The Adjective Rating Scale for Withdrawal: Validation of its ability to assess severity of prescription opioid misuse.

BACKGROUND: Withdrawal symptoms have been widely shown to be a useful indicator of the severity of opioid dependence. One of the most used instruments to assess them is the Adjective Rating Scale for Withdrawal (ARSW). However, there is a lack of adaptations and validations for its use with prescription opioids, even less for chronic pain patients under treatment with these analgesics. Thus, the aims of this study were to analyse the psychometric properties and invariance across gender of the ARSW in a sample of chronic noncancer pain patients.

METHODS: Data were collected from 208 consumers of opioid medication, chronic noncancer pain patients. Participants completed sociodemographic, ARSW, prescription opioid dependence (DSM-IV-TR) and prescription opioid-use disorder (DSM-5) measurements. Gender invariance was assessed through multigroup confirmatory factor analysis (CFA).

RESULTS: The ARSW showed a unidimensional factor structure and high internal consistency (Cronbach's alpha = 0.85). Multigroup CFA showed configural, metric, scalar and strict invariances of ARSW across gender. Predictive validity analyses indicated that ARSW has good capacity for identifying the severity of prescription opioid-use disorder, using both DSM-IV-TR and DSM-5 criteria.

CONCLUSIONS: These findings show that the ARSW is a valid and reliable tool for use in the assessment of the withdrawal of prescription opioids in chronic pain patients under treatment with these analgesics, regardless of their gender.

SIGNIFICANCE: Findings supported the reliability and validity of the ARSW to assess withdrawal of prescription opioids in individuals with chronic noncancer pain. The instrument can be applied indistinctly in men and women. An increase in the ARSW scores could be used as an indicator of potential risk of prescription opioid-use disorder during long-term treatments.