J Prev Med Public Health.  2018 Jan;51(1):33-40. 10.3961/jpmph.17.167.

Spatial Inequalities in the Incidence of Colorectal Cancer and Associated Factors in the Neighborhoods of Tehran, Iran: Bayesian Spatial Models

• Mansori K
• Solaymani-Dodaran M
• Mosavi-Jarrahi A
• Motlagh AG
• Salehi M
• Delavari A
• Asadi-Lari M

• KMID: 2403692
• DOI: http://doi.org/10.3961/jpmph.17.167

Abstract

OBJECTIVES
The aim of this study was to determine the factors associated with the spatial distribution of the incidence of colorectal cancer (CRC) in the neighborhoods of Tehran, Iran using Bayesian spatial models.
METHODS
This ecological study was implemented in Tehran on the neighborhood level. Socioeconomic variables, risk factors, and health costs were extracted from the Equity Assessment Study conducted in Tehran. The data on CRC incidence were extracted from the Iranian population-based cancer registry. The Besag-York-Mollié (BYM) model was used to identify factors associated with the spatial distribution of CRC incidence. The software programs OpenBUGS version 3.2.3, ArcGIS 10.3, and GeoDa were used for the analysis.
RESULTS
The Moran index was statistically significant for all the variables studied (p < 0.05). The BYM model showed that having a women head of household (median standardized incidence ratio [SIR], 1.63; 95% confidence interval [CI], 1.06 to 2.53), living in a rental house (median SIR, 0.82; 95% CI, 0.71 to 0.96), not consuming milk daily (median SIR, 0.71; 95% CI, 0.55 to 0.94) and having greater household health expenditures (median SIR, 1.34; 95% CI, 1.06 to 1.68) were associated with a statistically significant elevation in the SIR of CRC. The median (interquartile range) and mean (standard deviation) values of the SIR of CRC, with the inclusion of all the variables studied in the model, were 0.57 (1.01) and 1.05 (1.31), respectively.
CONCLUSIONS
Inequality was found in the spatial distribution of CRC incidence in Tehran on the neighborhood level. Paying attention to this inequality and the factors associated with it may be useful for resource allocation and developing preventive strategies in atrisk areas.

Keyword

Colorectal cancer; Spatial distribution; Incidence; Neighborhood; Besag-York-Mollié (BYM) model; Tehran; Iran

MeSH Terms

Colorectal Neoplasms*
Family Characteristics
Female
Health Care Costs
Health Expenditures
Humans
Incidence*
Iran*
Milk
Residence Characteristics*
Resource Allocation
Risk Factors
Socioeconomic Factors*