Opioid therapy for pain is associated with an increased risk for substance use disorders. This study's purpose was to determine the association between opioid misuse propensity (Screener and Opioid Assessment for Patients in Pain-Revised) and delay discounting (DD), a behavioral process linked to substance use disorders, which quantifies the extent to which outcomes are devalued because of their delay. Participants reporting chronic pain (N = 249) answered pain and opioid use questions and then completed 4 DD tasks. Each of these tasks assessed either money or pain consequences, framed as either rewards or punishments. Each task involved hypothetical choices between immediate smaller vs delayed larger consequences. The extant Monetary Choice Questionnaire assessed DD of money rewards, and a modified version assessed discounting of money losses (immediate smaller loss vs larger delayed loss). Based on the Monetary Choice Questionnaire, the novel Pain Relief Choice Questionnaire assessed choices between an immediate short duration of pain relief vs a longer duration of pain relief. Similarly, the novel Additional Pain Choice Questionnaire assessed choices between an immediate short duration of additional pain vs a longer duration of additional pain. Discounting of both additional pain and money losses were significantly associated with high Screener and Opioid Assessment for Patients in Pain-Revised scores-indicating participants at greatest risk for opioid misuse discount future punishments rather than future rewards compared with those at low risk. Measures of DD may have promise in more accurately identifying individuals at highest risk for opioid misuse during chronic opioid therapy.

Background and aims

Probability discounting refers to the effect of outcome uncertainty on decision making. Using probability discounting, we examined the degree to which self-identified chronic pain patients (CPP) were likely to try a novel analgesic medication given increasing addiction risk. We postulated that propensity for opioid misuse, trait impulsivity and previous opioid experience would be associated positively with likelihood of risky medication use.

Design

This cross-sectional on-line study determined state/trait associations with addiction-related medication decisions in CPP.

Setting

US-based CPP participated via Amazon Mechanical Turk; data were collected and analyzed in Baltimore, Maryland.

Participants

A total of 263 CPP (70.6% female) participated in the study from 12-13 December 2014.

Measurements

CPP responded to the Benefit versus Addiction Risk Questionnaire (BARQ) assessing likelihood of taking a hypothetical once-daily oral analgesic medication as a function of two factors: risk of addiction (0-50%) and duration of expected complete pain relief (3, 30 or 365 days). The primary outcome was the BARQ, quantified as area under the curve (AUC). Grouping of CPP at high or low risk for opioid misuse was based on the Screener and Opioid Assessment for Patients with Pain-Revised (SOAPP-R). Predictors included previous experience with opioids, as well as various measures of chronic pain and mental health.

Findings

Across hypothetical addiction risk assessed in the BARQ, the likelihood of taking a novel analgesic medication was elevated significantly in patients with high (≥18; n = 137) versus low (<18; n = 126) SOAPP-R scores [P < 0.001; 3-day: Cohen's d = 0.66, 95% confidence interval (CI) = 0.63, 0.69; 30-day: d = 0.74, 95% CI = 0.71, 0.78; 365-day: d = 0.75, 95% CI = 0.72, 0.79].

Conclusions

In the United States, self-identified chronic pain patients (CPP) at higher risk for opioid misuse were more likely to report willingness to try a novel analgesic despite increasing addiction risk than CPP with low risk of opioid misuse.