Validating the Use of Wrist-Level Light Monitoring for In-Hospital Circadian Studies

Abstract

This clinical methods comparison study describes the difference between light levels measured at the wrist (Actiwatch-L) and at the eye (Daysimeter) in a postoperative in-patient population. The mean difference between the two devices was less than 10 lux at light levels less than 5000 lux. Agreement between the devices was found to decrease as eye-level light exposure increased. Measurements at eye level of 5000 lux or more corresponded to a difference between the devices of greater than 100 lux. Agreement between the eye- and wrist-level light measurements also appears to be influenced by time of day. During the day, the measurement differences were on average 50 lux higher at eye level, whereas at night they were on average 50 lux lower. Although the wrist-level monitor was found to underestimate light exposure at higher light levels, it was well tolerated by participants in the clinical setting. In contrast, the eye-level monitor was cumbersome and uncomfortable for the patients to wear. This study provides light-exposure data on patients in real conditions in the clinical environment. The results show that wrist-level monitoring provides an adequate estimate of light exposure for in-hospital circadian studies.

Does Current Scientific Evidence Support a Link Between Light at Night and Breast Cancer Among Female Night-Shift Nurses?: Review of Evidence and Implications for Occupational and Environmental Health Nurses

“…After these measurements were compared to photometric measurements taken at women’s bedroom windows, the researchers concluded that satellite photometry was unrelated to personal light exposures (Rea, Brons, & Figueiro, 2011). Research shows that wrist-level monitoring (Actiwatch-L) provides an adequate estimate of light exposure for in-hospital circadian studies (Jardim et al, 2011). Third, the retrospective design of some of the reviewed studies is susceptible to recall bias about prior sleeping habits and shift work; future researchers should limit the potential for recall bias when designing studies.…”

The Influence of Light Exposure and Seasonal Changes on Short-Term and Longer-Term Changes in Axial Length of the Human Eye

“…However, previous studies suggest that wrist-level light measurements are significantly correlated with the light measurements at the eye level (Okudaira et al, 1983;Jardim et al, 2011). Furthermore, since the primary light exposure parameter used in our study was based upon a cut-off 126 Chapter 4: Light exposure and longitudinal axial length changes in young adults level to define bright outdoor light exposure (>1000 lux), we speculate that the differences in light levels associated with sensor placement (wrist level versus eye level) would have had minimal impact upon the time spent in bright outdoor light parameter.…”

“…This device is commonly used in studies of adults and children to objectively quantify sleep patterns, physical activity and light exposure (Puyau et al, 2004;Lichstein et al, 2006;Goulet et al, 2007;Auger et al, 2011;Ekblom et al, 2012;Read et al, 2014Read et al, , 2015. The device has also been shown to be valid and reliable (Ekblom et al, 2012) and previous studies have shown that light exposure readings from the wrist are highly correlated with light levels recorded at eye level (Okudaira et al, 1983;Jardim et al, 2011). We have included data from separate studies of both adults and children, since age-related differences in activity patterns may result in different sampling requirements to reliably quantify light exposure patterns.…”

“…Previous studies have shown that light levels at the wrist and eye correlate significantly (Okudaira et al, 1983;Jardim et al, 2011), however sensors capturing light closer to the eye would be expected to provide more precise estimates of ocular light exposure.…”

An Evaluation of Melanopsin Function and Light Exposure in Depressive Disorders

“…While a Daysimeter is a device that has a light sensor at eye level (Smolders et al, 2013), the Actiwatch-L (Philips Respironics, Eindhoven, Netherlands) has been validated against the Daysimeter (Rensselaer Polytechnic Institute, Troy, NY) in patients after cardiac surgery showing that the Actiwatch-L underestimates eye level light exposure by < 10 lux at light levels < 5000 lux (Jardim, Pawley, Cheeseman, Guesgen, Steele, & Warman, 2011); the difference increases with increase in light exposure at eye level. The spectral output from the Actiwatch used under direct exposure to sunlight also underestimate the actual light level (Cao et al, 2015b).…”