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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 10 000 steps everyday? How does this compare to more traditional types of physical activity or exercise?. one question:.
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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 10 000 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 O1 R T1O2 O3 O1 R T2O2 O3 O1 R O2 O3 • 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 – 10 000 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