Low back pain (LBP) is one of the most common healthcare complaints and musculoskeletal disorders seen in the emergency department (ED)[1,2]. The prevalence of LBP ranges from 49% to greater than 80% in the United States. While non-emergent LBP can be treated by primary care physicians, studies suggest that patients will visit the ED for evaluation of symptoms, potentially leading to overcrowding and distracting from other serious health complaints[4,5]. Patients presenting to the ED for non-emergent LBP have been found to receive unnecessary imaging with excess radiation, be admitted to the hospital for pain control, or be given prescriptions of opioid pain medication[6-8].
Studies have shown inconclusive results in the efficacy using opioids to treating patients for LBP, with worse outcomes at 6-month follow-up. Furthermore, studies have shown similar efficacy of opioids compared to non-opioid medications in the treatment of both acute and chronic LBP[9-12]. Within the past decade, opioid prescribing for non-cancer pain has increased dramatically, along with an increase in opioid abuse and resulting deaths[13-16]. Davies et al analyzed opioid prescribing rates from January 2005 to December 2015, stratifying patients by age. Their findings revealed that opioid prescriptions in patients older than the age of 85 increased nearly 2-fold. The American College of Emergency Physicians recommends utilizing opioids in the ED only when pain is severe, debilitating, or refractory to other treatments. Further guidelines were mandated by the American Academy of Emergency Medicine, recommending opioids as a second-line treatment. Despite the calls for regulation, evidence of deviation from guideline recommendations persists. Indeed, Hayden et al reported 5% of previously opioid-naïve patients who present to the emergency department for low back pain become prolonged opioid users.
Temporal trends of ED visits for LBP, opioid prescription patterns for non-emergent LBP, and patient factors associated with receiving an opioid prescription have not been well documented but are necessary to combat the continuing opioid epidemic in the United States. Therefore, the purpose of this study was to determine trends in non-emergent ED visits for back pain; annual trends in opioid prescriptions for patients presenting to the ED for back pain; and factors associated with receiving an opioid based prescription for non-emergent LBP in the ED
While it has been shown that the overall prescription rates of opioids within the United States are gradually decreasing over the past five years, there is a paucity of literature evaluating trends in opioid prescriptions specifically in patients presenting to the ED with non-emergent LBP. Overall, our study reports a significant decrease in the number of non-emergent LBP ED visits from 2010 to 2017, as well as a decrease in opioids prescribed at these visits. Furthermore, we noted several independent risk factors for increased opioid prescription following non-emergent LBP, including age over 43.84-years-old, higher income, private insurance, the obtainment of radiographic imaging in the ED, and region of the United States.
Our findings are consistent with previous literature demonstrating an overall decrease in ED opioid prescriptions[22-25]. Marra et al analyzed NHAMCS information from 2005 to 2015 for patients presenting to the ED with pain of all causes, finding that prescribing rates at discharge decreased significantly by 32% during the study duration. Since pain is one of the most common reasons for ED visits, a major limitation of Marra et al study was grouping pain causes into a single cohort. The decrease in opioid prescriptions for non-emergent LBP found in our study was representative of the overall decrease in ED opioid prescriptions for general pain over a similar time interval as established by Marra et al. As such, our findings provide needed granularity in terms of specifically the non-emergent LBP population presenting to the ED
In elderly individuals, non-emergent LBP has been shown to have a prevalence ranging from 21.7% to 75%, with a direct correlation between age and LBP. Our findings suggest that older age is an independent risk factor for increasing opioid prescriptions following ED admission for LBP, which may perhaps be due to older individuals presenting with increased severity of back pain. Severity of non-emergent LBP is known to be highly correlated with increasing age, particularly relative to other common causes of opioid prescriptions following ED admission such as pain secondary to trauma[27,28]. This increased LBP severity in older patients likely contributed to the increased opioid prescriptions in older patients shown in our analysis.
