Intervention Study in Elderly With Sleep Problems

The study lasts for 14 months and contains 6 visits. After the screening visit at the Centre for Chronobiology, Basel, Switzerland, participants are assigned to either the intervention or the control group which is followed by a 7-day baseline week at home and a co-design meeting to provide instructions to the intervention and the control group. At the occasion of 2 visits (spread over 6 months) at the participants' homes, different measurements will be performed such as saliva collection, questionnaires, cognitive performance tests, light and rest-activity measures. After the last visit at home, participants come for the second blood sample at the study centre. A follow-up visit 6 months after completion of the last data collection will provide qualitative feedback by the participants.

Inclusion criteria

at least 65 years old women and men

• Pittsburgh Sleep Quality Index (PSQI) > 5 (indicative of sleep problems)
• Living at home (including self-serviced retirement apartment)

Exclusion criteria

• Total blindness or VA < 0.5
• Progressive NCDs (e.g., cancer)
• Acute infections (e.g., Covid-19)
• Neurodegenerative disease
• Psychiatric disease
• Sleep disorder (sleep apnea, narcolepsy)
• Not German speaking