Trial Information

Physical Activity Promotion in Breast Cancer Survivors: A Population Based Randomized Controlled Trial

Approximately 300 breast cancer survivors living in Northern Alberta will be randomized to
one of four groups: (1) an exercise recommendation only group (viewed as the current
standard of care), (2) an exercise recommendation plus pedometer group, (3) an exercise
recommendation plus printed materials group, and (4) an exercise recommendation plus
pedometer and printed materials group. Our primary hypothesis is that participants in the
three intervention groups will report a greater positive change in physical activity than
participants in the exercise recommendation only group. Furthermore, we expect that
participants receiving the combined pedometer and printed materials intervention will report
the greatest change in physical activity. Our secondary hypotheses are that these
interventions will also result in improved QoL and more positive social cognitive beliefs
about exercise in breast cancer survivors. Our sample size was determined by a power
calculation. Based on the literature, we believe that an increase of 2,000 steps per day is
a meaningful change that will result in health benefits for breast cancer survivors. We
estimate a standard deviation of about 4,000 steps per day. Therefore, to detect a medium
standardized effect (d = .50) with a power of .80 and a two-tailed alpha <.05, we need 63
participants per group. To account for a possible 15% loss to follow up, we will randomize
75 participants to each group. Our printed materials will be developed based on the tenets
of the theory of planned behavior and will include activities designed to enhance
instrumental and affective attitudes, injunctive and descriptive norms, and self-efficacy
and perceptions of control. These materials will be developed based on our previous research
identifying the key beliefs that should be targeted in a theory of planned behavior-based
intervention.

Our procedure will be to identify and screen potential participants for eligibility through
the Alberta Cancer Registry. After obtaining written informed consent from the individual’s
treating oncologist, all eligible participants will be sent a letter of invitation to
participate in the study. Interested participants will complete a baseline questionnaire
that will include measures of physical activity (the Godin Leisure-Time Exercise
Questionnaire), QoL (Functional Assessment of Cancer Therapy-Breast and Anemia), and social
cognitive variables from the theory of planned behavior (based on the guidelines from Ajzen
and our previous research). Participants will also wear a pedometer for a 7-day monitoring
period to obtain baseline steps. Participants will then be randomized to one of four groups.
Depending on randomization, the participants will then receive the appropriate materials.
All groups will be recommended to accumulate at least 30 minutes of moderate intensity
physical activity at least five days per week which would result in about 15,000 steps per
week (or 2,000 steps per day). At the end of the 12-week intervention period, all
participants will complete the same post intervention questionnaire and undergo another
7-day monitoring period to obtain step values. Participants will be contacted at 6 months
for follow-up and complete the same questionnaire for a final time.