Demographic, Clinical, and Treatment Parameters Influencing the Outcome of Acute Cystitis

A meta-analysis of six double-blinded clinical trials was undertaken to identify risk factors associated with bacteriologic outcome in 3,108 women with acute cystitis. Eleven antibiotic regimens were used, including ciprofloxacin, ofloxacin, norfloxacin, trimethoprim-sulfamethoxazole, and nitrofurantoin. Entry criteria for all studies were identical. Among 2,409 patients who were defined to be valid for efficacy analysis, pathogens included Escherichia coli (78.6%), Staphylococcus saprophyticus (4.4%), Klebsiella pneumoniae (4.3%), Proteus mirabilis (3.7%), and other (9%). Causative bacteria were eradicated at the end of treatment in 93% of patients. The following parameters were associated with successful bacteriologic outcome: not using a diaphragm (P = .0041), treatment for ≥3 days (P =.0043), pathogen not other (P =.0043), symptom duration of <2 days (P =.0096), and African American race (P =.0147). K. pneumoniae (P =.0496) and other pathogens (P =.0018) were associated with increased probability of bacteriologic treatment failure. The presence of pyuria (≥10 WBCs per high-power field) did not correlate with outcome and was inversely correlated with the finding of ≥10 5 bacterial colony-forming units per mL of urine (P <.001). This large database identifies new parameters associated with treatment outcomes of acute cystitis and calls into question current clinical trial guidelines.