Differential patterns of opioid misuse between younger and older adults – a retrospective observational study using data from South Carolina’s prescription drug monitoring program

Background: Most research on opioid misuse focuses on younger adults, yet opioid-related mortality has risen fastest among older Americans over age 55. Objectives: To assess whether there are differential patterns of opioid misuse over time between younger and older adults and whether South Carolina’s mandatory Prescription Drug Monitoring Program (PDMP) affected opioid misuse differentially between the two groups. Methods: We used South Carolina’s Reporting and Identification Prescription Tracking System from 2010 to 2018 to calculate an opioid misuse score for 193,073 patients (sex unknown) using days’ supply, morphine milligram equivalents (MME), and the numbers of unique prescribers and dispensaries. Multivariable regression was used to assess differential opioid misuse patterns by age group over time and in response to implementation of South Carolina’s mandatory PDMP in 2017. Results: We found that between 2011 and 2018, older adults received 57% (p p p p p p Conclusion: Older adults may misuse opioids differently compared to younger adults. Assessment of policies to reduce opioid misuse should take into account subgroup differences that may be masked at the population level.