The clinical rate of antibiotic change following empiric treatment for suspected urinary tract infections.

purposeTo determine the rate of antibiotic change in an outpatient setting following empiric treatment of culture proven UTI and to identify risk factors associated with change.

methodsPatients with suspected UTI and urine culture were reviewed (January 2016-June 2016). Those with a positive culture were categorized by whether or not they were treated empirically. Empiric treatment was evaluated for associations with clinical-demographic data, symptoms and urinalysis (UA). Antibiotic change was evaluated with clinical-demographic data, urine culture, and resistance patterns.

results916 urine cultures (636 patients) were included. 391 (43%) cultures were positive, and 164 (42%) were treated empirically. Clinical-demographic data did not differ between groups. Those treated empirically had more documented UTI symptoms (93 vs 58%, P < 0.001), and UA abnormalities including positive nitrites (51 vs 29%, P < 0.001), 3 + leukocyte esterase (27 vs 19%, P = 0.002) and 3 + blood (13 vs 4%, P = 0.005). Of those treated empirically, 42/164 (26%) required an antibiotic change, and this was associated with immunosuppression (12 vs 2%, P = 0.027) resistance to > 3 antibiotics (33 vs 20%, P = 0.039) and also resistance to fluoroquinolone (50 vs 30%, P = 0.016), monobactam (19 vs 7% P = 0.042) and TMP-SMX (52 vs 19%, P < 0.001).

conclusionsAlmost one-quarter of patients treated empirically required antibiotic change. This was driven largely by bacterial resistance. New technologies allowing rapid bacterial identification and sensitivity may improve patient care.