Trial Outcomes & Findings for Testing Diet Intervention Versus Non-Diet Intervention for Management of Bowel Symptoms in Rectal Cancer Survivors (NCT NCT04205955)

95 participants were randomly assigned; 48 on the attention control arm and 47 on the intervention arm. Reasons for ineligibility include not completing run-in, withdraw of consent, and disease progression.

Testing Diet Intervention Versus Non-Diet Intervention for Management of Bowel Symptoms in Rectal Cancer Survivors

Will be measured by the Memorial Sloan-Kettering Cancer Center Bowel Function Instrument (BFI) total score. Score range 18-90. Higher scores indicate better bowel function. Will be conducted according to a modified intention-to-treat principle. Study arm differences in BFI at 18 weeks will be assessed by a linear regression model as a function of randomization assignment, BFI baseline value, and stratification factors.

Will describe using dietary, urgency, and frequency scales. Will be assessed by a repeated measures linear regression model as a function of randomization assignment, baseline value of the outcome, stratification factors, and visit. Robust standard errors will be estimated via generalized estimating equations to adjust for correlation between repeated outcome measures. The dependent variables will be transformed to approximate normality as appropriate.

LARS will be measured using the LARS Score. Will be assessed by a repeated measures linear regression model as a function of randomization assignment, baseline value of the outcome, stratification factors, and visit. Robust standard errors will be estimated via generalized estimating equations to adjust for correlation between repeated outcome measures. The dependent variables will be transformed to approximate normality as appropriate.

Will be measured by the City of Hope-Quality of Life-Colorectal Cancer. Will be assessed by a repeated measures linear regression model as a function of randomization assignment, baseline value of the outcome, stratification factors, and visit. Robust standard errors will be estimated via generalized estimating equations to adjust for correlation between repeated outcome measures. The dependent variables will be transformed to approximate normality as appropriate.

Will be based on the Healthy Eating Index 2015. Will be assessed by a repeated measures linear regression model as a function of randomization assignment, baseline value of the outcome, stratification factors, and visit. Robust standard errors will be estimated via generalized estimating equations to adjust for correlation between repeated outcome measures. The dependent variables will be transformed to approximate normality as appropriate.

Will be measured using a 10-item scale assessing motivation to change dietary behaviors in rectal cancer survivors. Will be assessed by a repeated measures linear regression model as a function of randomization assignment, baseline value of the outcome, stratification factors, and visit. Robust standard errors will be estimated via generalized estimating equations to adjust for correlation between repeated outcome measures. The dependent variables will be transformed to approximate normality as appropriate.

Will be measured using the Patient-Reported Outcomes Measurement Information System Self-Efficacy for Managing Symptoms - Short Form 4a. Will be assessed by a repeated measures linear regression model as a function of randomization assignment, baseline value of the outcome, stratification factors, and visit. Robust standard errors will be estimated via generalized estimating equations to adjust for correlation between repeated outcome measures. The dependent variables will be transformed to approximate normality as appropriate.

Will be measured using the International Positive and Negative Affect Schedule Short Form. Will be assessed by a repeated measures linear regression model as a function of randomization assignment, baseline value of the outcome, stratification factors, and visit. Robust standard errors will be estimated via generalized estimating equations to adjust for correlation between repeated outcome measures. The dependent variables will be transformed to approximate normality as appropriate.

Will be measured by the percentage of patients who successfully complete ("pass") the run-in period, and randomized. Accrual rates and feasibility will be summarized.

Will measure successful completion of intervention or attention control coaching calls. Adherence is defined as completing all five of sessions 1-5 and at least three of sessions 6-10 within 18 weeks after randomization. Study arm differences in adherence will be assessed by chi square tests.

Will be defined by completion of follow-up assessments in step 2, including those administered at follow-up site visits and the dietary recalls. Study arm differences in retention will be assessed by chi square tests.

Will be measured using the Acceptability of Intervention measure. Study program acceptability will be compared across arms via t-test.