C-reactive protein: guiding antibiotic prescribing decisions at the point of care

C-reactive protein (CRP) is an acute-phase protein, which was originally named for its capacity to precipitate the C-polysaccharide of Streptococcus pneumoniae . The acute-phase response comprises the non-specific physiological and biochemical response to most forms of tissue damage, infection and inflammation. It is now a widely used and acknowledged marker to diagnose and monitor infections, especially in secondary care. But it is now also being used increasingly by primary care physicians to identify patients who are unlikely to benefit from an antibiotic. Thus, CRP is potentially a useful tool to enhance antibiotic stewardship. In the current (March) issue of the BJGP , Lemiengre and colleagues performed a cluster-randomised trial in 2227 children with a non-severe acute infection.1 They were randomised to a brief intervention that elicited and attempted to address parent concerns, GP use of a CRP test, both, or usual care. The brief intervention paradoxically increased antibiotic prescribing, while GP use of CRP alone or GP use of CRP plus the brief intervention had no significant effect on prescribing. Hence, this large study performed in general practice indicates that GP use of CRP in children with non-severe acute infections cannot be supported. This is in line with another interesting paper from this group, which suggests that there may be a role for CRP to guide referral in children with infections, but only in those children at risk of serious infections based on a clinical decision rule.2 In this editorial we look at the role of CRP in guiding antibiotic prescribing decisions. Specifically, we identify the patient populations where we currently have evidence that CRP use by GPs improves prescribing decisions, and will discuss whether adding CRP to decision rules can further improve these antibiotic …