Pos0294 Risk Factors for Opioid-Related Hospital Admissions in Rheumatic and Musculoskeletal Disease Patients Newly Initiated on Opioids: A Retrospective Cohort Study

Background: In the last two decades, several countries in Western Europe have experienced a considerable rise in prescription opioid use, leading to increased hospital admissions. This trend is particularly alarming in Scotland, Northern Ireland, and England, where the highest rates of opioid-related hospital admissions in Europe have been reported [1]. Patient with Rheumatic and Musculoskeletal Diseases (RMDs) could potentially be predisposed to opioid-related harms and subsequent hospitalisations due to multimorbidity and high frequency of long-term use. Objectives: To identify factors associated with repeated opioid-related hospitalisations in RMD patients using UK-large scale data. Methods: A retrospective cohort study was conducted using the Clinical Research Practice Datalink, a nationally representative electronic health records database from the UK between January 1, 2006, to October 31, 2021. Patients were included if they were ≥18 years old and new opioid users diagnosed with one or more RMDs: osteoarthritis, fibromyalgia, rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, or psoriatic arthritis. Patients were excluded if they had a history of cancer. Hospital admissions associated with opioid-related harms (including opioid poisoning and abuse, fractures and falls, delirium, sleep disorders and constipation) were identified using both Hospital Episode Statistics (HES) Admitted Patient Care and Accident and Emergency Attendances. Variables selected based on clinical relevance from prior literature, included patient demographics, comorbidities, prescription history (including concomitant use of benzodiazepines, gabapentinoids, antidepressants and antipsychotics) and healthcare utilization. The 'Prentice, Williams, and Peterson Total Time' (PWP-TT) model (which allows for an increase in the baseline risk of admission with the number of prior admissions) was employed to estimate associations between patient- and prescription-level characteristics. Patients were considered to be 'at risk' from the time they received their first new opioid prescription and censored at death or loss of follow-up. Results: In the 15-year study period, 1,274,233 unique patients contributing to 18,594,836 opioid prescriptions were examined. Of new opioid users, 8% (101,198) experienced at least an opioid-related hospitalisation. Predominant diagnoses included fractures and falls (81.4%), opioid overdose and abuse (14.1%) and delirium (4.47%). Utilising the PWP-TT model, a nearly threefold higher hazard of opioid-related hospitalisation was identified for individuals with a history of alcohol misuse (hazard ratio [HR] 2.9, 95% CI: 2.7-3.0). Patients with substance abuse (HR 2.4, 95% CI 2.1-2.5), and patients with history of suicide and self-harm (HR 1.9, 95% CI 1.8- 2.0) were also associated with increased risk of hospital admissions. The use of antidepressants was associated with a 24% higher risk (HR 1.24, 95% CI 1.21-1.26), benzodiazepines with a 20% higher risk (HR 1.20, 95% CI 1.17-1.23), and gabapentinoids with a 18% higher risk (HR 1.18, 95% CI 1.14-1.21) of opioid-related hospitalisation compared to patients not using these medications. Factors such as level of obesity, migraine, back pain, and history of major surgery lacked statistical significance. Conclusion: An increased risk of opioid-related hospitalisation was observed among individuals with a history of alcohol-abuse, self-harm, and depression, suggesting that mental health factors may contribute to the complexity of opioid use and its outcomes. Concomitant use of benzodiazepines and gabapentinoids were also associated with higher risk, which may be due their interactions with opioids. Understanding the factors that contribute to repeated opioid-related hospitalisations in RMD patients would be helpful for future targeted and effective intervention strategies to help improve patient safety. REFERENCES: [1] Pierce, M., et al. (2021). Is Europe facing an opioid crisis like the United States? Eur Psychiatry, 64(1), e47. Acknowledgements: Funded by a FOREUM Career Research Grant and NIHR. MJ is supported by an NIHR Advanced Fellowship [NIHR301413]. The views expressed in this publication are those of the authors and not necessarily those of the NIHR, NHS or the UK Department of Health and Social Care. Disclosure of Interests: None declared.