Point-of-care C-reactive Protein Research Articles

Diagnostic Accuracy of Point-of-Care Testing of C-Reactive Protein, Interleukin-6, and Procalcitonin in Neonates with Clinically Suspected Sepsis: A Prospective Observational Study

Objective: Sepsis often prompts clinicians to start empirical antibiotics in suspected neonates while awaiting diagnosis. The next-generation testing with point-of-care (POC) techniques offers a lead-time advantage that could bridge the gap by providing a timely diagnosis. Materials and Methods: We conducted a prospective diagnostic study in 82 neonates enrolled between May and October 2022 in a level III neonatal intensive care unit. All neonates with a new episode of clinically suspected sepsis were included. Diagnostic accuracy of POC testing of C-reactive protein (CRP), interleukin-6 (IL-6), and procalcitonin (PCT) with standard laboratory methods was performed. Results: The mean gestation age and birth weight of the neonates were 33.17 ± 4.25 weeks and 1,695.4 ± 700.74 grams, respectively. Most neonates were preterm (75%) with nearly equal proportions of early (51.22%) and late-onset (48.78%) sepsis. The POC CRP correlated well with standard CRP (r = 0.8001, 95% CI: 0.706–0.867, p < 0.0001). Among the three biomarkers, CRP had the maximum diagnostic accuracy (area under the curve [AUC] – 0.73) followed by PCT (AUC – 0.65) and IL-6 (0.55). There was no significant difference in the diagnostic accuracy of CRP (p = 0.46), PCT (p = 0.29), and IL-6 (p = 0.60) in early- and late-onset sepsis. The mean time for POC estimation of IL-6, PCT, and CRP was 12 ± 3 min which was significantly less compared to 366 ± 61 min for standard techniques (p < 0.001). Conclusion: POC CRP correlates well with standard techniques of estimation, and CRP alone and in combination with PCT has good diagnostic accuracy in neonatal sepsis.

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.

Cost-effectiveness of point-of-care C-Reactive Protein test compared to current clinical practice as an intervention to improve antibiotic prescription in malaria-negative patients in Afghanistan.

Antimicrobial resistance (AMR) is a global health problem requiring a reduction in inappropriate antibiotic prescribing. Point-of-Care C-Reactive Protein (POCCRP) tests could distinguish between bacterial and non-bacterial causes of fever in malaria-negative patients and thus reduce inappropriate antibiotic prescribing. However, the cost-effectiveness of POCCRP testing is unclear in low-income settings. A decision tree model was used to estimate cost-effectiveness of POCCRP versus current clinical practice at primary healthcare facilities in Afghanistan. Data were analysed from healthcare delivery and societal perspectives. Costs were reported in 2019 USD. Effectiveness was measured as correctly treated febrile malaria-negative patient. Cost, effectiveness and diagnostic accuracy parameters were obtained from primary data from a cost-effectiveness study on malaria rapid diagnostic tests in Afghanistan and supplemented with POCCRP-specific data sourced from the literature. Incremental cost-effectiveness ratios (ICERs) reported the additional cost per additional correctly treated febrile malaria-negative patient over a 28-day time horizon. Univariate and probabilistic sensitivity analyses examined the impact of uncertainty of parameter inputs. Scenario analysis included economic cost of AMR per antibiotic prescription. The model predicts that POCCRP intervention would result in 137 fewer antibiotic prescriptions (6%) with a 12% reduction (279 prescriptions) in inappropriate prescriptions compared to current clinical practice. ICERs were $14.33 (healthcare delivery), $11.40 (societal), and $9.78 (scenario analysis) per additional correctly treated case. POCCRP tests could improve antibiotic prescribing among malaria-negative patients in Afghanistan. Cost-effectiveness depends in part on willingness to pay for reductions in inappropriate antibiotic prescribing that will only have modest impact on immediate clinical outcomes but may have long-term benefits in reducing overuse of antibiotics. A reduction in the overuse of antibiotics is needed and POCCRP tests may add to other interventions in achieving this aim. Assessment of willingness to pay among policy makers and donors and undertaking operational trials will help determine cost-effectiveness and assist decision making.

