
Methods: We identified children 6m-18y from 28 children’s hospitals admitted between Aug 2009 and Mar 2015 with a diagnosis of pneumonia and who received antibiotics within the first 2 hospital days. Each hospital was surveyed regarding local activities implemented after guideline release (eg, clinical practice guideline, CPG). Outcomes included the monthly percentage of children receiving penicillins or cephalosporins. Interrupted time series analysis was used to assess the national guideline impact by comparing the absolute change in prescribing at the end of the study ([observed % from post-guideline trend] –[expected % from pre-guideline trend]) aggregated across all hospitals. Hospital-level analyses assessed the impact of local activities.
Results: 58,559 pneumonia hospitalizations were included. Prior to the national guideline, penicillin use was rare (<10%); cephalosporins accounted for ~60% of prescribing. After guideline release, 19 hospitals (68%) implemented a new CPG and 20 (71%) implemented a new order set. By the end of the study and compared with pre-guideline trends, we noted an absolute increase in penicillin use of 27.6% (95% CI: 23.7%-31.5%)[Figure 1]. Cephalosporin use declined by a similar magnitude (not shown). Prescribing changes varied across hospitals[Figure 2]. Among hospitals implementing a CPG or order set, the median difference was 29.5 [IQR 19.6, 39.1] for penicillins, while among hospitals without local activities, the median difference was 20.1 [9.5, 44.5]; these differences were not statistically significant.
Conclusion: Antibiotic prescribing for pneumonia changed substantially after release of a national guideline, although institutional adoption varied. Local implementation efforts may enhance appropriate antibiotic selection, but room for improvement remains.

D. J. Williams,
None
J. S. Gerber, None
M. Neuman, None
A. L. Hersh, Merck: Grant Investigator , Research grant
T. Brogan, None
K. Parikh, None
S. Mahant, None
A. J. Blaschke, None
S. Shah, None
C. G. Grijalva, Thrasher Research Fund: Grant Investigator , Research grant
Pfizer: Grant Investigator , Research grant
Pfizer: Consultant , Consulting fee