Associations of Physical Pain, Alcohol Use, and Related Factors in the Daily Lives of Patients with Chronic Low Back Pain.

Background: Alcohol use and chronic pain are highly prevalent, costly, and have a bidirectional relationship. This may occur, in part, because of the analgesic effects of alcohol. Specifically, individuals may drink alcohol to address both physical pain and the subsequent increases in negative affect that may be brought on by painful experiences. The current project examined the Catastrophizing, Anxiety, Negative Urgency, and Expectancy (CANUE) model in daily life to better understand the association between alcohol use and pain.

Methods: Hypothesized paths of the CANUE model were examined using intensive longitudinal data (n=34; total n_observations=2,960) collected using ecological momentary assessment over fourteen days from patients with chronic lower back pain who reported drinking alcohol (n_{drinking episodes}=5.88). Multilevel models examined associations of pain, negative affect, and alcohol use, as well as potential moderators (pain-related cognitions, alcohol expectancies, and impulsivity) of these associations.

Results: Previous-occasion physical pain, but not cumulative-average pain, and pain-related alcohol expectancies, were associated with a greater likelihood of alcohol use. Though there was no main effect of cumulative-average negative affect on alcohol use, negative affect interacted with impulsivity, such that participants were more likely to continue drinking when experiencing increased negative affect and impulsivity. Results did not find a hypothesized indirect effect of pain on alcohol use via negative affect. Alcohol use was associated with reduced next-occasion pain and increased perceptions of alcohol-related pain relief.

Discussion: While cumulative-average pain was not associated with an increased likelihood of drinking, individuals were more likely to drink after occasions of elevated pain. This may indicate that participants drank to reduce pain, as was also suggested by the association between pain-related alcohol expectancies and drinking. This is one of the first studies to examine associations of alcohol use and chronic pain in daily life. The results provide evidence for the importance of pain as an antecedent to alcohol use. Findings supported some components of the CANUE model but also highlight the need for further investigation to inform potential revision of the mode.