Table 3.

Inputs to the cost utility model of interferon beta 1b for secondary progressive multiple sclerosis (Tayside 1993-5)

	Population cohort	Neurology subset
No needed to treat for 30 months to delay time to wheelchair dependence by 9 months for 1 person	18	14
No of hospital treated relapses prevented*	1	1
No of community treated relapses prevented†	2	1
No of untreated relapses prevented	3	2
Cost saved per hospital treated relapse prevented	£1700	£2130
Costs saved per community treated relapse prevented	£30	£30
QALYs gained per 9 months of wheelchair dependence avoided	0.281	0.281
QALYs gained per hospital treated relapse prevented	0.031	0.031
QALYs gained per community treated or untreated relapse prevented	0.021	0.021
Relative risk reduction of wheelchair dependence4	32%	32%
Relative risk reduction of hospital admission4	12%	12%
Relative risk reduction in corticosteroid use4	21%	21%
Relative risk reduction in untreated relapses4	31%	31%

^*As there was a 12.1% relative reduction in hospital admissions in the trial,⁴ one (0.49 rounded up to nearest integer) hospital admission would have been prevented for every 18 people treated for 30 months. 

^†As there was a 21% relative reduction in corticosteroid use in the trial,⁴ 2 (1.38 rounded up to nearest integer) community treated relapses would have been prevented for every 18 people treated for 30 months.