Antibiotic overuse and misuse is a common problem in nursing homes. Antibiotic time-out (ATO) interventions have led to improvements in antibiotic uses in hospitals, but their impact in nursing homes remain understudied.

To evaluate the impact of a stewardship intervention, promoting use of ATOs on the frequency and types of antibiotic change events (ACEs) in nursing homes.

Controlled before-and-after intervention study.

Nursing homes in Wisconsin and Pennsylvania.

Data on antibiotic prescriptions in 11 nursing homes were collected for 25 months. We categorized ACEs as (1) early discontinuation, (2) class modification, or (3) administration modification. Class modification ACEs were further classified based on whether the change narrowed, expanded, or had no effect on bacterial spectrum coverage. Analyses were performed using a difference-in-difference (DiD) approach.

Of 2,647 antibiotic events initiated in study nursing homes, 376 (14.2%) were associated with an ACE. The overall proportion of ACEs did not significantly differ between intervention and control nursing homes. Early discontinuation ACEs increased in intervention nursing homes (DiD, 2.5%; P = .01), primarily affecting residents initiated on broad-spectrum antibiotics (DiD, 2.9%; P < .01). Class modification ACEs decreased in intervention nursing homes but remained unchanged in control nursing homes.

The impact of an ATO intervention in study nursing homes was mixed with increases in early discontinuation ACEs offset by reductions in class modification ACEs. More research on the potential value of ATO interventions in nursing homes is warranted.