Analytical performance of 17 commercially available point-of-care tests for CRP to support patient management at lower levels of the health system

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.

Utilisation and consequences of CRP point-of-care-testing in primary care practices: a real-world multicentre observational study with 1740 patient cases in Germany

BACKGROUND

C-reactive protein point-of-care tests (CRP-POCTs) can support GPs' clinical decision making but they are not widely used in German general practices.

AIM

To investigate the utilisation of semi-quantitative CRP-POCTs in routine primary care.

DESIGN & SETTING

Prospective observational study in 49 general practices in Germany (from November 2022-April 2023).

METHOD

GPs were provided with CRP-POCTs and collected data for each CRP-POCT use, with standardised data-collection sheets.

RESULTS

Data from 1740 CRP-POCT uses were recorded. GPs employed CRP-POCTs mainly for patients with respiratory tract infections (RTIs; 71.2% of all cases) and to a lesser extent for gastrointestinal infections (GIs; 10.4%). In RTIs, CRP-POCTs were frequently used to distinguish between bacterial and viral aetiology (60.8%) and to guide decisions on antibiotic prescribing (62.8%). In GIs, CRP-POCTs were mainly used to rule out severe disease progressions (53.2%) and for decisions on further diagnostic procedures (45.6%). In RTIs, CRP-POCTs influenced antibiotic prescribing in 77.5% of the cases (32.3% in favour versus 45.2% waiver). In GIs, CRP levels mainly affected decisions on further diagnostic procedures. GPs reported that CRP-POCTs were helpful in 88.6% of all cases.

CONCLUSION

When available, German GPs predominantly use semi-quantitative CRP-POCTs to guide decisions on antibiotic prescribing in patients with RTIs. CRP-POCT use improves clinical decision making and increases the GP's clinical confidence.

Review: Diagnostic Potential for Collaborative Pharyngitis Biomarkers

Pharyngitis is an inflammatory condition of the pharynx and/or tonsils commonly seen in both children and adults. Viruses and bacteria represent the most common encountered etiologic agents-yeast/fungi and parasites are infrequently implicated. Some of these are predominantly observed in unique populations (eg, immunocompromised or unvaccinated individuals). This manuscript (part 3 of 3) summarizes the current state of biomarker diagnostic testing and highlights the expanding role they will likely play in the expedited diagnosis and management of patients with acute pharyngitis. Biomarkers, in conjunction with rapid antigen and/or nucleic acid amplification testing, will likely become the standard of care to accurately diagnose the etiologic agent(s) of pharyngitis. This novel testing paradigm has the potential to guide appropriate patient management and antibiotic stewardship by accurately determining if the cause of pharyngitis is due to a viral or bacterial etiology.

Technology supported High Intensity Training in chronic non-specific low back pain (the Techno-HIT trial): study protocol of a randomised controlled trial

Chronic low back pain (CLBP) is one of the most common chronic musculoskeletal disorders worldwide. Guidelines recommend exercise therapy (ET) in CLBP management, but more research is needed to investigate specific ET modalities and their underlying mechanisms. The primary goal of this study is to evaluate the short-term and long-term effectiveness of a time-contingent individualised high-intensity training (HIT) protocol on disability compared with a time-contingent moderate-intensity training (MIT) as used in usual care, in persons with severely disabling CLBP. Additionally, the effectiveness on central effects, the added value of prolonged training at home and technology support, and the cost-effectiveness are evaluated. In this randomised controlled trial, CLBP patients will be randomly divided into three groups of 56 participants. Group 1, 'TechnoHIT', receives HIT with technology-support in the home-phase. Group 2, 'HIT', receives HIT without technology support. Group 3, 'MIT', receives MIT, reflecting training intensity as used in usual care. The primary outcome is patient-reported disability, measured by the Modified Oswestry Disability Index. Secondary outcomes include quantitative sensory testing, psychosocial factors, broad physical fitness, quality of life, cost-effectiveness, adherence and usability of technology. Trial registration number NCT06491121.

Potential Utility of C-reactive Protein for Tuberculosis Risk Stratification Among Patients With Non-Meningitic Symptoms at HIV Diagnosis in Low- and Middle-income Countries

Background

The World Health Organization recommends initiating same-day antiretroviral therapy (ART) while tuberculosis (TB) testing is under way for patients with non-meningitic symptoms at HIV diagnosis, though safety data are limited. C-reactive protein (CRP) testing may improve TB risk stratification in this population.

Methods

In this baseline analysis of 498 adults (>18 years) with TB symptoms at HIV diagnosis who were enrolled in a trial of rapid ART initiation in Haiti, we describe test characteristics of varying CRP thresholds in the diagnosis of TB. We also assessed predictors of high CRP as a continuous variable using generalized linear models.

Results

Eighty-seven (17.5%) participants were diagnosed with baseline TB. The median CRP was 33.0 mg/L (interquartile range: 5.1, 85.5) in those with TB, and 2.6 mg/L (interquartile range: 0.8, 11.7) in those without TB. As the CRP threshold increased from ≥1 mg/L to ≥10 mg/L, the positive predictive value for TB increased from 22.4% to 35.4% and negative predictive value decreased from 96.9% to 92.3%. With CRP thresholds varying from <1 to <10 mg/L, a range from 25.5% to 64.9% of the cohort would have been eligible for same-day ART and 0.8% to 5.0% would have untreated TB at ART initiation.

