CONCLUSIONS

There is evidence that some POCTs are cost-effective in reducing antimicrobial prescribing, with potential concomitant clinical benefits. Such interventions-especially CRP POCTs in both high- and low-income settings-merit further, large-scale clinical evaluation.

Implementation of point-of-care testing of C-reactive protein concentrations to improve antibiotic targeting in respiratory illness in Vietnamese primary care: a pragmatic cluster-randomised controlled trial

BACKGROUND

In previous trials, point-of-care testing of C-reactive protein (CRP) concentrations safely reduced antibiotic use in non-severe acute respiratory infections in primary care. However, these trials were done in a research-oriented context with close support from research staff, which could have influenced prescribing practices. To better inform the potential for scaling up point-of-care testing of CRP in respiratory infections, we aimed to do a pragmatic trial of the intervention in a routine care setting.

METHODS

We did a pragmatic, cluster-randomised controlled trial at 48 commune health centres in Viet Nam between June 1, 2020, and May 12, 2021. Eligible centres served populations of more than 3000 people, handled 10-40 respiratory infections per week, had licensed prescribers on site, and maintained electronic patient databases. Centres were randomly allocated (1:1) to provide point-of-care CRP testing plus routine care or routine care only. Randomisation was stratified by district and by baseline prescription level (ie, the proportion of patients with suspected acute respiratory infections to whom antibiotics were prescribed in 2019). Eligible patients were aged 1-65 years and visiting the commune health centre for a suspected acute respiratory infection with at least one focal sign or symptom and symptoms lasting less than 7 days. The primary endpoint was the proportion of patients prescribed an antibiotic at first attendance in the intention-to-treat population. The per-protocol analysis included only people who underwent CRP testing. Secondary safety outcomes included time to resolution of symptoms and frequency of hospitalisation. This trial is registered with ClinicalTrials.gov, NCT03855215.

FINDINGS

48 commune health centres were enrolled and randomly assigned, 24 to the intervention group (n=18 621 patients) and 24 to the control group (n=21 235). 17 345 (93·1%) patients in the intervention group were prescribed antibiotics, compared with 20 860 (98·2%) in the control group (adjusted relative risk 0·83 [95% CI 0·66-0·93]). Only 2606 (14%) of 18 621 patients in the intervention group underwent CRP testing and were included in the per-protocol analysis. When analyses were restricted to this population, larger reductions in prescribing were noted in the intervention group compared with the control group (adjusted relative risk 0·64 [95% CI 0·60-0·70]). Time to resolution of symptoms (hazard ratio 0·70 [95% CI 0·39-1·27]) and frequency of hospitalisation (nine in the intervention group vs 17 in the control group; adjusted relative risk 0·52 [95% CI 0·23-1·17]) did not differ between groups.

INTERPRETATION

Use of point-of-care CRP testing efficaciously reduced prescription of antibiotics in patients with non-severe acute respiratory infections in primary health care in Viet Nam without compromising patient recovery. The low uptake of CRP testing suggests that barriers to implementation and compliance need to be addressed before scale-up of the intervention.

FUNDING

Australian Government, UK Government, and the Foundation for Innovative New Diagnostics.

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.

Biomarkers as point-of-care tests to guide prescription of antibiotics in people with acute respiratory infections in primary care

BACKGROUND

Acute respiratory infections (ARIs) are by far the most common reason for prescribing an antibiotic in primary care, even though the majority of ARIs are of viral or non-severe bacterial aetiology. It follows that in many cases antibiotic use will not be beneficial to a patient's recovery but may expose them to potential side effects. Furthermore, limiting unnecessary antibiotic use is a key factor in controlling antibiotic resistance. One strategy to reduce antibiotic use in primary care is point-of-care biomarkers. A point-of-care biomarker (test) of inflammation identifies part of the acute phase response to tissue injury regardless of the aetiology (infection, trauma, or inflammation) and may be used as a surrogate marker of infection, potentially assisting the physician in the clinical decision whether to use an antibiotic to treat ARIs. Biomarkers may guide antibiotic prescription by ruling out a serious bacterial infection and help identify patients in whom no benefit from antibiotic treatment can be anticipated. This is an update of a Cochrane Review first published in 2014.

