Time-to-Cessation of Postoperative Opioids: A Population-Level Analysis of the Veterans Affairs Health Care System

Abstract

Objective: This study aims to determine 1) the epidemiology of perioperative opioid use; and 2) the association between patterns of preoperative opioid use and time-to-cessation of postoperative opioids.

Design: Retrospective, cohort study.

Setting: National, population-level study of Veterans Healthcare Administration (VHA) electronic clinical data.

Subjects: All VHA patients (n = 64,391) who underwent surgery in 2011, discharged after stays of ≥1 day, and receiving ≥1 opioid prescription within 90 days of discharge.

Methods: Patients' preoperative opioid use were categorized as 1) no opioids, 2) tramadol only, 3) short-acting (SA) acute/intermittent (≤ 90 days fill), 4) SA chronic (> 90 days fill), or 5) any long-acting (LA). After defining cessation as 90 consecutive, opioid-free days, the authors calculated time-to-opioid-cessation (in days), from day 1 to day 365, after hospital discharge. The authors developed extended Cox regression models with a priori identified predictors. Sensitivity analyses used alternative cessation definitions (30 or 180 consecutive days).

Results: Almost 60% of the patients received preoperative opioids: tramadol (7.5%), SA acute/intermittent (24.1%), SA chronic (17.5%), and LA (5.2%). For patients opioid-free preoperatively, median time-to-cessation of opioids postoperatively was 15 days. The SA acute/intermittent cohort (HR =1.96; 95% CI =1.92-2.00) had greater risk for prolonged time-to-cessation than those opioid-free (reference), but lower risk than those taking tramadol only, SA chronic (HR = 9.09; 95% CI = 8.33-9.09), or LA opioids (HR = 9.09; 95% CI = 8.33-10.00). Diagnoses of chronic pain, substance-use, or affective disorders were weaker positive predictors. Sensitivity analyses maintained findings.

Conclusion: Greater preoperative levels of opioid use were associated with progressively longer time-to-cessation postoperatively.

Keywords: Cessation; Long-Acting Opioids; Perioperative; Pharmacoepidemiology; Short-Acting Opioids; Surgery.