A multicentre cluster-randomized clinical trial to improve antibiotic use and reduce length of stay in hospitals: comparison of three measurement and feedback methods.

BACKGROUND: Various metrics of hospital antibiotic use might assist in guiding antimicrobial stewardship (AMS). OBJECTIVES: To compare patient outcomes in association with three methods to measure and feedback information on hospital antibiotic use when used in developing an AMS intervention. METHODS: Three methods were randomly allocated to 42 clusters from 21 Dutch hospitals: (1) feedback on quantity of antibiotic use [DDD, days-of-therapy (DOT) from hospital pharmacy data], versus feedback on (2) validated, or (3) non-validated quality indicators from point prevalence studies. Using this feedback together with an implementation tool, stewardship teams systematically developed and performed improvement strategies. The hospital length of stay (LOS) was the primary outcome and secondary outcomes included DOT, ICU stay and hospital mortality. Data were collected before (February-May 2015) and after (February-May 2017) the intervention period. RESULTS: The geometric mean hospital LOS decreased from 9.5 days (95% CI 8.9-10.1, 4245 patients) at baseline to 9.0 days (95% CI 8.5-9.6, 4195 patients) after intervention (P < 0.001). No differences in effect on LOS or secondary outcomes were found between methods. Feedback on quality of antibiotic use was used more often to identify improvement targets and was preferred over feedback on quantity of use. Consistent use of the implementation tool seemed to increase effectiveness of the AMS intervention. CONCLUSIONS: The decrease in LOS versus baseline likely reflects improvement in the quality of antibiotic use with the stewardship intervention. While the outcomes with the three methods were otherwise similar, stewardship teams preferred data on the quality over the quantity of antibiotic use.