Original Article
Copyright ©2013 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Aug 28, 2013; 19(32): 5261-5270
Published online Aug 28, 2013. doi: 10.3748/wjg.v19.i32.5261
Human development index is associated with mortality-to-incidence ratios of gastrointestinal cancers
Qi-Da Hu, Qi Zhang, Wei Chen, Xue-Li Bai, Ting-Bo Liang
Qi-Da Hu, Qi Zhang, Wei Chen, Xue-Li Bai, Ting-Bo Liang, Department of Surgery, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, Zhejiang Province, China
Author contributions: Hu QD and Liang TB conceived the study; Hu QD and Zhang Q, Liang TB designed the study; Hu QD collected data; Hu QD, Zhang Q, Chen W and Bai XL analyzed the data; Hu QD, Zhang Q and Chen W drafted the manuscript; Liang TB finalized the manuscript, and took responsibility for the integrity of the data and the accuracy of the data analysis; all authors have read and approved the final manuscript.
Supported by The National Natural Science Funds for Distinguished Young Scholars, No. 30925033; and the Innovation and High-Level Talent Training Program of Department of Health of Zhejiang Province, China
Correspondence to: Ting-Bo Liang, MD, PhD, Department of Surgery, the Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, Zhejiang Province, China. liangtingbo@zju.edu.cn
Telephone: +86-571-87315006 Fax: +86-571-87315006
Received: May 18, 2013
Revised: July 7, 2013
Accepted: July 17, 2013
Published online: August 28, 2013
Processing time: 100 Days and 17.1 Hours
Abstract

AIM: To identify the role of human development in the incidence and mortality rates of gastrointestinal cancers worldwide.

METHODS: The age-standardized incidence and mortality rates for gastrointestinal cancers, including cancers of the esophagus, stomach, pancreas, liver, gallbladder, and colorectum, were obtained from the GLOBOCAN 2008 database and United States Cancer Statistics (USCS) report. The human development index (HDI) data were calculated according to the 2011 Human Development Report. We estimated the mortality-to-incidence ratios (MIRs) at the regional and national levels, and explored the association of the MIR with development levels as measured by the HDI using a modified “drug dose to inhibition response” model. Furthermore, countries were divided into four groups according to the HDI distribution, and the MIRs of the four HDI groups were compared by one-way ANOVA followed by the Tukey-Kramer post-hoc test. State-specific MIRs in the United States were predicted from the estimated HDI using the fitted non-linear model, and were compared with the actual MIRs calculated from data in the USCS report.

RESULTS: The worldwide incidence and mortality rates of gastrointestinal cancers were as high as 39.4 and 54.9 cases per 100000 individuals, respectively. Linear and non-linear regression analyses revealed an inverse correlation between the MIR of gastrointestinal cancers and the HDI at the regional and national levels (β < 0; P = 0.0028 for regional level and < 0.0001 for national level, ANOVA). The MIR differed significantly among the four HDI areas (very high HDI, 0.620 ± 0.033; high HDI, 0.807 ± 0.018; medium HDI, 0.857 ± 0.021; low HDI, 0.953 ± 0.011; P < 0.001, one-way ANOVA). Prediction of the MIRs for individual United States states using best-fitted non-linear models showed little deviation from the actual MIRs in the United States. Except for 28 data points (9.93% of 282), the actual MIRs of all gastrointestinal cancers were mostly located in the prediction intervals via the best-fit non-linear regression models.

CONCLUSION: The inverse correlation between HDI and MIR demonstrates that more developed areas have a relatively efficacious healthcare system, resulting in low MIRs, and HDI can be used to estimate the MIR.

Keywords: Gastrointestinal neoplasms; Mortality-to-incidence ratio; Human development index; Healthcare disparities; Socioeconomic factors

Core tip: This study is the first to explore the exact relationship between the epidemiology of gastrointestinal cancers and area-specific development disparities. We showed the association between the mortality-to-incidence ratios (MIRs) and the human development index at the regional and national levels using a modified “drug dose to inhibition response” model. Further prediction of the MIRs for individual United States states on the basis of best-fitted non-linear models showed little deviation from the actual MIRs in the United States.