Comparison of activity levels using the Caltrac accelerometer and five questionnaires.

The purpose of this study was to compare the physical activity levels of physical therapists using five activity questionnaires and one electronic motion sensor (Caltrac). Thirty-three physical therapists (26 female, seven male) were monitored for seven consecutive days. The Caltrac data were compared with five questionnaires, including the Baecke (Baecke); Godin and Shephard (Godin); Ross and Jackson (NASA); 3-d record (3-d); and 7-d recall (7-d). A significant (P < 0.01) Spearman rank order correlation coefficient was observed between the Caltrac reading and the 7-d recall (r = 0.79). A significant correlation was also observed between the Caltrac and the Godin (r = 0.45, P < 0.01). Three of the questionnaires were also significantly (P < 0.01) correlated with each other, including the NASA with the Baecke (r = 0.52), the NASA with the Godin (r = 0.54), and the Godin with the Baecke (r = 0.61). The 3-d record was not significantly correlated with any of the other measures. The strong, significant correlation observed between the Caltrac data and the 7-d recall suggests adequate validity for the 7-d recall. The 7-d recall questionnaire would be quicker, easier, and less expensive to use in a large population study than the Caltrac.