PEDS 409 Research Design: True Experimental

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PEDS 409 Research Design True Experimental

• BY Sherri Beauchamp, Marie Buchta, Avaleigh
  Wagner Jodi Spink

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Li, F. et al. (2001) Tai Chi Enhances
Self-Efficacy and Exercise Behavior in Older
Adults. Journal of Aging and Physical Activity
(9) 161-171.
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Authors and Affiliations

• Fuzhong Li Oregon Research Institute
• Edward McAuley
• Peter Harmer
• Terry E. Duncan
• Nigel R. Chaumeton
• Grants from National Institute on Drug Abuse and
  National Institute on Aging

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Research Question

• What are the effects of a Tai Chi intervention
  program on perceptions of personal efficacy and
  exercise behavior in older adults?

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Type of Research

• True Experimental
• One or more control groups AND one or more
  treatment groups
• Random assignment from population of interest
• Variables of interest can be manipulated directly

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Type of Research (cont)

• Randomized Control Trial Design
• R O1 X1 O2 X2 O3
• R O1 O2 O3
• R Randomized Samples
• O1-3 Observations
• X1-2 Tai Chi intervention

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Type of Research (cont)

• Advantages
• Good for assessing change during and after
  intervention
• Main threats are controlled (testing, maturation
  etc.)
• Disadvantages
• Attrition rates
• Diffusion of intervention (ie control group
  increases activity)
• Resentment for no intervention

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Research Methods

• Individuals responded to newspaper ads and flyers
  at senior centers
• Inclusion criteria
• 65 years of age or older
• Low active according to PASE (Physical Activity
  Scale for the Elderly) no involvement in regular
  exercise program within the last month
• Healthy exercise will not have negative
  physical effects
• Willingness to be randomly assigned

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Research Methods (cont)

• 98 individuals 65-96 years old were chosen
• Assigned to either a Tai Chi practice group or a
  waiting list
• Assessed demographic characteristics age,
  gender, education, income ethnicity
• 6 month trial

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Research Methods (cont)

• Intervention group
• Yang Style Tai Chi
• 60 min. practice sessions 2x/week for 6 months
• 15 min. warm up, 15 min cool down included in
  practice session

• Control Group
• Maintained routine activities
• Could not join new exercise programs
• Promised a 4 week Tai Chi program at the end

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What is Yang Style Tai Chi?
Yang Style Tai Chi is a slow moving form that
affects balance postural alignment concentration
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Research Methods (cont)Outcome Measures

• Barrier scale self-efficacy
• 5 items to assess perception of ability to
  perform Tai Chi regularly in the face of barriers
  (ie. Pain, boredom etc.)
• 0-100 confidence scale (0very little confidence,
  100complete confidence)

• Performance scale self-efficacy
• 3 item task-specific, time-based
• Degree of confidence in ability to successfully
  perform a series of slow, rhythmically changing
  body position movements
• 0-100 confidence scale

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Outcome Measures cont

• Class Attendance
• Exercise behavior was assessed by attendance
  taken by instructor
• Frequency of Measurements
• Baseline measures - prior to study
• 2nd measures week 12
• 3rd measures week 24
• (intervention group responded in class within 1
  week, control group responded by mail)

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Main Findings

• Tai Chi exercise program can significantly
  enhance perceptions of task-specific personal
  efficacy in older adults
• The Tai Chi group developed higher perceptions of
  efficacy, adhered better to the exercise program
  and spent more time engaged in exercise
  (therefore increased exercise participation)

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Main Findings (cont)

• Intervention (Tai Chi) group
• Both types of efficacy increase over time
• Initial boost from baseline to 2nd observation
• Maintenance from 2nd to 3rd observation
• Class attendance was significantly predicted by
  the changes in the 2 types of efficacy
• Control group
• Both types of efficacy decreased over time

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Main Findings (cont)
Change in barrier efficacy between Tai Chi and
Control
Change in performance efficacy between Tai Chi
and Control
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Brief Critique

• All subjects were volunteers this could make
  generalizability difficult
• Gender was recorded but not specified in results
  potential influence of a moderator variable
• Monitoring attendance issues no parameters set
  aside for absenteeism - assumption that
  absenteeism is due to self-efficacy
• All self-efficacy measures are self-reported
  therefore subject to social desirability biases

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Brief Critique (cont)

• Physical activity in control group was not
  monitored throughout the study
• No data comparing the decrease in self-efficacy
  to a decrease in activity
• Motivation issue feel obligated to attend
  because are in the study
• Would participants attend these classes if not in
  the study? (long term adherence)
• Validity of claim intervention should be
  compared to other organized activities/classes

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Brief Critique (cont)

• Ethical issues Control group was only offered a
  4 week Tai Chi class after the study, whereas
  intervention group got 6 months
• Self-efficacy measures are based on performance
  of Tai Chi not general daily activity (not
  applicable to control group)
• Warm up and Cool down not specified
• Sample size decreased due to attrition which
  could impact generalizability

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Future Research Suggestions

• Compare Tai Chi results to more Traditional forms
  of exercise (ie. Strength training, walking,
  stretching, etc.).
• Compare positive effects of Tai Chi in other age
  groups.
• Look at adherence over longer periods of time or
  post-intervention (months, years later)

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Future Research Suggestions (cont)

• Impact of Tai Chi on health related aging
  problems as compared to other activities/intervent
  ions.
• Examine impact of Tai Chi on adherence
  to/participation in activities of daily living

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Other questions that can be addressed with True
Experimental Research

• Can be used for any study involving an
  intervention (ie. Drug, exercise, acupuncture,
  rehabilitation therapy, any lifestyle factor
  etc.) on a sample of a specific population

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THE END