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

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. To evaluate the feasibility, based on clinical and operational outcomes, of POC CRP testing to support Western Australian community pharmacists' management of RTIs. Patients with RTI signs and symptoms were recruited from June-August 2019at 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. Clinical outcomes: CRP levels among the 131 participants recruited were: < 5mg/L (bacterial infection unlikely; n=60; 45.8%); 5-19mg/L (bacterial infection possible if suggestive routine assessment; n=52; 39.7%) and 20-100mg/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. 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 testing reduces antibiotics prescription in a community setting

BackgroundOveruse of antimicrobials and the threats posed by resistance are concerning. Most patients in primary care with respiratory tract symptoms are prescribed antibiotics, amounting between 80–90% of all prescriptions. The National Institute for Health and Care Excellence (NICE) recommends point-of-care (POC) testing of C-reactive protein (CRP) where there is uncertainty about prescribing antibiotics. Studies evaluating the use of POC CRP to reduce antibiotic prescribing for self-limiting respiratory illness in primary care have demonstrated heterogeneity in their results.AimTo evaluate the impact of POC CRP testing on antibiotic prescribing.MethodA retrospective case analysis was undertaken at a GP practice. Alere Afinion AS100 was used for POC CRP testing. Data were collected on patients presenting with cough or sore throat who had POC CRP testing used in their clinical decision making. Eighty-four cases were selected for inclusion. NICE clinical guideline CG191 was used as a standard comparator for antibiotic prescribing and patients were followed up over a 2-month period.ResultsPatients presented with cough (n = 56) and sore throat (n = 28). At initial presentation 23/84 (27.4%) of patients were prescribed antibiotics. Over the 2-month follow-up period 15/84 (17.8%) of patients had at least one further consultation related to their initial respiratory complaint with 6/84 (7.1%) being prescribed antibiotics. The overall effect was a reduction of antibiotic prescriptions by 65.5%.ConclusionThe use of POC CRP testing helped GPs reduce the rate of antibiotic prescription and improve antimicrobial stewardship by being an addition to their diagnostic armoury. It has also shown potential role in patient reassurance and modifying health seeking behaviour.

Point-of-care C-reactive protein and risk of early mortality among adults initiating antiretroviral therapy.

In resource-limited settings, mortality in the initial months following antiretroviral therapy (ART) initiation remains unacceptably high. Novel tools to identify patients at highest risk of poor outcomes are needed. We evaluated whether elevated C-reactive protein (CRP) concentrations predict poor outcomes among people living with HIV (PLWH) initiating ART. We enrolled and followed for 3-months consecutive PLWH with pre-ART CD4 T-cell counts 350 cells/μl or less initiating ART from two HIV clinics in Uganda. Pre-ART CRP concentrations were measured from capillary blood using a point-of-care (POC) assay. After excluding patients with prevalent tuberculosis - the leading cause of HIV death - we measured 3-month mortality rates using Kaplan-Meier curves, used Cox regression to compare differences in survival, and used logistic regression to compare differences in the odds of opportunistic infections, between patients with and without elevated POC CRP (≥8 mg/l). Of 1293 patients included [median CD4 T-cell count 181 (interquartile range 82-278)], 23 (1.8%) died within 3 months, including 19 of 355 (5.4%) with elevated POC CRP and four of 938 (0.4%) with nonelevated POC CRP. Eighty-six (6.7%) patients were diagnosed with opportunistic infections, including 39 of 355 (11.0%) with elevated POC CRP and 47 of 938 (5.0%) with nonelevated POC CRP. Elevated POC CRP was associated with mortality (adjusted hazard ratio 10.87, 95% confidence interval 3.64-32.47) and opportunistic infection (adjusted odds ratio 1.95, 95% confidence interval 1.23-3.07). Among PLWH with advanced HIV, elevated pre-ART POC CRP concentrations are associated with early mortality and opportunistic infections. Pre-ART POC CRP testing may reduce mortality by identifying patients at high risk for poor outcomes.

Understanding the adoption and use of point-of-care tests in Dutch general practices using multi-criteria decision analysis

