A meta-analysis of six double-blinded clinical trials was undertaken to ide
ntify risk factors associated with bacteriologic outcome in 3,108 women wit
h acute cystitis. Eleven antibiotic regimens were used, including ciproflox
acin, ofloxacin, norfloxacin, trimethoprim-sulfamethoxazole, and nitrofuran
toin. Entry criteria for all studies were identical. Among 2,409 patients w
ho were defined to be valid for efficacy analysis, pathogens included Esche
richia coli (78.6%), Staphylococcus saprophyticus (4.4%), Klebsiella pneumo
niae (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 greater than or equal to 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 = .0396)
and "other" pathogens (P = .0018) were associated with increased probabilit
y of bacteriologic treatment failure, The presence of pyuria (greater than
or equal to 10 WBCs per high-power field) did not correlate with outcome an
d was inversely correlated with the finding of greater than or equal to 10(
5) bacterial colony-forming units per mt of urine (P < .001). This large da
tabase identifies new parameters associated with treatment outcomes of acut
e cystitis and calls into question current clinical trial guidelines.