Culturally Tailoring an Advance Care Planning Intervention for American Indians
Phase: NA
Conditions: Advance Care Planning
Sponsor: Western Carolina University

 
 
 
 
 
 
 
Study Protocol and Statistical Analysis Plan 
Culturally Tailoring an Advance Care Planning Intervention for American Indians 
ID: 1685879-1 
June 30, 2024 
 

  
Study Aims 
This project had three specific aims: 1. Culturally tailor the content of the Make Your Wishes 
About You (MY WAY) ACP curriculum and guide for one American Indian Tribe; 2. Assess the 
feasibility of the culturally tailored MY WAY ACP curriculum and patient education guide with 
the tribe; and 3. Examine the preliminary outcomes of the culturally tailored MY WAY ACP 
curriculum guide with 70 tribal members.  
Study Protocol 
Study Design 
We used a quasi-experimental waitlist-controlled study design to test the hypothesis that 
after participating in the tailored MY WAY intervention, participants would experience decreased 
ACP barriers and increased ACP facilitators, readiness, self-efficacy, and completion. This 
design split our total participant pool into two cohorts to allow for a comparison group while still 
providing the intervention to all participants. Cohort 1 received the intervention immediately 
after study enrollment and served as the intervention group. Results from Cohort 1 were then 
compared to the waitlisted cohort, or Cohort 2, who waited over 3 months on average to receive 
the intervention.  
Intervention 
The intervention consisted of two steps: attendance at a Community Information Session 
(CIS) and attendance at an individual Sharing Session (SS).  
Recruitment 
Study eligibility criteria included being an enrolled Tribal member, spouse of a Tribal 
member, first descendant, or a member of another AIAN Tribe, aged ≥18 years, and residing 
within the Tribal service area. We recruited potential participants using convenience sampling 

techniques. We made in-person study recruitment announcements at 13 Tribal venues and left 
flyers and hung posters at 26 locations. We also ran an ad in the Tribal newspaper and on three 
billboards. Tribal programs distributed MY WAY information on our behalf via their social 
media and/or email listserv. We also developed a project website and ran a short video on the 
local Tribal television station. Interested people were directed to call the Project Coordinator by 
telephone and/or speak with staff at a CIS and then screened for study eligibility and enrolled, if 
eligible.  
Data Collection 
All study participants completed informed consent documents before study participation 
and all who completed the full intervention and the interviewer-administered surveys received 
$85 in gift card incentives. Data were collected via surveys from Cohort 1 immediately before 
the CIS (“intervention baseline survey”), 8-9-weeks after the CIS at posttest (“post-program 
survey”), and 6-month follow up (“follow-up survey”). For Cohort 2, survey data was collected 
at baseline (“control baseline survey”), an average of 13 weeks immediately before CIS 
attendance (“intervention baseline survey”), and an average of 12-weeks after the CIS (“post-
program survey”). The first survey administered with Cohort 2 participants occurred at study 
enrollment and served as a control baseline comparison to Cohort 1.  
Measures 
ACP barriers and facilitators were assessed with 16 yes/no questions (8 barriers and 8 
facilitators) derived from qualitative data regarding ACP and developed during the original MY 
WAY clinical trial, but never published.   
ACP readiness and self-efficacy were captured with the 9-item ACP Engagement 
Survey Process Measures identified from Behavioral Change Theory. The 6-item readiness and 

the 3-item self-efficacy subscales have 5-point, Likert responses of “not at all, a little, somewhat, 
fairly, extremely.” In a field test of these subscales, they demonstrated good reliability and 
discriminant validity (Sudore et al., 2017; 2013).  
For ACP completion, participants were asked if they had a legal advance directive. To 
confirm self-reports post-program, project staff documented whether the participant’s advance 
directive was notarized after SS and compared this to notary records. All sources of the 
participant’s advance directive completion measure were combined into a single binary variable 
(yes/no).   
Interview-administered intervention and control baseline surveys also included self-
reported demographic characteristics of age (in years), gender (male or female), marital status 
(married or not married), Tribal affiliation (member, first descendent, family of a member, 
member of another Tribe), education (on a scale of 1 = less than high school education to 5 = 
graduate degree), self-rated health (on a scale of 1 = very poor to 6 = excellent), and self-
reported diagnosis of any chronic conditions. Chronic conditions included chronic obstructive 
pulmonary disease, history of stroke, history of heart attack, cancer, chronic kidney disease, type 
2 diabetes, heart disease, high cholesterol, and chronic pain. 
Analyses 
 
All analyses were conducted in IBM SPSS Statistical Software (27) or Microsoft Excel. 
We examined participant demographic characteristics using descriptive statistics and stratified 
analyses. To determine if there were demographic or other differences between the cohorts, we 
conducted crosstabulation analyses with Bonferroni correction applied. To compare intervention 
baseline and post-program levels of barriers and facilitators, as well as analyze change over time 
in ACP readiness, self-efficacy, and completion, we combined the cohorts. As barriers and 

facilitators were asked as simple “yes/no” questions, the number of barriers and facilitators listed 
by participants was calculated before and after the intervention for comparison.  
Before combining the individual readiness and self-efficacy items, we ran selectivity and 
reliability analyses. To check for differences in the sample due to attrition, we computed Little's 
missing completely at random (MCAR) test. We then conducted crosstabulations again to look 
for relationships between demographic characteristics and ACP readiness, self-efficacy, and 
completion measures at intervention baseline. With our combined sample, we conducted a 3 
(readiness, self-efficacy, and completion) x 2 (pretest to 8-week posttest) way repeated measures 
analysis of variance (ANOVA) with demographic characteristics found to be related to 
intervention baseline measures as between-subjects variables. For 6-month follow-up surveys 
with Cohort 1, we conducted a separate one-way ANOVA ( intervention baseline, post-program, 
follow-up) for ACP readiness and self-efficacy. We tested the hypothesis that Cohort 2 
participants did not change ACP-related readiness and self-efficacy from control baseline to 
intervention baseline by conducting a third separate one-way repeated measures ANOVA. We 
also calculated difference scores from control baseline to intervention baseline among Cohort 2 
participants and intervention baseline to post-program among all participants.