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 points

• There 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.

Keywords:

• C-reactive protein
• respiratory tract infections
• primary health care
• antibacterial agents
• drug prescriptions
• general practice
• point-of-care systems
• Sweden

Acknowledgements

The authors would like to thank the personnel at the Närhälsan Primary Health Care Centers in Floda, Gråbo, Lerum, Sörhaga and Ängabo, Sweden for their help in gathering data, thus making this paper possible. They would also like to thank the patients who willingly participated in the study.

Ethical approval

The Regional Ethical Review Board in Gothenburg approved the study (Dnr 477-11). Written informed consent was obtained from physicians and patients.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Financial support was obtained from the research and development council of Södra Älvsborg, Västra Götaland Region, Sweden.