Impact of admission month and hospital teaching status on outcomes in subarachnoid hemorrhage: evidence against the July effect

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  • 1 Clinician Investigator Training Program, and
  • 2 Departments of Radiology and
  • 3 Neurosurgery, College of Medicine, Mayo Clinic, Rochester, Minnesota
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Object

The authors sought to identify the presence of a “July effect,” a transient increase in adverse outcomes during July, among a cohort of spontaneous subarachnoid hemorrhage (SAH) admissions recorded in the National Inpatient Sample (NIS).

Methods

The discharge status, admission month, patient demographics, treatment parameters, and hospital characteristics among spontaneous SAH admissions were extracted from the 2001–2008 NIS. Multivariate regression was used to determine whether an unfavorable discharge status and/or in-hospital mortality significantly increased in summer months in a pattern suggestive of a July effect. Additional models were generated to assess the impact of hospital teaching status on these outcomes.

Results

Among 57,663,486 hospital admissions from the 2001–2008 NIS, 52,879 cases of spontaneous SAH (ICD-9-CM 430) were treated at teaching (36,914 cases [70%]) and nonteaching (15,965 cases [30%]) facilities. Regression models failed to reveal a July effect for in-hospital mortality (χ2 = 0.75, p = 1.000) or unfavorable discharges (χ2 = 1.69, p = 0.999) among monthly SAH admissions, although they did suggest a significant reduction in these outcomes (in-hospital mortality, OR = 0.89, p < 0.001; unfavorable discharges, OR = 0.88, p < 0.001) among teaching hospitals as compared with nonteaching hospitals after adjustment for disparities in demographic, treatment, and hospital characteristics.

Conclusions

The discharge disposition among SAH admissions within the NIS was not suggestive of a July effect but did reveal that teaching institutions have significantly lower rates of adverse outcomes when compared with nonteaching hospitals. Note, however, that the origins of this difference related to teaching status remain unclear.

Abbreviations used in this paper: df = degrees of freedom; ER = emergency room; NIS = National Inpatient Sample; RR = relative risk; SAH = subarachnoid hemorrhage.

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Contributor Notes

Address correspondence to: Robert J. McDonald, M.D., Ph.D., Department of Radiology, Mayo Clinic, 200 1st Street SW, Rochester, Minnesota 55905. email: mcdonald.robert@mayo.edu.

Please include this information when citing this paper: published online September 23, 2011; DOI: 10.3171/2011.8.JNS11324.

  • 1

    Anderson KL, , Koval KJ, & Spratt KF: Hip fracture outcome: is there a “July effect”?. Am J Orthop 38:606611, 2009

  • 2

    Bakaeen FG, , Huh J, , Lemaire SA, , Coselli JS, , Sansgiry S, & Atluri PV, : The July effect: impact of the beginning of the academic cycle on cardiac surgical outcomes in a cohort of 70,616 patients. Ann Thorac Surg 88:7075, 2009

    • Search Google Scholar
    • Export Citation
  • 3

    Barry WA, & Rosenthal GE: Is there a July phenomenon? The effect of July admission on intensive care mortality and length of stay in teaching hospitals. J Gen Intern Med 18:639645, 2003

    • Search Google Scholar
    • Export Citation
  • 4

    Bederson JB, , Connolly ES Jr, , Batjer HH, , Dacey RG, , Dion JE, & Diringer MN, : Guidelines for the management of aneurysmal subarachnoid hemorrhage: a statement for healthcare professionals from a special writing group of the Stroke Council, American Heart Association. Stroke 40:9941025, 2009

    • Search Google Scholar
    • Export Citation
  • 5

    Berthelsen CL: Evaluation of coding data quality of the HCUP National Inpatient Sample. Top Health Inf Manage 21:1023, 2000

  • 6

    Birbeck GL, , Zingmond DS, , Cui X, & Vickrey BG: Multispecialty stroke services in California hospitals are associated with reduced mortality. Neurology 66:15271532, 2006

    • Search Google Scholar
    • Export Citation
  • 7

    Caughey AB: The July phenomenon: why don't we see it in obstetrics?. J Perinatol 27:7172, 2007

  • 8

    Claridge JA, , Schulman AM, , Sawyer RG, , Ghezel-Ayagh A, & Young JS: The “July phenomenon” and the care of the severely injured patient: fact or fiction?. Surgery 130:346353, 2001

    • Search Google Scholar
    • Export Citation
  • 9

    Dhaliwal AS, , Chu D, , Deswal A, , Bozkurt B, , Coselli JS, & Lemaire SA, : The July effect and cardiac surgery: the effect of the beginning of the academic cycle on outcomes. Am J Surg 196:720725, 2008

    • Search Google Scholar
    • Export Citation
  • 10

    Diringer MN: Management of aneurysmal subarachnoid hemorrhage. Crit Care Med 37:432440, 2009

  • 11

    Englesbe MJ, , Pelletier SJ, , Magee JC, , Gauger P, , Schifftner T, & Henderson WG, : Seasonal variation in surgical outcomes as measured by the American College of Surgeons–National Surgical Quality Improvement Program (ACS-NSQIP). Ann Surg 246:456465, 2007

    • Search Google Scholar
    • Export Citation
  • 12

    Ford AA, , Bateman BT, , Simpson LL, & Ratan RB: Nationwide data confirms absence of ‘July phenomenon’ in obstetrics: it's safe to deliver in July. J Perinatol 27:7376, 2007

    • Search Google Scholar
    • Export Citation
  • 13

    Garcia S, , Canoniero M, & Young L: The effect of July admission in the process of care of patients with acute cardiovascular conditions. South Med J 102:602607, 2009

