Evaluation of a Novel Ambient Light Survey Question in the Cancer Prevention Study-3

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Summary

This study validated a seven-environment ambient light survey for use in large-scale health studies, finding good agreement between self-reported and measured light exposure using both photopic illuminance and circadian stimulus metrics. The survey offers a practical tool for epidemiological research linking light exposure patterns to health outcomes such as cancer risk.

Key Findings

Test-retest reliability (kappa) for self-reported light environment was 0.61 on workdays and 0.49 on non-workdays comparing two annual surveys one year apart.
Agreement between annual survey and weekly diaries was higher: kappa = 0.71 on workdays and 0.57 on non-workdays.
Highest agreement for specific environments: darkness (95.3%), non-residential light (86.5%), and household light (75.6%) on workdays.
Estimated illuminance and CS correlated with measured values overall (r = 0.77 and r = 0.67, respectively), but correlations were lower within individual light environments (r = 0.23–0.43).
Measured data identified three distinct light exposure peaks corresponding to darkness, indoor lighting, and outdoor daytime light.

Categories

The Science of Light: Validates a survey method using photopic illuminance and circadian stimulus (CS) metrics to assess ambient light exposure in epidemiological research.

Sleep & Circadian Health: Investigates nighttime light exposure as a circadian disruptor potentially linked to cancer risk, requiring reliable population-level measurement tools.