Economic evaluation of oseltamivir phosphate for postexposure prophylaxis of influenza in long-term care facilities.
OBJECTIVE
To compare the cost-effectiveness of oseltamivir postexposure prophylaxis during influenza A outbreaks with that of amantadine postexposure prophylaxis or no postexposure prophylaxis in long-term care facilities (LTCFs).


METHODS
Cost-effectiveness analysis based on decision analytic model from a government-payer perspective.


METHODS
A Canadian LTCF, with high staff vaccination, at the beginning of influenza season.


METHODS
Elderly, influenza-vaccinated patients living in a Canadian LTCF.


METHODS
Incremental costs (or savings) per influenza-like illness case avoided compared with usual care.


RESULTS
From a government-payer perspective, this analysis showed that oseltamivir was a dominant strategy because it was associated with the fewest influenza-like illness cases, with cost savings of $1,249 per 100 patients in 2001 Canadian dollars compared with amantadine and $3,357 per 100 patients compared with no prophylaxis. Costs for amantadine dose calculation and hospitalization for adverse events contributed to amantadine being a more-expensive prophylaxis strategy than oseltamivir. Both prophylaxis strategies were more cost-effective than no prophylaxis.


CONCLUSIONS
Despite high influenza vaccination rates, influenza outbreaks continue to emerge in LTCFs, necessitating cost-effective measures to further limit the spread of influenza and related complications. Although amantadine has a lower acquisition cost than oseltamivir, it is associated with more adverse events, lower efficacy, and individualized dosing requirements, leading to higher overall costs and more influenza-like illness cases than oseltamivir. Therefore the use of oseltamivir postexposure prophylaxis is more cost-effective than the current standard of care with amantadine prophylaxis or no prophylaxis.
Risebrough
Nancy A
NA
Health Outcomes and PharmacoEconomics Research Center, Sunnybrook and Women's College Health Sciences Centre, Toronto, Canada. nancy.risenbrough@sw.ca
Bowles
Susan K
SK
Simor
Andrew E
AE
McGeer
Alison
A
Oh
Paul I
PI
D000081:Acetamides / Q000191:economics / Q000627:therapeutic use*; D000368:Aged; D000547:Amantadine / Q000191:economics / Q000627:therapeutic use*; D000998:Antiviral Agents / Q000191:economics / Q000627:therapeutic use*; D002170:Canada; D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D004196:Disease Outbreaks / Q000191:economics / Q000517:prevention & control*; D006801:Humans; D007251:Influenza, Human / Q000191:economics / Q000517:prevention & control*; D008134:Long-Term Care / Q000191:economics*; D018803:Models, Economic; D009735:Nursing Homes / Q000191:economics*; D053139:Oseltamivir
D000081:Acetamides; D000998:Antiviral Agents; D053139:Oseltamivir; D000547:Amantadine