The impact of July hospital admission on outcome after surgery for spinal metastases at academic medical centers in the United States, 2005 to 2008.
BACKGROUND
Despite widespread belief that patients admitted to teaching hospitals in July-the beginning of the academic year-have inferior outcomes, there has been little evidence to support the existence of the July phenomenon. Moreover, the impact of July admission on the outcomes after surgery for spinal metastases has not been investigated.


METHODS
Data from the Nationwide Inpatient Sample (2005-2008) were retrospectively extracted. Patients who underwent surgery for metastatic spinal disease and were admitted to a teaching hospital were included. Multivariate logistic regression was conducted to calculate the odds of in-hospital death, the occurrence of an intraoperative complication, and the development of a postoperative complication depending on whether admission was in July or between August and June. All analyses were adjusted for differences in patient age, sex, comorbidities, primary tumor histology, visceral metastases, myelopathy, insurance status, hospital volume, and admission type.


RESULTS
A total of 2920 admissions were evaluated. In-hospital mortality was higher in July compared with between August and June-7.5% versus 4.2%. The adjusted odds of in-hospital death were significantly higher for patients admitted in July (odds ratio [OR], 1.81; 95% confidence interval [CI], 1.13-2.91; P = .01). Patients admitted in July were significantly more likely to develop an intraoperative complication (OR, 2.11; 95% CI, 1.41-3.17; P < .001), but not a postoperative complication (OR, 1.08; 95% CI, 0.81-1.45; P = .60).


CONCLUSIONS
In this nationwide study based on an administrative database, patients undergoing surgery for metastatic spinal disease at teaching hospitals in July had higher rates of in-hospital mortality and intraoperative complications.
School of Medicine, Johns Hopkins University, Baltimore, Maryland 21287, USA.
Hormuzdiyar H
HH
Dasenbrock
Michelle J
MJ
Clarke
Richard E
RE
Thompson
Ziya L
ZL
Gokaslan
Ali
A
Bydon
D000046:Academic Medical Centers / Q000706:statistics & numerical data*; D002277:Carcinoma / Q000453:epidemiology* / Q000401:mortality / Q000556:secondary / Q000601:surgery*; D015897:Comorbidity; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007431:Intraoperative Complications / Q000453:epidemiology / Q000401:mortality; D008297:Male; D010343:Patient Admission / Q000706:statistics & numerical data*; D011183:Postoperative Complications / Q000453:epidemiology / Q000401:mortality; D012189:Retrospective Studies; D012621:Seasons; D013125:Spinal Neoplasms / Q000453:epidemiology* / Q000401:mortality / Q000556:secondary / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology