Objective: Colorectal cancer is the third most common cancer among adults in Iran. Colorectal cancer screening is the effective way in reducing deaths from this cancer. However, the screening rate of colorectal cancer is very low among Iranian adults. This study investigated predictors of Iranian average-risk adults ' intention to take up colorectal cancer screening with fecal occult blood test using a mediator model.
Methods: Participants of this cross-sectional study were comprised of 478 average-risk adults who were selected using a national sampling frame in Hamadan city, west of Iran. The data gathering instrument was a questionnaire based on the preventive health model constructs. Structural equation modeling (SEM) was employed to test the relationship using Smart PLS 2.0 software
Results: All measures were robust in terms of its reliability and validity. Benefit (b= 0.12, p<0.01), self efficacy (b= 0.36, p<0.01), social support (b= 0.12, p<.05) and barriers (b= -0.14, p<.01) predicted the intention to be screened for CRC. Self efficacy partly mediated effects of social support and perceived barriers on intention. The study model explained approximately 24% of the variance in CRC screening intention with fecal occult blood testConclusion: Our findings indicated that the preventive health model constructs such as self efficacy, social support and barriers are useful in understanding CRC screening intentions and can help health planners in developing effective interventions for encouraging Iranian adults to undergo CRC screening.
Ferlay J, Soerjomataram I, Dikshit R, Eser S, Mathers C, Rebelo M, et al. Cancer incidence and mortality worldwide: sources, methods and major patterns in GLOBOCAN 2012. Int J Cancer 2015;136(5):E359-E86. doi: 10.1002/ijc.29210.
Centers for Disease Control and Prevention, Noncommunicable deputy- cancer office. National Cancer Registry Report 2008 – 2009. Ministry of Health and Medical Education. Tehran; 2012.
Benson VS, Patnick J, Davies AK, Nadel MR, Smith RA, Atkin WS. Colorectal cancer screening: a comparison of 35 initiatives in 17 countries. Int J Cancer 2008;122(6):1357-67.doi: 10.1002/ijc.23273.
Levin B, Lieberman DA, McFarland B, Smith RA, Brooks D, Andrews KS, et al. Screening and surveillance for the early detection of colorectal cancer and adenomatous polyps, 2008: a joint guideline from the American Cancer Society, the US Multi‐Society Task Force on Colorectal Cancer, and the American College of Radiology . CA Cancer J Clin 2008;58(3):130-60. doi: 10.3322/CA.2007.0018.
Moghimi-Dehkordi B, Safaee A. An overview of colorectal cancer survival rates and prognosis in Asia. World J Gastrointest Oncol 2012;4(4):71-5. doi:10.4251/wjgo.v4.i4.71.
Smith RA, Andrews K, Brooks D, DeSantis CE, Fedewa SA, Lortet‐Tieulent J, et al. (2016). Cancer screening in the United States, 2016: A review of current American Cancer Society guidelines and current issues in cancer screening. CA Cancer J Clin 2016;66(2):96-114.doi: 10.3322/caac.21336.
Mousavinezhad M, Majdzadeh R, Akbari Sari A, Delavari A, Mohtasham F. The effectiveness of FOBT vs. FIT: A meta-analysis on colorectal cancer screening test. Med J Islam Repub Iran 2016;30(1):454-68.
Sung JJ, Lau JY, Young GP, Sano Y, Chiu H, Byeon J, et al. Asia Pacific consensus recommendations for colorectal cancer screening. Gut 2008;57(8):1166-76. doi:10.1136/gut.2007.146316.
Tappenden P, Eggington S, Nixon R, Chilcott J, Sakai H, Karnon J. Colorectal cancer screening options appraisal. Cost–effectiveness, cost–utility and resourse impact of alternative screening options for colorectal cancer. Report to the English Bowel Cancer Screening Working Group 2004.
Tsoi K, Ng S, Leung M, Sung J. Cost‐effectiveness analysis on screening for colorectal neoplasm and management of colorectal cancer in Asia. Aliment Pharmacol Ther 2008; 28(3):353-63. doi: 10.1111/j.0269-2813.2008.03726.x.