In particular, our study found age over 43.84-years to be an independent risk factor for opioid prescriptions in non-emergent LBP patients. However, the direct relationship between age and ED opioid prescriptions found in our study has not been demonstrated for all chief complaints presenting to the ED For instance, Ward et al utilized the Data to Intelligence database aggregating electronic health record data from EDs within the United States from January 1, 2014 to May 31, 2014, and found no direct relationship between increasing age and opioid prescription. In their study, patients between the ages of 18 to 27 had the highest adjusted odds ratio (OR: 1.09) of being discharged with an opioid prescription, followed by patients between the ages of 40 to 54 (OR: 1.08), and lastly between the ages of 28 to 39 (OR: 1.02). Ward et al studied all ED admissions, not limited to back pain, and attempted to account for variations in chief complaints utilization a categorization approach, however, the authors acknowledged remaining heterogeneity in terms of the chief complaints in their dataset. In comparison, our study only included patients presenting with non-emergent LBP, such that the chief complaints were entirely homogenous, which contributed to the direct correlation we found between age and ED opioid prescriptions in non-emergent LBP patients.
With respect to insurance status, Ali et al reported that 8% of patients with private insurance had potentially problematic opioid prescriptions, compared to 14% of patients with Medicaid. Problematic opioid prescription was defined in their study as opioid prescriptions which did not match the indication severity based on protocol established in previous literature. Although our study did not address problematic opioid prescriptions, we did find that patients with private insurance or who were self-payers were more likely to be prescribed an opioid for non-emergent LBP compared to Medicaid patients.
In terms, of the Medicaid population specifically, Janakiram et al performed a multistate analysis utilizing the Truven Marketscan Database from 2013 to 2015 and found Medicaid patients were more likely to receive prescriptions from an ED provider compared to a general practitioner, with back pain (14%) being the third leading cause for receiving an opioid prescription. Implementation of prior authorization plans within Medicaid plans has shown to not only minimize opioid-related morbidity within this cohort, but also discourage the initiation of long-acting opioid therapy[30,31]. Interestingly, studies have shown patients who present to the ED could be more appropriately managed by their primary care physician, which would potentially driving down ED visits. These studies demonstrate that adequate care reduces annual ED visits and decreases healthcare expenditure[32-34], therefore, lack of access to primary care may be the driving force of increasing patient visits to the ED especially for non-emergent indications such as LBP[35-37]. In other words, limited access to various primary care is likely associated with increased ED visits in patients with underlying mental and physical comorbid conditions.
Extended access primary care services have also been shown to decreased the amount of ED visits as well as pain prescriptions for non-emergent presentations. Extended access primary care services offer patients the ability to book appointments outside of core contractual hours, either in the early morning, evening or at weekends. Whittaker et al measured the impact of extended access in 56 primary care practices by offering seven-day extended access through providing care during the evenings and weekends, compared to 469 primary care practices with routine working hours. Implementing this extended access of care demonstrated a reduction in both the frequency and cost of patient-initiated ED visits for “minor” problems. The majority of non-emergent LBP fits within this categorization of “minor” problems, so it is possible that more widespread extended access primary care services have the potential to reduce ED admissions and opioid prescriptions.
LBP has also been shown to be more prevalent and severe in older men compared to older women. Interestingly, our study found no difference in opioid prescriptions between men and women presenting to the ED with non-emergent LBP.
Finally, numeric pain scores have been implicated in contributing to the prescribed opioid epidemic, with opioids being administered to those who report higher pain scores. In a recent cross-sectional study, Monitto et al explored the association of patient factors with opioid dispensing, consumption, and medication remaining on completion of therapy after hospital discharge. Their findings suggest higher discharge pain scores can predict higher opioid dispensing and consumption. This is consistent with our findings as increasing pain scales was significantly associated with discharge from the ED with an opioid prescription. With further validation, these pain scales can be potentially utilized to predict and ultimately standardize the number of opioids patients presenting to the ED with non-emergent LBP should be prescribed.
This study has a few limitations which must be considered when interpreting our results, most of which are inherent to the use of an administrative database. First, recent studies have addressed concern regarding the validity of the NHAMCS database due to slight variability in documentation across the years. Our study limited this potential issue by purposely utilizing variables that were collected in a consistent fashion over the years studied. Second, since information from the database is ascertained from individual ED visits, the study did not allow for longitudinal information on these patients or allowing us to determine the appropriateness of therapy. For example, we were unable to identify patients with a history of substance abuse. However, this limitation does not preclude the validity of our findings as our study methodology included only cases of non-emergent back pain that presented to the ED and did not warrant admission. Finally, our study assessed data from 2010 to 2017, as this was the only time interval available from NHAMCS. Despite these limitations, the study provides valuable information regarding annual trends in ED visits for back pain, prescribing patterns, and patient risk factors for being discharged with an opioid prescription.