a b s t r a c t

Background: We examine recent trends in U.S. emergency department (ED) and hospital care for stroke and tran- sient ischemic attack (TIA).

Method: We used national ED and inpatient data from the Healthcare Cost and Utilization Project 2006-14. We explored trends in care and outcomes for patients treated in U.S. hospitals with stroke and TIA using descriptive statistics, as well as Intracranial Hemorrhage , a complication of stroke treatment.

Results: From 2006 to 14, there were 3.9 million U.S. ED visits with stroke and 2.5 million with TIA. Over the study, stroke visits grew 25% while TIA decreased 2%. Both conditions were more common among women and older adults, and most had Medicare insurance; however, Medicaid increased from 5.8% to 9.6% for stroke and 4.3% to 7.5% for TIA. Full Inpatient hospitalizations fell for stroke from 89% to 83%, and TIA from 61% to 47%. Transfers from the ED for stroke & TIA increased from 4% to 8% and 2% to 5%, respectively. inpatient mortality decreased for stroke & ICH and costs increased for all three conditions; however, length of stay (LOS) did not significantly change.

Conclusion: Over this nine-year study period, the average age of stroke & TIA patients was unchanged in U.S. hos- pitals; however, the proportion with Medicaid insurance increased considerably. Stroke incidence increased while TIA decreased slightly. Full inpatient hospitalizations are declining for both conditions, while transfers are on the rise. Average inpatient costs increased dramatically for all three conditions while mortality for stroke & ICH fell significantly.

(C) 2018

1. Introduction

Stroke is a common, debilitating condition. It is the 5th leading cause of mortality in the U.S. Each year there are approximately 800,000 strokes, and 140,000 deaths from stroke-related causes [1,2]. The financial cost of stroke is estimated at $34 billion per year in the United States [2]. This in- cludes the cost of health care services, medications to treat stroke, as well as missed days of work. Stroke primarily impacts older adults; however, 25% of patients develop stroke before the age of 65 years [2].

The treatment of stroke and its definition have changed over the last two decades. Currently, intravenous tissue plasminogen activator (tPA) is the mainstay of early therapy [3]. However, recent trials have demon- strated effectiveness of catheter-based endovascular treatments and

? All authors have read and approved the submitted manuscript, the manuscript has not been submitted elsewhere nor published elsewhere in whole or in part.

?? There are no identified conflicts of interest or grant funding to this study.

* Corresponding author at: 2100 Pennsylvania Ave. N.W Room 314, Washington, DC 20037, USA.

E-mail address: [email protected] (J.M. Pines).

Mechanical thrombectomy [4]. Stroke prevention has also changed with increased use of warfarin and novel oral anticoagulant medications in atrial fibrillation, and implanted devices. No studies to our knowledge have traced the epidemiology of stroke and Transient ischemic attack in U.S. emergency departments (ED) using national data, specifi- cally examining the longitudinal incidence of stroke, ED disposition rates, costs, and inpatient outcomes.

In this study, we use nationally representative data from the Healthcare Cost and Utilization Project (HCUP) to assess trends in Emer- gency Department (ED) visits and hospitalizations for stroke and TIA in the United States, as well as inpatient costs and outcomes for intracra- nial hemorrhage (ICH) which is a complication of tPA.

1. Methods

We conducted a retrospective study using data from HCUP to exam- ine national statistics on stroke, TIA, as well as ICH. ICH was included be- cause it is the most significant adverse effect of the main treatment of stroke, tPA. HCUP contains information on inpatient stays from the Na- tional Inpatient Sample (NIS) and ED treat & release visits from the

https://doi.org/10.1016/j.ajem.2018.08.013

0735-6757/(C) 2018

I.I. Bedaiwi et al. / American Journal of Emergency Medicine 36 (2018) 1870–1873 1871

Table 1

Demographics of ischemic stroke & TIA patients in US emergency departments in 2006 & 2014.

		Stroke		P	TIA		P
		2006	2014	value	2006	2014	value
Sex	Male	46.1%	49.3%	b0.001	42.3%	43.5%	b0.001
	Female	53.8%	50.6%		57.7%	56.5%
Age (mean)	Male	68.5	67.8	1.0	68.7	68.5	1.0
	Female	73.7	72.4		71.8	70.5
Payer	Medicare	68.3%	64.9%	b0.001	66.6%	65.3%	b0.001
	Medicaid	5.8%	9.5%		4.3%	7.5%
	Private insurance Uninsured	18.5% 5.1%	18.6% 4.6%		22.7% 4.3%	21.1% 3.8%
	Other	2.0%	2.1%		2.0%	2.3%

as a full inpatient admission, while discharge included treat and release as well as patients assigned to Observation status. Further distinction is not available in HCUP. We then present trends in data for the inpatient population of both conditions as well as ICH. This includes length of stay, costs and mortality. We compared data from 2006 and 2014 using Chi- square tests. A test for trend was used to calculate trends in inpatient stays and length of stay (LOS) over the 9-year study period. A P-value b0.05 was considered significant.

