Shiftwork is the name of an additional questionnaire, which was an initiative from the National Institute for Public Health and the Environment (RIVM). Using QSHI, health effects of chronic circadian disturbance due to shift work or evening blue light exposure in adults are studied via self-reported questionnaire data. Self-reported data can be linked to the period where biological samples were collected in Visit 2 of General Assessment 2A, thereby creating opportunity to study biological effects of shiftwork and blue light exposure.
A similar additional questionnaire on blue light exposure and sleeping patterns was sent to underage participants.

SHIQ was sent out between October 2017 and January 2018. Participants were asked about shiftwork and blue light exposure, specifically over the time period when they visited Lifelines for Visit 2 of General Assessment 2A (i.e. date of biomaterial donation). During the SHIQ, questions about shiftwork were only presented to participants with a job >12h per week.

The selection criteria were the following:

• Visited Lifelines for Visit 2 of General Assessment 2A
• Donated biomaterials collected in Visit 2 of General Assessment 2A
• 18 years or older

~78,000 participants were invited for SHIQ
The response rate was [37]% (n=~30,000).

The following variables were collected on electronic device use and shiftwork: