Validity of Domain-Specific Sedentary Time Using Accelerometer and Questionnaire with activPAL Criterion

Area of Science:

• Occupational Health
• Physical Activity Measurement
• Biomedical Engineering

Background:

• Sedentary time (ST) research commonly uses accelerometers with cut-point methods, but mixed cut-points present challenges.
• Metabolic equivalents (METs)-based accelerometers offer a potential alternative for more accurate ST assessment.

Purpose of the Study:

• To validate a METs-based accelerometer (OMRON HJA-750C) and the Workers Living Activity-time Questionnaire (WLAQ) for domain-specific ST measurement.
• To compare the validity of these measures against the activPAL criterion measure.
• To examine differences in measurement validity based on gender and occupation.

Main Methods:

• A validation study involving 242 workers who simultaneously wore an activPAL (thigh) and an OMRON accelerometer (waist) for seven days.
• Participants completed the WLAQ to assess domain-specific ST (commuting, working, non-working time on workdays and non-workdays).
• Intraclass correlation coefficients (ICC) and Spearman's rho were used for validity analyses.

Main Results:

• The OMRON accelerometer demonstrated acceptable validity for overall domain-specific ST (r = 0.67–0.86, ICC = 0.63–0.87).
• Working time emerged as the most accurate domain for ST assessment, with higher ICC values for both the OMRON accelerometer (0.87) and WLAQ (0.68).
• No significant differences in measurement validity were observed between genders or occupations.

Conclusions:

• METs-based accelerometers possess acceptable validity for measuring ST in occupational settings.
• Assessing ST during working hours provides the most accurate objective and subjective measurement.
• These findings can enhance the quality and reliability of ST research in the workforce.