Conclusions

CRP concentrations can be used to improve TB risk stratification, facilitating same-day decisions about ART initiation. Depending on the CRP threshold, one-quarter to two-thirds of patients could be eligible for same-day ART, with a reduction of 3- to 20-fold in the proportion with untreated TB, compared with a strategy of same-day ART while awaiting TB test results.

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.

Comparison of commercially available, rapid, point-of-care C-reactive protein assays among children with febrile illness in southwestern Uganda

In Uganda, children with febrile illness are often treated with antibiotics even though most have self-limiting, likely viral, infections. C-reactive protein (CRP) measurement can help identify those who are more likely to have a bacterial infection and therefore need antibiotic treatment. Implementation of a CRP rapid diagnostic test (RDT) at the point-of-care in resource-constrained settings with minimal laboratory infrastructure could reduce unnecessary antibiotic use. In this study, we evaluated the performance of three semi-quantitative CRP RDTs (Actim, BTNX, Duo) against a reference CRP assay requiring an electrically powered analyzer (Afinion). While both tests demonstrated substantial agreement with Afinion, Actim had slightly higher agreement than BTNX. The sensitivity was higher for the BTNX test, whereas the Actim test had a higher specificity, at cut-offs of 40 mg/L and 80 mg/L. At a cut-off of 20 mg/L, Duo demonstrated substantial agreement with the Afinion test as well. Our results demonstrate the reliability of CRP RDTs when compared to a reference standard. CRP RDTs without the need for a laboratory-based analyzer are promising tools for optimizing antibiotic use in low-resource settings.

Potential Utility of C-reactive Protein for Tuberculosis Risk Stratification among Patients with Non-Meningitic Symptoms at HIV Diagnosis in Low- and Middle-Income Countries

Article Summary

We assessed the association between C-reactive protein (CRP) and Mycobacterium tuberculosis (TB) diagnosis in symptomatic patients at HIV diagnosis. We found that CRP concentrations can improve tuberculosis risk stratification, facilitating decision making about whether (specific) tuberculosis testing is indicated before antiretroviral therapy initiation.

Background

The World Health Organization recommends initiating same-day ART while tuberculosis testing is underway for patients with non-meningitic symptoms at HIV diagnosis, though safety data are limited. C-reactive protein (CRP) testing may improve tuberculosis risk stratification in this population.

Methods

In this baseline analysis of 498 adults (>18 years) with tuberculosis symptoms at HIV diagnosis who were enrolled in a trial of rapid ART initiation in Haiti, we describe test characteristics of varying CRP thresholds in the diagnosis of TB. We also assessed predictors of high CRP (≥3 mg/dL) using generalized linear models.

Results

Eighty-seven (17.5%) patients were diagnosed with baseline TB. The median CRP was 33.0 mg/L (IQR: 5.1, 85.5) in those with TB, and 2.6 mg/L (IQR: 0.8, 11.7) in those without TB. As the CRP threshold increased from ≥1 mg/L to ≥10 mg/L, the positive predictive value for TB increased from 22.4% to 35.4%, and negative predictive value decreased from 96.9% to 92.3%. With CRP thresholds varying from <1 to <10 mg/L, a range from 25.5% to 64.9% of the cohort would have been eligible for same-day ART, and 0.8% to 5.0% would have untreated TB at ART initiation.

Conclusions

CRP concentrations can be used to improve TB risk stratification, facilitating same-day decisions about ART initiation. Depending on the CRP threshold, one-quarter to two-thirds of patients could be eligible for same-day ART, with a reduction of 3-fold to 20-fold in the proportion with untreated TB, compared with a strategy of same-day ART while awaiting TB test results.

Preparing of Point-of-Care Reagents for Risk Assessment in the Elderly at Home by a Home-Visit Nurse and Verification of Their Analytical Accuracy

With the rising number of older adults residing at home, there is a growing need for risk assessment and patient management in home nursing. This study aims to develop point-of-care test (POCT) reagents that can aid in risk assessment and home care, especially in settings with limited resources. Our focus was on creating a C-reactive protein (CRP) POCT, which can accurately diagnose clinically significant judgment values in home nursing. Additionally, we assessed the utility of the HemoCue WBC DIFF system in providing differential counts of white blood cells (WBC). These performances were compared with a laboratory test using blood samples from patients with pneumonia. The CRP POCT showed a comparable result to that of a laboratory method, with an average kappa index of 0.883. The leukocyte count showed good agreement with the reference method. While the correlation coefficients for both neutrophil and lymphocyte counts were deemed acceptable, it was observed that the measured values tended to be smaller in cases where the cell count was higher. This proportional error indicates a weak correlation with the neutrophil-to-lymphocyte ratio. CRP POCT and WBC counts provided reliable and accurate judgments. These tools may benefit risk management for older adults at home, patients with dementia who cannot communicate, and those living in depopulated areas.