Impact of hospital volume on postoperative complications and in-hospital mortality after musculoskeletal tumor surgery: analysis of a national administrative database.
BACKGROUND
We are aware of only one report describing the relationship between operative volume and outcomes in musculoskeletal tumor surgery, although numerous studies have described such relationships in other surgical procedures. The aim of the present study was to use a nationally representative inpatient database to evaluate the impact of hospital volume on the rates of postoperative complications and in-hospital mortality after musculoskeletal tumor surgery.


METHODS
We used the Japanese Diagnostic Procedure Combination administrative database to retrospectively identify 4803 patients who had undergone musculoskeletal tumor surgery during 2007 to 2010. Patients were then divided into tertiles of approximately equal size on the basis of the annual hospital volume (number of patients undergoing musculoskeletal tumor surgery): low, twelve or fewer cases/year; medium, thirteen to thirty-one cases/year; and high, thirty-two or more cases/year. Logistic regression analyses were performed to examine the relationships between various factors and the rates of postoperative complications and in-hospital mortality adjusted for all patient demographic characteristics.


RESULTS
The overall postoperative complication rate was 7.2% (348 of 4803), and the in-hospital mortality rate was 2.4% (116 of 4803). Postoperative complications included surgical site infections in 132 patients (2.7%), cardiac events in sixty-four (1.3%), respiratory complications in fifty-one (1.1%), sepsis in thirty-one (0.6%), pulmonary emboli in sixteen (0.3%), acute renal failure in eleven (0.2%), and cerebrovascular events in seven (0.1%). The postoperative complication rate was related to the duration of anesthesia (odds ratio [OR] for a duration of more than 240 compared with less than 120 minutes, 2.44; 95% confidence interval [CI], 1.68 to 3.53; p < 0.001) and to hospital volume (OR for high compared with low volume, 0.73; 95% CI, 0.55 to 0.96; p = 0.027). The mortality rate was related to the diagnosis (OR for a metastatic compared with a primary bone tumor, 3.67; 95% CI, 1.66 to 8.09; p = 0.001), type of surgery (OR for amputation compared with soft-tissue tumor resection without prosthetic reconstruction, 3.81; 95% CI, 1.42 to 10.20; p = 0.008), and hospital volume (OR for high compared with low volume, 0.26; 95% CI, 0.14 to 0.50; p < 0.001).


CONCLUSIONS
We identified an independent effect of hospital volume on outcomes after adjusting for patient demographic characteristics. We recommend regionalization of musculoskeletal tumor surgery to high-volume hospitals in an attempt to improve patient outcomes.
Departments of Orthopaedic Surgery (K.Ogura, Y.S., S.T., H.K.), Health Management and Policy (H.Y., H.H.), and Medical Informatics and Economics (K.Ohe), Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan. E-mail address for H. Kawano: hkawano-tky@umin.net.
Koichi
K
Ogura
Hideo
H
Yasunaga
Hiromasa
H
Horiguchi
Kazuhiko
K
Ohe
Yusuke
Y
Shinoda
Sakae
S
Tanaka
Hirotaka
H
Kawano
D000328:Adult; D000368:Aged; D016208:Databases, Factual; D005260:Female; D017052:Hospital Mortality; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D007564:Japan; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009140:Musculoskeletal Diseases / Q000401:mortality / Q000601:surgery*; D009369:Neoplasms / Q000401:mortality / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate