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Differentiation between complicated and uncomplicated appendicitis: diagnostic model development and validation study

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Abstract

Purpose

Differentiating complicated appendicitis has become important, as multiple trials showed that non-operative management of uncomplicated appendicitis is feasible. We developed and validated a diagnostic model to differentiate complicated from uncomplicated appendicitis.

Methods

This retrospective study included 1153 patients (mean age ± standard deviation, 30 ± 8 years) with appendicitis on CT (804 patients for development, and 349 for validation). Complicated appendicitis was confirmed in 300 and 121 patients in the development and validation datasets, respectively. The reference standard was surgical or pathological report except in 7 patients who underwent percutaneous abscess drainage. We developed a model using multivariable logistic regression and Bayesian information criterion. We assessed calibration and discriminatory performance of the model in the validation dataset via calibration plot and the area under the curve (AUC), respectively. We measured sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and proportion of false- and true-negatives of the model in the validation dataset, targeting 95% sensitivity.

Results

Five CT features (contrast-enhancement defect of the appendiceal wall, abscess, moderate or severe periappendiceal fat stranding, appendiceal diameter, and extraluminal air) and percentage of segmented neutrophil were included in our model. The calibration slope was 1.03, and AUC was 0.81 (95% CI 0.77–0.85) in the validation dataset. The sensitivity, specificity, PPV, NPV, and proportion of false- and true-negatives were 93.4% (91.8–99.1), 28.1% (13.6–24.1), 40.8% (35.0–46.8), 88.9% (79.3–95.1), 2.3%, and 18.3%, respectively.

Conclusion

Our model may identify patients with unequivocally uncomplicated appendicitis, who may benefit from non-operative management with low risk of failure.

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Acknowledgements

The data in our study were obtained from the database of a randomized controlled trial by the LOCAT Group.

Funding

This study was funded by grants of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (HI16C0451) and Seoul National University Bundang Hospital Research fund (16-2016-008).

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Authors and Affiliations

  1. Department of Radiology, Seoul National University Bundang Hospital, Gyeonggi-do, Korea

    Hae Young Kim & Sung Soo Lee

  2. Department of Radiology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 463-707, Korea

    Ji Hoon Park, Chang Jin Yoon & Kyoung Ho Lee

  3. Department of Statistics, University of Seoul, Seoul, Korea

    Jong-June Jeon

  4. Program in Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Korea

    Kyoung Ho Lee

  5. Interdisciplinary Program in Bioengineering, Seoul National University, Seoul, Korea

    Kyoung Ho Lee

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  1. Hae Young Kim
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Contributions

Conceptualization: JHP, HYK, KHL; formal analysis and investigation: CJY, JHP, SSL, J-JJ; writing—original draft preparation: JHP, HYK; writing—review and editing: all authors; funding acquisition: JHP; supervision: JHP, HYK; all authors read and approved the final manuscript.

Corresponding author

Correspondence to Ji Hoon Park.

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Conflict of interest

Ji Hoon Park has received grants from Korea Health Industry Development Institute and Seoul National University Bundang Hospital. Other authors declare no competing interests.

Ethical approval

The institutional review board at each site approved this retrospective multi-center study and waived the requirement for patient informed consent.

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Kim, H.Y., Park, J.H., Lee, S.S. et al. Differentiation between complicated and uncomplicated appendicitis: diagnostic model development and validation study. Abdom Radiol 46, 948–959 (2021). https://doi.org/10.1007/s00261-020-02737-7

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  • DOI: https://doi.org/10.1007/s00261-020-02737-7

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