Methods: Data on antibiotic use in five Wisconsin NHs were collected prospectively. Appropriateness of prescribing events were determined using Loeb criteria. Multivariable analyses using generalized estimating equations (GEE) were employed to assess relationships between antibiotic appropriateness and several “fixed” resident characteristics, including age, gender, life-sustaining treatment preferences, cognitive and functional status, comorbidity, and presence of a chronic wound or indwelling medical device. Sub-group analyses stratified by type of infection were also explored
Results: Data on 1108 prescribing events were collected during the study period. 534 (48%) antibiotic courses were prescribed for UTI, 321 (29%) for RTI, and 253 (23%) for SSTI. Overall, 447 (40%) antibiotic courses were appropriate by Loeb criteria. On multivariable analyses, female gender (OR=1.3, 95% CI=1.1-1.7, p=0.01), increasing comorbidity (OR=1.2, 95% CI=1.0-1.3, p=0.02), and active DNR order (OR=1.7, 95% CI=1.4-2.1, p<0.01) were associated with a higher likelihood of receiving appropriate antibiotic therapy. The combination of impaired cognition and increasing comorbidity (OR=0.9, 95% CI=0.8-0.9, p<0.01) was associated with a lower likelihood of appropriate antibiotic therapy. When stratified by type of infection, similar relationships were identified. Additionally, presence of a chronic wound (OR=0.6, 95% CI=0.5-0.7, p<0.01) and/or indwelling medical device (OR=0.5, 95% CI=0.2-1.0, p=0.05) were associated with lower likelihood of appropriate antibiotic therapy for events in which antibiotics were prescribed for SSTI.
Conclusion: Our study shows that “fixed” resident factors, those independent of the acute change-in-condition (e.g., fever), are associated with appropriateness of antibiotic prescribing in nursing homes. This suggests that resident case-mix should be considered when performing benchmarking of antibiotic utilization in NHs and developing interventions to improve prescribing in this setting.
T. Hess, None
C. Crnich, None