QUANTIFYING THE DISUTILITY OF TAKING PILLS FOR PREVENTING HEART DISEASE

Purpose: The utility attributed to taking pills for prevention can have major effects on the cost-effectiveness of interventions, but few published studies have systematically quantified this value.  We quantified the utility value of taking pills used for prevention of cardiovascular disease.

Method: We conducted a cross-sectional Internet-based survey of people ages 30 and older across the U.S. in March 2014.   Our main outcome was utility values for taking one pill daily assessed using time trade-off.  We also assessed utility values for taking one pill daily using modified standard gamble and willingness-to-pay methods.  For all three methods, we also looked at the percentage who would not be willing to trade anything, equating to a utility of 1.0. In addition to demographics, we assessed numeracy and health literacy using brief screeners.

Result: Mean age of respondents (n=1000) was 50 years. The majority were female (59%) and Caucasian (63%).  A minority (28%) had less than a college degree.  About 51% answered both numeracy questions correctly. A majority (69%) took at least two pills per day while 21% took no daily pills. The mean utility value using the time trade-off method was: 0.990 (95% CI 0.988-0.992) for one pill daily.  Approximately 70% were not willing to trade any time. The utility value for 1 pill daily using the standard gamble method was 0.991 (0.989-0.993) with 62% not willing to risk any chance of death. The utility value for taking 1 pill daily using the willingness-to-pay method was 0.994 (0.940-0.997) with respondents willing to pay $2,452 to not have to take 1 pill daily for the rest of their life.  Approximately 33% were not willing to pay anything.  Time trade-off utility values for 1 pill daily varied by age (with decreasing utility as age increases) and income (increasing utility as income increases), but did not vary by sex, education level, literacy, numeracy, difficulty obtaining or paying for pills, number of pills taken per day, or number of times pills were taken per day.

Conclusion: The utility value of taking pills daily for cardiovascular disease prevention is approximately 0.990, which appears to vary little across demographic characteristics.  The value only varies slightly by utility elicitation technique with willingness-to-pay having the highest utility (0.994) and time trade-off having the lowest utility (0.990).