Opioid prescribing and health outcomes in opioid-naive patients: Analysis of a statewide health information exchange

Cohort study of new off-label gabapentin prescribing in chronic opioid users

INTRODUCTION

Gabapentin is commonly prescribed as an off-label adjunct to opioids because of its safer risk profile. Recent evidence has shown an increased risk of mortality when coprescribed with opioids. Therefore, we aimed to evaluate whether the addition of off-label gabapentin in patients with chronic opioid use is associated with a reduction in opioid dosage.

METHODS

We performed a retrospective cohort study of patients with chronic opioid use with a new off-label gabapentin prescription (2010-2019). Our primary outcome of interest was a reduction in opioid dosage measured via oral morphine equivalents (OME) per day after the addition of a new off-label gabapentin prescription.

RESULTS

In our cohort of 172,607 patients, a new off-label gabapentin prescription was associated with a decrease in opioid dosage in 67,016 patients (38.8%) (median OME/day reduction:13.8), with no change in opioid dosage in 24,468 patients (14.2%), and an increase in opioid dosage in 81,123 patients (47.0%) (median OME/day increase: 14.3). A history of substance/alcohol use disorders was associated with a decrease in opioid dosage after the addition of a new off-label gabapentin (aOR 1.20, 95% CI 1.16 to 1.23). A history of pain disorders was associated with a decrease in opioid dosage after the initiation of a new gabapentin prescription including arthritis (aOR 1.12, 95% CI 1.09 to 1.15), back pain (aOR 1.10, 95% CI 1.07 to 1.12), and other pain conditions (aOR 1.08, 95% CI 1.06 to 1.10).

CONCLUSIONS

In this study of patients with chronic opioid use, an off-label gabapentin prescription did not reduce opioid dosage in the majority of patients. The coprescribing of these medications should be critically evaluated to ensure optimal patient safety.

Defining opioid naïve and implications for monitoring opioid use: A population-based study in Alberta, Canada

PURPOSE

Reducing initial exposure of "opioid naïve" patients to opioids is a public health priority. Identifying opioid naïve patients is difficult, as numerous definitions are used. The objective is to summarize current definitions and evaluate their impact on opioid naïve measures in Alberta.

METHODS

An exploratory data analysis of the literature was conducted over the last 10 years to identify definitions commonly used in the literature to define opioid naïve. Then, using these definitions as a guide, we descriptively report the proportion of patients in Alberta between 2017 and 2021 who would be considered as opioid naïve using these definitions and all opioid dispensing data.

RESULTS

Three categories of definitions were broadly identified: (1) no opioid use within the previous 30 days/6 months/1 year, based on dispensation date; (2) no opioid use based on dispensation date plus days of supply; and, (3) exclusion of codeine from Definitions 1 and 2. Applying these definitions to the Alberta population showed a very wide range in the proportion who would be considered as opioid naïve. Overall, 36.4% of Albertans (n = 1 551 075) had an opioid dispensation in 2017-2021. The average age was 46.6 ± 18.8 and 52.8% were female. The proportion of opioid naïve were most affected by the "opioid free" period, with 97.4%, 83.2%, and 65.6% being classified as opioid naïve using time windows from Definition 1 (30 days, 6 months, 1 year of no prior opioid use). Definitions 2 and 3 did not materially change the results. Further extending the "opioid free" period to 2 years showed only 35% were opioid naïve.

CONCLUSIONS

The most convenient definition for "opioid naïve" was the use of an "opioid free" period. The choice of window would depend on how the information may be used to assistant in clinical decisions with longer windows more likely to reflect true opioid naïve patients. Irrespective of definition used, a large proportion of opioid users would be considered opioid naïve in Alberta.