National trends in emergency department antibiotic prescribing for elders with urinary tract infection, 1996-2005

Abstract

Objectives: Given reported increases in antibiotic resistance among elders with urinary tract infection (UTI) and pyelonephritis, the authors identified national rates and trends in emergency department (ED) trimethoprim-sulfamethoxazole (TMP-SMX) and fluoroquinolone prescribing for older adults from 1996 to 2005.

Methods: This was a retrospective analysis utilizing the ED component of the 1996-2005 National Hospital Ambulatory Medical Care Survey (NHAMCS). The authors included NHAMCS ED entries aged >or=18 years with a diagnosis of UTI or pyelonephritis; pregnancy was excluded. Records were divided into 18-64 years ("adults") and >or=65 years ("elders"). Primary outcome measures were prescription of TMP-SMX monotherapy, fluoroquinolone monotherapy, and combination therapy with two or more antibiotics. Estimated visit totals and rates were calculated and trends analyzed.

Results: From 1996 to 2005, there were 5 million elder ED visits for UTI or pyelonephritis. Approximately 9.4% (95% confidence interval [CI] = 7.9% to 11%) of elders received TMP-SMX monotherapy with rates decreasing over time (p-value for trend = 0.031). Overall, 35% (95% CI = 32% to 38%) of elders received fluoroquinolone monotherapy, which increased from 21% (95% CI = 14% to 27%) in 1996 to 45% (95% CI = 39% to 50%) in 2005 (p-value for trend < 0.001). Therapy with a fluoroquinolone plus a second antibiotic was used in only 4.2% (95% CI = 3.1% to 5.3%) of older patients.

Conclusions: From 1996 to 2005, TMP-SMX monotherapy in elder ED patients decreased while fluoroquinolone therapy increased. The majority of older patients receiving fluoroquinolone therapy received a single agent. Given the continued prevalence of monotherapy for elder ED patients with UTI or pyelonephritis, antibiotic resistance patterns in these patients should be better characterized to ensure institution of appropriate empiric therapy.