Population based cost utility study of interferon beta-1b in secondary progressive multiple sclerosis.
OBJECTIVE
To evaluate the cost utility of interferon beta-1b in secondary progressive multiple sclerosis.


METHODS
Population based cost utility model (healthcare perspective). Data on use of health services were obtained from case records and routine morbidity data and utility values from a EuroQol survey. Local and published costs were used. Effectiveness was modelled using data on relative risk reductions from a randomised trial of interferon beta-1b.


METHODS
Tayside region, 1993-5.


METHODS
132 ambulatory people with secondary progressive multiple sclerosis.


METHODS
Cost per quality adjusted life year (QALY) gained. Rate of relapse and proportion becoming wheelchair dependent over three years.


RESULTS
The number needed to treat for 30 months to delay time to wheelchair dependence in one person by nine months was 18 (95% confidence interval 5 to 26). For every 18 people treated for 30 months, six relapses would be prevented, gaining 0.397 discounted QALYs. The cost per QALY gained was 1 024 667 pounds sterling (276 466 pounds sterling to 485 499 pound sterling). If treatment was restricted to patients attending neurology services, the number needed to treat was 14 (cost per QALY gained 833 pounds sterling 514 (161 358 pounds sterling to infinity)). The cost per QALY gained was not sensitive to changes in cost which took account of a societal perspective.


CONCLUSIONS
The cost per QALY gained from interferon beta is high because of the high drug cost and modest clinical effect. Resources could be used more efficiently elsewhere.
Forbes
R B
RB
Department of Neurology, Ninewells Hospital and Medical School, Dundee DD1 9SY. raeburn.forbes@royalhospitals.n-i.nhs.uk
Lees
A
A
Waugh
N
N
Swingler
R J
RJ
D000203:Activities of Daily Living; D000276:Adjuvants, Immunologic / Q000191:economics* / Q000627:therapeutic use; D015331:Cohort Studies; D003362:Cost-Benefit Analysis; D016527:Drug Costs; D006801:Humans; D000068556:Interferon beta-1a; D000068576:Interferon beta-1b; D016899:Interferon-beta / Q000191:economics* / Q000627:therapeutic use; D009103:Multiple Sclerosis / Q000188:drug therapy / Q000191:economics*; D019057:Quality-Adjusted Life Years; D012008:Recurrence; D012606:Scotland; D012680:Sensitivity and Specificity; D014910:Wheelchairs / Q000191:economics
D000276:Adjuvants, Immunologic; D000068576:Interferon beta-1b; D016899:Interferon-beta; D000068556:Interferon beta-1a