BackgroundThe increasing number of available point-of-care (POC) tests challenges clinicians regarding decisions on which tests to use, how to efficiently use them, and how to interpret the results. Although POC tests may offer benefits in terms of low turn-around-time, improved patient’s satisfaction, and health outcomes, only few are actually used in clinical practice. Therefore, this study aims to identify which criteria are, in general, important in the decision to implement a POC test, and to determine their weight. Two POC tests available for use in Dutch general practices (i.e. the C-reactive protein (CRP) test and the glycated haemoglobin (HbA1c) test) serve as case studies. The information obtained from this study can be used to guide POC test development and their introduction in clinical practice.MethodsRelevant criteria were identified based on a literature review and semi-structured interviews with twelve experts in the field. Subsequently, the criteria were clustered in four groups (i.e. user, organization, clinical value, and socio-political context) and the relative importance of each criterion was determined by calculating geometric means as implemented in the Analytic Hierarchy Process. Of these twelve experts, ten participated in a facilitated group session, in which their priorities regarding both POC tests (compared to central laboratory testing) were elicited.ResultsOf 20 criteria in four clusters, the test’s clinical utility, its technical performance, and risks (associated with the treatment decision based on the test result) were considered most important for using a POC test, with relative weights of 22.2, 12.6 and 8.5%, respectively. Overall, the experts preferred the POC CRP test over its laboratory equivalent, whereas they did not prefer the POC HbA1c test. This difference was mainly explained by their strong preference for the POC CRP test with regard to the subcriterion ‘clinical utility’.ConclusionsThe list of identified criteria, and the insights in their relative impact on successful implementation of POC tests, may facilitate implementation and use of existing POC tests in clinical practice. In addition, having experts score new POC tests on these criteria, provides developers with specific recommendations on how to increase the probability of successful implementation and use.

Cost-Effectiveness Analysis of the Use of Point-of-Care C-Reactive Protein Testing to Reduce Antibiotic Prescribing in Primary Care.

More appropriate and measured use of antibiotics may be achieved using point-of-care (POC) C-reactive protein (CRP) testing, but there is limited evidence of cost-effectiveness in routine practice. A decision analytic model was developed to estimate the cost-effectiveness of testing, compared with standard care, in adults presenting in primary care with symptoms of acute respiratory tract infection (ARTI). Analyses considered (1) pragmatic use of testing, reflective of routine clinical practice, and (2) testing according to clinical guidelines. Threshold and scenario analysis were performed to identify cost-effective scenarios. In patients with symptoms of ARTI and based on routine practice, the incremental cost-effectiveness ratios of CRP testing were £19,705 per quality-adjusted-life-year (QALY) gained and £16.07 per antibiotic prescription avoided. Following clinical guideline, CRP testing in patients with lower respiratory tract infections (LRTIs) cost £4390 per QALY gained and £9.31 per antibiotic prescription avoided. At a threshold of £20,000 per QALY, the probabilities of POC CRP testing being cost-effective were 0.49 (ARTI) and 0.84 (LRTI). POC CRP testing as implemented in routine practice is appreciably less cost-effective than when adhering to clinical guidelines. The implications for antibiotic resistance and Clostridium difficile infection warrant further investigation.

Point-of-care CRP matters: normal CRP levels reduce immediate antibiotic prescribing for acutely ill children in primary care: a cluster randomized controlled trial

Objective: Antibiotics are prescribed too often in acutely ill children in primary care. We examined whether a Point-of-Care (POC) C-reactive Protein (CRP) test influences the family physicians’ (FP) prescribing rate and adherence to the Evidence Based Medicine (EBM) practice guidelines.Design: Cluster randomized controlled trial.Setting: Primary care, Flanders, Belgium.Intervention: Half of the children with non-severe acute infections (random allocation of practices to perform POC CRP or not) and all children at risk for serious infection were tested with POC CRP.Subjects: Acutely ill children consulting their FP.Main outcome measure: Immediate antibiotic prescribing.Results: 2844 infectious episodes recruited by 133 FPs between 15 February 2013 and 28 February 2014 were analyzed. A mixed logistic regression analysis was performed. Compared to episodes in which CRP was not tested, the mere performing of POC CRP reduced prescribing in case EBM practice guidelines advise to prescribe antibiotics (adjusted odds ratio (aOR) 0.54 (95% Confidence Interval (CI) 0.33–0.90). Normal CRP levels reduced antibiotic prescribing, regardless of whether the advice was to prescribe (aOR 0.24 (95%CI 0.11–0.50) or to withhold (aOR 0.31 (95%CI 0.17–0.57)). Elevated CRP levels did not increase antibiotic prescribing.Conclusion: Normal CRP levels discourage immediate antibiotic prescribing, even when EBM practice guidelines advise differently. Most likely, a normal CRP convinces FPs to withhold antibiotics when guidelines go against their own gut feeling. Future research should focus on whether POC CRP can effectively identify children that benefit from antibiotics more accurately, without increasing the risks of under-prescribing.Key pointsWhat is previously known or believed on this topic•Antibiotics are prescribed too often for non-severe conditions. Point-of-care (POC) C-reactive Protein (CRP) testing without guidance does not reduce immediate antibiotic prescribing in acutely ill children in primary care.What this research adds•FPs clearly consider CRP once available: normal CRP levels discourage immediate antibiotic prescribing, even when EBM practice guidelines advise differently. Most likely, a normal CRP convinces FPs to withhold antibiotics when guidelines go against their own gut feeling.•Future research should focus on whether POC CRP can effectively identify children that benefit from antibiotics more accurately, without increasing the risks of under-prescribing.

