Improvements in Antibiotic Appropriateness for Cystitis in Older Nursing Home Residents: A Quality Improvement Study With Randomized Assignment

Abstract

Objective: To determine the impact of an educational quality improvement initiative on the appropriateness of antibiotic prescribing restricted to uncomplicated cystitis in older noncatheterized nursing home residents.

Design: Quality improvement study with randomized assignment.

Settings and participants: Twenty-five nursing homes in United States were randomized to the intervention or usual care group by strata that included state, urban/rural status, bed size, and geographic separation.

Methods: A 12-month trial of a low-intensity multifaceted antimicrobial stewardship intervention focused on uncomplicated cystitis in nursing home residents vs usual care. The outcome was the modified Medication Appropriateness Index as assessed by a blinded geriatric clinical pharmacist and consisted of an assessment of antibiotic effectiveness, dosage, drug-drug interactions, and duration.

Results: There were 75 cases (0.15/1000 resident days) in intervention and 92 (0.22/1000 resident days) in control groups with a probable cystitis per consensus guidelines. Compared with controls, there was a statistically nonsignificant 21% reduction in the risk of inappropriate antibiotic prescribing (nonzero Medication Appropriateness Index score rate 0.13 vs 0.21/1000 person days; adjusted incident rate ratio 0.79; 95% confidence interval 0.45‒1.38). There was a favorable comparison in inappropriateness of duration (77% vs 89% for intervention vs control groups, respectively; P = .0394). However, the intervention group had more problems with drug-drug interactions than the control group (8% vs 1%, respectively; P = .0463). Similarly, the intervention group had a nonsignificant trend toward more problems with dosage (primarily because of the lack of adjustment for decreased renal function) than the control group (32% vs 25%, respectively; P = .3170). Both groups had similar rates of problems with choice/effectiveness (44% vs 45%; P = .9417). The most common class of antibiotics prescribed inappropriately was quinolones (25% vs 23% for intervention versus control groups, respectively; P = .7057).

Conclusions and implications: A low-intensity intervention showed a trend toward improved appropriate antibiotic prescribing in nursing home residents with likely uncomplicated cystitis. Efforts to improve antibiotic prescribing in addition to the low-intensity intervention might include a consultant pharmacist in a nursing home to identify inappropriate prescribing practices.

Keywords: Aged; antibacterial-agents; cystitis; inappropriate prescribing; nursing homes; randomized controlled trial.