American Journal of Emergency Medicine 32 (2014) 1159–1167

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American Journal of Emergency Medicine journal homepage: www.elsevier.com/locate/ajem

Original Contribution

The impact of age and gender on resource utilization and profitability in ED patients seen and released☆,☆☆ Philip L. Henneman, MD a, b,⁎, Brian H. Nathanson, PhD c, Kara Ribeiro, BS d, Hari Balasubramanian, PhD d a

Baystate Medical Center, Springfield, MA Tufts University School of Medicine, Boston, MA Optistatim, LLC. Longmeadow, MA d University of Massachusetts, Amherst, MA b c

a r t i c l e

i n f o

Article history: Received 3 May 2014 Received in revised form 20 June 2014 Accepted 25 June 2014

a b s t r a c t Objective: To determine how age and gender impact resource utilization and profitability in patients seen and released from an Emergency Department (ED). Methods: Billing data for patients seen and released from an Emergency Department (ED) with N100,000 annual visits between 2003 and 2009 were collected. Resource utilization was measured by length of stay (placement in ED bed to leaving the bed) and direct clinical costs (e.g., ED nursing salary and benefits, pharmacy and supply costs, etc.) estimated using relative value unit cost accounting. The primary outcome of profitability was defined as contribution margin per hour. A patient's contribution margin by insurance type (excluding self-pay) was determined by subtracting direct clinical costs from facility contractual revenue. Results are expressed as medians and US dollars. Results: In 523 882 outpatient ED encounters, as patients' aged, length of stay and direct clinical cost increased while the contribution margin and contribution margin by hour decreased. Women of childbearing age (15-44) had higher median length of stay (2.1 hours), direct clinical cost ($149), and contribution margin per hour ($103/hour) than men of same age (1.7, $131, $85/hour, respectively). Resource utilization and profitability by gender were similar in children and adults over 45. Conclusion: Resource utilization increased and profitability decreased with increasing age in patients seen and released from an ED. The care of women of childbearing age resulted in higher resource utilization and higher profitability than men of the same age. No differences in resource utilization or profitability by gender were observed in children and adults over 45. © 2014 Elsevier Inc. All rights reserved.

1. Introduction Although we know that Emergency Department (ED) visits are increasing, that the population in the United States is aging, and that more adult women visit the ED than men, there are no published reports on the impact of age and gender on the cost and revenue of ED visits in the United States. The annual number of ED visits in the United States in the past 2 decades has increased by 40%; in 1994 there were 93 million visits and in 2010 there were 130 million [1,2]. The number of ED visits is growing faster than the United States population [3]. There are clear differences in gender with ED visits: males are more likely to go the ED among patients younger than 15 years while the trend is reversed for patients older than 15 years ☆ Presented in part at the American College of Emergency Physicians Research Forum in San Francisco, CA, October 2011. ☆☆ Author contribution: BHN conceived the study; PLH organized data collection; BHN, KR, and HB did the statistical analysis; BHN and PLH drafted the article; and all authors contributed to its revision. ⁎ Corresponding author. 109 Lake Ave, Sunapee, NH 03782. E-mail address: [email protected] (P.L. Henneman). http://dx.doi.org/10.1016/j.ajem.2014.06.030 0735-6757/© 2014 Elsevier Inc. All rights reserved.

[1,2,4–8]. In addition, the population in the United States is aging; between 2000 and 2010 the number of persons in the United States 65 years and older rose by 15% [9]. Between 2001 and 2009, the number of ED patients over the age 65 years increased by 24%, of which 59% were women [10]. Between 2002 through 2009, increasing age in ED patients was associated with increasing frequency of admission to the hospital, admission to a critical care unit, endotracheal intubation, cardiopulmonary resuscitation, and death [11]. Clearly, age and gender have a significant impact on ED visits in the United States. The above results come from the National Hospital Ambulatory Medical Surveys (NHAMCS) that annually include approximately 35 000 ED patients from 400 hospitals [1–11]. Unfortunately, these surveys do not include patient cost and revenue so the financial implications of age and gender are unclear. Several articles have reported costs, revenue, and hospital length of stay by insurance type of patients admitted to the hospital from the ED [12–14]. These reports show that profitability of hospital admissions (contribution margin per day) is dependent on insurance type, source of admission (ED versus non ED), admitting service, diagnoses, and length of stay. Admitted patients, however, represent

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P.L. Henneman et al. / American Journal of Emergency Medicine 32 (2014) 1159–1167

