An international prospective cohort study of mobile phone users and health (COSMOS): Factors affecting validity of self-reported mobile phone use
Abstract
Overview
This study evaluates the accuracy of self-reported mobile phone use by analyzing data from 75,993 adults in the COSMOS cohort study. Mobile phone use was compared against operator records over a three-month period.
Findings
- Kappa Agreement: The agreement was moderate for call duration (κ=0.50) and fair for call frequency (κ=0.35).
- Sensitivity and Specificity: High sensitivity was observed for self-reported low call frequency and duration; however, sensitivity for high use was notably lower, showing a trend where individuals often underreported their usage.
- Impact of Symptoms: The accuracy of self-reports was generally lower among women, younger individuals, and notably those experiencing symptoms such as headaches or dizziness post-use.
Conclusion
The study highlights concerns regarding the reliability of self-reported data in epidemiological studies of mobile phone use. Differences in self-reporting accuracy based on gender, age, and post-use symptoms may introduce bias, possibly overestimating health risk associations in some cases.