Cost-Effectiveness Analysis of Fosfomycin for Treatment of Uncomplicated Urinary Tract Infections in Ontario

Table 2

Probability values used in the model for decision-tree nodes and ranges used in the sensitivity analyses.

Variable	Base case	Range tested	References
Sensitive isolate: UTI resolution (clinical cure)	0.94	—	[27–32]
Resistant isolate: UTI resolution (clinical cure)	0.74	—	[33]
Pyelonephritis due to initial treatment failure	0.04	0–0.08	[27, 28, 34, 35], hypothesis of plausible range
Hospitalization for pyelonephritis	0.20	0–0.40	[36], hypothesis of plausible range
Empirical extended treatment due to initial treatment failure (switch from initial treatment to another antibiotic)	0.75/0.25; (0.25/0.75 for ciprofloxacin)	—	[27, 28, 35]
Pathogens present in UTI
E. coli	0.841	0.767–0.918	[7, 22, 37]
Enterococcus spp.	0.028	—	[37]
K. pneumoniae	0.038	—	[37]
P. mirabilis	0.026	—	[37]
Treatment with fosfomycin	0.0177	0–0.250	Pharmastat, hypothesis of plausible range
Treatment with sulfonamides	0.2566	—	Pharmastat
Treatment with nitrofurantoins	0.5410	—	Pharmastat
Treatment with fluoroquinolones	0.1848	—	Pharmastat
E. coli resistance to fosfomycin	0.006	0.004–0.012	[6, 21, 22]
E. coli resistance to sulfonamides (TMP–SMX)	0.26	0.141–0.294	[15, 16]
E. coli resistance to fluoroquinolones (ciprofloxacin)	0.21	0.191–0.245	[6, 15, 22]
E. coli resistance to nitrofurantoin	0.01	0.0016–0.019	[15, 16, 22]

TMP–SMX, trimethoprim–sulfamethoxazole; UTI, urinary tract infection.
erived from urinary, respiratory, wound, and blood isolates.