the minority of national ED visits. In the NHAMCS from 2005 through 2010, only 13% of patients were admitted [2,4–8]. For many hospitals, the cost and revenue of ED admissions is allocated to the inpatient service lines. Thus, the ED service line consists of patients seen and released from the ED (ie, outpatients). Recently, we reported the cost and revenue of ED outpatient visits from a single institution over 7 years. We found that contribution margin per ED bed hour (ie, profitability) varied significantly by insurance type and facility billing level. For commercially insured patients, contribution margin per hour increased with higher billing levels, but for Medicare and Medicaid patients, contribution margin per hour decreased with increasing billing levels. Cost and length of stay by billing level were similar for all insurance types (Commercial, Medicare, and Medicaid) but costs and length of stay (bed time) for patients in each insurance type increased over the seven years of the study [15]. The purpose of the present study was to examine how age and gender impact resource utilization and profitability in ED patients seen and released from a single institution. We believe this information will help the health care community understand how age and gender may impact EDs in the United States in the future. 2. Methods Facility billing and demographic data for patients seen and released from an urban, academic ED with N 100 000 annual visits between October 1, 2002, and September 30, 2009, were collected from ED and hospital databases. The dates used reflect the fiscal year, which was October 1 through September 30. The analysis was at the encounter rather than patient level as each encounter is associated with a new cost and length of stay (ie, we did not distinguish between a visit from a new versus previously seen patient). The small number of patients who were transferred to another hospital (0.9%) or died (0.3%) were included as they were “released” from the ED. Patients who left without being seen and those who were admitted to the hospital, including observation admissions, were not included in the study. Patient visits were also excluded if they had no listed billing level, if key data elements were missing or if there were obvious data entry errors (negative or zero costs, missing time of bed placement or discharge, or length of stay was missing, zero or less than 5 minutes). In our institution, there is a separate treatment area, not part of the ED, for women in their third trimester of pregnancy with any complaints that might be due to their pregnancy; these women are therefore not included in our results. The institutional review board approved the study. Surrogate measures of resource utilization in our study include length of stay (bed time) and direct clinical costs. Length of stay in an ED bed is an important factor in resource utilization as beds are one the ED’s primary resources. Length of stay was from placement in the ED bed to the time the patient left that bed. Time stamps for specific steps in the process of a patient's care are methodically collected and recorded in the ED database with the patient's visit. Direct clinical costs include the cost of all services utilized during an encounter as well as staff time to provide them. Included and excluded costs are listed in Appendix 1. ED staff costs include the salaries and benefits for all full time, part-time and temporary ED nurses, clerks, medical assistants and orderlies. ED clinical equipment and supply costs included all billable and non-billable supplies and all equipment depreciation. ED pharmacy and drug costs included all billable and non-billable medications used in the ED. All costs were allocated to each patient using relative value cost accounting [16]. Each cost center in the hospital takes their direct divisional costs and assigns them to the specific units of service they provide. A unit of service may be a medication for the pharmacy, a blood test for the laboratory, an x-ray for radiology, or a respiratory treatment for respiratory therapy, or a facility billing level in the ED. The charge for a

patient's assigned facility billing level was used as the relative value unit to allocate the cost of ED staff, medications, and supplies to an individual patient. The costs of all services utilized by a patient (eg, ED staff time and supplies, blood tests, x-rays, respiratory treatments) were summed to obtain an individual patient's direct clinical cost [16]. Costs and revenue from admitted patients were not included. Neither were hospital overhead and physician cost and revenue. Profitability of an individual ED patient is probably best measured by contribution margin per bedtime [15]. Contribution margin per case was determined at the encounter level by subtracting direct clinical costs from contractual revenue. Contractual revenue was the expected revenue from the patient’s insurance based upon the patient’s billing level. Contractual revenue was not actual revenue but rather what the expected revenue for the individual patient would be based upon the contractual arrangement with each payer: Commercial, Medicare, or Medicaid. Contractual revenue represents 96%, 100%, and 99% of actual revenue by insurance type in our institution, respectively. The 4% in decreased revenue from Commercial insurance represents co-pays not obtained. Contribution margins were listed by facility billing level Evaluation and Management (E&M) codes of 1 to 5 with level 1 being the lowest billing level and level 5 being the highest billing level. Billing level is a surrogate marker for case complexity, acuity, and intensity of care. Profitability of an ED encounter is not only dependent on contribution margin but also on the time the patient spends in a bed. In an ED where all beds are usually occupied, the longer the average patient spends in an ED bed, the fewer patients can be seen by that ED, which results in less total revenue (or less profit). Therefore, a patient who stays twice as long in a bed as another patient and generates the same contribution margin is less profitable. Contribution margin was therefore divided by the time from bed placement to ED discharge to obtain the contribution margin per hour. This was our main outcome measure. Self-pay/other were those patients without commercial, Medicare, or Medicaid insurance. Self-pay patients include those with no insurance, those assigned to get free care by the hospital, and those without an assigned payer. Self-pay patients have no insurance and therefore no contractual arrangement to reduce their charges to a predetermined level. In our financial database these patients are assigned contractual revenue equal to their charges, which is an unrealistic expectation. Consequently, we did not include these patients when deriving revenue, contribution margin, or contribution margin per hour results in the tables. However, these patients are represented when we derive patient level costs, charges, billing mix, length of stay data, and demographics. To categorize the reason for the ED visit, we used the Healthcare Cost and Utilization Project (HCUP) Clinical Classification Software (CCS) Category software to group patients by CCS category based on each patient's primary ICD-9 code [17]. Results are expressed as percentages or medians with interquartile ranges (IQR) where appropriate. Monetary amounts are expressed in US dollars. Statistical inferences comparing medians were done using the Wilcoxon ranksum test (Mann-Whitney U test) and inferences on proportions were done using Pearson's χ 2 test. Given our initial sample sizes by gender and overall estimates of the means and standard deviations, we had over 90% power to detect a $10 difference in contribution margin per hour at α = .05. All statistical analyses were done with Stata/SE 11.2 for Windows (StataCorp, College Station, TX). 3. Results There were 752 777 patients that registered to be seen in the ED between October 1, 2002, and September 30, 2009 (fiscal year 2003-2009). Six percent of the patients left the ED after registration (walk-outs) and 21% were admitted, leaving 550 490 patients who were seen and released from the ED. Of these, 26 608 (4.8%) had

