Measuring pain medication expectancies in adults treated for substance use disorders.

BACKGROUND The U.S. prevalence of misuse of prescription opioid analgesics has increased substantially over the past decade but research on the factors influencing misuse of these medications remains preliminary. In the literature on alcohol, marijuana and stimulants, substance-related expectancies have been found to predict level of substance use. A similar line of research is needed to better understand reasons for misusing pain medications. METHODS This study utilized a sample of adults presenting to a large residential addictions treatment program (N=351). Participants were administered a new instrument, the Pain Medication Expectancy Questionnaire (PMEQ) as well as questions about current alcohol, illegal drug and pain medication misuse. Exploratory factor analysis was used to determine underlying factors of the PMEQ. RESULTS Results of the factor analysis supported a three-factor solution focusing on pleasure/social enhancement, pain reduction and negative experience reduction. In general, greater perceived expectancy of the positive effects of Prescription Opiate Analgesics (POAs) in all three domains were correlated with greater frequency of substance use and poorer mental health functioning. Expectancies directly related to the pain-reducing properties of POAs were also related to greater pain and poorer physical functioning. CONCLUSIONS This new measure of pain medication expectancies had sound psychometric properties and the resulting factors were associated with other clinically important aspects of patient functioning. The results highlight the need to assess for and address perceptions related to pain medication use in patients presenting to addictions treatment.