UCSF

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.