title: Cost-Effectiveness of Integrating a Clinical Decision Rule and Staged Imaging Protocol for Diagnosis of Appendicitis.
abstract: OBJECTIVE
  To evaluate the cost-effectiveness of a diagnostic protocol for appendicitis in children, the use of a validated clinical decision rule (CDR) and a staged imaging protocol, compared with usual care.
  
  
  METHODS
  We estimated the cost-effectiveness of the three competing strategies using parameters from existing literature as well as a Markov model developed to simulate the effects of exposure to ionizing radiation from a single computed tomography (CT) study in the course of diagnosis. The simulation model was applied to a hypothetical cohort of 100,000 boys and girls, age 10 years, presenting with acute abdominal pain to emergency departments in the United States.
  
  
  RESULTS
  The integrated strategy, the CDR followed by staged imaging, was found to be the most cost-effective approach. Cost savings accrued from the reduction in CT utilization for low-risk patients compared with the other two strategies. The addition of ultrasound (US) to the CDR strategy reduced CT utilization by an additional 10.9%, its main cost advantage, with negligible change in net health benefits from false-negative US results, and associated morbidity or mortality.
  
  
  CONCLUSIONS
  Results suggest that the integration of staged imaging with the CDR for the diagnosis of appendicitis in children is a cost-effective and cost-saving approach. The model estimates a further 10.9% reduction in the number of CTs from the incorporation of US for patients scoring high or medium risk, in excess of the 19.5% reduction estimated in the CDR validation study.
authors.affiliation: Department of Health Policy and Management, College of Public Health, and Department of Pediatrics, Morsani College of Medicine, University of South Florida, Tampa, FL, USA. Electronic address: seangregory@health.usf.edu.
authors.forename: Sean
authors.initials: S
authors.lastname: Gregory
authors.affiliation: Department of Health Policy and Management, School of Public Health, University of Minnesota, Delaware, MN, USA.
authors.forename: Karen
authors.initials: K
authors.lastname: Kuntz
authors.affiliation: Department of Health Policy and Management, School of Public Health, University of Minnesota, Delaware, MN, USA.
authors.forename: François
authors.initials: F
authors.lastname: Sainfort
authors.affiliation: Pediatric Emergency Medicine, Children's Hospital and Clinics of Minnesota, Minneapolis, MN.
authors.forename: Anupam
authors.initials: A
authors.lastname: Kharbanda
mesh_terms: D001062:Appendectomy / Q000009:adverse effects / Q000191:economics*; D001064:Appendicitis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000601:surgery; D002648:Child; D002985:Clinical Protocols; D003362:Cost-Benefit Analysis; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008297:Male; D008390:Markov Chains; D019057:Quality-Adjusted Life Years; D000069079:Radiation Exposure; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000191:economics*; D014463:Ultrasonography / Q000191:economics*; D014481:United States
keywords: appendicitis; computed tomography; cost-effectiveness; decision rule; diagnosis