P.L. Henneman et al. / American Journal of Emergency Medicine 32 (2014) 1159–1167

incomplete or invalid data for billing level, cost, or length of stay and were excluded, leaving 523 882 patient visits included in the study. These excluded patients did not differ significantly by age and had similar percentages of female patients (52.5% vs 50.7%) and those at E&M level 5 (8.0% vs 7.1%) but had a higher percentage of E&M level 1 (12.6% vs 0.8%). Fig. 1 shows the age and gender distribution of the study patients along with the age and gender distribution of the United States population in 2009. Fig. 1 shows that our ED treats and releases more younger children, more young and middle aged adults, and less older adults than found in the general United States population. Of note, the age and sex distribution of the study patients mirrors the distribution of ED patients in the 2002 through 2009 National Hospital Ambulatory Medical Care Surveys [11]. Table 1A and B show the demographic, billing levels, length of stay, cost and CCS Categories by age group for female and male ED outpatients. Billing levels, cost, and length of stay increase with age for both male and female patients. While sprains, superficial injuries, and abdominal pain were the top 3 CCS categories in the study population, there were differences by gender and age groups. Both men and women have sprains as their most common CCS category. The second and third most prevalent CCS categories were abdominal pain and superficial injuries for women, and superficial injuries and back problems for men. Table 2A and B show the median (IQR) charges, costs, revenue, contribution margin, length of stay, and contribution margin per hour by insurance type and age group for females and males. Costs and lengths of stay by billing level are similar across insurance types. However, the contribution margins in the Medicare and Medicaid groups were markedly lower in the adult age groups when compared to the commercial group due to contracted revenue agreements. In fact, the hospital often lost money (ie, negative contribution margin) treating Medicaid patients who were 75 or older, and the Medicare patients were only slightly profitable (ie, positive contribution margin). Table 3 shows the median (IQR) charges, costs and length of stay by age group for female and male self pay/other patients. Revenue and contribution margin are not included. There were almost twice as many male self pay/other patients than female (47 392 vs 26 465). Charges, costs and length of stay by age for self pay/other patients were similar to patients with insurance. Fig. 2 shows how median length of stay, cost, revenue and contribution margin per hour by insurance type changes with age.

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Length of stay and cost increase with age, while revenue only marginally increases with age. Contribution margin per hour, on the other hand, decreases with age for commercial and Medicaid patients while remaining relatively constant for Medicare patients. Fig. 3 shows how median length of stay and contribution margin per hour changes for males and females by age. We found that women of childbearing age (15-44 years) had higher median length of stay (2.1 hours), direct clinical cost ($149), and contribution margin per hour ($103 per hour) than men of same age (1.7 hours, $131, and $85/hour, respectively; P b.001 in all 3 comparisons). Length of stay, cost, and contribution margin per hour were similar for males and females younger than 15 years and greater than 45 years. Table 4A and B shows the median (IQR) cost, length of stay, revenue, contribution margin and contribution margin per hour for the top 5 CCS diagnoses for males and females 15 to 44 years old (six categories are listed as the top 5 differed by one by gender). While sprain was the most common CCS category for both genders, women were more likely to have headache/migraines or abdominal pain and men were more likely to have open wounds of the extremities. With the exception of open wounds of the extremities, the median contribution margin per hour (excluding self pay/other patients) were higher (ie, more profitable) by approximately $20 to $30 for women in these categories. However, it is notable that length of stay, costs, and profitability measures were similar by gender when stratified by insurance type, with the exception of abdominal pain. Abdominal pain was twice as common among women than men in this age group (7.7% vs 3.5%, P b .001). Moreover, median revenue was much higher among women than men with commercial insurance ($936 vs $656, P b .001). Median length of stay for women with abdominal pain was longer than for men (4.1 vs 3.4 hours, P b .001), which offsets the higher revenue, producing similar median contribution margins per hour for women and men with commercial insurance ($153 and $141, respectively). For Medicare and Medicaid patients in this age group, revenue and contribution margin per hour were similar by gender. However, when examining all patients 15 to 44 years old, we found women with abdominal pain to have higher contribution margins per hour than men ($92 vs $72, P = .01). Finally, chest pain was also common in both women and men (3.1% and 3.2%, respectively). Again, we observed that length of stay was higher for women than for men (2.7 and 2.4 hours, respectively, P b 0.001), and median revenue and contribution margin

Fig. 1. Histogram of age and gender of ED patients seen and released compared to the 2009 US census.

1162

Table 1 A. Patient characteristics⁎ by age category for females; B. Patient characteristics⁎ by age category for males b1

1-4

5-14

15-24

25-44

45-64

65-74

75+

Overall

Counts (%) Insurance type Commercial Medicaid Medicare Self-pay/other Facility billing level 1 2 3 4 5 Resource variables Direct costs ($) Length of stay (h) Top 5 CCS categories (listed in descending order of prevalence)

8206 (3.0%)

17 867 (6.5%)

22 468 (8.2%)

55 549 (20.2%)

92 993 (33.8%)

51 946 (18.9%)

10 185 (3.7%)

15 572 (5.7%)

274 786 (100%)

80.8% 15.48% 0.0% 3.7%

83.5% 12.59% 0.0% 3.9%

79.2% 16.85% 0.0% 4.0%

64.0% 19.62% 1.6% 14.8%

61.7% 18.53% 8.0% 11.8%

54.1% 20.14% 16.0% 9.8%

16.6% 3.26% 78.4% 1.8%

7.6% 0.66% 90.9% 0.8%

59.4% 16.9% 14.1% 9.6%

0.7% 30.8% 51.4% 16.2% 0.9%

1.0% 29.3% 52.5% 16.0% 1.3%

0.8% 23.8% 51.8% 19.7% 4.0%

0.7% 16.1% 44.3% 32.2% 6.6%

0.7% 14.9% 42.1% 34.8% 7.6%

0.6% 11.8% 40.1% 37.9% 9.6%

0.6% 8.5% 37.0% 42.3% 11.7%

0.4% 5.3% 32.3% 48.7% 13.3%

0.7% 15.9% 43.2% 32.9% 7.3%

114 [70, 166] 1.7 [1.1, 2.8] Other upper respiratory infection Fever unknown origin Viral infection

