Tab. IX.

Utility decrements (by population).

Population	Base case input	Source
Spinal cord injury (SCI) catheter users	0.08	Bermingham et al. (2013) [17] ~ The utility for SCI for a cohort of catheter users aged 40 years old with 80% male was provided by the above (0.831). The utility norm for a cohort aged 40 years old with 80% male was obtained from the model (0.91), and 0.831 was subtracted from this to estimate the utility decrement for SCI catheter users.
Multiple sclerosis (MS) catheter users	0.33	Orme et al. (2007) [18] ~ Utility for EDSS 5 (reflects MS of middling severity) is assumed to be averagely representative of a MS patient with bladder impairment. This takes a value of 0.518. The study was carried out in a population with mean age 51.4 so a decrement was calculated by subtracting 0.518 from the utility norm of a 51 year old (0.845). It is assumed that this utility accounts for catheter usage and so no further utility decrement was applied for catheterization.