Agreement Between Accelerometer-Assessed and Self-Reported Physical Activity and Sedentary Time in Colon Cancer Survivors

Aim: Research conducted on the general population indicates self-reported measures of physical activity and sedentary behaviour are inaccurate, however it is not clear if this also applies to cancer survivors. The aim of this study was to compare accelerometer-based and self-reported measures of moderate- to vigorous-intensity physical activity (MVPA) and sedentary time among colon cancer survivors.

Methods: A total of 176 colon cancer survivors, recruited from the Western Australia and Alberta Cancer Registries, wore an Actigraph® GT3X+ accelerometer for seven consecutive days and completed self-reported questions about recent MVPA (Leisure Score Index of the Godin Leisure-Time Exercise Questionnaire) and sedentary time (Marshall Domain-Specific Sitting Questionnaire). The accelerometer data were processed using 60 second epochs and summarised using Freedson cutpoints. As per the self-report method, only bouts of 10 or more minutes of MVPA were taken into account in the accelerometer-derived estimates of MVPA. Spearman’s rho was used to compare daily sedentary time and MVPA estimates from the two methods.

Results: The total mean minutes per day spent in MVPA was 12 minutes based on accelerometer data and 26 minutes based on self-reported data. Agreement between the methods was fair (Spearman’s rho=0.4). For sedentary time, the mean time spent sedentary per day was similar in both methods (~8.7 hours), however agreement between the two methods was poor (Spearman’s rho=0.2).

Conclusion: These results suggest that there is poor to fair agreement between the self-reported measures used in this study and accelerometer-based assessments of sedentary time and MVPA in colon cancer survivors.