Purpose: In drug studies, research designs requiring no prior exposure to certain drug classes may restrict important populations. Since abuse-deterrent formulations (ADF) of opioids are routinely prescribed after other opioids, choice of study design, identification of appropriate comparators, and addressing confounding by “indication” are important considerations in ADF post-marketing studies. Methods: In a retrospective cohort study using claims data (2006-2018) from a North Carolina private insurer [NC claims] and Merative MarketScan [MarketScan], we identified patients (18-64 years old) initiating ADF or non-ADF extended-release/long-acting (ER/LA) opioids. We compared patient characteristics and described opioid treatment history between treatment groups, classifying patients as traditional (no opioid claims during prior six-month washout period) or prevalent new users. Results: We identified 8,415 (NC claims) and 147,978 (MarketScan) ADF, and 10,114 (NC claims) and 232,028 (MarketScan) non-ADF ER/LA opioid initiators. Most had prior opioid exposure (ranging 64-74%), and key clinical differences included higher prevalence of recent acute or chronic pain and surgery among patients initiating ADFs compared to non-ADF ER/LA initiators. Concurrent immediate-release opioid prescriptions at initiation were more common in prevalent new users than traditional new users. Conclusions: Careful consideration of the study design, comparator choice, and confounding by “indication” is crucial when examining ADF opioid use-related outcomes.

This study aimed to examine gabapentin utilization trends among older adults with different cognitive statuses and investigate concurrent medication use of potentially inappropriate medications. Data were extracted from National Alzheimer’s Coordinating Center Uniform Data Set (2006-2019). We estimated the yearly prevalence of gabapentin use, both overall and within subgroups defined by cognitive status [normal, mild cognitive impairment, and dementia] and demographics [age and sex] for participants aged 65+. Additionally, we assessed the prevalence of concurrent use of gabapentin with opioids, combined opioids and benzodiazepine, antidepressant, and antipsychotic. Participants reported gabapentin use increased from 2006 to 2019 in both overall and every participant subgroup. About 10-30% of gabapentin users reported to concurrently use of opioids, and more than 50% gabapentin users with dementia reported to concurrently use gabapentin with antidepressants. Given increasing use among older adults, rigorous studies are needed to examine the safety of gabapentin in this population.