title: Variation in inpatient diagnostic testing and management of bronchiolitis.
abstract: OBJECTIVE
  We know little about the variation in diagnosis and management of bronchiolitis. The objectives of this study were (1) to document variations in treatment and diagnostic approaches, lengths of stay (LOSs), and readmission rates and (2) to determine which potentially modifiable process of care measures are associated with longer LOSs and antibiotic usage.
  
  
  METHODS
  We used the Pediatric Health Information System, which includes demographic, diagnostic, and detailed patient-level data on 30 large children's hospitals. We examined infants who were younger than 1 year and hospitalized for bronchiolitis (October 2001-September 2003). Multivariate analysis of variance was used to determine whether the variance in the outcomes was hospital related after controlling for other covariates. Linear regression was used to model predictors of increased LOS. Logistic regression was used to model antibiotic usage. Analyses were stratified by age group (<3 months and 3-11 months).
  
  
  RESULTS
  A total of 17397 patients were included in the analysis. The mean LOS was 2.97 days; 72% of patients received chest radiographs, 45% received antibiotics, and 25% received systemic steroids. The mean LOS varied considerably across hospitals (range: 2.40-3.90 days), and hospital remained a significant contributor to LOS variation after controlling for our covariates. Variations in the use of diagnostic tests and medications as well as readmission rates also existed and also remained significant after controlling for covariates. The factors associated with the greatest increases in LOS in the regression analyses included higher severity scores and use of antibiotics, bronchodilators, and corticosteroids. The strongest predictors of antibiotic use in the logistic regression analyses were higher severity scores and receipt of a blood or cerebrospinal fluid culture. Receiving a chest radiograph was a significant predictor of antibiotic use in older but not younger infants.
  
  
  CONCLUSIONS
  Considerable, unexplained variation exists in the inpatient management of bronchiolitis. The development of national guidelines and controlled trials of new therapies and different management approaches are indicated.
authors.affiliation: Department of Pediatrics, University of Washington, Seattle, Washington, USA. dachris@u.washington.edu
authors.forename: Dimitri A
authors.initials: DA
authors.lastname: Christakis
authors.forename: Charles A
authors.initials: CA
authors.lastname: Cowan
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Garrison
authors.forename: Richard
authors.initials: R
authors.lastname: Molteni
authors.forename: Edgar
authors.initials: E
authors.lastname: Marcuse
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Zerr
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001988:Bronchiolitis / Q000175:diagnosis* / Q000188:drug therapy*; D001993:Bronchodilator Agents / Q000627:therapeutic use; D003430:Cross-Sectional Studies; D005260:Female; D006760:Hospitalization; D006776:Hospitals, Pediatric; D006801:Humans; D007223:Infant; D007902:Length of Stay; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D015999:Multivariate Analysis; D010359:Patient Readmission; D011859:Radiography; D012044:Regression Analysis; D012189:Retrospective Studies
chemical_list: D000305:Adrenal Cortex Hormones; D000900:Anti-Bacterial Agents; D001993:Bronchodilator Agents