Impact on antibiotic prescription of rapid antigen detection testing in acute pharyngitis in adults: a randomised clinical trial.

BACKGROUND Acute pharyngitis is one of the most frequent reasons for a GP consultation, and in most cases an antibiotic is prescribed. AIM To determine the impact of rapid antigen detection testing (RADT) to identify group A beta haemolytic streptococcus in acute pharyngitis on the utilisation of antibiotics and appropriateness of their use. DESIGN AND SETTING Cluster randomised controlled trial in primary care centres in Catalonia, Spain. METHOD Patients with acute pharyngitis aged 14 years or older with at least one Centor criterion (fever, tonsillar exudate, tender enlarged anterior cervical lymph nodes, or absence of cough) were recruited. Participant physicians were randomly assigned to one of two study arms: an intervention group (assigned to RADT) and a control group (following usual care, without RADT). RESULTS Of the 557 adults enrolled, 543 could be evaluated for analysis (281 [51.7%] in the intervention group and 262 [48.3%] in the control group). GPs without access to RADT were more likely to prescribe antibiotics compared with those who performed rapid tests (64.1% versus 43.8%, P<0.001). The more Centor criteria the patients presented, the greater the number of antibiotics prescribed, regardless of whether RADT was available (P<0.001). Antibiotics were prescribed in 30.7% of the cases with negative RADT results. Inappropriate antibiotic prescription was observed in 226 cases (43%), and was significantly greater in the control than in the intervention group (60% versus 26.9%; P<0.001). CONCLUSION Even though more than 30% of negative RADT results resulted in antibiotic prescribing, the study findings support the use of RADT in the consultation. This strategy has an important impact on reducing antibiotic prescription among adults with acute pharyngitis.