Observational Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Feb 15, 2017; 9(2): 87-93
Published online Feb 15, 2017. doi: 10.4251/wjgo.v9.i2.87
Bayesian adjustment for over-estimation and under-estimation of gastric cancer incidence across Iranian provinces
Nastaran Hajizadeh, Mohamad Amin Pourhoseingholi, Ahmad Reza Baghestani, Alireza Abadi, Mohammad Reza Zali
Nastaran Hajizadeh, Ahmad Reza Baghestani, Alireza Abadi, Department of Biostatistics, Shahid Beheshti University of Medical Sciences, Tehran 1971653313, Iran
Mohamad Amin Pourhoseingholi, Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran 1985717413, Iran
Mohammad Reza Zali, Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran 1985717413, Iran
Author contributions: Pourhoseingholi MA was principal investigator and countributing in writing the manuscript; Hajizadeh N contributed to study conception and data analysis; Baghestani AR and Abadi A contributed to study conception and design; Zali MR contributed to interpretation the results; all authors contributed to editing, reviewing and final approval of the article.
Institutional review board statement: The study was reviewed and approved by research committee of research institute for gastroenterology and liver diseases (Tehran).
Informed consent statement: Hereby it is attested that this manuscript which is submitted for publication in World Journal of Gastrointestinal Oncology has been read and approved by all authors, has not been published, totally or partly, in any other journal.
Conflict-of-interest statement: There are no conflicts of interest to report.
Data sharing statement: No additional data are available.
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. Mohamad Amin Pourhoseingholi, PhD, Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tabnak Avenue, Yaman Street, Tehran 1985717413, Iran. amin_phg@yahoo.com
Telephone: +98-21-22432515 Fax: +98-21-22432517
Received: August 17, 2016
Peer-review started: August 19, 2016
First decision: October 21, 2016
Revised: November 2, 2016
Accepted: November 27, 2016
Article in press: November 29, 2016
Published online: February 15, 2017
Abstract
AIM

To correct the misclassification in registered gastric cancer incidence across Iranian provinces in cancer registry data.

METHODS

Gastric cancer data is extracted from Iranian annual of national cancer registration report 2008. A Bayesian method with beta prior is implemented to estimate the rate of misclassification in registering patient’s permanent residence in neighboring province. Each time two neighboring provinces with lower and higher than 100% expected coverage of cancer cases are selected to be entered in the model. The expected coverage of cancerous patient is reported by medical university of each province. It is assumed that some cancer cases from a province with a lower than 100% expected coverage are registered in their neighboring province with more than 100% expected coverage.

RESULTS

The condition was true for 21 provinces from a total of 30 provinces of Iran. It was estimated that 43% of gastric cancer cases of North and South Khorasan provinces in north-east of Iran was registered in Razavi Khorasan as the neighboring facilitate province; also 72% misclassification was estimated between Sistan and balochestan province and Razavi Khorasan. The misclassification rate was estimated to be 36% between West Azerbaijan province and East Azerbaijan province, 21% between Ardebil province and East Azerbaijan, 63% between Hormozgan province and Fars province, 8% between Chaharmahal and bakhtyari province and Isfahan province, 8% between Kogiloye and boyerahmad province and Isfahan, 43% Golestan province and Mazandaran province, 54% between Bushehr province and Khozestan province, 26% between Ilam province and Khuzestan province, 32% between Qazvin province and Tehran province (capital of Iran), 43% between Markazi province and Tehran, and 37% between Qom province and Tehran.

CONCLUSION

Policy makers should consider the regional misclassification in the time of programming for cancer control, prevention and resource allocation.

Keywords: Cancer incidence registry, Misclassification, Bayesian correction, Gastric cancer, Iran

Core tip: Due to the lack of equipped health facilities in some provinces of the country, patients seek health care in neighboring full-featured provinces and they do not mention their own permanent residence. It makes misclassification error in cancer registry data. This error flaws planning for resource allocation to different regions of the country for cancer control and prevention. The aim of this study is to use a Bayesian method to estimate the rate of misclassification in cancer incidence registry among neighboring provinces of Iran and re-estimating the rate of gastric cancer in each province.