Improving compliance with hospital antibiotic guidelines: a time-series intervention analysis

Objectives: This study investigated the impact of a combined intervention strategy to improve antimicrobial prescribing at University Hospital Groningen. For the intervention, the antimicrobial treatment guidelines were updated and disseminated in paperback and electronic format. The credibility of the guidelines was improved by consultation with users. In a second phase, academic detailing (AD) was used to improve specific areas of low compliance with the guidelines. Materials and methods: Prescribing data were prospectively collected for 2869 patients receiving 7471 prescriptions for an antimicrobial for an infection covered by the guidelines between July 2001 and September 2003. After collection of baseline data, the guidelines were actively disseminated in February 2002. Next, after a 5 month interval, a second intervention, i.e. an AD approach, addressed suboptimal prescribing of ciprofloxacin and co-amoxiclav. Segmented regression analysis was used to analyse the interrupted time-series data. Results: At baseline, compliance with the drug choice guidelines was 67%. The first intervention showed a significant change in the level of compliance of +15.5% (95% CI: 8%; 23%). AD did not lead to statistically significant additional changes in already high levels +12.5% (95% CI:-3%; 28%) of compliance. Post-intervention compliance was stable at 86%. Conclusions: Updating the guidelines in close collaboration with the specialists involved followed by active dissemination proved to be an efficient way to improve compliance with guideline recommendations. An 86% compliance level was achieved in this study without compulsory measures. A ceiling effect may have limited the added value of AD