Aging veterans are the largest growing cohort in the VHA population and pain related disorders are the most prevalent of health related conditions. Observational studies have raised questions about the safety and effectiveness of conventional analgesic regimens for pain treatment in older adults. In particular, these studies have raised concerns about the safety of opioids versus non-steroidal anti-inflammatory drugs (NSAIDs) of analgesics in older adults, medications commonly prescribed to veterans. Research gaps in optimal older adult pain treatment remain and more evidence-based research is needed before conclusive recommendations and guidelines can be endorsed.
The objectives of the following proposal are to expand upon the limitations of these studies by evaluating the safety and effectiveness of 3 commonly used analgesic medications types (opioids, NSAIDs, coxibs) for patients with histories of chronic pain conditions. This will be done with 2 concurrent projects evaluating analgesic use in older veterans diagnosed with arthritis. The first will be a prospective cohort study, the second will use national administrative data. Specific aims will be to determine: 1. the safety of commonly used analgesic medications, 2. the effectiveness of these analgesics, and 3. the factors that predict positive and negative analgesic treatment outcomes for this cohort.
These are observational studies of older veterans (50+ years age) with osteoarthritis diagnoses of the knee or hip. The first is a longitudinal prospectively survey of subjects from outpatient clinics at 4 VA centers with geographic and prescribing practice variation. Prospective data collection include self-reported pain levels, over the counter analgesic use, functional scores, and health behavior factors (e.g., smoking). The second project is an expanded, retrospective version of the first, however using VA data from 2010-2017. VHA data, linked to Medicare and Medicaid claims data, will allow for a robust evaluation of patient safety outcomes. With these datasets we will use propensity score-matched cohorts and instrumental variable analyses to compare the safety and effectiveness of analgesics in a national cohort of veterans with osteoarthritis.
Although we are still collecting data, preliminary findings suggest discordance between analgesic prescription data and self-reported analgesic use in older veterans. When looking at self-report and prescription records at baseline (N=595), agreement was fair (k=0.26). But across all surveys (N=1,037), there was slight agreement (k=0.20) that fluctuated between baseline (k=0.21), 30D (k=0.20), 90D (k=0.16), and 180D (k=0.19).
Based on the information collected via survey, we examined how perceived health need affects the number and type of self-reported analgesics taken. In a subset of our sample (N=786), we determined that patients who thought pain medicine a necessity were more likely to use opioids and have a greater rate of analgesic use.
When examining the impact of analgesics on physical function by comparing change in WOMAC scores at baseline and 30D later (N=497), opioid respondents (N=137) had improved function (2.1 points, p<0.01) while NSAID (N=200) and control respondents (N=160) had no significant change. Respondents prescribed opioids were more likely to have a clinically important improvement in physical function (OR=2.49, p<0.01) when compared to controls.
When examining the national data collected for this study from 2012-2016, we were able to calculate standardized monthly rates for each analgesic class before and after the VHA opioid safety initiative. As reported in other studies, VHA opioid prescribing has been steadily decreasing. Our findings indicate there has been a concurrent increase in non-opioid analgesic prescribing for acetaminophen and coxibs, with no overall impact on reported pain scores.
Based on preliminary results, discordance exists between analgesic prescription data and self-reported analgesic use in older veterans. Use of prescription data as a proxy for actual analgesic use should take these differences into consideration. Other early findings indicate opioids may have a short term association with improved physical function. Finally, while prescription rates for opioids within the VA have decreased over the last several years, there has been increasing use of other analgesics (e.g., acetaminophen, coxibs) with no net impact on overall pain score levels.
None at this time.
Aging, Older Veterans' Health and Care, Musculoskeletal Disorders
Treatment - Comparative Effectiveness
Best Practices, Medication Management, Outcomes - Patient, Pain, Patient Preferences, Quality of Care, Quality of Life