What a difference a CRP makes. A prospective observational study on how point-of-care C-reactive protein testing influences antibiotic prescription for respiratory tract infections in Swedish primary health care

Abstract

Objective: To explore how C-reactive protein (CRP) tests serve to support physicians in decisions concerning antibiotic prescription to patients with respiratory tract infections (RTI). Design. Prospective observational study. Setting: Primary health care centres in western Sweden. Subjects. Physicians in primary health care. Patients with acute RTI. Main outcome measures: Physician willingness to measure CRP, their ability to estimate CRP, and changes in decision-making concerning antibiotic treatment based on error estimate and the physician’s opinion of whether CRP measurement was crucial. Results: Data from 340 consultations were gathered. CRP testing was found to be crucial in 130 cases. In 86% of visits decisions regarding antibiotic prescription were unchanged. Physicians considering CRP crucial and physicians making an error estimate of CRP altered their decisions concerning antibiotic prescription after CRP testing more often than those who considered CRP unnecessary, and those making a more accurate estimate. Physicians changed their decision on antibiotic prescription in 49 cases. In the majority of these 49 cases physicians underestimated CRP levels, and the majority of changes were from “no” to “yes” as to whether to prescribe antibiotics. Conclusion: CRP is an important factor in the decision on whether to prescribe antibiotics for RTIs. Error estimates of CRP and willingness to measure CRP are important factors leading to physicians changing decisions on antibiotic treatment.Key pointsThere is a generally low antibiotic prescription rate and a high frequency of C-reactive protein (CRP) testing for respiratory tract infections (RTIs) in Sweden.CRP testing was considered essential to further management in 38% of cases.In 86% of visits decisions concerning antibiotic prescription were unchanged.The strongest predictors for revised decisions on antibiotic treatment were error estimates of CRP and the physician’s opinion that CRP measurement was crucial.

Change in the use of diagnostic tests in the management of lower respiratory tract infections: a register-based study in primary care

“…Use of CRP is known to be frequent in the assessment of respiratory infections in Scandinavia, but it is not recommended in the initial judgment of pneumonia in primary care. 6,12,15 In the present study, CRP testing increased and the frequency was high (71.4%) compared to a 2009 Swedish study by Engström et al, in which the corresponding frequency was only 38% in pneumonia diagnosis, and another 2016 study by Tyrstrup et al in which the testing rate was 60.4%, indicating that usage of point of care CRP has progressively increased. 16,17 Earlier studies have shown that assessment of pneumonia differs between countries.…”

Out-of-hours antibiotic prescription after screening with C reactive protein: a randomised controlled study

“… 26 Another recently published Swedish study where both children and adults were included found CRP testing in 38% and that CRP pretesting correlated with increased antibiotic prescription. 27 …”

Impact of point-of-care C reactive protein in ambulatory care: a systematic review and meta-analysis

“…Sixteen studies on POC CRP testing were excluded at full-text screening because they were not in an ambulatory care setting,26 27 no comparator group without POC CRP testing was present,28–31 the effect of the POC CRP could not be assessed separately or did not guide treatment decisions,32–34 the focus was cost-effectiveness modelling35–37 or decision-making analysis,38 39 or it was not a clinical trial (study protocol or response to systematic review)40 41 (online supplementary file 3).…”