Trends in Hospitalization for Opioid Overdose among Rural Compared to Urban Residents of the United States, 2007-2014

For each study year, we combined results on overdose admissions with data on the total populations for each of these 3 areas in the US based on American Community Survey data in order to calculate rates of each type of admission per 100,000 persons. To compare pharmaceutical opioids to heroin, we examined pharmaceutical-only overdoses and heroin-only overdoses. We also examined patient age, sex, race and/or ethnicity, and whether they were admitted to a rural or urban hospital based on the hospital location code contained in NIS, and compared these characteristics across residence categories; we presented characteristics for years 2012 to 2014 combined as recent characteristics are most relevant.

The authors had full access to and take full responsibility for the integrity of the data. All analyses were conducted using SAS statistical software version 9.2 (SAS Institute, Cary, North Carolina). The study was reviewed by the University of Iowa Institutional Review Board and the Iowa City Veterans Affairs Healthcare System Research and Development Committee and was judged human subject research exempt.

RESULTS

Characteristics of Patients with Opioids Overdose Admissions

An estimated 43,935 individuals experienced an opioid overdose-related hospitalization in the US in 2007 and 71,280 in 2014. Characteristics of admitted patients varied by residence: a greater proportion of rural patients in older age categories were female (57.3%) and were Caucasian (90.1%; Table). The overwhelming majority of large and small urban residence patients were admitted to urban hospitals (99.4% and 98.3%, respectively) compared with 37.2% of rural patients. The proportion of total opioid overdose admissions due to prescription opioids was higher among rural than urban residents (92.6% for rural residents, 85.6% small urban, and 77.5% large urban). The proportion of large urban (3.5%) and small urban (4.0%) patients admitted as hospital transfers was small in comparison to 14.3% of rural patients. The proportion of admitted patients who died in the hospital varied by patient residence (Table).

Opioid Overdose Admission Trends by Patient Residence

Opioid admission rates increased between 2007 and 2011 in all groups; trends then diverged (panel A in Figure 1). In 2007, 13.8 (95% confidence interval [CI], 11.9-15.8) people per 100,000 had opioid overdose admissions among large urban residents, compared with 17.5 (95% CI, 15.1-19.8) among rural residents. By 2014, these rates were 21.5 (95% CI, 20.1-22.9) among urban residents, and 21.8 (95% CI, 19.9-23.7) among rural residents. Rates for POD admissions followed a similar pattern. POD admission rates rose in all groups until 2011 and then started to decline among large urban residents while continuing to increase among small urban residents. Among rural residents, POD admission rates peaked in 2012 and then declined in 2013 and again in 2014 (panel B in Figure 1). Rates for HOD admissions were highest among urban residents during each study year, increasing from 2.0 per 100,000 residents (95% CI, 1.6-2.4) in 2007 to 5.5 (95% CI, 5.0-6.0) in 2014. Among rural residents, the rate increased from 0.5 (95% CI, 0.3-0.7) to 2.1 (95% CI, 1.8-2.4) over the same time period (panel C in Figure 1).

Opioid Overdose Admissions among Rural Residents to Urban and Rural Hospitals

The estimated total number of patients residing in rural areas who were admitted with opioid overdose to rural hospitals decreased from 6731 in 2007 to 6550 in 2014. Rural patients admitted to urban hospitals increased from 2014 to 4595 over that same time period; the proportion of rural patients admitted to urban hospitals increased from 23.1% in 2007 to 41.2% in 2014 (Figure 2).

DISCUSSION

Up until 2013, hospital admissions for POD occurred at a higher rate among rural US residents than their urban counterparts. Rates of admission of rural residents for POD have decreased since 2012; a similar trend was not observed among urban residents. Over this same interval, rates of hospitalization for HOD among rural residents continued to increase.

Hospital admission is one sequela of harm related to opioid use: patients experiencing opioid overdose or poisoning may be treated by emergency responders, in emergency departments or on observation status, or may die prior to receiving medical attention or presenting for hospital admission. Factors potentially driving the trends described include patient behaviors, opioid availability, prehospital and hospital treatment practices, and hospital closures. Recent work describing increased opioid overdose deaths¹⁵ and high opioid-related mortality in rural areas¹⁶ suggests that overdose admission and death rates may be divergent. Changing policies governing naloxone availability and administration¹⁷ and ongoing trends in rural hospital closures¹¹ may differentially affect the rates at which rural and urban residents who experience overdose are hospitalized.

Hospital admission also represents a potential point-of-entry into subsequent treatment to reduce risk of further opioid-related harms. Decreasing rates of admission could conceivably result in decreasing opportunities to engage in care. Rural and urban patient populations are distinct; an understanding of these distinctions may help to inform how hospitals structure inpatient treatment and discharge planning for overdose patients. Overdose is likely to suggest either an underlying substance use disorder or a chronic pain condition requiring risky levels of prescribed opioids, and therefore is indicative of a persistent condition requiring follow-up care. Thus, there is a need for treatment models and transition care systems aimed at providing adequate care for these populations both in the acute setting and following hospital discharge. The increasing proportion of rural residents admitted to urban hospitals with opioid overdoses highlights the need for urban hospitals to develop relationships with substance use treatment and chronic pain services in rural areas to facilitate linkage to treatment at discharge.

Limitations of this study include the use of ICD-9-CM codes from administrative data to identify hospitalizations for prescription opioid and heroin overdose. While we have used the common term “overdose,” opioid adverse events may occasion hospitalization in the absence of overdose or as a result of patients taking opioid doses in the quantity prescribed. As such, the term overdose does not necessarily imply the behavior of intentional or unintentional excess use. Additionally, coding depends on providers diagnosing and documenting conditions and may be subject to secular trends independent of overdose prevalence. We included data through 2014, the most recent year of data available at time of analyses.