121 [97, 210] 1.7 [1.0, 2.9] Superficial Injury

146 [107, 296] 2.0 [1.1, 3.5] Sprain

152 [108, 299] 2.1 [1.1, 3.6] Sprain

198 [113, 315] 2.4 [1.3, 3.9] Sprain

253 [125, 341] 2.9 [1.7, 4.3] Abdominal pain

284 [144, 359] 3.4 [2.2, 4.8] Superficial Injury

148 [108, 297] 2.2 [1.2, 3.7] Sprain

Abdominal pain

Abdominal pain

Abdominal pain

Abdominal pain

Superficial injuries

Back problem

Back problem

Urinary tract infection Abdominal pain

Abdominal pain

Sprain

Superficial injury Back problem

Superficial injury

Nausea/vomiting

113 [72, 152] 1.7 [1.0, 2.7] Other upper respiratory infection Fever unknown origin Open wound-head, neck, or trunk Otitis media

Other complications of pregnancy

Headache or migraine

Superficial injury

Chest pain

Back problem

Back problem

Otitis media

Superficial injury

Chest pain

1-4

25-44

Headache or migraine 45-64

Sprain

b1

Other upper respiratory infection 15-24

Superficial injury

Age Group, Male

Other upper respiratory infection Fracture—upper limb 5-14

65-74

75+

Headache or migraine Overall

Counts (%) Insurance type Commercial Medicaid Medicare Self-pay/other Facility billing level 1 2 3 4 5 Resource variables Direct costs ($) Length of stay (h) Top five CCS categories (listed in descending order of prevalence)

10 145 (4.1%)

22 062 (8.9%)

27 995 (11.2%)

43 956 (17.7%)

82 269 (33.0%)

46 283 (18.6%)

7663 (3.1%)

8723 (3.5%)

249 096 (100%)

80.9% 15.7% 0.0% 3.4%

83.5% 12.9% 0.0% 3.6%

77.9% 18.5% 0.0% 4.0%

50.6% 18.5% 1.5% 29.3%

41.3% 19.2% 9.7% 29.9%

45.6% 18.6% 19.8% 16.0%

18.7% 2.0% 76.2% 3.1%

8.5% 0.8% 89.3% 1.4%

51.4% 17.0% 12.6% 19.0%

0.6% 29.8% 51.3% 17.3% 1.1%

1.0% 28.8% 52.1% 16.7% 1.4%

0.7% 23.2% 54.0% 17.9% 4.4%

0.9% 19.1% 51.1% 22.9% 6.0%

1.0% 18.0% 47.2% 26.7% 7.3%

0.8% 12.7% 40.6% 35.5% 10.4%

0.6% 9.3% 37.4% 40.9% 11.8%

0.5% 7.1% 33.7% 44.5% 12.3%

0.9% 18.6% 47.3% 26.4% 6.8%

118 [72, 174] 1.8 [1.1, 2.9] Other upper respiratory infection Fever unknown origin

113 [72, 155] 1.6 [0.9, 2.6] Other upper respiratory infection Open wound—head, neck, or trunk

120 [99, 182] 1.7 [1.0, 2.7] Superficial injury

130 [103, 254] 1.6 [0.9, 2.8] Sprain

132 [103, 272] 1.7 [0.9, 3.2] Sprain

174 [111, 313] 2.4 [1.2, 4.0] Back problem

267 [131, 350] 3.2 [1.9, 4.5] Superficial injury

132 [103, 272] 1.9 [1.0, 3.2] Sprain

Open wound—head, Superficial injury neck, or trunk

Back problem

Sprain

247 [120, 340] 2.7 [1.6, 4.2] Superficial injury Abdominal pain

Superficial injury

Viral Infection

Asthma

Fracture—arm

Superficial injury

Superficial injury

Back Problem

Genitourinary symptoms and ill-defined conditions Abdominal Pain

Nausea/Vomiting

Otitis media

Chest pain

Back problem

Fever unknown origin

Open wounds of extremities Abdominal pain

Chest pain

Bronchitis

Open wounds of extremities Sprain

Abdominal pain

Sprain

Other lower respiratory disease

⁎ Number, percent, median (IQR), and US dollars ($).

Open wounds of extremities Open wounds—Head, neck, or trunk Other upper respiratory infection

Back problem Open wounds of extremities Open wound—Head, neck, or trunk

P.L. Henneman et al. / American Journal of Emergency Medicine 32 (2014) 1159–1167

Age Group, Female

Table 2 A. Resource measures⁎ by age and insurance type: females. B. Resource measures⁎ by age and insurance type: males Commercial

b1

1-4

5-14

15-24

25-44

45-64

65-74

75+

Overall

Counts (N) Charges ($) Direct costs ($) Revenue ($) Contribution margin ($) Length of stay (hours) Contribution margin per hour ($/hour)

6628 584 [356, 844] 117 [70, 171] 312 [198, 439] 193 [110, 282] 1.8 [1.1, 2.9] 112 [64, 177]

14 924 584 [397, 844] 114 [72, 154] 312 [194, 434] 192 [108, 291] 1.6 [1.0, 2.7] 119 [65, 200]

17 794 642 [480, 1088] 121 [99, 204] 320 [196, 512] 195 [105, 352] 1.7 [1.0, 2.9] 124 [64, 222]

35 548 759 [509, 1519] 144 [107 292] 399 [252, 807] 247 [124, 537] 2.0 [1.0, 3.4] 155 [75, 272]

