Case Control Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jun 26, 2019; 7(12): 1393-1402
Published online Jun 26, 2019. doi: 10.12998/wjcc.v7.i12.1393
Clinical differentiation of acute appendicitis and right colonic diverticulitis: A case-control study
Yosuke Sasaki, Fumiya Komatsu, Naoyasu Kashima, Takahiro Sato, Ikutaka Takemoto, Sho Kijima, Tadashi Maeda, Takamasa Ishii, Taito Miyazaki, Yoshiko Honda, Nagato Shimada, Yoshihisa Urita
Yosuke Sasaki, Fumiya Komatsu, Naoyasu Kashima, Takahiro Sato, Ikutaka Takemoto, Sho Kijima, Tadashi Maeda, Takamasa Ishii, Taito Miyazaki, Yoshiko Honda, Nagato Shimada, Yoshihisa Urita, Department of General Medicine and Emergency Care, Toho University School of Medicine, Ota-ku, Tokyo 143-8541, Japan
Author contributions: Sasaki Y designed the research, collected data, and wrote the manuscript; Komatsu F and Kashima N collected data with Sasaki Y; Takemoto I and Kijima S assisted with data collection; Ishii T supervised data collection; Sato T, Maeda T, and Miyazaki T provided supervision and discussion as experts of infectious diseases; Honda Y and Shimada N provided supervision and discussion as surgeons; and Urita Y supervised the research and supervised statistical analyses.
Institutional review board statement: The ethics committee of Toho University Medical Center Omori Hospital approved the study’s protocol (M17057).
Informed consent statement: The center’s ethics committee approved waiver of individual informed consent subject to public announcement of the research because of the retrospective and noninvasive study design. Comprehensive consents were obtained by all participants.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Yosuke Sasaki, MD, PhD, Assistant Professor, Department of General Medicine and Emergency Care, Toho University School of Medicine, Omori Hospital, 6-11-1 Omori-Nishi, Ota-Ku, Tokyo 143-8541, Japan. yousuke.sasaki@med.toho-u.ac.jp
Telephone: +81-3-37624151 Fax: +81-3-37656518
Received: March 12, 2019
Peer-review started: March 13, 2019
First decision: March 19, 2019
Revised: April 13, 2019
Accepted: May 10, 2019
Article in press: May 11, 2019
Published online: June 26, 2019
ARTICLE HIGHLIGHTS
Research background

Because of the high prevalence of right colonic diverticulosis in Asian countries, acute right colonic diverticulitis (ARCD) is an important differential diagnosis of acute appendicitis (AA) in Asian countries. However, studies on the clinical differentiation of AA and ARCD are limited.

Research motivation

Given the cost, limited availability in primary care settings and concern for radiation exposure in young patients of computed tomography (CT) scan, evidence on the clinical differentiation of ARCD and AA based on history, physical signs, and easily available laboratory data will be useful for clinicians who care for Asian patients with acute abdomen.

Research objective

This study aimed to reveal clinical findings, such as symptoms, physical signs, and widely available laboratory data that are useful for differentiating AA from ARCD.

Research methods

We performed a single-center retrospective case-control study that evaluated 236 patients with AA and 133 patients with ARCD, who were hospitalized in Toho University Medical Center Omori Hospital between 2012 and 2016. We compared patients’ characteristics, symptoms, physical signs, and widely available laboratory data. We performed logistic regression for clinical differentiation between AA and ARCD.

Research results

Median ages were 35.5 and 41.0 years in the AA and ARCD groups, respectively (P = 0.011). Median onset-to-visit intervals were 1 and 2 days in the AA and ARCD groups, respectively (P < 0.001). Prevalences of epigastric/periumbilical pain, nausea/vomiting, anorexia, and history of unresected appendicitis were significantly higher in the AA group, whereas RLQ pain and history of diverticulitis were more prevalent in the ARCD group. Median leukocyte counts in the AA and ARCD groups were 12600 and 11500/mm3, respectively (P = 0.002). Median CRP levels in the AA and ARCD groups were 1.1 and 4.9 mg/dL, respectively (P < 0.001). The logistic regression model showed a significantly high odds ratio (OR) in nausea/vomiting (OR: 3.89) and anorexia (OR: 2.13). ORs were significantly lower with a longer onset-to-visit interval (OR: 0.84), RLQ pain (OR: 0.28), history of diverticulitis (OR: 0.034), and CRP level > 3.0 mg/dL (OR: 0.25), suggesting that ARCD was more likely.

Research conclusions

Our logistic regression model for differentiating AA from ARCD showed that nausea/vomiting and anorexia increase the probability of AA rather than ARCD. Conversely, longer onset-to-visit interval, RLQ pain, history of diverticulitis, and CRP level > 3.0 mg/dL at the time of visit increase the probability of ARCD rather than AA. Our study suggests that clinical findings can differentiate AA and ARCD based on clinical information in advance of imaging studies.

Research perspectives

Given the lack of previous study on clinical differences between AA and ARCD, and the cost, limited availability, and concern for radiation exposure of CT scanning, our findings will provide useful evidence for physicians managing Asian patients with acute abdomen.