Advertisement

Caveat emptor: The accuracy of claims data in appendicitis research

Published:August 16, 2022DOI:https://doi.org/10.1016/j.surg.2022.06.014

      Abstract

      Background

      International Classification of Disease, ninth/tenth revision codes are used to identify patients with appendicitis and classify severity of disease for research and hospital reimbursement. We sought to determine accuracy of International Classification of Disease, ninth/tenth revision codes in classifying appendicitis as uncomplicated versus complicated (defined as perforated, necrotic, or abscess) compared with the clinical gold standard: surgeon characterization of the appendix in the operative report.

      Methods

      Retrospective review of operative reports and discharge International Classification of Disease, ninth/tenth revision codes for patients ≥18 years old who underwent noninterval, nonincidental appendectomy between January 2012 and December 2019 at a tertiary referral center. Sensitivity, specificity, and positive predictive value were calculated for International Classification of Disease, ninth/tenth revision codes to classify appendicitis accurately as complicated compared with surgeon description. ICD-9/10 codes and surgeon description were categorized into complicated/uncomplicated based on the American Association for the Surgery of Trauma grading system.

      Results

      In the study, 1,495 patients with acute appendicitis underwent appendectomy. Per surgeon description, 200 (13%) were complicated and 1,295 (87%) uncomplicated. Compared with surgeon description, discharge International Classification of Disease, ninth/tenth revision codes did not accurately identify complicated appendicitis: sensitivity = 0.68, positive predictive value = 0.77. As a sensitivity analysis, the cohort was stratified by public versus private payers, and the results did not change.

      Conclusion

      International Classification of Disease, ninth/tenth revision codes do not accurately identify surgeon-described complicated appendicitis. Nearly one-third of the cases of complicated appendicitis were coded as uncomplicated. Such misclassification negatively impacts reimbursement for complicated appendicitis care and could lead to misleading results in research and quality improvement activities that rely on these codes.
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to Surgery
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Addiss D.G.
        • Shaffer N.
        • Fowler B.S.
        • et al.
        The epidemiology of appendicitis and appendectomy in the United States.
        Am J Epidemiol. 1990; 132: 910-925
        • Mouch C.A.
        • Cain-Nielsen A.H.
        • Hoppe B.L.
        • et al.
        Validation of the American Association for the Surgery of Trauma grading system for acute appendicitis severity.
        J Trauma Acute Care Surg. 2020; 88: 839-846
        • Cohen J.
        A Coefficient of agreement for nominal scales.
        Educ Psychol Meas. 1960; 20: 37-46
        • Furlan L.
        • Solbiati M.
        • Pacetti V.
        • et al.
        Diagnostic accuracy of ICD-9 code 780.2 for the identification of patients with syncope in the emergency department.
        Clin Auton Res. 2018; 28: 577-582
        • Paquette I.M.
        • Zuckerman R.
        • Finlayson S.R.G.
        Perforated appendicitis among rural and urban patients: implications of access to care.
        Ann Surg. 2011; 253: 534-538
        • Golz R.A.
        • Flum D.R.
        • Sanchez S.E.
        • et al.
        Geographic association between incidence of acute appendicitis and socioeconomic status.
        JAMA Surg. 2020; 155: 330-338
        • Zimmerman B.
        5 safety-net hospitals, health systems to know. Becker’s Hospital Review.
        • Livingston E.H.
        • Woodward W.A.
        • Sarosi G.A.
        • et al.
        Disconnect between incidence of nonperforated and perforated appendicitis: implications for pathophysiology and management.
        Ann Surg. 2007; 245: 886-892
        • Nordin A.B.
        • Diefenbach K.
        • Sales S.P.
        • et al.
        Gangrenous appendicitis: no longer complicated.
        J Pediatr Surg. 2019; 54: 718-722
        • Hernandez M.
        • Aho J.M.
        • Habermann E.B.
        • et al.
        Increased anatomic severity predicts outcomes: validation of the American Association for the Surgery of Trauma’s emergency general surgery score in appendicitis.
        J Trauma Acute Care Surg. 2017; 82: 73-79
        • Pieracci F.M.
        • Eachempati S.R.
        • Barie P.S.
        • et al.
        Insurance status, but not race, predicts perforation in adult patients with acute appendicitis.
        J Am Coll Surg. 2007; 205: 445-452
        • Finnesgard E.J.
        • Hernandez M.C.
        • Aho J.M.
        • et al.
        The American Association for the Surgery of Trauma Emergency General Surgery Anatomic Severity Scoring System as a predictor of cost in appendicitis.
        Surg Endosc. 2018; 32: 4798-4804
        • Anandalwar S.P.
        • Cameron D.B.
        • Graham D.A.
        • et al.
        Association of intraoperative findings with outcomes and resource use in children with complicated appendicitis.
        JAMA Surg. 2018; 153: 1021-1027
        • Flum D.R.
        • Koepsell T.D.
        Evaluating diagnostic accuracy in appendicitis using administrative data.
        J Surg Res. 2005; 123: 257-261
      1. Coward S, Kareemi H, Clement F, et al. Incidence of appendicitis over time: a comparative analysis of an administrative healthcare database and a pathology-proven appendicitis registry. Smalheiser NR, ed. PLOS One. 2016;11:e0165161.

        • Duraiswamy S.
        • Ignacio A.
        • Weinberg J.
        • et al.
        Comparative accuracy of ICD-9 vs ICD-10 codes for acute appendicitis.
        J Am Coll Surg. 2022; 234: 7
        • Frolova N.
        • Bakal J.A.
        • McAlister F.A.
        • et al.
        Assessing the use of International Classification of Diseases-10th revision codes from the emergency department for the identification of acute heart failure.
        JACC Heart Fail. 2015; 3: 386-391
        • Flum D.R.
        • Davidson G.H.
        • et al.
        • CODA Collaborative
        A randomized trial comparing antibiotics with appendectomy for appendicitis.
        N Engl J Med. 2020; 383: 1907-1919
        • Lietzén E.
        • Grönroos J.M.
        • Mecklin J.-P.
        • et al.
        Appendiceal neoplasm risk associated with complicated acute appendicitis: a population based study.
        Int J Colorectal Dis. 2019; 34: 39-46
        • Centers for Disease Control and Prevention
        ICD-10-CM: Coordination and maintenance committee.
        (Published February 22, 2021)