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
Processing time: 107 Days and 4.6 Hours
Abstract
BACKGROUND

Acute right colonic diverticulitis (ARCD) is an important differential diagnosis of acute appendicitis (AA) in Asian countries because of the unusually high prevalence of right colonic diverticula. Due to qualitative improvement and the high penetration rate of computed tomography (CT) scanning in Japan, differentiation of ARCD and AA mainly depends on this modality. But cost, limited availability, and concern for radiation exposure make CT scanning problematic. Differential findings of ARCD from AA are based on several small studies that used univariate comparisons from Korea and Taiwan. Previous studies on clinical and laboratory differences between AA and ARCD are limited.

AIM

To determine clinical differences between AA and ARCD for differentiation of these two diagnoses by creating a logistic regression model.

METHODS

We performed an exploratory single-center retrospective case-control study evaluating 369 Japanese patients (age ≥ 16 years), 236 (64.0%) with AA and 133 (36.0%) with ARCD, who were hospitalized between 2012 and 2016. Diagnoses were confirmed by CT images. We compared age, sex, onset-to-visit interval, epigastric/periumbilical pain, right lower quadrant (RLQ) pain, nausea/vomiting, diarrhea, anorexia, medical history, body temperature, blood pressure, heart rate, RLQ tenderness, peritoneal signs, leukocyte count, and levels of serum creatinine, serum C-reactive protein (CRP), and serum alanine aminotrans-ferase. We subsequently performed logistic regression analysis for differentiating AA from ARCD based on the results of the univariate analyses.

RESULTS

In the AA and ARCD groups, median ages were 35.5 and 41.0 years, respectively (p=0.011); median onset-to-visit intervals were 1 [interquartile range (IQR): 0-1] and 2 (IQR: 1-3) days, respectively (P < 0.001); median leukocyte counts were 12600 and 11500/mm3, respectively (P = 0.002); and median CRP levels were 1.1 (IQR: 0.2-4.1) and 4.9 (IQR: 2.9-8.5) mg/dL, respectively (P < 0.001). In the logistic regression model, odds ratios (ORs) were significantly high in nausea/vomiting (OR: 3.89, 95%CI: 2.04-7.42) and anorexia (OR: 2.13, 95%CI: 1.06-4.28). ORs were significantly lower with a longer onset-to-visit interval (OR: 0.84, 95%CI: 0.72-0.97), RLQ pain (OR: 0.28, 95%CI: 0.11-0.71), history of diverticulitis (OR: 0.034, 95%CI: 0.005-0.20), and CRP level > 3.0 mg/dL (OR: 0.25, 95%CI: 0.14-0.43). The regression model showed good calibration, discrimination, and optimism.

CONCLUSION

Clinical findings can differentiate AA and ARCD before imaging studies; nausea/vomiting and anorexia suggest AA, and longer onset-to-visit interval, RLQ pain, previous diverticulitis, and CRP level > 3.0 mg/dL suggest ARCD.

Keywords: Abdominal pain; Acute abdomen; Appendicitis; Clinical difference; C-reactive protein; Diverticulitis; Right lower quadrant pain

Core tip: Right colonic diverticulitis is an important differential diagnosis of appendicitis in Asian countries because of the unusually high prevalence of right colonic diverticula; however, studies reporting clinical differentiation between appendicitis and right colonic diverticulitis are still limited. Our case-control study using a logistic regression model shows that nausea/vomiting [odds ratio (OR): 3.89] and anorexia (OR: 2.13) suggest that appendicitis is more likely. On the other hand, longer onset-to-visit interval (OR: 0.84), right lower quadrant pain (OR: 0.28), history of diverticulitis (OR: 0.034), and CRP level > 3.0 mg/dL (OR: 0.25) suggest that right colonic diverticulitis is more likely.