Randomised controlled trial of CRP rapid test as a guide to treatment of respiratory infections in general practice

Scand J Prim Health Care. 2000 Mar;18(1):39-43. doi: 10.1080/02813430050202541.


Objective: To assess whether the frequency of antibiotic prescriptions to patients with respiratory infections is reduced when general practitioners (GPs) use a C-reactive protein (CRP) rapid test in support of their clinical assessment, and to study whether using the test will have any effect on the course of disease

Design: Randomised controlled trial.

Setting: 35 general practices, County of Funen, Denmark.

Patients: 812 patients with respiratory infection.

Main outcome measures: Frequency of antibiotic prescriptions and morbidity 1 week after the consultation, as stated by the patients.

Results: In the CRP group the frequency of antibiotic prescriptions was 43% (179/414) compared with 46% (184/398) in the control group (odds ratio (OR) = 0.9, NS). After 1 week, increased or unchanged morbidity was stated more frequently in the CRP group (12%) than in the control group (8%) (OR = 1.6, p = 0.05). In the control group, the variable having the greatest influence on whether the GP prescribed antibiotics was the patients' general well-being (OR = 2.9, p < 0.0001), whereas in the CRP group the CRP value had the greatest influence (OR = 1.1 per unit increase (mg/l), p < 0.0001).

Conclusion: Based on the present study, the use of the CRP rapid test in support of a possible antibiotic treatment for respiratory infections in general practice cannot be recommended.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / therapeutic use*
  • C-Reactive Protein / analysis*
  • Child
  • Child, Preschool
  • Denmark
  • Drug Utilization Review
  • Family Practice / methods*
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Middle Aged
  • Practice Guidelines as Topic
  • Practice Patterns, Physicians'
  • Reagent Kits, Diagnostic
  • Respiratory Tract Infections / blood
  • Respiratory Tract Infections / diagnosis*
  • Respiratory Tract Infections / drug therapy*
  • Treatment Outcome


  • Anti-Bacterial Agents
  • Reagent Kits, Diagnostic
  • C-Reactive Protein