Point-of-care C-reactive protein to assist in primary care management of children with suspected non-serious lower respiratory tract infection: a randomised controlled trial.

BackgroundOverprescription of antibiotics for lower respiratory tract infections (LRTIs) in children is common, partly due to diagnostic uncertainty, in which case the addition of point-of-care (POC) C-reactive protein (CRP) testing can be of aid.AimTo assess whether use of POC CRP by the GP reduces antibiotic prescriptions in children with suspected non-serious LRTI.Design & settingAn open, pragmatic, randomised controlled trial in daytime general practice and out-of-hours services.MethodChildren between 3 months and 12 years of age with acute cough and fever were included and randomised to either use of POC CRP or usual care. Antibiotic prescription rates were measured and compared between groups using generalising estimating equations.ResultsThere was no statistically significant reduction in antibiotic prescriptions in the GP use of CRP group (30.9% versus 39.4%; odds ratio [OR] 0.6; 95% confidence interval [CI] = 0.29 to 1.23). Only the estimated severity of illness was related to antibiotic prescription. Forty-six per cent of children had POC CRP levels <10mg/L.ConclusionIt is still uncertain whether POC CRP measurement in children with non-serious respiratory tract infection presenting to general practice can reduce the prescription of antibiotics. Until new research provides further evidence, POC CRP measurement in these children is not recommended.

Point-of-care C-reactive protein-based tuberculosis screening for people living with HIV: a diagnostic accuracy study

BackgroundSymptom-based screening for tuberculosis (TB) is recommended for all people living with HIV (PLHIV) resulting in unnecessary Xpert MTB/RIF testing for the vast majority of individuals living in TB endemic areas and thus, poor implementation of intensified case finding (ICF) and TB preventive therapy. Novel approaches to TB screening are therefore critical in achieving global targets for TB elimination.MethodsIn a prospective study of PLHIV with CD4+ T-cell count ≤350 cells/uL initiating antiretroviral therapy (ART) from two HIV/AIDS clinics in Uganda, we evaluated the performance of C-reactive protein (CRP) measured using a rapid and inexpensive point-of-care (POC) assay as a screening tool for active pulmonary TB.FindingsOf 1177 HIV-infected adults (median CD4+ T-cell count 168 cells/µL) enrolled, 163 (14%) had culture-confirmed TB. POC CRP had 89% (145/163) sensitivity and 72% (731/1014) specificity for culture-confirmed TB. Compared to the WHO symptom screen, POC CRP had lower sensitivity (difference −7% [95% CI: −12 to −2], p=0.002) but substantially higher specificity (difference +58% [95% CI: +61 to +55], p<0.0001). When Xpert MTB/RIF results were used as the reference standard, sensitivity of POC CRP and the WHO symptom screen were similar (94% [79/84] vs. 99% [83/84]; difference −5% [95% CI: −12 to +2], p=0.10).InterpretationThe performance characteristics of CRP support its use as a TB screening test for PLHIV with CD4+ T-cell count ≤350 cells/µL initiating ART. HIV/AIDS programs should consider POC CRP-based TB screening to improve the efficiency of ICF and increase uptake of TB preventive therapy.FUNDINGNational Institutes of Health; Presidential Emergency Plan for AIDS Relief; University of California, San Francisco, Nina Ireland Program for Lung Health

Analysis of recruitment in a pragmatic observational study on C-reactive protein point-of-care testing in primary care

