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Cancer Control Research

5R21CA121066-02
Rhyne, Robert L.
COLORECTAL CANCER SCREENING IN SOUTHWESTERN HISPANICS AND NATIVE AMERICANS

Abstract

DESCRIPTION (provided by applicant): In 2005, colorectal cancer (CRC) was the second leading cause of cancer deaths in the United States. Nationally the age-adjusted incidence rate of CRC has steadily decreased since 1975, at a rate of 0.8% per year; the US Hispanic rates have been relatively steady; and American Indians have had a steeper decline of 1.8% annually. The opposite is found in New Mexico (NM), where the annual incidence rates for Hispanics and American Indians have increased at alarming rates of 3.6% and 4.7%, respectively, for the same period. The CRC screening rates for these NM minorities are 30-50% lower than the national rates for FOBT and endoscopy. The long range goal is to increase CRC screening rates in NM; however, before an intervention to accomplish this can be designed, the reasons why screening rates are so low in these unique populations must be explored and understood. Very little information exists on these populations regarding CRC screening. Two specific aims will be addressed in this study: 1) To determine which patient and provider factors in the CRC orous qualitative analysis, and 2) To develop, pilot, and finalize a survey instrument for quantitatively measuring the components of the patient decision making process that are barriers to CRC screening, among New Mexico Hispanic and American Indian populations. Qualitative focus groups and semi-structured interviews will be conducted through RIOS Net; a primary care practice-based research network formed specifically to conduct research of direct relevance to the Southwest's rural, culturally diverse and underserved populations. A conceptual model of 10 constructs that determines CRC screening behavior forms the basis of the study, and will be explored in-depth in physicians and community health worker (CHW) semi-structured interviews and patient focus groups. Sampling will be based on type of practice setting, Community Health Center or Indian Health Service, which is reflective of ethnicity of service population. Sample size will be determined by points of data saturation within each sampling cell, and it is estimated that 14 randomly selected physicians, 14 CHWs, and 42 patient focus groups with 336 participants will be required to reach data saturation. Patient eligibility criteria include ethnicity (Hispanic or American Indian), age (e50 years), and no prior history of CRC. A rigorous analysis of interview and focus group transcript data will be conducted by researchers experienced in qualitative methods. The unique aspects of each construct that contribute to CRC screening behavior will be identified. The new information developed by this project will expand the knowledge base of the conceptual model in new populations, will be used to design a survey that can quantitatively measure the screening behaviors in Hispanics and Native Americans, and will be used to design a culturally sensitive RO1 intervention study designed to increase CRC screening rates among NM Hispanics and American Indians. While the rates for colorectal cancer in the US are decreasing, the rates for New Mexico Hispanics and American Indians are increasing; this represents a worsening public health problem in two US minority populations. The reasons why disease rates are increasing are unknown, but a contributing factor is very low screening rates in these populations. This qualitative study will explore the reasons why screening rates are low and this new knowledge will contribute to the design of culturally sensitive interventions to increase screening rates, which has the potential to reverse this public health problem by decreasing the colorectal cancer disease rates in these vulnerable populations.


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