Co-prescription of gabapentinoids and opioids among adults with and without osteoarthritis in the United Kingdom between 1995 and 2017

Abstract

Objectives
To produce national and regional estimates and trends of gabapentinoid-opioid co-prescribing rates in patients with osteoarthritis, both in absolute terms and relative to matched controls without osteoarthritis.

Methods
Using the UK Clinical Practice Research Datalink database we first constructed age-sex-practice-date 1:1 matched cohorts of patients aged =40 years with and without a new diagnosis of osteoarthritis between 1995-2017 and estimated the relative incidence of first gabapentinoid prescription. Incident gabapentinoid users in both cohorts were followed to estimate and compare the event-rate of gabapentinoid-opioid co-prescription (prescription from both classes within the same 28-day window).

Results
The incidence of first gabapentinoid prescription was 3-fold higher in patients with osteoarthritis than in matched controls (n=215,357; incidence rate ratio (IRR) 2.93; 95%CI: 2.87-3.00). Among incident gabapentinoid users with osteoarthritis (n=27,374, median follow-up 3.9 years) the event-rate of gabapentinoid-opioid co-prescription was 4.03 (4.02-4.05) per person-year. The rate was higher in osteoarthritis patients classed as long-term gabapentinoid users (6.24; 6.22-6.26). These rates were significantly higher than incident gabapentinoid users without osteoarthritis (adjusted-IRR: 1.29 (1.28-1.30)). This elevated risk was observed across age, sex, geographic-regions, and calendar-years, when restricted to strong-opioids and to long-term gabapentinoid users, and when co-prescription was defined as within 14-days and same-day prescribing.

Conclusions
Patients with osteoarthritis not only have a higher risk of being prescribed a gabapentinoid but, once prescribed a gabapentinoid, are also at greater risk of opioid co-prescription. Strict restriction of gabapentinoid-opioid co-prescription, and improved access to, and uptake of, effective non-pharmacological and surgical alternatives for osteoarthritis are required.