Objective: To characterize postdischarge opioid use and examine factors associated with variation in opioid prescribing and consumption.
Methods: We conducted a prospective observational cohort study by recruiting all women undergoing cesarean delivery during an 8-week period, excluding those with major postoperative morbidities or chronic opioid use. Starting on postoperative day 14, women were queried weekly regarding number of opioid pills used, amount remaining, and their pain experience until they had stopped opioid medication. Demographic and delivery information and in-hospital opioid use were recorded. The state Substance Monitoring Program was accessed to ascertain prescription-filling details. Morphine milligram equivalents were calculated to perform opioid use comparisons. Women in the highest quartile of opioid use (top opioid quartile use) were compared with those in the lowest three quartiles (average opioid use).
Results: Of 251 eligible patients, 246 (98%) agreed to participate. Complete follow-up data were available for 179 (71% of eligible). Most women (83%) used opioids after discharge for a median of 8 days (interquartile range 6-13 days). Of women who filled their prescriptions (165 [92%]), 75% had unused tablets (median per person 75 morphine milligram equivalents, interquartile range 0-187, maximum 630) and the majority (63%) stored tablets in an unlocked location. This amounts to an equivalent of 2,540 unused 5-mg oxycodone tablets over our study period. Women who used all prescribed opioids (n=40 [22%]) were more likely to report that they received too few tablets than women who used some (n=109 [61%]) or none (n=30 [17%]) of the prescribed opioids (33% compared with 4% compared with 5%, P<.001). The top quartile was more likely to be smokers than average users and consumed more opioid morphine milligram equivalents per hour of inpatient stay than average opioid users (1.6, interquartile range 1.1-2.3 compared with 1.0, interquartile range 0.5-1.4, P<.001).
Conclusion: Most women-especially those with normal in-hospital opioid use-are prescribed opioids in excess of the amount needed.