Table 1.

List characteristics of studies included in the federated analysis

Study	Country; sample; deaths	Year of baseline assessment; mean follow-up	Device; method of sleep time assessment	Method of death ascertainment	Covariates
ABC	Sweden; n=841 (370 men, 471 women); 78 deaths	2001–2002; 14.5 years	ActiGraph 7164 (lower back); NA	National death register	Age, sex, education level, alcohol consumption status, smoking status, self-assessed health
NHANES	USA; n=2927 (1453 men; 1474 women); 283 deaths	2003–2006; 6.7 years	ActiGraph 7164 (hip); NA	National Death Index	Age, sex, ratio of family income to poverty, alcohol consumption, smoking status, energy intake, self-assessed health, physical limitations on movement, existing diagnosed medical condition (coronary heart disease, stroke, cancer, diabetes), hypertension
REGARDS	USA; n=7076 (3257 men; 3819 women); 477 deaths	2003–2007; 5.7 years	Actical (hip); NA	Review of death certificates, medical records and administrative databases	Age, sex, BMI, education, race, region of residence, season accelerometer was worn, current smoking, alcohol use, diabetes, hypertension, dyslipidaemia, estimated glomerular filtration rate, atrial fibrillation, history of coronary heart disease, history of stroke, self-assessed health
UK Biobank	UK; n=98 819 (43 229 men; 55 590 women); 2411 deaths	2013–2015; 5.4 years	Axivity AX3 (dominant wrist); self-report	National Health Service central registers	Age, sex, BMI, education, race, Townsend deprivation index, alcohol consumption, smoking status, self-assessed health, fruit and vegetable consumption, oily fish consumption, salt intake, red meat consumption, use of blood pressure or cholesterol medicine, physical limitations on movement, existing medical condition (cardiovascular disease, stroke, cancer), existing diagnosis of diabetes (self-reported diagnosis or use of insulin)
Whitehall II	UK; n=3900 (2891 men; 1009 women); 140 deaths	2012–2013; 5.3 years	GENEActiv Original (non-dominant wrist); accelerometer	National Health Service central registers	Age, sex, occupational position, alcohol consumption, smoking status, fruit and vegetable consumption, health state (multimorbidity index made of history of diabetes, coronary heart disease, stroke, depression, cancers, arthritis, chronic obstructive pulmonary disease, dementia and Parkinson’s disease)
Women’s Health Study	USA; n=16 676 (all women); 503 deaths	2011–2015; 4.3 years	ActiGraph GT3X+ (hip); NA	Review of medical records, death certificates or the National Death Index	Age, sex, income, smoking status, alcohol consumption, saturated fat intake, fibre intake, fruit and vegetable consumption, hormone therapy, family history of myocardial infarction, family history of cancer, general health, history of cardiovascular disease, history of cancer, results of cancer screen

BMI, body mass index; NA, not applicable; NHANES, National Health and Nutrition Examination Survey.