Capillary CRP in primary care in France: an observational study

Antibiotic resistance causes 700,000 deaths annually worldwide. In France, diagnostic uncertainty in consultations leads to inappropriate prescribing of antibiotics, which increases antibiotic resistance. Capillary C-reactive protein (CRP) machines can provide a CRP measurement in primary care in two minutes and can help general practitioners in their prescribing decisions. The aim of this study was to evaluate the use of capillary CRP in primary care, as well as its impact on the following: the main reasons for consultation, the influence of the results on antibiotic prescribing, and patient outcomes at eight days and three months. This was a multicentre (four centres) cross-sectional observational study including all patients with capillary CRP measurements during primary care consultations from January 1, 2022, to March 1, 2023. Patients in centre 1 were called by phone at eight days and at three months after their consultation to evaluate their recovery (patient perception). During the study period, 91 capillary CRP measurements were performed on 90 patients. A CRP level ≥ 20 mg/L was statistically associated with antibiotic prescription (odds ratio: 12.0, 95% confidence interval: 1.91 to 75.8, p = 0.008). The 45 patients from centre 1 called by phone were cured of bacterial infections at three months, none were hospitalised, and 20.0% returned for another consultation. When the CRP concentration was < 20 mg/L, doctors prescribed fewer antibiotics. Antibiotic prescriptions appear to decrease in France with the use of capillary CRP.