Cost-utility analysis evaluates the cost of medical care in relation to the gain in quality-adjusted life years (QALYs). Our purpose was to develop a cost model for surgical care for adult strabismus, to estimate the mean cost per case, to determine the associated gain in QALYs, and to perform cost-utility analysis.
Methods
A cost model incorporated surgery, pre- and postoperative care, and a mean of 1.5 procedures per patient. The gain in QALYs was based on the improvement of utility on a scale from 0 (death) to 1 (perfect health). Utility was measured through physician-conducted interviews employing a time tradeoff question (seeking to estimate the portion of life expectancy a patient would be willing to trade for being rid of disease and associated effects). The interviews were conducted before and 5 to 8 weeks after surgery in 35 strabismic patients (age 19-75 years).
Results
The cost model resulted in an estimated total cost of $4,254 per case. A significant improvement of utility was found: 0.96 ± 0.11 postoperatively versus 0.85 ± 0.20 preoperatively (p = 0.00008). Based on the mean life expectancy (36.0 years) of these patients, and discounting outcomes and costs by 3% annually, this resulted in a mean value gain of 2.61 QALYs after surgery and a cost-utility for strabismus surgery of $1,632/QALY.
Conclusions
In the United States, treatments <$50,000/QALY are generally considered “very cost-effective.” Strabismus surgery in adults falls well within this range.
aDepartment of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas
bCenter for Evidence Based Medicine, Flourtown, Pennsylvania
ABSTRACT