RCT’s and exercise Terra C Murray

Background We know that physical activity is good for people, especially at the population level But what are the outcomes of walking steps everyday? How does this compare to more traditional types of physical activity or exercise?

one question: What are the outcomes associated with different ‘types’ of physical activity? population? Activity? Measures? Physiological, psychological….. Design of study

Health First research study what’s in a name…… “Couch Potato” study Funding source: CIHR

The “team” PI (Dr. Rodgers) and then Co-I’s (Drs. Bell, Courneya and Harber). RA’s: in the trenches (Murray, Loitz, Scime, Wild…) Assistants (Johnston); Consultants (Fraser); Paid help/contracted work (SPU, DKML); Practicum students

Study design What is the best way to answer the question? Randomized Clinical Trial O 1 R T 1 O 2 O 3 O 1 R T 2 O 2 O 3 O 1 R O 2 O 3 R provides a time point when the groups start to diverge in ways that might be unpredictable (LaValley, 2003)

Intention to Treat Analysis Typically RCT’s use ITT analysis Includes all randomized participants, regardless of adherence, treatment, withdrawal, or deviation from protocol Pragmatic vs Explanatory Hypotheses Pragmatic: identify the utility or effectiveness of treatment Explanatory: isolate and identify biologic effects – often need to exclude noncompliant participants from analysis LaValley, 2003

6 months of activity + about 1 month for pre and post measures Target N = 226 Population: sedentary men and women Measures: fitness, blood lipid and glucose, HR, BP, body comp., attitudes to exercise, social support, self-efficacy ……. Groups or treatment arms: Blue: traditional fitness center based CV program Yellow: lifestyle walking program – steps Red: daily maintenance (control)

$$$$$$$$ Pedometers, HR monitors, blood pressure cuffs, blood measures, freezer to store blood, physiological tests, photocopying, mailing, t- shirts, water bottles, computer, research assistants …………….. “I lost my pedometer….”

recruitment Who and how? Sedentary but “healthy” volunteers Inclusion and exclusion criteria High BP, too active, diabetic, 25-65, Dr. says no Often changes or alters

Randomization and Rx After all pre-measures, randomization is performed and participants are notified Challenges Control group Fit Center Group Walking Group

Issues in RCT and exercise Don’t like your group Assigned to a control group Friends, partners/spouses….. Intention to Treat analysis Don’t comply with the “prescription” Do not complete the trial (we have no post measure)

Minimize withdrawal and noncompliance Cannot impact the integrity of study or the “question” Weekly contact with all participants Solicit their advice, ask how things are going Incentives during trial Incentives when trial is completed