Workplace stress can significantly affect workers sleep, physical health and mental wellbeing. Recognizing and characterizing obstacles to healthy sleep patterns in office workers can help identify targets for corporate interventions that improve productivity and workplace wellbeing. Following the investigator's experience with the NUS1000 study in 1st year students conducted in Aug-Dec 2023, the investigators will now track daily sleep, wellbeing and time-use in NUS staff for 1 year in the present study. These data will reveal work-related stressors that impact daily sleep and mood. In addition, the investigators will investigate whether daily sleep and stress are associated with cardiovascular health in this middle-age cohort.

The investigators aim to answer the following questions using a combination of objective sleep tracking (Oura ring), smartphone-based questionnaires (EMA), passive tracking of interactions on smartphones (Quantactions) and one-time arterial stiffness measures (SphygmoCor).

1. Identify obstacles to healthy sleep patterns in NUS staff 1.1) How do staff sleep, in terms of duration, timing, regularity and napping behaviour? 1.2) What is the gulf between sleep aspiration and attained sleep? 1.3) What are self-perceived obstacles to achieving better sleep? 1.4) What activities potentially displace time for sleep?
2. Understand inter-relationships between sleep, workplace stressors and wellbeing outcomes 2.1) How is sleep is modulated over the year? 2.2) How do work patterns (e.g., after-hours/vacation emails) correlate with sleep, physical activity, subjective wellbeing, physiological markers of stress? 2.3) How do work, social, status stress and other life events contribute to sleep, wellbeing and subjective perceptions of work productivity?
3. Examine the association between sleep, workplace stress, mental health, cardiovascular risks in middle-aged cohort 3.1) How do daily sleep, work place events and acute/chronic stress contribute to cardiovascular health atmiddle age? 3.2) How is subjective wellbeing associated with objective cardiovascular wellbeing?
4. Examine the effects of any structural organizational efforts to promote wellbeing on staff sleep and stress

The investigators hypothesize that acute stressors, such as receiving emails after office hours and during vacation periods, will negatively impact sleep duration and regularity, as well as subjective stress rating over a short period. Chronic stressors, such as family care burden and pressure from supervisor, will be associated with longer-term insufficient and irregular sleep. Staff members reporting high chronic stress and frequent acute stress may be more likely to have high cardiovascular and cerebrovascular risks. In general, irregular/short sleep, constant high subjective stress, and frequent routine disruption (i.e., after hours work) will be associated with high cardiovascular risk in middle-aged participants.

Inclusion Criteria:

• NUS staff between the age of 35-70 with smartphones operating on Android 8.0 and up, or iOS 14.0 or later

Exclusion Criteria:

Participants will be required to :

1. Have their sleep and physical activity rhythms recorded via wearable sensors, while they continue daily life as usual.
2. Complete periodic questionnaires and short daily surveys on their smartphones.
3. Agree to interactions with their smartphones and NUS e-services (e.g., email) tracked.

Participants who do not agree to have these measures recorded will not be eligible for the study. Shift workers (e.g., security personnel, doctors and nurses), nursing/pregnant woman, and patients with existing sleep/psychological disorders (e.g., insomnia and major depression) will also be excluded.

1000 National University of Singapore staff