Introduction: Failure to recruit all eligible study patients can lead to biased results. Little is known on selective patient recruitment in studies on implementation of diagnostic devices.Objectives: The aim of this observational study was to measure recruitment of patients in an implementation study in primary care on use of point-of-care (POC) C-reactive protein (CRP) and to evaluate recruitment bias and its impact on the study endpoint.Methods: In a cross-sectional observational study on POC CRP implementation and related antibiotics prescribing, we compared included patients with all eligible patients to assess the representativeness of the included subjects. Eligible patients were adults presenting with acute cough in primary care between March and September 2012. The frequency of POC CRP testing and the proportion of prescribed antibiotics were compared between recruited and non-recruited patients. As measure of bias, odds ratios (ORs) with accompanying 95% confidence intervals (CIs) for the association between CRP level (<20 mg/l or not) and antibiotic prescribing were computed.Results: Of all 1473 eligible patients 348 (24%) were recruited. In recruited patients, POC CRP tests were conducted and antibiotics prescribed more frequently as compared to non-recruited patients (81% versus 6% and 44% versus 29%, respectively). The ORs were 18.2 (95%CI: 9.6–34.3), 30.5 (95%CI: 13.2–70.3) and 3.8 (95%CI: 0.9–14.8) respectively in all eligible patients, the recruited and the non-recruited patients.Conclusion: Selective recruitment resulted in an overestimation of POC CRP test use and antibiotic prescribing.

C-reactive protein point-of-care testing and associated antibiotic prescribing

In clinical trials, the potential of point-of-care (POC) C-reactive protein (CRP) tests was demonstrated in decreasing antibiotic prescribing in adults with acute cough in general practice, but effects of implementation are unknown. To determine the overall effect of POC CRP testing on antibiotic prescribing rate in general practice. In an observational study, GPs were instructed to use POC CRP in adults with acute cough following current guidelines. After routine history taking and physical examination, they reported whether they intended to prescribe antibiotics ('pre-test decision'). They reported their revised decision after receiving the POC CRP test result ('post-test decision'). Primary outcome was the percentage of patients in whom the GP changed his or her decision to prescribe antibiotics. Secondary outcome was the difference between 'pre-test' and 'post-test' antibiotic prescribing % at group level. A total of 40 GPs enrolled 939 patients, 78% of whom were tested for CRP. GPs changed their decision after POC CRP testing in 200 patients (27%). Antibiotic prescribing before and after CRP testing did not differ ('pre-test' 31%, 'post-test' 28%; 95% confidence interval of difference -7 to 1). In 41% of the tested patients, the indication for testing was in accordance with the guidelines. POC CRP influenced GPs to change their decision about antibiotic prescribing in patients with acute cough. POC CRP testing does not reduce overall antibiotic prescribing by GPs who already have a low antibiotic prescribing rate.

Accuracy and feasibility of point-of-care white blood cell count and C-reactive protein measurements at the pediatric emergency department.

BackgroundSeveral point-of-care (POC) tests are available for evaluation of febrile patients, but the data about their performance in acute care setting is sparse. We investigated the analytical accuracy and feasibility of POC tests for white blood cell (WBC) count and C-reactive protein (CRP) at the pediatric emergency department (ED).MethodsIn the first part of the study, HemoCue WBC and Afinion AS100 CRP POC analyzers were compared with laboratory’s routine WBC (Sysmex XE-2100) and CRP (Modular P) analyzers in the hospital central laboratory in 77 and 48 clinical blood samples, respectively. The POC tests were then adopted in use at the pediatric ED. In the second part of the study, we compared WBC and CRP levels measured by POC and routine methods during 171 ED patient visits by 168 febrile children and adolescents. Attending physicians performed POC tests in capillary fingerprick samples.ResultsIn parallel measurements in the laboratory both WBC and CRP POC analyzers showed good agreement with the reference methods. In febrile children at the emergency department (median age 2.4 years), physician performed POC determinations in capillary blood gave comparable results with those in venous blood analyzed in the laboratory. The mean difference between POC and reference test result was 1.1 E9/L (95% limits of agreement from -6.5 to 8.8 E9/L) for WBC and -1.2 mg/L (95% limits of agreement from -29.6 to 27.2 mg/L) for CRP.ConclusionsPOC tests are feasible and relatively accurate methods to assess CRP level and WBC count among febrile children at the ED.