57 377 831 [514, 1630] 152 [108, 299] 398 [252, 832] 238 [110, 554] 2.3 [1.2, 3.8] 152 [68, 266]

28 096 1089 [569, 1749] 202 [113, 317] 403 [254, 836] 216 [89, 558] 2.3 [1.2, 3.8] 127 [45, 244]

1690 1221 [639, 1891] 238 [121, 338] 424 [250, 776] 181 [62, 487] 2.6 [1.4, 4.0] 90 [27, 249]

1179 1428 [747, 2022] 272 [138, 351] 484 [296, 874] 209 [65, 586] 3.2 [2.0, 4.5] 69 [22, 223]

163 236 748 [509, 1505] 140 [105, 286] 371 [236, 733] 219 [108, 483] 2.0 [1.1, 3.4] 139 [63, 249]

Medicare

b1

1-4

5-14

15-24

24-44

45-64

65-74

75+

Overall

870 1220 [638, 1732] 235 [121, 322] 309 [189, 460] 73 [34, 158] 2.8 [1.6, 4.5] 32 [16, 61]

7417 1132 [553, 1683] 229 [113, 309] 283 [167, 427] 62 [32, 134] 2.5 [1.3, 4.2] 32 [16, 59]

8325 1177 [590, 1755] 239 [115, 324] 297 [174, 444] 63 [33, 138] 2.7 [1.5, 4.4] 31 [15, 56]

7982 1334 [680, 1904] 258 [127, 342] 342 [194, 513] 79 [42, 192] 3.0 [1.7, 4.4] 35 [17, 65]

14 160 1500 [813, 2033] 285 [145, 360] 384 [246, 563] 102 [49, 219] 3.4 [2.2, 4.8] 35 [17, 68]

38 761 1333 [666, 1884] 256 [125, 339] 336 [193, 502] 76 [40, 181] 3.0 [1.7, 4.5] 33 [16, 63]

Medicaid

b1

1-4

5-14

15-24

24-44

45-64

65-74

75+

Overall

Counts (n) Charges ($) Direct costs ($) Revenue ($) Contribution margin ($) Length of stay (hours) Contribution margin per hour ($/hour)

1270 560 [356, 806] 113 [70, 159] 154 [98, 226] 43 [4, 89] 1.8 [1.1, 2.9] 25 [2, 60]

2249 557 [356, 791] 113 [70, 150] 153 [93, 212] 39 [−2, 89] 1.6 [0.9, 2.7] 24 [−1, 62]

3785 621 [446, 1103] 121 [97, 236] 158 [115, 229] 40 [−13, 90] 1.8 [1.0, 3.1] 22 [−5, 59]

10 896 855 [514, 1597] 167 [110, 313] 178 [123, 279] 34 [−57, 97] 2.4 [1.2, 3.9] 16 [−22, 53]

17 228 917 [514, 1659] 177 [110, 312] 161 [116, 257] 22 [−85, 84] 2.3 [1.2, 4.0] 12 [−27, 52]

10 462 1118 [554, 1712] 223 [113, 322] 170 [120, 279] 20 [−93, 83] 2.7 [1.4, 4.3] 9 [−28, 45]

332 1255 [624, 1883] 253 [125, 350] 161 [111, 275] −11 [−129, 60] 3.0 [1.6, 4.7] −4 [−35, 28]

102 1540 [841, 2164] 274 [142, 395] 191 [120, 337] −10 [−166, 107] 3.5 [2.2, 4.8] −4 [−44, 50]

46 324 823 [514, 1580] 155 [109, 304] 162 [117, 259] 29 [−61, 89] 2.3 [1.2, 3.9] 14 [−23, 52]

Commercial

b1

1-4

5-14

15-24

25-44

45-64

65-74

75+

Overall

Counts (N) Charges ($) Direct costs ($) Revenue ($) Contribution margin ($) Length of stay (hours) Contribution margin per hour ($/hour)

8209 585 [356, 860] 119 [72, 175] 314 [198, 448] 196 [110, 284] 1.8 [1.1, 2.9] 113 [64, 179]

18 429 585 [417, 843] 114 [72, 156] 312 [198, 440] 196 [110, 294] 1.6 [0.9, 2.7] 125 [67, 211]

21 793 658 [490, 1087] 120 [99, 181] 318 [198, 509] 196 [103, 355] 1.7 [1.0, 2.7] 134 [65, 240]

22 258 741 [509, 1375] 132 [104 258] 387 [226, 690] 239 [113, 492] 1.7 [0.9, 2.8] 171 [75, 321]

33 955 740 [508, 1482] 134 [104, 275] 363 [213, 687] 202 [92, 475] 1.7 [0.9, 3.1] 147 [57, 286]

21 105 1055 [559, 1787] 187 [112, 321] 398 [242, 820] 204 [83, 553] 2.3 [1.2, 3.7] 122 [41, 253]

1434 1260 [642, 1891] 242 [120, 341] 403 [254, 805] 173 [59, 532] 2.5 [1.5, 3.8] 85 [24, 259]

744 1361 [689, 1976] 257 [132, 355] 504 [287, 970] 267 [81, 663] 2.8 [1.7, 4.2] 109 [32, 264]

127 927 705 [492, 1368] 129 [101, 262] 345 [231 615] 202 [102, 417] 1.8 [1.0, 4.2] 136 [60, 258]

Medicare

b1

1-4

5-14

Counts (N) Charges ($) Direct costs ($) Revenue ($) Contribution margin ($) Length of stay (hours) Contribution margin per hour ($/hour)

15-24

24-44

45-64

65-74

75+

Overall

660 1065 [514, 1558] 213 [111, 295] 271 [158, 384] 52 [31, 109] 2.5 [1.2, 4.3] 30 [13, 60]

