Prevalence and predictors of cancer screening among American Indian and Alaska native people: the EARTH study.

PURPOSE: The purpose of this study was to examine the prevalence rates for cervical, breast, and colorectal cancer screening among American Indian and Alaska Native people living in Alaska and in the Southwest US, and to investigate predictive factors associated with receiving each of the cancer screening tests. METHODS: We used the Education and Research Towards Health (EARTH) Study to measure self-reported cancer screening prevalence rates among 11,358 study participants enrolled in 2004-2007. We used prevalence odds ratios to examine demographic, lifestyle and medical factors associated with receiving age- and sex-appropriate cancer screening tests. RESULTS: The prevalence rates of all the screening tests were higher in Alaska than in the Southwest. Pap test in the past 3 years was reported by 75.1% of women in Alaska and 64.6% of women in the Southwest. Mammography in the past 2 years was reported by 64.6% of women aged 40 years and older in Alaska and 44.0% of those in the Southwest. Colonoscopy or sigmoidoscopy in the past 5 years was reported by 41.1% of study participants aged 50 years and older in Alaska and by 11.7% of those in the Southwest US. Multivariate analysis found that location (Alaska versus the Southwest), higher educational status, income and the presence of one or more chronic medical condition predicted each of the three screening tests. Additional predictors of Pap test were age (women aged 25-39 years more likely to be screened than older or younger women), marital status (ever married more likely to be screened), and language spoken at home (speakers of American Indian Alaska Native language only less likely to be screened). Additional predictors of mammography were age (women aged 50 years and older were more likely to be screened than those aged 40-49 years), positive family history of breast cancer, use of smokeless tobacco (never users more likely to be screened), and urban/rural residency (urban residents more likely to be screened). Additional predictors of colonoscopy/sigmoidoscopy were age (men and women aged 60 years and older slightly more likely to be screened than those aged 50-59 years), family history of any cancer, family history of colorectal cancer, former smoking, language spoken at home (speakers of American Indian Alaska Native language less likely to be screened), and urban/rural residence (urban residents more likely to be screened). CONCLUSION: Programs to improve screening among American Indian and Alaska Native people should include efforts to reach individuals of lower socioeconomic status and who do not have regular contact with the medical care system. Special attention should be made to identify and provide needed services to those who live in rural areas, and to those living in the Southwest US.

Development, implementation, and evaluation of a computerized self-administered diet history questionnaire for use in studies of American Indian and Alaskan native people.

Collection of dietary intake in epidemiologic studies involves using methods that are comprehensive yet appropriate for the population being studied. Here we describe a diet history questionnaire (DHQ) that was developed using an audio self-administered computer-assisted interview technique. The DHQ was developed for use in a cohort of American Indians and Alaskan Natives with tribal input and area-specific modules to incorporate local food availability. The DHQ includes 54 main food group questions, specific food items within the main food group, and food preparation and general eating practice questions. The questionnaire was programmed to be self-administered using a computer with a touch screen. The average time for the first 6,604 participants to complete the questionnaire was 36 minutes. Almost 100% of participants had complete DHQ data and the average number of food items selected was 70. The methods developed for collection of dietary data appear to be appropriate for the targeted population and may have usefulness for other populations where collecting dietary data in a self-administered format is desirable.