Future projections of opioid use and cost in patients with chronic osteoarthritis pain in Spain
Authors: Rejas-Gutierrez Javier , Sicras-Mainar Antoni , Darbà Josep 
Published: April 2021

Background: Opioids are widely used in moderate-to-severe chronic pain which is non-responsive to standard analgesics. Prescriptions have increased in Europe in the last decade, although remain lower than in USA. This work projected the future utilization and costs of opioids in chronic osteoarthritis (OA) pain in the Spanish National Health System (NHS). Methods: An epidemiological model was populated with the opioid dispensing trends from 2010 to 2019 using Spanish Medicinal Agency rates of opioid utilization in subjects over 18 years of age and the real-world OPIOIDS study to estimate chronic-OA-pain patients receiving opioids. A best-fitted trend analysis model was applied estimating the likely number of DHD (defined daily dose/1000 inhabitants per day) to calculate projected opioid utilization and costs for the period 2020–2029. Results: In 2010, an estimated 5.67 DHD were dispensed for the equivalent of 217,076 chronic OA pain patients per day [1.99 DHD, 76,084 refractory to non-steroidal anti-inflammatory drugs (NSAIDs)]. From these trends and OA prevalence, the projected number of DHDs is expected to increase more than threefold to 17.98 DHDs by the year 2029 for the equivalent of 727,356 chronic OA pain patients per day (8.18 DHD, 330,720 refractory to NSAIDs); 41.8% on strong opioids. The estimated cost was €116.9m (€45.0m in NSAID-refractory OA) in 2010 rising by 222% to €376.1m (€199.7m refractory to NSAIDs) by 2029. Conclusion: Chronic-OA-pain-related opioid dispensing and costs to the NHS are set to increase more than threefold from 2010 to 2029 in Spain. Using opioids for OA pain is concerning given disease chronicity and other related costs not computed in these projections. Plain language summary • Opioids are widely used in chronic pain which is non-responsive to standard analgesics. Prescriptions have increased in Europe, although remain lower than in USA. Osteoarthritis (OA) is a degenerative joint disease usually accompanied by pain. Despite not recommended, opioids use in OA have been expanded because this health condition is increasing with ageing and, also, because physicians both primary and specialist boosted their use. • This study aimed to quantify the current burden of opioids used for chronic moderate-to-severe OA pain by estimating the number of defined daily doses per 1000 inhabitants per day (DHD) and associated costs, and to forecast the likely burden on the National Health System (NHS) in Spain for the years 2020–2029. • In 2010, an estimated 5.67 DHDs were dispensed for the equivalent of 217,076 chronic OA pain patients per day. From these trends, the projected number of DHDs is expected to increase more than threefold to 17.98 DHDs by the year 2029 for the equivalent of 727,356 chronic OA pain patients per day; 41.8% on strong opioids. The estimated cost was €116.9m in 2010 rising by 222% to €376.1m by 2029. • Chronic OA-pain-related opioid dispensing and costs to the NHS are set to increase substantially (threefold to more than fourfold) from 2010 to 2029 in Spain. Thus, using opioids for OA pain is concerning given disease chronicity, aging population and other related costs not computed in these projections. Our findings can inform payors and clinicians about ongoing discussions on appropriate analgesic management for longer-term OA pain, including resource requirements at a national level. Clinicians who prescribe opioids for OA pain should consider the potential implications of side effects such as sedation, cognitive deterioration, incremental need of caregivers, particularly in older people, and carefully consider the risk–benefit balance.