COST-UTILITY ANALYSIS OF CONTAMINATED APPENDECTOMY WOUNDS

BACKGROUND: The influence of patient preference and treatment costs ha s not been considered in previous analyses of wound management decisio ns for contaminated right lower quadrant incisions. STUDY DESIGN: We p erformed a decision and cost-utility analysis, conducting a MEDLINE se arch of the postappendectomy wound infection literature to establish a ssumptions and assign baseline probability estimates. Institution-spec ific cost data were obtained, and utility assignments were made by the authors. Studies used to assign baseline probabilities fulfilled the following criteria: perforated appendix or gangrenous appendicitis, us e of perioperative antibiotics active against aerobic and anaerobic ba cteria, and data stratified by wound management, operative findings, a nd infection rate. RESULTS: We constructed a decision tree comparing t hree methods of wound management for contaminated right lower quadrant incisions: primary closure, delayed primary closure, and secondary cl osure. Utility (a quality of life measure) was assigned to ultimate he alth states to incorporate patient preference. We calculated the cost- utility for each method of wound management and found that primary clo sure was of optimum cost-utility compared with delayed primary closure and secondary closure. To gain one quality-adjusted life year treatin g a population of patients with contaminated incisions, primary closur e saves $22,635 over delayed primary closure and another $22,340 over secondary closure. This decision, tested by two-way sensitivity analys es, was sensitive only to high primary closure infection rates. CONCLU SIONS: Challenging traditional surgical dogma, cost-utility analysis s hows that primary closure is the favored method of management for cont aminated right lower quadrant incisions. This analysis is specific to right lower quadrant incisions and the conclusion is valid for all est imated primary infection rates less than 0.27.