Title | Reactivity in baseline accelerometer data from a physical activity behavioral intervention. |
Publication Type | Journal Article |
Year of Publication | 2012 |
Authors | Motl RW, McAuley E, Dlugonski D |
Journal | Health Psychol |
Volume | 31 |
Issue | 2 |
Pagination | 172-5 |
Date Published | 2012 Mar |
ISSN | 1930-7810 |
Keywords | Actigraphy, Adult, Behavior Therapy, Female, Humans, Male, Middle Aged, Multiple Sclerosis, Reference Values, Self Report, Walking |
Abstract | OBJECTIVE: This brief report describes the possibility of reactivity in the baseline assessment of physical activity using accelerometry from two separate randomized controlled trials of a behavior intervention for increasing physical activity in persons with multiple sclerosis (MS). METHOD: The samples included 18 persons with multiple sclerosis (MS) from Study 1 and 20 from Study 2 who were randomized into treatment arms of the intervention. The participants initially wore an accelerometer over a 7-day period for collection of baseline data, and one week later wore a pedometer over a 7-day period for collection of data for self-monitoring and goal setting in week 1 of the 12-week intervention. The accelerometer and pedometer data were both expressed in average steps per day over a 7-day period. RESULTS: There was a moderate (d = .56), statistically significant (p = .03) difference of 1,822 steps per day between baseline and week 1 of the intervention in Study 1. There was a large (d = 1.36), statistically significant (p = .0001) difference of 2,338 steps per day in Study 2. CONCLUSION: We are unaware of other research describing a significant change in physical activity between baseline and the first week of a behavioral intervention and believe that this change reflects reactivity in the baseline assessment using accelerometry. |
DOI | 10.1037/a0025965 |
Alternate Journal | Health Psychol |
PubMed ID | 22023436 |