We used Microsoft Excel 2016 (Microsoft, Corporation, Redmond,

Washington) for data management and statistical testing.

1. Results

Median income	Low	28.1%	29.5%	b0.001	27.6%	29.2%	b0.001	3.1. Demographics
for zip code	Not low	69.9%	68.1%		70.4%	68.7%
Area of residence	Large central	24.6%	24.7%	b0.001	21.8%	22.4%	b0.001	Both stroke and TIA were more common in women, and the mean

metro

Suburbs 24.4% 21.3% 25.6% 22.4%

Medium & 31.7% 34.6% 31.5% 35.2%

small metro

Rural 18.7% 18.7% 20.8% 19.6%

National Emergency Department Sample (NEDS). The NIS and NEDS are 20-percent stratified samples of all discharges and ED visits from the 953 U.S. community hospitals in 34 states that participate in HCUP. We used the online system (HCUPnet) to gather the data for the study. This was not human subjects’ research and was exempt from re- view by the Institutional Review Board at our institution.

We used international classification of diseases (ICD-9 clinical mod- ification) codes to identify ED visits and hospitalizations for stroke, TIA, and ICH. Our study cohort included data from 2006 to 2014 in HCUP. We used the following ICD-9 codes: (433.11, 434.01, 434.11, and 434.91) for Ischemic Stroke, ICD-9 codes: (435.3, 435.8, and 435.9) for TIA and the ICD-9 codes: (430, 431, 432.1, and 432.9) for ICH. Other codes that have similar pathology (e.g. Persistent Migraine Aura with Ischemic In- farction) were excluded as the incidence was extremely rare and the number of cases was insignificant compared to the included codes.

We present descriptive data on stroke and TIA, specifically demo- graphics of the patient and region (age, gender, income in patient’s area of residence zip code [low vs. not-low where low is defined as the lowest quartile according to national statistics], area of residence [large metro, small metro, suburban, rural]), insurance (Uninsured, Medicaid, Medicare, private insurance). We tabulate these data for each year from 2006 to 2014.

We then display trends in ED care, including hospitalization rates, transfer rates, and routine discharge rates. Hospitalization was defined

age remained stable from 2006 to 2014. The mean age was approxi- mately 68 years for males and 72 years for females for both conditions. The majority of patients had Medicare insurance; however, the propor- tion with Medicaid increased from 5.8% in 2006 to 9.6% in 2014 for stroke and 4.3% to 7.5% for TIA. Comparing 2006 and 2014, the propor- tion of patients seen in hospitals who live in zip code areas with lower income significantly increased for both stroke and TIA. In addition, an increasing proportion of patients were seen in medium/small metropol- itan communities, and decreasing proportions in the suburbs (Table 1).

Visit rates and incidence

From 2006 to 14, there were 6.4 million U.S. ED visits with a diagno- sis of stroke (3.9 million) and TIA (2.5 million). ED visits grew over the study for stroke by 25%, while TIA visits decreased by 2%. The yearly stroke incidence grew from 0.13% in 2006 to 0.15% of the U.S. population in 2014, while TIA incidence fell from 0.09% to 0.08% of the population. The percentage of admitted patients fell from 89% to 83% for stroke and from 61% to 47% for TIA. For both conditions, transfers from the ED to another hospital increased: from 4% to 8% of overall visits for stroke and from 2% to 5% for TIA (Table 2).

Inpatient outcomes

Inpatient data showed statistically significant declines in mortality for stroke and ICH. For stroke, mortality fell from 5.8% in 2006 to 4.3% and ICH mortality fell from 23.9% to 20.4%. TIA mortality was very small but was not significantly changed. There were no significant changes in hospital LOS over the study period; however, inpatient hos- pital charges approximately doubled for all three conditions (Table 3).

Table 2

Trends in US emergency departments disposition for ischemic stroke & Transient ischemic attack from 2006 to 2014.

