peds 409 research design: true experimental
DESCRIPTION
PEDS 409 Research Design: True Experimental. BY: Sherri Beauchamp, Marie Buchta, Avaleigh Wagner & Jodi Spink. Li, F. et al. (2001) Tai Chi Enhances Self-Efficacy andExercise Behavior in Older Adults. Journal of Aging and Physical Activity (9): 161-171. Authors and Affiliations. - PowerPoint PPT PresentationTRANSCRIPT
PEDS 409 Research Design: True Experimental
BY: Sherri Beauchamp, Marie Buchta, Avaleigh Wagner & Jodi
Spink
Li, F. et al. (2001) Tai Chi Enhances Self-Efficacy andExercise Behavior in Older Adults. Journal of Aging and Physical Activity (9): 161-171.
Authors and Affiliations
Fuzhong Li: Oregon Research InstituteEdward McAuleyPeter HarmerTerry E. DuncanNigel R. ChaumetonGrants from: National Institute on Drug
Abuse and National Institute on Aging
Research Question
What are the effects of a Tai Chi
intervention program on perceptions of
personal efficacy and exercise behavior
in older adults?
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
Type of Research (con’t)
Randomized Control Trial DesignR O1 X1 O2 X2 O3
R O1 O2 O3
R = Randomized SamplesO1-3 = ObservationsX1-2 = Tai Chi intervention
Type of Research (con’t)
AdvantagesGood for assessing change during and after
interventionMain threats are controlled (testing, maturation
etc.)Disadvantages
Attrition ratesDiffusion of intervention (ie control group increases
activity)Resentment for no intervention
Research Methods
Individuals responded to newspaper ads and flyers at senior centers
Inclusion criteria 65 years of age or olderLow 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
Research Methods (con’t)
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
Research Methods (con’t)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 GroupMaintained
routine activitiesCould not join
new exercise programs
Promised a 4 week Tai Chi program at the end
What is Yang Style Tai Chi?Yang Style Tai Chi is a slow moving form that affects balance
postural alignment & concentration
Research Methods (con’t):Outcome Measures
Barrier scale self-efficacy5 items to assess
perception of ability to perform Tai Chi regularly in the face of barriers (ie. Pain, boredom etc.)
0-100 confidence scale (0=very little confidence, 100=complete confidence)
Performance scale self-efficacy3 item task-specific,
time-basedDegree of confidence
in ability to successfully perform a series of slow, rhythmically changing body position movements
0-100 confidence scale
Outcome Measures con’t
Class AttendanceExercise behavior was assessed by
attendance taken by instructorFrequency of Measurements
Baseline measures - prior to study2nd measures – week 123rd measures – week 24
(intervention group responded in class within 1 week, control group responded by mail)
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)
Main Findings (con’t)
Intervention (Tai Chi) groupBoth types of efficacy increase over time
Initial boost from baseline to 2nd observationMaintenance from 2nd to 3rd observation
Class attendance was significantly predicted by the changes in the 2 types of efficacy
Control groupBoth types of efficacy decreased over time
Main Findings (con’t)
Change in barrier efficacy between Tai Chi and Control
Change in performance efficacy between Tai Chi and Control
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
Brief Critique (con’t)
Physical activity in control group was not monitored throughout the studyNo data comparing the decrease in self-efficacy to a
decrease in activityMotivation issue – feel obligated to attend
because are in the studyWould participants attend these classes if not in the
study? (long term adherence)Validity of claim: intervention should be
compared to other organized activities/classes
Brief Critique (con’t)
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 specifiedSample size decreased due to attrition which
could impact generalizability
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)
Future Research Suggestions (con’t)
Impact of Tai Chi on health & related aging problems as compared to other activities/interventions.
Examine impact of Tai Chi on adherence to/participation in activities of daily living
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