7937 813 [514, 1558] 148 [108, 295] 245 [147, 387] 56 [32, 120] 2.3 [1.2, 4.1] 32 [15, 62]

9174 1139 [559, 1729] 229 [113, 319] 286 [169, 438] 62 [33, 140] 2.7 [1.5, 4.4] 30 [14, 57]

5836 1283 [638, 1891] 251 [120, 342] 329 [189, 511] 75 [40, 191] 2.8 [1.7, 4.3] 35 [17, 70]

7791 1394 [706, 1958] 268 [130, 350] 361 [209, 547] 92 [44, 216] 3.2 [2.0, 4.6] 35 [17, 71]

31 410 1168 [581, 1767] 234 [115, 325] 298 [173, 468] 66 [35, 161] 2.8 [1.5, 4.4] 33 [16, 64]

b1

1-4

5-14

15-24

24-44

45-64

65-74

75+

Overall

Counts (N) Charges ($) Direct costs($) Revenue ($) Contribution margin ($) Length of stay (hours) Contribution margin per hour ($/hour)

1595 574 [356, 842] 116 [70, 179] 154 [98, 226] 42 [−2, 88] 1.9 [1.1, 3.0] 25 [−1, 55]

2841 560 [356, 803] 112 [70, 153] 155 [98, 230] 41 [5, 89] 1.6 [0.9, 2.6] 26 [3, 64]

5190 624 [457, 1054] 119 [96, 211] 160 [120, 229] 45 [2, 97] 1.7 [1.0, 2.9] 26 [1, 66]

8141 717 [509, 1370] 133 [108, 266] 171 [129, 264] 43 [−14, 101] 1.8 [1.0, 3.2] 25 [−7, 70]

15 778 734 [509, 1500] 139 [108, 287] 162 [119, 264] 36 [−30, 95] 2.1 [1.0, 3.8] 19 [−13, 61]

8604 1027 [517, 1681] 192 [111, 313] 177 [127, 283] 35 [−67, 100] 2.8 [1.4, 5.0] 13 [−17, 49]

152 1154 [592, 1673] 233 [116, 332] 193 [126, 334] 41 [−62, 98] 3.0 [2.0, 5.0] 11 [−16, 37]

66 1396 [705, 2128] 269 [127, 371] 212 [113, 326] −34 [−180, 71] 3.2 [2.0, 4.6] −14 [−45, 22]

42 367 706 [508, 1421] 134 [105, 277] 164 [120, 261] 39 [−23, 97] 2.0 [1.1, 3.7] 20 [−10, 61]

⁎ Number (N), median (IQR) and US dollars ($).

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Medicaid

P.L. Henneman et al. / American Journal of Emergency Medicine 32 (2014) 1159–1167

Counts (n) Charges ($) Direct costs ($) Revenue ($) Contribution margin ($) Length of stay (hours) Contribution margin per hour ($/hour)

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Table 3 Charges, cost and length of stay by age and gender for self pay/other patients⁎ Self-pay/other for females

b1

1-4

5-14

15-24

25-44

45-64

65-74

75+

Overall

Counts (n) Charges ($) Direct costs ($) Length of stay (hours)

306 490 [335, 644] 101 [66 135] 1.5 [0.8, 2.3]

690 548 [348, 681] 111 [66, 135] 1.4 [0.9, 2.3]

888 556 [323, 841] 114 [65, 151 1.6 [0.9, 2.7]

8235 696 [490, 1392] 134 [103, 281] 1.8 [1.0, 3.2]

10 971 671 [482, 1348] 126 [100, 261] 1.7 [0.9, 3.0]

5063 711 [493, 1421] 133 [103, 269] 1.7 [0.9, 3.2]

181 857 [509,1527] 142 [105, 283] 2.0 [1.0, 3.4]

131 1337 [667, 1972] 217 [112 362] 2.8 [1.5, 4.5]

26 465 674 [490, 1348] 128 [101, 264] 1.7 [0.9, 3.1]

Self-pay/other for males

b1

1-4

5-14

15-24

25-44

45-64

65-74

75+

Overall

Counts (n) Charges ($) Direct costs ($) Length of stay (hours)

341 526 [339, 739] 112 [70, 151] 1.7 [1.1, 2.7]

787 560 [356, 717] 111 [66, 137] 1.5 [0.8, 2.5]

1005 584 [417, 876] 114 [69, 149] 1.5 [0.9, 2.4]

12 897 668 [484, 1197] 122 [99, 232] 1.5 [0.8, 2.6]

24 599 672 [490, 1280] 123 [101, 245] 1.5 [0.8, 2.7]

7400 752 [509, 1507] 134 [104, 279] 1.9 [1.0, 3.3]

241 888 [541, 1623] 150 [111, 301] 2.3 [1.3, 3.8]

122 1387 [764, 2051] 262 [131, 353] 2.8 [1.7, 4.4]

47 392 676 [490, 1280] 124 [100, 246] 1.6 [0.9, 2.8]

⁎ Number (N), median (IQR) and US dollars ($).

per hour for commercial patients was higher for women ($523 and $143/hour) than for men ($448 and $97/hour, P b .001).

