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Updated: Aug 8, 2026
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Setup of Consumer Wearable Devices for Exposure and Health Monitoring in Population Studies
Published on: February 3, 2023
Is self-reported daylight exposure reliable? A validation study with actigraphy in urban environments
Fernanda S Bonatto1,2, Pedro de O Macedo1,2, Rogério B Borges3,4
1Laboratório de Cronobiologia e Sono, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Chronobiology International
|August 7, 2026
Summary
Self-reported outdoor daylight exposure shows moderate agreement with objective measurements from wearable sensors. This suggests self-reports are a valid proxy for assessing daylight exposure in large population studies.
Area of Science:
- Environmental health
- Chronobiology
- Human health
Background:
- Daylight exposure significantly impacts human health.
- Accurate measurement of real-world daylight exposure at scale is challenging.
- Self-reported time outdoors is often used as a proxy for daylight exposure, but its validity is uncertain.
Purpose of the Study:
- To evaluate the agreement between self-reported outdoor daylight exposure and objective light measurements.
- To investigate the influence of depressive symptoms on this agreement.
Main Methods:
- 172 adults in Brazil were monitored for up to 44 days.
- Objective light measurements included device illuminance, photopic illuminance, and melanopic equivalent daylight illuminance (EDI).
- Agreement was assessed using Lin's concordance correlation coefficient and ROC analyses.
Main Results:
- Moderate agreement was found between self-reported and actigraphy-based daylight exposure.
- Highest concordance occurred at outdoor daylight levels (>1000 lux for photopic and melanopic EDI).
- 30 minutes of outdoor exposure was the most accurately self-reported duration; depressive symptoms did not impact agreement.
Conclusions:
- Self-report questionnaires can be reliably used to estimate outdoor daylight exposure.
- Findings support the use of self-reports in clinical applications and health studies.
- This method aids in understanding environmental factors influencing health.
