4122 — Variation in Clinical Characteristics and Longitudinal Outcomes in Individuals with Opioid Use Disorder Diagnosis Codes
Lead/Presenter: Victoria Powell,
COIN - Ann Arbor
All Authors: Powell VD (Geriatrics Research, Education, and Clinical Center, Ann Arbor VA; Division of Geriatric and Palliative Medicine, University of Michigan), Macleod C (Division of General Medicine, University of Michigan, Ann Arbor, MI); Sussman J (VA Center for Clinical Management Research (CCMR), VA Ann Arbor Healthcare System, Ann Arbor MI, Division of General Medicine, University of Michigan, Ann Arbor, MI); Lin LA (VA Center for Clinical Management Research (CCMR), VA Ann Arbor Healthcare System, Ann Arbor MI; Addiction Center, Department of Psychiatry, University of Michigan, Ann Arbor, MI); Bohnert ASB (VA Center for Clinical Management Research (CCMR), VA Ann Arbor Healthcare System, Ann Arbor MI; Department of Anesthesiology, University of Michigan, Ann Arbor, MI); Lagisetty P ((VA Center for Clinical Management Research (CCMR), VA Ann Arbor Healthcare System, Ann Arbor MI, Division of General Medicine, University of Michigan, Ann Arbor, MI)
Patterns of opioid use vary, including prescribed use without aberrancy, limited aberrant use, and potential opioid use disorder (OUD). In clinical practice, similar opioid-related International Classification of Disease (ICD) codes are applied across this spectrum, limiting understanding of how groups vary by sociodemographic factors, comorbidities, and long-term risks. This study aimed to 1) Examine how Veterans assigned opioid abuse/dependence ICD codes vary at diagnosis and with respect to long-term risks. 2) Determine whether those with limited aberrant use share more similarities to likely OUD vs those using opioids as prescribed.
This was a longitudinal observational cohort study of a national sample of Veterans categorized as having: (1) likely OUD (2) limited aberrant opioid use or (3) prescribed, non-aberrant use based upon enhanced medical chart review. We compared sociodemographic and clinical factors at diagnosis and rates of age-adjusted mortality, non-fatal opioid overdose, and hospitalization after diagnosis. An exploratory machine learning analysis investigated how closely those with limited aberrant use resembled those with likely OUD.
Veterans (n = 483) were categorized as likely OUD (62.1%), limited aberrant use (17.8%), and prescribed, non-aberrant use (20.1%). Age, proportion experiencing homelessness, chronic pain, anxiety disorders, and non-opioid substance use disorders differed by group. All-cause mortality was high (44.2 per 1,000 person-years (95% CI 33.9, 56.7)). Hospitalization rates per 1,000 person-years were highest in the likely OUD group (831.5 (95% CI 771.0, 895.5)), compared to limited aberrant use (739.8 (95% CI 637.1, 854.4)), and prescribed, non-aberrant use (411.9 (95% CI 342.6, 490.4). The exploratory analysis reclassified 29.1% of those with limited aberrant use as having likely OUD with high confidence.
Veterans assigned opioid abuse/dependence ICD codes are heterogeneous and face variable long-term risks. Limited aberrant use confers increased risk compared to no aberrant use, and some may already have OUD. Findings warrant future investigation of this understudied population.
Veterans assigned an OUD diagnosis code in medical records are highly heterogeneous. Overall, they face higher risks of all-cause mortality and hospitalization than general population samples of similar age. To our knowledge, this study provides the first estimate of how these outcomes differ when individuals with OUD-related ICD codes are grouped according to OUD likelihood. Those categorized as likely OUD were at the highest risk, followed by those with limited aberrant use; those with prescribed, non-aberrant use had the lowest risk. Preliminary analyses focusing on individuals with limited aberrant opioid use suggested approximately one-third share many features of OUD. These findings suggest that a simple binary classification of patients prescribed opioids for chronic pain and those with OUD is an over-simplification of the opioid use spectrum. While some with limited aberrant behaviors may have emerging or mild OUD, others may be experiencing a complex, dynamic relationship between chronic pain and opioid dependence, warranting further investigation into different treatment approaches.