4. Discussion We found that resource utilization, as measured by length of stay and direct clinical costs, increases with age in ED patients seen and released from a single institution. For women of child bearing years, this increase is greater than for men of similar age. For children and adults younger than 45 years, resource utilization as measured by length of stay and cost were similar for men and women. Our study also shows that profitability of ED outpatients, as measured by contribution margin per hour, is clearly dependent on insurance type and length of stay. For commercially insured and Medicaid patients, profitability decreases with increasing age, while remaining relatively constant for Medicare patients. Profitability of women of childbearing years is greater than the profitability of men of the same age for patients with certain conditions such as abdominal pain and chest pain. The differences we found in resource utilization

and profitability are more pronounced as adult women were more common ED outpatients than men. We submit that our findings that length of stay and direct clinical costs increase with increasing age have high face validity. Elderly patients have more co-morbidities so their complaints have greater complexity than similar complaints in younger patients; this understandably would result in more testing, more treatments, and longer length of stays. Data from NHAMCS and HCUP show an association between age and acuity (i.e., Emergency Severity Index), and age and length of stay [3,10,11,18]. We now show an association between age, cost, and billing level. Analysis of data from NHAMCS shows that test ultilization increased significantly in the United States during the years of our study; these additional tests would result in increased costs in our analysis [3]. If our findings are generalizable on a national level, then the efficiency of ED care in the United States may decrease as our population ages. Patients seen and released from the ED will stay longer and the costs of their care will increase. We have previously reported that contribution margin per hour is dependent on insurance; we now show that age also plays a role in profitability by insurance type [15]. Contribution margin per hour is

Fig. 2. Median length of stay, direct clinical costs, revenue, and contribution margin per hour by age and insurance type. Note self pay/other patients are only included in length of stay and cost figures.

P.L. Henneman et al. / American Journal of Emergency Medicine 32 (2014) 1159–1167

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Fig. 3. Length of stay and resource variables by age and gender.

highest for commercial patients and increases with age; it is low but positive for all adults with Medicare and does not change with age. Contribution margin per hour is lowest for patients with Medicaid and

becomes negative with advanced age. Unless ED outpatient payments by governmental payors increase, EDs will also become less profitable as their communities age.

Table 4 A. Resource measures⁎ by CCS category for females 15 to 44 years old. B. Resource measures⁎ by CCS category for males age 15-44 Females

Sprain

Superficial injury

Abdominal pain

Back problem

Open wound—extremities

Headache or migraine

CCS category N % Total Direct costs ($) Length of stay (hours) Revenue—commercial ($) Revenue—Medicare ($) Revenue—Medicaid ($) Contribution margin commercial ($) Contribution margin Medicare ($) Contribution margin Medicaid ($) Contribution margin per hour commercial ($/hour) Contribution margin per hour Medicare ($/hour) Contribution margin per hour Medicaid ($/hour)

232 14 022 9.4% 116 [88, 147] 1.2 [0.8, 2.3] 387 [218, 599] 194 [146, 269] 161 [131, 201] 272 [148, 448] 63 [33, 107] 55 [28, 88] 240 [134, 387] 47 [27, 82] 49 [16, 103]

239 8501 5.7% 127 [101, 159] 1.4 [0.8, 2.3] 399 [238, 648] 197 [159, 325] 156 [125, 206] 281 [144, 486] 66 [43, 113] 42 [3, 79] 220 [115, 379] 45 [24, 74] 29 [1, 72]

251 11 376 7.7% 363 [261, 480] 4.1 [2.7, 5.8] 936 [403, 1599] 503 [321, 768] 193 [154, 441] 590 [176, 1138] 137 [59, 333] −34 [−205, 123] 153 [62, 249] 37 [19, 65] −10 [−46, 43]

205 8135 5.5% 110 [96, 143] 1.3 [0.8, 2.3] 305 [189, 454] 167 [142, 260] 116 [97, 155] 193 [111, 321] 44 [31, 66] 31 [−15, 56] 170 [88, 286] 36 [21, 55] 17 [−10, 59]

236 3035 2.0% 111 [72, 134] 1.2 [0.8, 2.3] 319 [215, 463] 244 [181, 309] 170 [138, 231] 218 [116, 327] 100 [50, 146] 62 [23, 123] 167 [87, 270] 53 [26, 106] 45 [13, 96]

84 8274 5.6% 237 [113, 270] 2.4 [1.5, 3.7] 595 [312, 969] 311 [199, 433] 149 [106, 278] 382 [153, 710] 91 [57, 190] 6 [−102, 87] 166 [78, 272] 48 [28, 82] 3 [−35, 44]

Males

Sprain

Superficial injury

Abdominal pain

Back problem

Open wound—extremities

Headache or migraine

CCS category N % Total Direct costs ($) Length of stay (hours) Revenue—commercial ($) Revenue—Medicare ($) Revenue—Medicaid ($) Contribution margin commercial ($) Contribution margin Medicare ($) Contribution margin Medicaid ($) Contribution margin per hour commercial ($/hour) Contribution margin per hour Medicare ($/hour) Contribution margin per hour Medicaid ($/hour)

232 13 918 11.0% 116 [92, 143] 1.2 [0.7, 2.0] 380 [215, 598] 189 [143, 247] 162 [154, 206] 250 [128, 449] 58 [33, 92] 58 [31, 97] 239 [128, 397] 50 [28, 83] 49 [20, 107]

239 9759 7.7% 128 [104, 167] 1.4 [0.8, 2.3] 412 [227, 717] 193 [147, 293] 156 [134, 212] 288 [128, 549] 61 [37, 105] 44 [3, 92] 231 [111, 407] 46 [28, 82] 31 [1, 78]

251 4435 3.5% 296 [149, 402] 3.4 [2.1, 5.1] 656 [319, 1373] 463 [272, 741] 193 [189, 433] 381 [102, 1010] 151 [56, 346] 46 [−118, 142] 141 [45, 265] 43 [21, 75] 16 [−30, 67]

205 7646 6.1% 108 [60, 129] 1.2 [0.7, 2.0] 302 [176, 436] 167 [141, 246] 116 [105, 153] 187 [103, 305] 44 [31, 70] 34 [3, 58] 166 [79, 301] 39 [22, 65] 24 [2, 67]

236 6392 5.1% 115 [99, 140] 1.3 [0.7, 1.8] 324 [220, 490] 250 [188, 309] 169 [138, 252] 218 [114, 353] 119 [59, 154] 60 [18, 119] 163 [86, 287] 63 [35, 112] 43 [10, 101]

84 2687 2.1% 222 [107, 294] 2.3 [1.3, 3.5] 505 [286, 996] 298 [166, 473] 149 [131, 234] 306 [125, 719] 89 [46, 194] 33 [−81, 95] 160 [71, 272] 48 [30, 73] 20 [−26, 70]

⁎ Number, percent, median (IQR) and US dollars ($).

