Clinical and technical evidence
A literature search was carried out for this briefing in accordance with the published process and methods statement. This briefing includes the most relevant or best available published evidence relating to the clinical effectiveness of the technology. The literature search strategy, evidence selection methods and detailed data extraction tables are available on request by contacting firstname.lastname@example.org.
Six studies are summarised in this briefing. Two randomised controlled trials investigated the potential of the predecessor QuikRead 101 CRP system to improve antibiotic stewardship in patients with respiratory tract infections. Little et al. (2013) carried out a multinational, cluster randomised controlled trial which prospectively enrolled 4,264 patients with lower or upper respiratory tract infections from 246 primary care practices. A study by Cals et al. (2010) randomised 258 patients with lower respiratory tract infections or rhinosinusitis into C-reactive protein (CRP)-assisted care (intervention; n=129) or standard care, (control; n=129).
Miravitlles et al. (2013) used the QuikRead 101 system to retrospectively analyse CRP levels in blood samples taken from patients with chronic obstructive pulmonary disease (COPD) who had been recruited into the placebo arm of a randomised controlled trial (n=152).
A nested case-control study (Minnaard et al. 2015) aimed to determine the diagnostic accuracy of 5 point-of-care CRP tests, including the QuikRead go and QuikRead 101 systems, and whether they added diagnostic value in predicting radiographic-diagnosed pneumonia in adults presenting with acute cough in primary care (n=200).
Table 3 summarises the clinical evidence as well as its strengths and weaknesses.
Details of intervention and comparator(s)
Strengths and limitations
Cluster randomised factorial controlled trial
Multinational (246 practices from 6 countries)
Belgium, Spain, Wales, England, Poland, Netherlands
CRP testing using QuikRead 101 (n=1,062), enhanced-communication training (n=1,170), CRP testing in combination with enhanced-communication training (n=1,162) compared with standard care (n=870).
The antibiotic prescribing rate was lower with CRP training than without and with enhanced-communication training than without (33% compared with 48%, adjusted risk ratio 0.54, 95% confidence interval 0.42 to 0.69). The combined intervention was associated with the greatest reduction in prescribing rate.
There was a higher admission rate in the CRP group compared with the non-CRP group, but this was of borderline statistical significance when controlled for all potential confounders.
The symptom severities in the CRP group were similar to those in the non-CRP group. Rates of new or worsening symptoms did not differ significantly.
This was a large trial on the QuikRead 101 CRP system, powered to detect a 10% reduction in antibiotic prescribing.
Several practices were excluded before and after randomisation because of recruitment issues.
Randomised controlled trial
Multicentre (11 centres)
CRP-assisted prescribing strategy (QuikRead 101 analyser intervention, n=129) compared with standard care (non-CRP-assisted prescribing strategy, control, n=129).
Patients in the CRP-assisted group used fewer antibiotics than those in the control group after the index consultation and during 28‑day follow-up.
There were fewer delayed prescriptions in the CRP-assisted group. Of those with delayed prescriptions, fewer prescriptions were filled in the CRP-assisted group than in the control group.
Recovery was similar across both groups and patient satisfaction with care was higher in the CRP-assisted group.
The study was not powered to detect differences between the 2 groups.
Patients were individually randomised and allocation concealment was done, reducing selection bias.
The authors did a sensitivity analysis and accounted for variation at physician level.
Patients with COPD from placebo arm of randomised controlled trial
QuikRead 101 analyser with QuikRead CRP assay compared with Anthonisen criteria.
The only factors significantly associated with an increased risk of clinical failure (defined as incomplete resolution, persistence,
or worsening of symptoms that needed a new course of antibiotics, oral corticosteroids, or hospitalisation) without antibiotics were the increase in sputum purulence (included in the Anthonisen criteria) and a CRP concentration ≥ 40mg/litre.
The use of a point-of-care CRP test statistically significantly increased the predictive accuracy of clinical failure.
Only study to evaluate clinical outcomes associated with CRP ≥ 40mg/litre (cut-off determined on the basis of previous analysis).
Authors could not rule out some placebo effect because the criteria for success were based on clinical evaluation.
Retrospective diagnostic case-control study
Multinational (16 primary care research networks across 12 European countries)
Belgium, Finland, Germany, Hungary, Italy, Netherlands, Norway, Poland, Spain, Slovakia, Sweden, UK
5 point-of-care devices including QuikRead go and QuikRead 101, compared against a laboratory reference standard (Vitros 5.1 FS, Ortho Diagnostics; Dimension Vista Systems, Siemens).
Diagnostic accuracy outcomes were determined from 200 patient blood samples (100 with pneumonia, 100 without pneumonia).
A clinical algorithm was used to determine the incremental predictive power of each CRP test to predict pneumonia.
The sensitivity and specificity of QuikRead go in predicting pneumonia was consistent with other point-of-care systems and a laboratory reference test.
In all cases the discriminatory power of the tests to predict pneumonia were reduced when a higher threshold of CRP (>100mg/litre) was used. Sensitivity was 52% and 20% for low (20 mg/litre) and high (100 mg/litre) thresholds respectively for the detection of radiographic pneumonia, and specificity was 72% and 99%.
Retrospective case-control design subject to inherent bias (likely to overestimate effect).
Radiographs were used as the reference standard.
Samples were analysed retrospectively at a central laboratory.
A diagnostic model was used to evaluate the incremental predictive power of CRP when added to symptoms and signs. This may not completely represent clinical judgement in real life.
Analytical performance study
8 point-of-care devices including QuikRead go, compared with a comparative laboratory method (Synchron CRP).
All blood samples were from GPs' patients, aged over 18 years, with CRP concentrations ranging from 5 to 200 mg/litre, determined with the Synchron analyser.
The linear regression equation of QuikRead go revealed an underestimation of CRP values compared with the laboratory method.
The coefficient of variation of QuikRead go met the criteria of <10%.
The correlation of the CRP tests to the reference standard varied considerably.
Patient blood samples were used with CRP values determined from an appropriate reference standard.
Patient characteristics and diagnosis were not reported.
Analytical performance study
5 point-of-care devices including QuikRead 101 and QuikRead go, compared with a laboratory method (Olympus AU2700).
Residual stored material from routinely done laboratory blood tests was pooled to obtain lithium heparin plasma pools with CRP concentrations of approximately 10, 15, 20, 25, 50, 90, 100 and 110 mg/litre.
The within-day coefficient of variations for low and high CRP concentration samples were smaller for the QuikRead go compared with the QuikRead 101 and other point-of-care devices.
The between-day coefficient of variations for high CRP concentration samples was also lowest with the QuikRead go CRP test.
For high CRP values (>100mg/litre), agreement with the laboratory standard systematically decreased for all 5 point-of-care tests.
The analytical performance and agreement of the CRP tests to the laboratory method varied considerably, but was considered adequate.
Lithium heparin plasma samples were used instead of blood obtained by finger prick.
A separate plasma pool was created to evaluate the QuikRead 101 device.
Abbreviations: COPD, chronic obstructive pulmonary disease; CRP, C-reactive protein.
The diagnostic accuracy and analytical performance studies were done in a laboratory setting and may not be representative of the primary care setting the technology is intended for.
Although there is no evidence with clinical outcomes for the QuikRead go, the studies that compared the diagnostic accuracy and analytical performance of QuikRead 101 and QuikRead go showed that the systems were comparable. The antibiotic prescribing rates described in the 2 randomised controlled trials on the QuikRead 101 system and clinical outcomes in the prognostic study are therefore likely to be generalisable to the QuikRead go system.