Problems in interpreting cost effectiveness in clinical trials. Experimental versus implementation costs.
OBJECTIVE
To demonstrate the difficulty of estimating cost effectiveness of alternative implementation strategies using clinical trial data.


METHODS
Two examples drawn from a hearing-aid intervention trial and a physical-therapy trial for frail elderly are used to demonstrate how alternative implementation strategies may affect cost effectiveness. Sensitivity analysis is used to document a range of possible economic outcomes for each example and show how assumptions based on trials may bias implementation decisions.


METHODS
Costs and cost-effectiveness ratios are estimated for alternative implementation strategies and compared with trial results.


RESULTS
Staffing and equipment substitutions, reconfigurations, and economies of scale can reduce the cost of trial interventions substantially. Such resource alterations as well as protocol and target group modifications may also have an impact on effectiveness. In both examples effectiveness can be reduced by as much as 50% and under certain conditions alternative implementation strategies will still be cost effective.


CONCLUSIONS
Cost effectiveness of implementations can differ substantially from a trial when different resources or target populations are incorporated. Institutions must conduct preimplementation studies which consider alternative resource configurations before adopting an intervention based on trial results.
De Nino
L A
LA
Geriatric Research, Education and Clinical Center, Audie L. Murphy Memorial Veterans Hospital, San Antonio, TX 78284.
Mulrow
C D
CD
Gerety
M B
MB
Averyt
E C
EC
D000368:Aged; D000369:Aged, 80 and over; D002986:Clinical Trials as Topic / Q000191:economics*; D003362:Cost-Benefit Analysis / Q000379:methods*; D003661:Decision Support Techniques; D016330:Frail Elderly; D015276:Health Care Rationing / Q000191:economics; D006310:Hearing Aids / Q000191:economics; D006801:Humans; D009735:Nursing Homes; D017063:Outcome Assessment, Health Care / Q000191:economics*; D026741:Physical Therapy Modalities / Q000191:economics; D011788:Quality of Life; D013781:Texas; D026712:Value of Life