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Our finding that women of child bearing years have longer length stay, higher direct clinical costs and higher profitability than men of the same age range is interesting. This age range includes at least 50% of patients in our study and those in NHAMCS [3]. This difference seems to be mainly due to the more common diagnosis of abdominal pain in women in this age range which resulted in higher length of stay, higher costs, and higher billing levels than the common diagnoses for men in the same age range. Since women in their third trimester of pregnancy with abdominal pain are not seen in our ED, this is not the cause for the increased length of stay, cost and profitability seen in women of child bearing age in our study. In a survey of 509 adult clinic patients at a single university medical center, women (mean age 41) had a lower self reported physical and mental health status, and had higher primary clinic, specialty clinic, emergency department, diagnostic services, and total charges than men (mean age 42) collected prospectively over the subsequent year. There was no difference in hospital charges between sexes [19]. Unfortunately, these data were not broken out by age, and charges have variable association with cost and revenue. We found no differences by gender in length of stay, direct clinical costs, and profitability for children and adults over 45 years of age, and marked differences for those of child bearing years. Others have found no sex differences in management, test utilization, and diagnoses of geriatric patients with abdominal pain (age N 70), but we are not aware of any reports of gender differences in cost and revenue of the common CCS group diagnoses in any other age group [20]. 5. Limitations While the clear strengths of our study include detailed accounting methods and a large dataset, our study has some limitations. Although the total number of patients in our study is twice that included in the NHAMCS for the same years, their statistical sample of patients were from almost 400 EDs, whereas, ours are from a single institution making our results less generalizable. As a Level 1 trauma center, and pediatric and adult tertiary referral center, our ED admissions are probably different from those found in many hospitals. However, by focusing on patients not admitted to the hospital, our sample is likely similar in acuity to those seen in many EDs in the United States. Also, our age and sex distribution mirrors that seen in the NHAMCS [11]. Like NHAMCS, we found that males were more common pediatric patients and females were more common adult patients (NHAMCS 2004-2010) [2,4–8]. Like NHAMCS and HCUP, we found that length of stay increases with age [3,10,18]. The most common diagnoses seen in our ED by each age group were similar to the age specific diagnoses reported in NHAMCS [2,4–8]. From NHAMCS, we know that test utilization increased significantly in the United States during the same years as our study which is consistent with the increase in costs we report [3]. Unfortunately, data from NHAMCS do not include cost and profitability results and we do not have specific data on test utilization or other components of costs by patients. While this highlights the importance of our work, we cannot make a direct comparison with NHAMCS, nor can we say why direct clinical costs vary by age and gender in our institution. Since EDs in the United States have different distributions of facility billing levels and insurance types, we have reported results by insurance type and facility billing level to improve comparability. We do not have revenue data on self pay patients so are unable to determine the impact of age and gender on profitability in these patients. Self pay patients make up 10% of the females in our study and 19% of males; clearly gender affects who is a self pay patient in our ED. Also many institutions have a greater percentage of patients without insurance than we do; this is partly due to the implementation of the Massachusetts Health Care Reform Law (aka RomneyCare) halfway through our study period. Although our study was over seven years, we did not include an inflation factor, though we do not believe this distorts our conclusions. Also, the data includes all ED visits, so some

patients were included multiple times over the 7 years of our study; each year approximately one third of our ED visits are from repeat patients [21]. Finally, we do not know how our contractual arrangements with commercial insurers compare to other hospitals. While contractual arrangements by Medicaid vary by state, Medicare payments for facility E&M billing levels are more uniform across the country. 6. Conclusion In our hospital, resource utilization among ED patients seen and released, increased with increasing age, and profitability decreased with increasing age. Also, the care of women of childbearing age resulted in higher resource utilization and higher profitability than men of the same age, particularly for abdominal pain and chest pain but not for other common diagnoses like superficial injuries or open wounds of the extremities. Resource utilization and profitability of outpatient ED visits by children and adults over 45 were the same for males and females. Appendix 1. Included and excluded costs and revenue Included costs

Not included costs and revenue Overhead

Other

ED staff salaries and benefits (nurses, technicians, orderlies) ED clinical equipment and supplies ED pharmacy/drugs ED respiratory therapy

Hospital administration

Physician salaries, benefits and revenue

Information services

ED equipment depreciation ED laboratory/diagnostic imaging ED nursing administration

Financial services Facility depreciation

ED expenses for discharged patients

Power/water/utilities

ED expenses for admitted patientsa Physician malpractice Resident salary and benefits IME and DME revenue Other teaching expenses Research related costs Research grants

ED/hospital security

Medical library

Hospital malpractice Nutrition services

Engineering/maintenance

IME, indirect medical expenses; DME, direct medical expenses. a ED expenses for admitted patients includes all supplies, pharmacy, and staff time for patients admitted inpatient or observation.

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