Abstract
BACKGROUND/AIMS: Opioids are used to manage chronic painful conditions associated with obesity. It is unknown whether weight loss attained after bariatric surgery results in a change in chronic opioid use and if so, over what timeframe. We explored the effect of bariatric surgery and associated weight loss on chronic opioid use. METHODS: This retrospective cohort study included patients from ten Scalable Partnering Network for Comparative Effectiveness Research (SPAN) sites who had bariatric surgery between 1/1/2005 and 12/31/2009. Patients had health plan enrollment and a drug benefit during the year before and after surgery. Patients were classified based on total oral or transdermal opioid days’ supply dispensed during the year prior to surgery as having no, some, or chronic use. To assess change in opioid use in the year following surgery relative to the year prior to surgery, total opioid use for each user was determined using morphine equivalents. Dispensings within 30 days post-surgery were excluded. Longitudinal mixed effects models were used to assess change in morphine equivalents dispensed before/after surgery. RESULTS: The cohort included 11,719 patients. Overall, 1016 had chronic opioid use in the year before surgery and 1222 had chronic opioid use in the year after surgery. Of the chronic users pre-surgery, 760 (74.8%) remained chronic users post-surgery. Of the 10,703 with some or no opioid use pre-surgery, 462 (4.3%) became chronic users post-surgery. The most commonly dispensed opioids were hydrocodone combinations, oxycodone, and codeine combinations. Among pre-surgery chronic users, median daily morphine equivalents increased from 22.36 pre-surgery to 25.22 post-surgery (paired sign test P <.0001). CONCLUSIONS: During the year after bariatric surgery opioid use appears to increase in the overall bariatric surgery population or in those with pre-surgery chronic opioid use. Longer timeframes should also be evaluated.