Concurrent validation of the bouchard diary with an accelerometry-based monitor

Purpose: This study was conducted to examine the relationships between the Bouchard activity diary and a temporally matched objective measure: the Tritrac-R3D (Professional Products. Reining International, Madison, WI) accelerometer. A secondary purpose was to examine the intraindividual variability in correlation coefficients between the two temporally matched measures. Methods: A total of 70 participants (ages 18-23 yr) wore a Tritrac monitor and completed the Bouchard activity diary during a 24-h period. Estimates of activity energy expenditure (AEE) and total energy expenditure (TEE) were compared using correlations. t-tests, and Bland-Altman graphical procedures. Results: A strong linear relationship was found between the Tritrac and the Bouchard measure for both AEE (r = 0.72) and TEE (r = 0.86). Large and significant differences were seen in the estimates of AEE (576 +/- 381 kcal) and TEE (645 494) from the two instruments. The Bouchard diary yielded higher estimates of TEE than the Tritrac for nearly all participants (97%) and the Bland-Altman plots revealed a systematic bias in the relationships (smaller bias for lower energy expenditure levels and higher bias for higher energy expenditure estimates). Intraindividual Correlations between estimated TEE from the Tritrac and Bouchard diary ranged from 0.34 to 0.93 (mean r = 0.74). Conclusion: The overall response indicates that individuals are able to provide reasonable self-reported estimates of their activity levels across a day.