The clinical and economic correlates of misdiagnosed appendicitis: nationwide analysis

Abstract

Background: Negative appendectomy (NA)--the nonincidental removal of a normal appendix--occurs commonly but the associated clinical- and system-level costs are not well studied.

Hypothesis: The frequency of adverse clinical outcomes and associated financial burden of hospitalizations during which NA is performed is greater than previously recognized and varies widely among demographic groups.

Design: Population-based, retrospective cohort study.

Setting: The 1997 Nationwide Inpatient Sample of the Health Care Utilization Project.

Patients: All surveyed patients assigned International Classification of Diseases, Ninth Revision procedure codes for appendectomy but without an associated diagnosis of acute appendicitis.

Main outcome measures: The age- and sex-stratified rates of NA, the incidence of associated infectious complications and case fatality, and the average length of stay and hospitalization charges during those admissions.

Results: Nationwide, an estimated 261 134 patients underwent nonincidental appendectomies in 1997, and 39 901 (15.3%) were negative for appendicitis. Women had a higher rate of NA as did patients younger than 5 years and older than 60 years. When compared with patients with appendicitis, NA was associated with a significantly longer length of stay (5.8 vs 3.6 days, P<.001), total charge-admission ($18 780 vs $10 584, P<.001), case fatality rate (1.5% vs 0.2%, P<.001), and rate of infectious complications (2.6% vs 1.8%, P<.001). An estimated $741.5 million in total hospital charges resulted from admissions in which a NA was performed.

Conclusions: There are significant clinical and financial costs incurred by patients undergoing NA during the treatment of presumed appendicitis. These should be considered when evaluating system-level interventions to improve the management of appendicitis.