Siegel R, Ward E, Brawley O, Jemal A. Cancer statistics, 2011. CA Cancer J Clin 2011;61(4):212-36. doi: 10.3322/caac.20121.
Smith RA, Cokkinides V, Brawley OW. Cancer screening in the United States, 2008: a review of current American Cancer Society guidelines and cancer screening issues. CA Cancer J Clin 2008;58(3):161-79. doi: 10.3322/CA.2007.0017.
Salimzadeh H, Eftekhar H, Delavari A, Malekzadeh R. Psycho-social Determinants of Colorectal Cancer Screening in Iran. Int J Prev Med 2014 5(2):185.
Gregory TA, Wilson C, Duncan A, Turnbull D, Cole SR, Young G. Demographic, social cognitive and social ecological predictors of intention and participation in screening for colorectal cancer. BMC Public Health 2011;11(1):1. doi: 10.1186/1471-2458-11-38.
Glanz K, Rimer BK, Viswanath K. Health behavior and health education: theory, research, and practice: John Wiley & Sons; 2008.
Cole SR, Zajac I, Gregory T, Mehaffey S, Roosa N, Turnbull D, et al. Psychosocial variables associated with colorectal cancer screening in South Australia. Int J Behav Med 2011;18(4):302-9. doi: 10.1007/s12529-010-9101-1.
Hollier JM, Hinojosa-Lindsey M, Sansgiry S, El-Serag HB, Naik AD. Clinical and psychosocial variables associated with behavioral intentions to undergo surveillance endoscopy. BMC Gastroenterol 2014; 14(1):1. doi: 10.1186/1471-230X-14-107.
Watts BG, Vernon SW, Myers RE, Tilley BC. Intention to be screened over time for colorectal cancer in male automotive workers. Cancer Epidemiol Biomarkers Prev 2003;12(4):339-49.
Rosenstock IM. The health belief model and preventive health behavior. Health Educ Behav 1974; 2(4):354-86. doi: 10.1177/109019817400200405.
Ajzen I, Fishbein M. Understanding attitudes and predicting social behavior.1980.
Bandura A. Social foundations of thought and action: A social cognitive theory: Prentice-Hall, Inc; 1986.
Myers RE, Ross E, Jepson C, Wolf T, Balshem A, Millner L, et al. Modeling adherence to colorectal cancer screening. Prev Med 1994; 23(2):142-51.
McQueen A, Vernon SW, Rothman AJ, Norman GJ, Myers RE, Tilley BC. Examining the role of perceived susceptibility on colorectal cancer screening intention and behavior. Ann Behav Med 2010;40(2):205-17. doi:10.1007/s12160-010-9215-3.
Salimzadeh H, Eftekhar H, Majdzadeh R, Montazeri A, Delavari A. Effectiveness of a theory-based intervention to increase colorectal cancer screening among Iranian health club members: a randomized trial. J Behav Med 2014; 37(5):1019-29. doi:10.1007/s10865-013-9533-6.
Thirlaway K, Upton D. The Psychology of Lifestyle: promoting healthy behavior: Routledge; 2009.
Gage GS. Social Support and Positive Health Practices in Black Late Adolescents The Role of Mediating Variables. Clin Nurs Res 2015. doi: 10.1177/1054773815594579.
Zhang S, Edwards H, Yates P, Li C, Guo Q. Self-efficacy partially mediates between social support and health-related quality of life in family caregivers for dementia patients in Shanghai. Dement Geriatr Cogn Disord 2013;37(1-2):34-44. doi:10.1159/000351865.
Dishman RK, Motl RW, Sallis JF, Dunn AL, Birnbaum AS, Welk GJ, et al. Self-management strategies mediate self-efficacy and physical activity. Am J Prev Med 2005;29(1):10-8. doi:10.1016/j.amepre.2005.03.012.
Manne S, Kashy D, Albrecht T, Wong Y-N, Flamm AL, Benson AB, et al. Knowledge, attitudes, and self-efficacy as predictors of preparedness for oncology clinical trials a mediational model. Med Decis Making 2014;34(4):454-63. doi: 10.1177/0272989X13511704.
Hill K, Startup M (2013). The relationship between internalized stigma, negative symptoms and social functioning in schizophrenia: the mediating role of self-efficacy. Psychiatry Res 2013; 206(2):151-7.