OBJECTIVES

To assess the benefits and harms of point-of-care biomarker tests of inflammation to guide antibiotic treatment in people presenting with symptoms of acute respiratory infections in primary care settings regardless of patient age.

SEARCH METHODS

We searched CENTRAL (2022, Issue 6), MEDLINE (1946 to 14 June 2022), Embase (1974 to 14 June 2022), CINAHL (1981 to 14 June 2022), Web of Science (1955 to 14 June 2022), and LILACS (1982 to 14 June 2022). We also searched three trial registries (10 December 2021) for completed and ongoing trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in primary care patients with ARIs that compared the use of point-of-care biomarkers with standard care. We included trials that randomised individual participants, as well as trials that randomised clusters of patients (cluster-RCTs).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data on the following primary outcomes: number of participants given an antibiotic prescription at index consultation and within 28 days follow-up; participant recovery within seven days follow-up; and total mortality within 28 days follow-up. We assessed risk of bias using the Cochrane risk of bias tool and the certainty of the evidence using GRADE. We used random-effects meta-analyses when feasible. We further analysed results with considerable heterogeneity in prespecified subgroups of individual and cluster-RCTs.

MAIN RESULTS

We included seven new trials in this update, for a total of 13 included trials. Twelve trials (10,218 participants in total, 2335 of which were children) evaluated a C-reactive protein point-of-care test, and one trial (317 adult participants) evaluated a procalcitonin point-of-care test. The studies were conducted in Europe, Russia, and Asia. Overall, the included trials had a low or unclear risk of bias. However all studies were open-labelled, thereby introducing high risk of bias due to lack of blinding. The use of C-reactive protein point-of-care tests to guide antibiotic prescription likely reduces the number of participants given an antibiotic prescription, from 516 prescriptions of antibiotics per 1000 participants in the control group to 397 prescriptions of antibiotics per 1000 participants in the intervention group (risk ratio (RR) 0.77, 95% confidence interval (CI) 0.69 to 0.86; 12 trials, 10,218 participants; I² = 79%; moderate-certainty evidence).  Overall, use of C-reactive protein tests also reduce the number of participants given an antibiotic prescription within 28 days follow-up (664 prescriptions of antibiotics per 1000 participants in the control group versus 538 prescriptions of antibiotics per 1000 participants in the intervention group) (RR 0.81, 95% CI 0.76 to 0.86; 7 trials, 5091 participants; I² = 29; high-certainty evidence). The prescription of antibiotics as guided by C-reactive protein tests likely does not reduce the number of participants recovered, within seven or 28 days follow-up (567 participants recovered within seven days follow-up per 1000 participants in the control group versus 584 participants recovered within seven days follow-up per 1000 participants in the intervention group) (recovery within seven days follow-up: RR 1.03, 95% CI 0.96 to 1.12; I² = 0%; moderate-certainty evidence) (recovery within 28 days follow-up: RR 1.02, 95% CI 0.79 to 1.32; I² = 0%; moderate-certainty evidence). The use of C-reactive protein tests may not increase total mortality within 28 days follow-up, from 1 death per 1000 participants in the control group to 0 deaths per 1000 participants in the intervention group (RR 0.53, 95% CI 0.10 to 2.92; I² = 0%; low-certainty evidence). We are uncertain as to whether procalcitonin affects any of the primary or secondary outcomes because there were few participants, thereby limiting the certainty of evidence. We assessed the certainty of the evidence as moderate to high according to GRADE for the primary outcomes for C-reactive protein test, except for mortality, as there were very few deaths, thereby limiting the certainty of the evidence.