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

Background. The results obtained from various point-of-care (POC) test devices for estimating C-reactive protein (CRP) levels in a laboratory setting differ when compared to a laboratory reference test. We aimed to determine whether such differences meaningfully affect the accuracy and added diagnostic value in predicting radiographic pneumonia in adults presenting with acute cough in primary care. Methods. A nested case control study of adult patients presenting with acute cough in 12 different European countries (the Genomics to combat Resistance against Antibiotics in Community-acquired LRTI in Europe [GRACE] Network). Venous blood samples from 100 patients with and 100 patients without pneumonia were tested with five different POC CRP tests and a laboratory analyzer. Single test accuracy values and the added value of CRP to symptoms and signs were calculated. Results. Single test accuracy values showed similar results for all five POC CRP tests and the laboratory analyzer. The area under the curve of the different POC CRP tests and the laboratory analyzer (range 0.79–0.80) were all comparable and higher than the clinical model without CRP (0.70). Multivariable odds ratios were the same (1.2) for all CRP tests. Conclusions. Five POC CRP test devices and the laboratory analyzer performed with similar accuracy in detecting pneumonia both as single test, and when used in addition to clinical findings. Variability in results obtained from standard CRP laboratory and POC test devices do not translate into clinically relevant differences when used for prediction of pneumonia in patients with acute cough in primary care.

Analytical performance, agreement and user-friendliness of five C-reactive protein point-of-care tests

Background. Point-of-care (POC) C-reactive protein (CRP) testing is increasingly used in primary care to assist general practitioners (GPs) in the diagnostic workup for various complaints. The present study compares analytical performance, agreement and user-friendliness of five of these POC CRP tests. Methods. The following five POC CRP tests were evaluated: Afinion and NycoCard Reader II (both Alere), Eurolyser Smart 700/340 (Eurolyser), QuikRead go and QuikRead 101 (both Orion Diagnostica). Results were compared with those of a standard immunoturbidimetric method performed on a routine analyzer (Olympus AU 2700, Beckman Coulter). Analytical performance and agreement with the laboratory standard for the five different POC tests were analyzed. Subsequently, user-friendliness of the POC tests was assessed. Results. Within-day CVs varied from 2.6% (QuikRead go) to 19.4% (Eurolyser Smart 700/340) for low CRP values (< 20 mg/L), and 1.1% (QuikRead go) to 17.5% (Eurolyser Smart 700/340) for high values (> 100 mg/L). Between-day CVs varied from 4.6% (Afinion) to 30.5% (Eurolyser Smart 700/340) for low values and 4.0% (QuikRead go) to 18.0% (Eurolyser Smart 700/340) for high values. With high CRP values (> 100 mg/L) agreement with the laboratory standard systematically decreased for all POC tests. Regarding user-friendliness Afinion and Eurolyser Smart 700/340 were judged easiest to operate. Conclusions. Analytical performance, agreement, and user-friendliness of the POC CRP tests varied considerably, yet overall four devices showed adequate analytical performance and agreement.

Cost-effectiveness of point-of-care C-reactive protein testing to inform antibiotic prescribing decisions

Point-of-care C-reactive protein (POCCRP) is a biomarker of inflammation that offers clinicians a rapid POC test to guide antibiotic prescribing decisions for acute cough and lower respiratory tract infections (LRTI). However, evidence that POCCRP is cost-effective is limited, particularly outside experimental settings. To assess the cost-effectiveness of POCCRP as a diagnostic tool for acute cough and LRTI from the perspective of the health service. Observational study of the presentation, management, and outcomes of patients with acute cough and LRTI in primary care settings in Norway and Sweden. Using hierarchical regression, data were analysed in terms of the effect on antibiotic use, cost, and patient outcomes (symptom severity after 7 and 14 days, time to recovery, and EQ-5D), while controlling for patient characteristics (self-reported symptom severity, comorbidities, and health-related quality of life) at first attendance. POCCRP testing is associated with non-significant positive reductions in antibiotic prescribing (P = 0.078) and increased cost (P = 0.092). Despite the uncertainty, POCCRP testing is also associated with a cost per quality-adjusted life year (QALY) gain of €9391. At a willingness-to-pay threshold of €30,000 per QALY gained, there is a 70% probability of CRP being cost-effective. POCCRP testing is likely to provide a cost-effective diagnostic intervention both in terms of reducing antibiotic prescribing and in terms of QALYs gained.