McQueen A, Vernon SW, Myers RE, Watts BG, Lee ES, Tilley BC. Correlates and predictors of colorectal cancer screening among male automotive workers. Cancer Epidemiol Biomarkers Prev 2007;16(3):500-9. doi: 10.1158/1055-9965.EPI-06-0757.
Statistical center of Iran, the president’s office deputy of strategic planning and control.National population and housing census 2011 (1390): selected findings . Tehran; 2011.
Rashidian A, Karimi-Shahanjarini A, Khosravi A, Elahi E, Beheshtian M, Shakibazadeh E, et al. Iran'Multiple Indicator Demographic and Health Survey (IrMIDHS-2010): Study protocol. Int J Prev 2014; Med,5(5).
Griffin MJ. Health belief model, social support, and intent to screen for colorectal cancer in older African American men. [PhD thesis]. School of Nursing, University of North Carolina at Greensboro; 2011.
Vernon SW, Myers RE, Tilley BC. Development and validation of an instrument to measure factors related to colorectal cancer screening adherence. Cancer Epidemiol Biomarkers Prev 1997; 6(10):825-32.
Hoyle RH. Structural equation modeling: Concepts, issues, and applications: Sage Publications; 1995.
Ringle CM, Wende S, Will. SmartPLS (Version 2.0 (beta)). Hamburg, Germany; 2005.
Hair JF, Ringle CM, Sarstedt M. PLS-SEM: Indeed a silver bullet. Journal of Marketing theory and Practice 2011; 19(2):139-152. doi 10.2753/MTP1069-6679190202.
Chin WW. The partial least squares approach to structural equation modeling. Modern methods for business research. Edited by Marcoulides GA. New York: Psychology Press 1998; 295-336.
Straub D, Boudreau M-C, Gefen D. Validation guidelines for IS positivist research. The Communications of the Association for Information Systems 2004;13(1):63. doi: 10.1007/978-3-540-32827-8_29.
Haenlein M, Kaplan AM. A beginner's guide to partial least squares analysis. Understanding statistics 2004;3(4):283-97.
Tenenhaus M, Amato S, Esposito Vinzi V, editors. A global goodness-of-fit index for PLS structural equation modeling. Proceedings of the XLII SIS scientific meeting;2004.
Zheng Y-F, Saito T, Takahashi M, Ishibashi T, Kai I. Factors associated with intentions to adhere to colorectal cancer screening follow-up exams. BMC Public Health 2006;6(1):1. doi: 10.1186/1471-2458-6-272.
Boonyasiriwat W, Hung M, Hon SD, Tang P, Pappas LM, Burt RW, et al. Intention to undergo colonoscopy screening among relatives of colorectal cancer cases: a theory-based model. Ann Behav Med 2014;47(3):280-91. doi:10.1007/s12160-013-9562-y.
Honda K, Kagawa-Singer M. Cognitive mediators linking social support networks to colorectal cancer screening adherence. J Behav Med 2006; 29(5):449-60. doi:10.1007/s10865-006-9068-1.
Power E, Van Jaarsveld CH, McCaffery K, Miles A, Atkin W, Wardle J. Understanding intentions and action in colorectal cancer screening. Ann Behav Med 2008;35(3):285-94. doi:10.1007/s12160-008-9034-y.
Tolma EL, Reininger BM, Evans A, Ureda J. Examining the theory of planned behavior and the construct of self-efficacy to predict mammography intention. Health Education & Behavio 2006; 33(2):233-51. doi: 10.1177/1090198105277393.
Bunn JY, Bosompra K, Ashikaga T, Flynn BS, Worden JK. Factors influencing intention to obtain a genetic test for colon cancer risk: a population-based study. Prev Med 2002; 34(6):567-77. doi:10.1006/pmed.2002.1031.
Witte K. Putting the fear back into fear appeals: The extended parallel process model. Commun Monogr 1992; 59(4):329-49. doi: 10.1080/03637759209376276.
Christou A, Thompson SC. Colorectal cancer screening knowledge, attitudes and behavioral intention among Indigenous Western Australians. BMC Public Health 2012; 12(1):1. doi: 10.1186/1471-2458-12-528.