Criterion-Referenced Validation of the Sedentary Behavior Record Instrument

Background: Objective measures of sedentary behavior (SB) have been validated and used in a number of studies. However, these devices are limited in their ability to provide contextual information regarding the nature of SB. The Sedentary Behavior Record (SBR) is an adaptation of the 3-day Physical Activity Record for quantifying time spent in SB over a 24-hr period. The SBR includes 3 domains (work sitting, non-work sitting, and lying down/reclining) and a choice of 3 activities under each domain (transportation, screen time, and other) to quantify time spent in SB by 15-min blocks for each day. The contextual information provided by the SBR could be used to enhance interventions by targeting specific times or behaviors related to high SB.

Purpose: The purpose of this study was to validate the SBR as a measure of SB using criterion-referenced standards.

Methods: A total of 12 adults (mean age 42.17 ± 11.52 yrs) were recruited for this study. Participants wore an Actigraph GT3X+ accelerometer and completed the SBR for 7 consecutive days. Accelerometer SB time was calculated where activity counts were < 100 counts/min. SB time was calculated from the SBR in 15-min blocks, through summation of SB minutes. To determine the classification accuracy between SBR and Actigraph measures, Contingency coefficients (C) and Kappa (K) were computed for each day. Paired sample t-tests were used to compare the classification accuracy indexes between morning (AM) and evening (PM) hours and between weekdays and weekend days. Alpha level was set at .025, adjusted by the Bonferroni technique.

Results: Overall, the classification accuracy for SBR and Actigraph was high (C: .74 ± .06; K: .69 ± .07). Additionally, significant differences were found in the classification agreement between SBR and Actigraph during AM and PM hours for both C (t11=4.89, p <.025) and K (t11=4.87, p <.025). However, there were no differences between weekdays and weekend days for C (t11=.028, p =.978) and K (t11=.100, p =.922).

Conclusion: The results of this study suggest that the SBR is an acceptable subjective measure of SB in adults. In this study, it was identified that classification errors are higher in the PM hours. Future studies should investigate potential sources of this increased classification error.