Antibiotic prescribing and C-reactive protein testing for pulmonary infections in patients with intellectual disabilities

Excessive prescribing of antibiotics in patients with lower respiratory tract infections (LRTIs) is common in the general population. Due to communication difficulties, it is hypothesised that prescriptions are even more commonplace in the primary care of individuals with intellectual disabilities. Point-of-care C-reactive protein (POC-CRP) testing might lead to more efficient prescribing of antibiotics. To evaluate the effect of POC-CRP testing on antibiotic prescriptions for LRTIs by physicians specialising in the care of individuals with intellectual disabilities. A prospective case-control study in four care centres for individuals with intellectual disabilities in The Netherlands. Between 27 October 2010 and 27 October 2011, a prospective efficiency study was performed with a base population of 1472 individuals. This population consisted of 882 individuals in whom POC-CRP tests were used and a control group (n = 590) in whom no POC-CRP test was performed. Of the 48 patients in the control group who were diagnosed as having an LRTI, 43 (90%) received antibiotics, compared with 59 out of the 144 patients (41%) in the case group (OR = 12.0; 95% CI = 4.1-35.3). No significant differences in outcome were found between both groups during a follow-up period of 1 month. This study shows that the use of POC-CRP testing in patients with intellectual disabilities and LRTIs can lead to a significant reduction in antibiotic prescriptions, with no significant differences in outcome during follow-up.

Evaluating the evidence for the implementation of C-reactive protein measurement in adult patients with suspected lower respiratory tract infection in primary care: a systematic review

Excessive prescription of antibiotics in patients with lower respiratory tract infection (LRTI) is common in primary care and might be reduced by rapid point-of-care (POC) C-reactive protein (CRP) testing. However, the exact benefits of this test are unclear. To review the available evidence for the role of POC CRP measurement in (i) guiding antibiotic prescription, (ii) predicting aetiology, (iii) prognosis and (iv) diagnosis (pneumonia) in LRTI patients. For each research question, studies were retrieved through an electronic literature search in Medline, Embase and the Cochrane Library using synonyms for CRP and LRTI combined with different relevant subheadings. Study quality was assessed using validated instruments and predefined outcome measures were extracted from each study. The search yielded 13 articles, each answering one or more questions; one was excluded by insufficient internal validity. (i) One of four studies showed a significant reduction in the antibiotic prescriptions when applying POC CRP measurement [relative risk (RR) 0.6, 95% confidence interval (CI) 0.5-0.7]. (ii) Three studies on aetiology demonstrated that an elevated CRP was associated with bacterial [odds ratio (OR) 2.46-4.8] and one with viral (OR 2.7) aetiology. (iii) Results on the prognostic value were contradictory, providing evidence for faster symptom resolution (RR 1.16, 95% CI 1.1-1.3), higher mortality rate (RR 2.5, 95% CI 1.2-5.1) and no difference in outcome in patients with high CRP levels. (iv) Four studies showed that CRP had limited value as a single predictor of pneumonia. When combined with clinical assessment, its value increased according to two of these studies (receiver operating characteristic area from 0.7 to 0.9). However, methodological flaws and/or wide CIs limit the generalizability of findings in all studies. The evidence for the benefits of POC CRP measurement in LRTI patients in primary care is limited, contradictory and does not support its use to guide treatment decisions yet.

Evaluation of a point‐of‐care test for canine C‐reactive protein

In veterinary medicine, there is increasing interest in measuring C-reactive protein (CRP) as a tool for diagnosis and monitoring of inflammatory diseases. Reported CRP concentrations for healthy dogs have ranged from 0 to 8.9 mg/L. The aims of this study were to evaluate a canine-specific point-of-care (POC) lateral flow immunoassay for qualitative CRP measurement in healthy and diseased dogs and to compare results with those obtained by a quantitative ELISA. Blood samples from 73 client-owned dogs were available for testing: 16 healthy dogs and 57 dogs with a variety of infectious, inflammatory, or neoplastic diseases. CRP was measured in heparinized whole blood samples and serum with the TECO medical Dog CRP-visual POC test. A red line develops in the POC device if CRP is ≥ 5 mg/L, and results are scored as negative or positive. An ELISA validated previously for canine serum was used as the reference method. For all dogs, serum CRP concentrations measured by the ELISA ranged from 0.1 to ≥ 350 mg/L (median = 38 mg/L). Percentages of the CRP POC test results that agreed with the ELISA results were 98.6% for whole blood and 97.3% for serum samples. For serum samples, sensitivity of the POC test was 96.4% and specificity was 81.3%. For whole blood, sensitivity was 94.7% and specificity was 93.8%. The POC test had very good agreement with the ELISA test and had high sensitivity and specificity; therefore, it can be used as a qualitative test to screen for increases in CRP concentrations.