Does laboratory antibiotic susceptibility reporting influence primary care prescribing in urinary tract infection and other infections?

OBJECTIVES: Using a prospective interrupted time series design, our goal was to determine whether a change in urine antibiotic susceptibility reporting from co-amoxiclav to cefalexin to community clinicians served by Southmead General Hospital led to a change in antibiotic prescribing. METHODS: We used longitudinal data on antibiotic prescribing using a clinician questionnaire to identify prescribing for urinary tract infections (UTIs) when a urine specimen was submitted to microbiology; MIQUEST computer search in general practices for prescribing for all UTIs in the community; and Prescribing Analysis and Cost (PACT) data to determine antibiotic prescribing for all infections. RESULTS: Cefalexin and cephalosporin prescribing increased when cefalexin was reported and co-amoxiclav prescribing decreased when co-amoxiclav was not reported by the laboratory. This was seen for episodes of UTI in which a general practitioner (GP) sent a specimen as determined with: the questionnaire results (9-fold rise in cephalosporins, 70% fall in co-amoxiclav); episodes of UTI identified by MIQUEST searches in the practice (50% increase in cefalexin, 25% reduction in co-amoxiclav); and overall antibiotic prescribing in the practice determined with PACT data (20% increase in cefalexin, 8% reduction in co-amoxiclav). MIQUEST data indicated that prescribing reverted to pre-intervention levels once the change in antibiotic reporting had stopped. CONCLUSIONS: Our data provide more evidence that changing laboratory antibiotic susceptibility reporting has a direct effect on antibiotic prescribing by GPs. Our data indicate that much of the change in prescribing was attributable to the use of cefalexin and co-amoxiclav for persistent or recurrent infections. Microbiology laboratories can influence antibiotic use by selectively reporting antibiotics they would prefer GPs to prescribe.

In vitro evaluation of five rapid antigen detection tests for group A beta-haemolytic streptococcal sore throat infections.

BACKGROUND: Using accurate and easy to use rapid antigen detection tests (RADTs) to identify group A beta-haemolytic Streptococci (GABHS) sore throat infections could reduce unnecessary antibiotic prescribing and antimicrobial resistance. Although there is no international consensus on the use of RADTs, these kits have been widely adopted in Finland, France and the USA. Yet in the UK, the Clinical Knowledge Summaries, that provide the main online guidance for GPs, discourage RADTs use, citing their poor sensitivity and inability to impact on prescribing decisions in acute sore throat infections. OBJECTIVE: The purpose of this study was to evaluate the ease of use and in vitro accuracy (sensitivity and specificity) of the five most commonly used RADTs in Europe (OSOM Ultra, Quickvue Dipstick, Streptatest, Clearview Exact Strep A and IMI Test Pack). METHODS: To ensure the RADTs were evaluated objectively, a standardized in vitro method using known concentrations of GABHS was used to remove the inherent biases associated with clinical studies. RESULTS: The IMI Test Pack was the easiest RADT to use overall. The ability to detect all positive GABHS (sensitivity) varied considerably between kits from 95% [95% confidence interval (CI): 88-98%], for the IMI Test Pack and OSOM, to 62% (95% CI: 51-72%) for Clearview, at the highest GABHS concentration. None of the RADTs gave any false-positive results with commensal flora-they were 100% specific. CONCLUSIONS: The IMI Test Pack is most suitable for use in primary care, as it had high sensitivity, high specificity and was easy to use.