title: Economic burden of postoperative ileus associated with colectomy in the United States.
abstract: BACKGROUND
  Postoperative ileus, a transient impairment of gastrointestinal motility, is a common cause of delay in return to normal bowel function after abdominal surgery. Colectomy surgery patients who develop postoperative ileus could have greater health care resource utilization, including prolonged hospitalization, compared with those who do not develop postoperative ileus. Very few studies have assessed the impact of postoperative ileus on resource utilization and costs using retrospective analysis of administrative databases.
  
  
  OBJECTIVE
  To assess health care utilization and costs in colectomy surgery patients who developed postoperative ileus versus those who did not.
  
  
  METHODS
  A retrospective cohort study design was used. Adult patients with a principal procedure code for colectomy (ICD-9-CM procedure codes 45.71-45.79), discharged between January 1, 2004, and December 31, 2004, were identified from the Premier Perspective database of inpatient records from more than 500 hospitals in the United States. The colectomy patients were further classified for the presence of postoperative ileus, identified by the presence, in any diagnosis field on the administrative patient records, of a code for paralytic ileus (ICD-9-CM code 560.1) and/or digestive system complications (ICD-9-CM code 997.4) during the inpatient stay. Code 997.4 was used to account for cases in which postoperative ileus would be reported as a complication of anastomosis, as could be the case in colectomy surgeries. Hospital length of stay (LOS) and hospitalization costs were compared using t-tests. Multivariate analyses were performed with log-transformed LOS and log-transformed cost as the dependent variables. Patient demographics, mortality risk, disease severity, admission source, payment type (retrospective/prospective), and hospital characteristics were used as covariates.
  
  
  RESULTS
  A total of 17,876 patients with primary procedure code for colectomy were identified, of whom 3115 (17.4%) patients were classified for presence of postoperative ileus (including paralytic ileus only [n=1216; 6.8%], digestive system complications only [n=383; 2.1%], or both [n=1516; 8.5%]). A majority of the colectomy patients with and without postoperative ileus, respectively, were male (54.1% vs. 50.3%, P < 0.001), Caucasian (70.5% vs. 69.3%, P = 0.170), and aged 51-64 years (51.1% vs. 49.7%, P = 0.143). The mean [SD] hospital LOS was significantly longer in patients with postoperative ileus (13.8 [13.3] days) compared with patients without postoperative ileus (8.9 [9.5] days; P < 0.001). Presence of postoperative ileus was found to be a significant predictor of LOS (P < 0.001) in the regression model, controlling for covariates. Female gender (P = 0.002), greater severity level (P < 0.001), and hospital bed size of more than 500 (P = 0.013) were other significant predictors of hospital LOS. Presence of postoperative ileus was found to be a significant predictor of hospitalization costs (P < 0.001), controlling for covariates.
  
  
  CONCLUSIONS
  Postoperative ileus in colectomy patients is a significant predictor of hospital resource utilization.
authors.affiliation: Wyeth Pharmaceuticals, 500 Arcola Road, Collegeville, PA 19403, USA. iyers1@wyeth.com
authors.forename: Shrividya
authors.initials: S
authors.lastname: Iyer
authors.forename: William B
authors.initials: WB
authors.lastname: Saunders
authors.forename: Stephen
authors.initials: S
authors.lastname: Stemkowski
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003082:Colectomy / Q000009:adverse effects* / Q000191:economics; D016208:Databases, Factual; D005260:Female; D006760:Hospitalization / Q000191:economics / Q000706:statistics & numerical data*; D006801:Humans; D045823:Ileus / Q000191:economics* / Q000453:epidemiology* / Q000209:etiology / Q000628:therapy; D007902:Length of Stay / Q000191:economics / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000191:economics* / Q000209:etiology / Q000628:therapy; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult