Procalcitonin-guided antibiotic use vs a standard approach for acute respiratory tract infections in primary care

Arch Intern Med. 2008 Oct 13;168(18):2000-7; discussion 2007-8. doi: 10.1001/archinte.168.18.2000.


Background: Acute respiratory tract infections are the most common reason for antibiotic therapy in primary care despite their mainly viral etiology. A laboratory test measuring procalcitonin levels in blood specimens was suggested as a tool to reduce unnecessary prescribing of antibiotics. We consider whether antibiotic therapy guided by procalcitonin reduces the use of antibiotics without increasing the restrictions experienced by patients by more than 1 day.

Methods: Fifty-three primary care physicians recruited 458 patients, each patient with an acute respiratory tract infection and, in the physician's opinion, in need of antibiotics. Patients were centrally randomized to either a procalcitonin-guided approach to antibiotic therapy or to a standard approach. For patients randomized to procalcitonin-guided therapy, the use of antibiotics was more or less strongly discouraged (procalcitonin level, < or =0.1 or < or =0.25 microg/L, respectively) or recommended (procalcitonin level, >0.25 microg/L). Follow-up data were collected at 7 days by treating physicians and at 14 and 28 days by blinded interviewers.

Results: Adjusted for baseline characteristics, the mean increase at 14 days in days in which activities were restricted was 0.14 with procalcitonin-guided therapy (95% confidence interval [CI], -0.53 to 0.81 days), which met our criterion of an increase in days in which activities were restricted by no more than 1 day. With procalcitonin-guided therapy, the antibiotic prescription rate was 72% lower (95% CI, 66%-78%) than with standard therapy. Both approaches led to a similar proportion of patients reporting symptoms of ongoing or relapsing infection at 28 days (adjusted odds ratio, 1.0 [95% CI, 0.7-1.5]).

Conclusions: As an adjunct to guidelines, procalcitonin-guided therapy markedly reduces antibiotic use for acute respiratory tract infections in primary care without compromising patient outcome. In practice, this could be achieved with 1 to 2 procalcitonin measurements in patients for whom the physician intends to prescribe antibiotics.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Disease
  • Adult
  • Anti-Bacterial Agents / administration & dosage
  • Anti-Bacterial Agents / therapeutic use*
  • Biomarkers / blood
  • Calcitonin / blood*
  • Calcitonin Gene-Related Peptide
  • Dose-Response Relationship, Drug
  • Female
  • Follow-Up Studies
  • Glycoproteins
  • Humans
  • Male
  • Middle Aged
  • Primary Health Care / methods*
  • Protein Precursors / blood*
  • Respiratory Tract Infections / blood
  • Respiratory Tract Infections / drug therapy*
  • Retrospective Studies
  • Treatment Outcome


  • Anti-Bacterial Agents
  • Biomarkers
  • CALCA protein, human
  • Glycoproteins
  • Protein Precursors
  • Calcitonin
  • Calcitonin Gene-Related Peptide

Associated data

  • ISRCTN/ISRCTN73182671