Evaluation of a cell phone-based physical activity diary

Area of Science:

• Health and Exercise Science
• Digital Health Technologies
• Biomedical Informatics

Background:

• Self-reported physical activity (PA) is prone to recall errors.
• Traditional PA diaries, while reducing errors, can be burdensome for users.
• Developing efficient and accurate methods for PA assessment is crucial for public health.

Purpose of the Study:

• To compare the reliability and validity of a cell phone-based PA diary against a paper-based diary.
• To assess user preferences and satisfaction with the cell phone PA diary.
• To validate the cell phone PA diary against objective measures like accelerometers.

Main Methods:

• A pilot study compared cell phone and paper PA diaries over three weeks in 48 adults (ages 45-65).
• A larger validation study involved 623 middle-aged participants using the cell phone diary and accelerometers over two 7-day periods.
• PA questionnaires and indirect validation criteria (fitness, BMI, body fat) were also utilized.

Main Results:

• Cell phone and paper diaries yielded similar PA estimates (P > 0.49).
• A majority of users preferred the cell phone diary (59.6%) over the paper version (35.4%).
• The cell phone diary showed moderate correlations with questionnaires (ρ = 0.25-0.59) and accelerometers (ρ = 0.27-0.35), with higher reliability for vigorous PA (intraclass correlation = 0.63).

Conclusions:

• A cell phone-based PA diary is a viable alternative to paper diaries, demonstrating comparable accuracy.
• The digital diary is user-acceptable and offers a reliable and valid method for self-reported physical activity assessment.
• This technology can facilitate more accurate and convenient PA monitoring in research and clinical settings.