	Stroke										P value
	Year	2006	2007	2008	2009	2010	2011	2012	2013	2014
	Total number of visits: N	396,463	399,829	410,323	420,639	438,070	444,313	438,508	473,238	498,092
	Routine discharge	4.6%	4.30%	4.70%	5%	4.50%	4.70%	5.10%	5%	6%	b0.001
	Transfer from ED	3.9%	4.9%	5.4%	5.8%	7.3%	7.7%	8.1%	8.2%	8.1%	b0.001
	Rehab/nursing facility, AMA and missing data	2.2%	1.8%	2.0%	2.4%	1.7%	2.0%	2.3%	2.4%	2.5%	b0.001
	Admission	89.1%	88.8%	87.9%	86.7%	86.3%	85.4%	84.4%	84.2%	83.3%	b0.001
	TIA										P value
	Year	2006	2007	2008	2009	2010	2011	2012	2013	2014
	Total number of visits: N	274,492	277,431	284,676	276,986	275,237	286,120	269,712	270,953	268,336
	Routine discharge	32.9%	31.8%	32.2%	33.7%	31.1%	31.5%	34.6%	37.4%	42.2%	b0.001
	Transfer from ED	1.9%	2.3%	2.6%	2.7%	3.5%	3.7%	4.0%	4.3%	5.0%	b0.001
	Rehab/nursing facility, AMA and missing data	4.4%	3.9%	3.8%	3.7%	4.0%	4.3%	4.3%	5.4%	5.7%	b0.001
	Admission	60.7%	61.8%	61.1%	59.6%	61.1%	60.4%	56.9%	52.7%	46.8%	b0.001

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Table 3

US hospitals’ mean length of stay (LOS) by days, mean hospital charges & In-hospital Death rate for patients diagnosed with ischemic stroke, Transient ischemic attack & Intracranial hemorrhage from 2006 to 2014.

	Stroke										P value
	Year	2006	2007	2008	2009	2010	2011	2012	2013	2014
	LOS, days (mean)	5.6	5.5	5.4	5.2	5.2	4.9	4.9	4.9	4.9	0.4
	Charges, $ (mean)	27,947	30,754	33,909	35,953	40,088	40,781	43,213	46,087	48,299	b0.001
	In-hospital deaths	5.8%	5.4%	5.6%	5.1%	5.1%	4.4%	4.5%	4.4%	4.3%	b0.001
	TIA										P value
	Year	2006	2007	2008	2009	2010	2011	2012	2013	2014
	LOS, days (mean)	2.9	2.8	2.7	2.6	2.6	2.5	2.4	2.3	2.4	0.4
	Charges, $ (mean)	16,017	17,336	18,318	19,557	21,546	22,159	23,267	24,919	27,031	b0.001
	In-hospital deaths	0.18%	0.14%	0.15%	0.15%	0.14%	0.12%	0.13%	0.12%	0.14%	0.3
	ICH										P value
	Year	2006	2007	2008	2009	2010	2011	2012	2013	2014
	LOS, days (mean)	8.9	8.5	8.6	8.3	8.6	8.0	8.3	8.1	8.3	0.4
	Charges, $ (mean)	63,831	70,681	79,108	82,538	88,255	90,174	99,460	104,362	112,833	b0.001
	In-hospital deaths	23.9%	22.8%	22.8%	22.4%	21.7%	20.9%	21.1%	20.1%	20.4%	b0.001

1. Discussion

Among patients with stroke and TIA in the U.S. from 2006 to 14, there was a female predominance with higher rates among older adults; however, the proportion of males with stroke increased significantly. The average age did not change meaningfully from 2006 and 2014 for either conditions and was younger among males (~68 years) compared to females (~72 years). Accordingly, the majority of U.S. stroke and TIA patients have Medicare insurance, the coverage for citizens aged 65 and older. Prior reports have also found that almost 90% of strokes and stroke-related deaths occur in older adults (65 years and older) [6]. However, our study found an increase in patients with Medicaid, with slight reductions in Medicare and the uninsured populations. This re- flects the changing landscape of U.S. insurance coverage with increasing shifts to Medicaid through the Affordable Care Act‘s Medicaid expan- sions in 2014 and in other, earlier state-level programs [7].

At the ED and population-level, visits for stroke increased while TIA visits declined. Increases in stroke may be driven by increased stroke detection through the use of advanced imaging – specifically magnetic resonance imaging (MRI). In addition, the definition of TIA changed in 2009 to being defined by Imaging results (i.e. lack of stroke findings on MRI) rather than symptoms [5]. However, there was no clear inflec- tion point in 2010 where TIA diagnoses fell rapidly, being replaced by di- agnoses for stroke. Rather, our data demonstrate a more gradual decline suggesting factors outside of the definition may be driving falling TIA rates. At a population-level there was an increase in patients from low-income zip code areas. This may reflect differential access to pre- vention and other Healthcare resources. Alternatively, education efforts may be increasing the recognition of stroke and TIA more in low income regions as opposed to higher income regions – where education and health literacy may have been at a higher level in the beginning of the study.