AUTHORS' CONCLUSIONS

The use of C-reactive protein point-of-care tests as an adjunct to standard care likely reduces the number of participants given an antibiotic prescription in primary care patients who present with symptoms of acute respiratory infection. The use of C-reactive protein point-of-care tests likely does not affect recovery rates. It is unlikely that further research will substantially change our conclusion regarding the reduction in number of participants given an antibiotic prescription, although the size of the estimated effect may change.  The use of C-reactive protein point-of-care tests may not increase mortality within 28 days follow-up, but there were very few events. Studies that recorded deaths and hospital admissions were performed in children from low- and middle-income countries and older adults with comorbidities.  Future studies should focus on children, immunocompromised individuals, and people aged 80 years and above with comorbidities. More studies evaluating procalcitonin and potential new biomarkers as point-of-care tests used in primary care to guide antibiotic prescription are needed.  Furthermore, studies are needed to validate C-reactive protein decision algorithms, with a specific focus on potential age group differences.

The Impact of Point-of-Care Blood C-Reactive Protein Testing on Prescribing Antibiotics in Out-of-Hours Primary Care: A Mixed Methods Evaluation

Improving prescribing antibiotics appropriately for respiratory infections in primary care is an antimicrobial stewardship priority. There is limited evidence to support interventions to reduce prescribing antibiotics in out-of-hours (OOH) primary care. Herein, we report a service innovation where point-of-care C-Reactive Protein (CRP) machines were introduced to three out-of-hours primary care clinical bases in England from August 2018-December 2019, which were compared with four control bases that did not have point-of-care CRP testing. We undertook a mixed-method evaluation, including a comparative interrupted time series analysis to compare monthly antibiotic prescription rates between bases with CRP machines and those without, an analysis of the number of and reasons for the tests performed, and qualitative interviews with clinicians. Antibiotic prescription rates declined during follow-up, but with no clear difference between the two groups of out-of-hours practices. A single base contributed 217 of the 248 CRP tests performed. Clinicians reported that the tests supported decision making and communication about not prescribing antibiotics, where having 'objective' numbers were helpful in navigating non-prescribing decisions and highlighted the challenges of training a fluctuant staff group and practical concerns about using the CRP machine. Service improvements to reduce prescribing antibiotics in out-of-hours primary care need to be developed with an understanding of the needs and context of this service.

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.

Point of care testing, antibiotic prescribing and prescribing confidence for respiratory tract infections in primary care: Prospective audit in 18 European countries

BACKGROUND

Between-country differences have been described in antibiotic prescribing for RTI in primary care, but not yet for diagnostic testing procedures and prescribing confidence.

AIM

To describe between-country differences in RTI management, particularly diagnostic testing and antibiotic prescribing, and investigate which factors relate to antibiotic prescribing and GPs' prescribing confidence.

DESIGN & SETTING

Prospective audit in 18 European countries.

METHOD

GPs registered patient-, clinical- and management characteristics, and confidence in their antibiotic prescribing decision for patients presenting with sore throat and/or lower RTI (n=4,982). Factors related to antibiotic prescribing and confidence were analysed using multi-level logistic regression.

RESULTS

Antibiotic prescribing proportions varied considerably:<20% in four countries, and >40% in six countries. There was also considerable variation in POC testing (0% in Croatia, Moldova, Romania, and >65% in Denmark, Norway, mainly CRP and Strep A), and in lab/hospital-based testing (<3% in Hungary, Netherlands, Spain, and >30% in Croatia, Georgia, Greece, Moldova, mainly chest X-ray and white blood cell counting). Antibiotic prescribing was related to illness severity, comorbidity, age, fever and 'country', but not to having performed a POC test. In nearly 90% of consultations, GPs were confident in their antibiotic prescribing decision.

CONCLUSION

Despite high confidence in decisions about antibiotic prescribing, there is considerable variation in the primary care of RTI in European countries, with GPs prescribing antibiotics overall more often than is considered appropriate. POC testing may enhance the quality of antibiotic prescribing decisions if it can safely reverse decisions confidently made on clinical grounds alone to prescribe antibiotics.