Attitude and Intention to Abuse Controlled Prescription Drugs: A Conditional Indirect Effects Model

Abstract

Background: Over 6 million people misuse prescription opioids yearly in the U.S. resulting in adverse events and deaths. Little is known about why people turn to opioid misuse. Objectives: This study objective was to examine the influence of moderators (when) and mediators (how) on pain level, drug seeking, and misuse (misuse scenario) to predict intention to misuse prescription opioids. Two theoretical models: Protection Motivation Theory (PMT) and the Theory of Planned Behavior (TPB) were integrated serving as the study framework. Risk of addiction and self-efficacy were the moderators, while attitude, perceived severity, perceived vulnerability, intrinsic rewards, extrinsic rewards, and subjective norms were the mediators. Methods: The web-administered instrument included PMT and TPB items. It underwent pretest (5 subjects) and qualitative testing (13 subjects) to assess readability/sensibility and face validity. An additional 160 patients participated in the survey. Subjects were patients of the University of Michigan Health System Spine Clinic, age 18 years or older, diagnosed with chronic pain, taking an opioid for over a month, outpatient only, and without cancer-related pain. Subjects were randomized into one of two controlled vignettes created to standardize experimental misuse scenario conditions. Analysis: Qualitative responses were grouped by question and response similarity. Moderator and mediator association with intention to misuse prescription opioids was assessed using chi-square, t-tests, and regression analysis. Results: The interviews revealed that the vignettes, survey questions, and response options were understandable. Changes were suggested to perceived severity and extrinsic rewards questions to enhance realism. Risk of addiction and self-efficacy were significant moderating variables. Attitude, perceived vulnerability, and intrinsic rewards were significant mediating variables. Discussion/Conclusion: Risk of addiction and self-efficacy predicted “when” perceived vulnerability, severity, intrinsic rewards, and attitude would describe “how” misuse scenario influenced intention to misuse prescription drugs. This theory-based study was among the first examining the effects of moderators and mediators on intention to misuse opioids. The perceived behavioral control factors and full model need to be tested. This study is a first step towards the development of instruments and interventions to measure individual predictors of opioid misuse by chronic pain patients and target prevention, detection, and treatment of opioid use disorders.