Over the study period, several treatments emerged for stroke pre- vention including new oral anticoagulant medications in atrial fibrilla- tion and an increased focus on stroke prevention through tools such as CHA₂DS₂-VASC. Despite this, there was an increasing incidence of ED patients seen for stroke, suggesting increases in patients with stroke seeking ED care may have a greater impact on observed visits than stroke Prevention efforts. The trend toward lower Hospital admission rates for both conditions may be explained by increased use of risk strat- ification tools such as ABCD-2 and growth in observation services as a substitute for inpatient admission. However, due to data limitations we could not differentiate observation services and treat and release pa- tients. Another study found falling chest pain admission rates and

increased observation use in the Medicare population from 2008 to 10 with a stable treat and release rate [8]. Therefore, observed reductions in admission rates may be due to the administrative classification of ob- servation v. inpatient rather than higher treat & release rates. In addition to increased use of the observation status, there has been increased use of ED or hospital-based Observation Units, where TIA risk stratification has proven safe [9].

The rapid rise in ED transfers to other hospitals may also reflect in- creased utilization of specialized stroke centers for definitive diagnosis and management, particularly to deliver tPA. Increased transfers come with Logistical challenges. A potential alternative in stroke is telemedi- cine, which has been shown to improve tPA use especially in rural areas. Tele-stroke can provide easier access and allows Rural patients to be treated in their home hospital rather than being transferred to spe- cialized centers. One study found a 5-fold increase in the eligibility of patients for tPA when utilizing tele-stroke [10]. However, given more recent technology that emerged after the end of the study period – spe- cifically thrombectomy – future research should assess how stroke care evolves over time.

An important finding in our study is the fall in mortality rates for both stroke & ICH despite declining admission rates in patients that are largely similar demographically. This may suggest an increase in care quality delivered for stroke and a broader focus on quality in U.S. healthcare. Outcomes may be improving for a variety of reasons, such as efforts to reduce complications related to stroke, like falls and pres- sure ulcers [11], as well as more aggressive approaches to treatment and rehabilitation [12]. Declining mortality has also been demonstrated for cardiovascular conditions and infectious disease in the U.S., linked in part to increased implementation of Evidence-based guidelines [13,14]. In 2015, the US spent over $3.2 trillion on health care [15]. The Cen- ters for Medicare and Medicaid services estimate that US health spend- ing will increase 5.6% per year between 2016 and 2025. This dramatic increase was observed in our data. Several factors contribute to this in- crease, such as rapid population growth in general, utilization rates and prices, the increase in prevalence of chronic diseases and the aging pop- ulation which leads to a higher proportion of seniors and overall capita

spending [16].

Future studies in this area should further explore the relative contri- bution of observation increases and increases in ED discharge rates to falling hospitalization rates. In addition, studies exploring long-term outcomes after stroke should be conducted, as complications may occur later after discharge. Studying post-acute care in stroke may also improve the ability to study overall Costs of care. This will become in- creasingly important with the expansion of new payment models.

I.I. Bedaiwi et al. / American Journal of Emergency Medicine 36 (2018) 1870–1873 1873

Additional studies should also examine more recent trends, particularly with data showing improvements in outcomes with mechanical thrombectomy [4].

Our study has several limitations as an observational study. First, we used a single database where information was extracted from charts. While HCUP databases are widely used in health services research and care is taken to ensure data integrity, we were not able to validate our findings with direct chart review. We also used the online portal for HCUP which limited our ability to conduct more complex analysis, risk stratification or regression which may have provided more detailed es- timates of the trends. Specifically, HCUPnet produces aggregate data rather than patient-level data. We also used ICD-9 codes to define stroke, TIA and ICH – which comes from billing records, and we were not able to assess whether ICH was related to tPA based solely on billing codes. Another limitation of our study was our inability to differentiate treat and release v. observation admissions, which did not allow us to assess whether ED discharge rates are increasing. HCUPnet also doesn’t differentiate between new and recurrent cases. Finally, we only assessed mortality as an outcome. We did not assess functional out- comes or outcomes after discharge.

1. Conclusion

From the years of 2006 to 2014, the average age of stroke & TIA pa- tients in U.S. hospitals was unchanged. The proportion with Medicaid insurance increased considerably, while it fell for those covered by Medicare. Private insurance coverage fell for TIA but increased slightly for stroke. The incidence of stroke incidence increased considerably compared to TIA which fell slightly; however, the definition of TIA changed in 2009. Full inpatient hospitalizations are declining for both stroke and TIA, while transfers are rising, likely with changing patterns of care. Costs for caring for these conditions, as well as ICH, increased dramatically while inpatient mortality for stroke & ICH fell significantly.

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