Case Control Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 21, 2016; 22(15): 4002-4008
Published online Apr 21, 2016. doi: 10.3748/wjg.v22.i15.4002
Socio-economic status and lifestyle factors are associated with achalasia risk: A population-based case-control study
Helen G Coleman, Ronan T Gray, Kar W Lau, Conall McCaughey, Peter V Coyle, Liam J Murray, Brian T Johnston
Helen G Coleman, Ronan T Gray, Kar W Lau, Liam J Murray, Cancer Epidemiology and Health Services Research Group, Centre for Public Health, Queen’s University Belfast, Belfast BT12 6BJ, United Kingdom
Conall McCaughey, Peter V Coyle, Regional Virus Laboratory, Royal Victoria Hospital, Belfast, Belfast BT12 6BJ, United Kingdom
Brian T Johnston, Department of Gastroenterology, Royal Victoria Hospital, Belfast, Belfast BT12 6BJ, United Kingdom
Author contributions: Coyle PV, McCaughey C, Murray LJ and Johnston BT were involved in the study design; Lau KW oversaw the recruitment of patients and controls; Coleman HG conducted the statistical data analysis; Coleman HG and Gray RT drafted the first version of the manuscript; all authors contributing to the editing of the final manuscript and approved its submission.
Institutional review board statement: This study was ethically approved by the Office for Research Ethics Committees Northern Ireland (ORECNI: 05/NIR02/132).
Informed consent statement: Written informed consent was obtained from all study participants.
Conflict-of-interest statement: No potential conflicts of interest relevant to this article were reported.
Data sharing statement: For data sharing queries, please contact the corresponding author.
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/
Correspondence to: Dr. Helen G Coleman, Cancer Epidemiology and Health Services Research Group, Centre for Public Health, Queen’s University Belfast, Grosvenor Rd, Belfast BT12 6BJ, United Kingdom. h.coleman@qub.ac.uk
Telephone: +44-2890-978953 Fax: +44-2890-635900
Received: December 11, 2015
Peer-review started: December 14, 2015
First decision: December 30, 2015
Revised: January 14, 2016
Accepted: January 30, 2016
Article in press: January 30, 2016
Published online: April 21, 2016
Processing time: 114 Days and 1.7 Hours
Core Tip

Core tip: Little is known about achalasia aetiology, with roles suggested for genetic conditions, auto-immune diseases and infectious agents. This population-based case-control study investigated lifestyle and household factors in adulthood and childhood in relation to achalasia risk, for the first time. Results indicate that achalasia is a disease of inequality, and individuals from low socio-economic backgrounds are at highest risk. The burden of achalasia in lower socio-economic groups cannot be explained by smoking or alcohol intake. Pet ownership was associated with a two-fold increased risk of achalasia. Further studies of environmental factors and achalasia risk are warranted.