Our objectives in this project are to develop and evaluate the feasibility and effectiveness of the Mobile Web App Breast Cancer Screening (wMammogram) intervention that is culturally tailored for AI women residing in rural areas. The proposed study will be a multi-method, two-phase research project that will take place in South Dakota over a three-year period. The two phases are: (1) developing the wMammogram intervention and (2) evaluating the feasibility and efficacy of the wMammogram. Phase 1 incorporates a community-based participatory research approach and a series of focus groups with various stakeholders in American Indian (AI) communities to design a culturally informed and practically refined intervention. Phase 2 uses a randomized clinical trial (RCT) design with AI women. The wMammogram intervention will be applied throughout a seven-day period, with assessment at three intervals: baseline (survey), one-week post-intervention (survey), and six-month follow-up (telephone survey).

The wMammogram intervention will be implemented with AI women using the two-arm RCT that includes recruiting a total of 120 AI women aged 40 to 70 years and randomly assigning them to either (a) the wMammogram intervention group (n=60) to receive culturally and personally tailored multilevel and multimedia messages through a Mobile Web App along with health navigator services or (b) the control group (n=60) to receive the mailing of printed educational materials on breast cancer and relevant screening guidelines along with health navigator services.

Hypotheses: In assessing the efficacy and feasibility of the wMammogram, Investigators hypothesize that:

(H1)The wMammogram intervention participants will show a higher rate of mammograms received than will participants in the educational materials intervention.

(H2)The wMammogram intervention participants will show improvements in knowledge, attitude, and beliefs about breast cancer screening and readiness for mammography as compared to participants in the educational materials intervention.

(H3)The wMammogram intervention participants will demonstrate greater satisfaction with and acceptance of the intervention than would participants in the educational materials intervention.

Sample Size and Power Analysis: Investigators will have 120 participants in both the intervention and the control group by the six-month follow-up assessment. Considering that the possible sample attrition at the six-month follow-up is expected to be no higher than 20% (n=24), a total of 144 participants will be recruited for the baseline assessment; half will be randomly assigned to intervention (n=72) and another half assigned to control condition (n=72). Using a one-sided nonparametric Wilcoxon rank-sum test and the mixed effect ANOVA at the 0.05 level and assuming continuous scores, this sample size (60 per arm) would provide 80 percent power to reject the null hypothesis of the equality of score-changes for both groups. The key objective of the study is to acquire preliminary estimates of breast cancer screening rates after the intervention to assess if further study is warranted. As such, Investigators stress on the precision with which Investigators can estimate the breast cancer screening rate post-intervention rather than our ability to reject a specific null hypothesis. A sample size of 60 participants for each arm reflects a compromise between keeping the scope of the project within the objectives of a pilot study while ensuring a large enough sample size to estimate the breast cancer screening rate post-intervention.

Quantitative Measures (Baseline, One-Week, and Six-Month Follow-Up Assessment): Measures will be selected based on the frequency of use in cancer and health literature, psychometric properties, previous applications with AI populations, and inputs from the Community Advisory Board (CAB) and focus groups. The primary outcome criterion for efficacy is mammography receipt after the intervention, which will be measured by self-report (yes or no) at six-month follow-up. The measure has been widely used and found reliable in cancer screening research. The secondary outcome criteria for efficacy include breast cancer knowledge, health beliefs, cultural attitudes, and intent to undergo screening. These measures will be administered at multiple points: baseline and one-week post-intervention. In order to assess feasibility, investigators will measure participant satisfaction and intervention effectiveness. These measures will be administered at one week after the intervention. Confounding covariates (e.g., background, sociodemographic, and health-related information) will be collected only at the baseline assessment and used for assessing the influence of such contextual factors.

Quantitative Data Analysis: Prior to our hypotheses tests, group equivalence in terms of baseline characteristics will be examined using t-tests and chi-square tests. For Hypothesis 1, Investigators will compare the percentage of women from each condition who receive mammograms or have scheduled a mammography appointment using a chi-square test. Investigators will supplement this with logistic regression analyses to adjust for confounding covariates. For Hypothesis 2, the averages of score change (pre- to post-test) from the two conditions will be compared using the two-sample t-test, and/or the Wilcoxon rank-sum tests after assessing normality of the scores. The group difference in terms of changes in the given constructs will be tested by a mixed-effect analysis of variance (ANOVA). The mixed-effect ANOVA includes both within-subject (i.e., time: repeated measures) and between-subject factors (i.e., group: intervention versus control) and aims to examine whether there is an interaction between these two factors on the dependent variable. Bonferroni correction will be used to reduce the probability of Type 1 error for multiple comparisons. Investigators will supplement this with a regression analysis of score change in order to adjust for confounding covariates. For Hypothesis 3, averages of general satisfaction and effectiveness scores from each group will be compared using the two-sample t-test. Also, the percentage of participants from each group who endorse "yes" for the intention and recommendation items will be compared using the chi-square test. To minimize a potential non-participation bias, Investigators will closely monitor and compare the first and fourth quartiles of responses for differences in background variables and key constructs. Investigators will also carefully document the response rate over the course of this project. IBM SPSS version 25 will be used for data analyses.

Inclusion Criteria:

• Women who are self-identified AI women of the YST in SD
• Women who are aged 40 to 70 years
• Women who have not received a mammogram in the past two years
• Women who are willing to use their own mobile phone, iPad, tablets, and computers, or a mobile phone borrowed from the research team for the wMammogram intervention.

Exclusion Criteria:

• Women who received a mammogram in the past year
• Women who are under 40 or over 70 years of age.

Not sharing IPD with other researchers

Adverse events were not collected or reviewed for participants

No adverse events were collected or reported on participants

Research within a single tribe, like the Yankton Sioux Tribe, offers valuable insights into that community's unique dynamics. However, these findings cannot be broadly generalized. Each tribe has distinct traditions, languages, and community structures that shape health behaviors and outcomes, making cross-tribal generalization challenging.

Participants are unaware of which group they have been assigned to.