    • Search Google Scholar
    • Export Citation
  • 14

    Highstead RG, , Johnson LS, , Street JH III, , Trankiem CT, , Kennedy SO, & Sava JA: July—as good a time as any to be injured. J Trauma 67:10871090, 2009. (Erratum in J Trauma 69:1637, 2010)

    • Search Google Scholar
    • Export Citation
  • 15

    Huckman RS, & Barro JR: Cohort turnover and productivity: the July phenomenon in teaching hospitals. Presented at the annual meeting of the Economics of Population Health: Inaugural Conference of the American Society of Health Economists Madison, WI 2006. (Abstract) (http://www.allacademic.com/meta/p90940_index.html) [Accessed August 8, 2011]

    • Search Google Scholar
    • Export Citation
  • 16

    Inaba K, , Recinos G, , Teixeira PGR, , Barmparas G, , Talving P, & Salim A, : Complications and death at the start of the new academic year: is there a July phenomenon?. J Trauma 68:1922, 2010

    • Search Google Scholar
    • Export Citation
  • 17

    Kestle JRW, , Cochrane DD, & Drake JM: Shunt insertion in the summer: is it safe?. J Neurosurg 105:3 Suppl 165168, 2006

  • 18

    Kowalski RG, , Claassen J, , Kreiter KT, , Bates JE, , Ostapkovich ND, & Connolly ES, : Initial misdiagnosis and outcome after subarachnoid hemorrhage. JAMA 291:866869, 2004

    • Search Google Scholar
    • Export Citation
  • 19

    Kraus JJ, , Metzler MD, & Coplin WM: Critical care issues in stroke and subarachnoid hemorrhage. Neurol Res 24:Suppl 1 S47S57, 2002

  • 20

    Leder DM, , Peterson ED, , Roe MT, , DeLong ER, , Chen AY, & Ohman EM, : The “July Phenomenon” revisited: is the quality of care for patients presenting with acute coronary syndromes affected by house officer inexperience? Insights from CRUSADE. Circulation 113:E818E819, 2006

    • Search Google Scholar
    • Export Citation
  • 21

    Meguid RA, , Brooke BS, , Perler BA, & Freischlag JA: Impact of hospital teaching status on survival from ruptured abdominal aortic aneurysm repair. J Vasc Surg 50:243250, 2009

    • Search Google Scholar
    • Export Citation
  • 22

    Myles TD: Is there an obstetric July phenomenon?. Obstet Gynecol 102:10801084, 2003

  • 23

    Nicholson WK, , Witter F, & Powe NR: Effect of hospital setting and volume on clinical outcomes in women with gestational and type 2 diabetes mellitus. J Womens Health (Larchmt) 18:15671576, 2009

    • Search Google Scholar
    • Export Citation
  • 24

    Orandi BJ, , Sharma V, , Upchurch GR, & Napolitano LM: Is there a “July phenomenon” in central venous catheter placement?. Crit Care Med 35:Suppl 12 A155, 2007. (Abstract)

    • Search Google Scholar
    • Export Citation
  • 25

    Phillips DP, & Barker GEC: A July spike in fatal medication errors: a possible effect of new medical residents. J Gen Intern Med 25:774779, 2010

    • Search Google Scholar
    • Export Citation
  • 26

    Qualls M, , Pallin DJ, & Schuur JD: Parametric versus nonparametric statistical tests: the length of stay example. Acad Emerg Med 17:11131121, 2010

    • Search Google Scholar
    • Export Citation
  • 27

    Rosen DS, & Macdonald RL: Subarachnoid hemorrhage grading scales: a systematic review. Neurocrit Care 2:110118, 2005

  • 28

    Schroeppel TJ, , Fischer PE, , Magnotti LJ, , Croce MA, & Fabian TC: The “July phenomenon”: is trauma the exception?. J Am Coll Surg 209:378384, 2009

    • Search Google Scholar
    • Export Citation
  • 29

    Silverman AT, , Goldfarb MA, & Baker T: When should a surgical resident call an attending surgeon?. J Surg Educ 65:206212, 2008

  • 30

    Smith ER, , Butler WE, & Barker FG II: Is there a “July phenomenon” in pediatric neurosurgery at teaching hospitals?. J Neurosurg 105:3 Suppl 169176, 2006

    • Search Google Scholar
    • Export Citation
  • 31

    Stout CL, , Chapman JR, , Scoglietti VC, , Long EL, , Vaughn DM, & Abercrombie CL, : “July Effect”: an evaluation of a level I teaching hospital's trauma service seasonal mortality rates. Am Surg 74:878879, 2008

    • Search Google Scholar
    • Export Citation
  • 32

    Turner PD, , Bramble JD, & Rich EC: Cost of care in academic health centers: the July phenomenon revisited. J Gen Intern Med 15:Suppl 1 150151, 2000. (Abstract)

    • Search Google Scholar
    • Export Citation
  • 33

    Yaghoubian A, , de Virgilio C, , Chiu V, & Lee SL: “July effect” and appendicitis. J Surg Educ 67:157160, 2010

  • 34

    Yeaton-Massey A, , Cheng Y, , Handler S, , Granados J, & Caughey A: The July phenomenon: does it apply to obstetrics?. Am J Obstet Gynecol 201:Suppl 1 S223, 2009. (Abstract)

    • Search Google Scholar
    • Export Citation
  • 35

    Zimmerman JE, , Shortell SM, , Knaus WA, , Rousseau DM, , Wagner DP, & Gillies RR, : Value and cost of teaching hospitals: a prospective, multicenter, inception cohort study. Crit Care Med 21:14321442, 1993

    • Search Google Scholar
    • Export Citation

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