Discounting of qualitatively different delayed health outcomes in current and never smokers

Abstract

In delay discounting, temporally remote outcomes have less value. Cigarette smoking is associated with steeper discounting of money and consumable outcomes. It is presently unclear whether smokers discount health outcomes more than nonsmokers. We sought to establish the generality of steep discounting for different types of health outcomes in cigarette smokers. Seventy participants (38 smokers and 32 nonsmokers) completed 4 hypothetical outcome delay-discounting tasks: a gain of $500, a loss of $500, a temporary boost in health, and temporary cure from a debilitating disease. Participants reported the duration of each health outcome that would be equivalent to $500; these durations were then used in the respective discounting tasks. Delays ranged from 1 week to 25 years. Smokers' indifference points for monetary gains, boosts in health, and temporary cures were lower than indifference points from nonsmokers. Indifference points of 1 outcome were correlated with indifference points of other outcomes. Smokers demonstrate steeper discounting across a range of delayed outcomes. How a person discounts 1 outcome predicts how they will discount other outcomes. These 2 findings support our assertion that delay discounting is in part a trait.

Figure 1

Median indifference points with lines of best fit. Model fits to the data from smokers and non-smokers for four delay discounting outcomes. Present value is expressed as a proportion of the undiscounted amount of the delayed outcome. For each line, the highest quality model is shown. See text and Table 2 for model selection.

Figure 2

Scatterplots of adjusted mean indifference point ranks for smokers with non-parametric Spearman’s Rho correlation reported and line of best fit. Alcohol Use Disorder Identification Test, Information Inventory, and education scores included as covariates. Axes on each figure are the rank of the mean adjusted indifference points. Note: * p < .05, ** p < .01

Figure 3

Scatterplots of adjusted mean indifference point ranks for non-smokers with non-parametric Spearman’s Rho correlation reported and line of best fit. Alcohol Use Disorder Identification Test, Information Inventory, and education scores included as covariates. Axes on each figure are the rank of the mean adjusted indifference points. Note: * p < .05, ** p < .01