Table 1

Characteristics of studies included in the meta-analysis on the association between sitting time and cardiovascular and cancer mortality.

ReferenceCountry; study and participant characteristicsYears of follow-upMortality number of casesCase ascertainmentCovariates adjusted for in original publicationsHarmonised exposures for meta-analyses
Sitting
Katzmarzyk
et al 10
Canada; Canada Fitness Survey (CFS); 17 013 men and women; 18–90 years12.9 years (maximum)CVD, 759; cancer, 547Canadian Mortality DatabaseAge, sex smoking, alcohol consumption Sitting: (almost none of time=1, one-fourth time=2, half time=3, three-fourth time=4 and almost all of the time=5)
MET-hour/week: MET-hour/week summed up and stratified into quartiles
Inoue et al 12 Japan; Japan Public Health Center-based Prospective Study; 83 034 men and women; 45–74 years8.7 yearsCVD, 974; cancer, 2044Death certificate provided by Ministry of Health, Labour, and Welfare and classified using ICDAge, sex, geographical area, occupation, history of diabetes, smoking, alcohol consumption, BMI and total energy intake Sitting: <3=1; 3–8=3; ≥8 hour/day=4
MET-hour/week: based on time spent in physical occupation and extreme sports (none=0*4.5 METS; <1=0.5*4.5 METS*7; >1 hour/day*4.5 METS*7). MET summed into three groups (0, 15.75 and 94.75 MET-hour/week)
Patel et al 13 USA; American Cancer Society Cancer Prevention Study II Nutrition Cohort (CPS-II); 123 216 men and women; 50–74 years14 years (maximum)CVD 6369; cancer, 6989NDI and classified using ICDAge, sex, race, education, BMI, alcohol consumption, smoking status, marital status, total energy intake and comorbidity Sitting: 0–3=1; 3–5=2; 6–8=3; ≥8 hour/day=4
MET-hour/week: based on duration of recreational activities total MET-hour/week was calculated for four groups
Matthews et al 11 USA; NIH-AARP Diet and Health Study; 240 814 men and women; 50–71 years8.5 yearsCVD, 4684; cancer, 7652Social Security Administration and the NDIAge, sex, race, education, BMI, smoking and diet Sitting: <3 and 3–4=1; 5–6=2; 7–8=3 and 9+ hour/day=4
MET-hour/week: never, rarely, weekly but <1=0*4.0 METS; 1–3=1*4 METS; 4–7=4*4.0METS and >7 hour/week=7*4.0 METS. Categorised into four groups equal to Q1–Q4
Kim et al 14 USA; Multiethnic Cohort Study; 134 596 men and women; 45–75 years13.7 yearsCVD, 6535; cancer, 6697Death certificate linked to NDI and classified using ICDAge, sex race/ethnicity, education, smoking history, history of diabetes or hypertension, energy intake and alcohol consumption Sitting: never, <1, 1–2, 3–4=1; 5–6=2; 7–10=3; and ≥11 hour/day=4
MET-hour/week: MVPA=hour/week*4.0 METS; strenous sports=hour/week*7.2 METS. Then MET-hour/week summed up and stratified into quartiles.
Petersen et al 16 Denmark; Danish Health Examination
Survey; 71 363 men and women; 18–99 years
5.4 yearsCVD, 308Danish Civil Registration systemAge, sex, educational level, smoking habits, BMI, alcohol consumption and hypertension Sitting: 0–4=1; 4–6=2; 6–8=3; 8–10=4 and ≥10 hour/day=5
MET-hour/week: based on time spent in walking, MPA and VPA (walking=hour/week*3.3 METS; MPA=hour/week*4.0 METS; VPA=hour/week*7 METS). Summed and stratified into quartiles
Matthews et al 15 USA; Southern Community Cohort Study, 63 308 men and women; 40–79 years6.4 yearsCVD, 1376; cancer, 1227Social Security Administration and the NDI and classified using ICDAge, sex, source of enrolment, race, education, income, marital status, occupational status, comorbid conditions, alcohol intake, smoking history, BMI and sleep duration Sitting: 0–4=1; 4–6=2; 6–8=3; 8–10 and ≥10 hour/day=4
MET-hour/week: time spent in light, moderate, and vigorous activities, summed up and stratified into quartiles
Krokstad et al 17 Norway; The Nord-Trøndelag Health Study (HUNT); 40 752 men and women; 19–99 years18.1 yearsCVD, 1537; cancer, 1536Norwegian Causes of death registry and classified using ICDAge, sex, BMI, smoking, alcohol, blood pressure and medication Sitting: 0–4=1; 4–6=2; 6–8=3; 8–10=4 and ≥10 hour/day=5
MET-hour/week: based duration of light and vigorous activity (None=0 hour,<1 = 0.5, 1–2=1.5 and ≥3 = 5.5 hour/week). MET-hour/week calculated by multiplying hour/week of light with 2.5 METS and hour/week of vigorous with 7 METS. Summed and stratified into quartiles
WHIOS*USA; Women’s health Initiative; 92 234 women; 50–79 years10.2 yearsCVD, 3206; cancer, 4338Hospital records, autopsy records, death certificates and National Centre for Health Statistic’s NDIAge, race/ethnicity, education, marital status, BMI, smoking, alcohol consumption, number of chronic diseases, number of falls in the past year, hormone use, depressed mood, living alone and activities of daily living disability Sitting: 0–4=1; 4–6=2; 6–8=3; 8–10 and≥10 hour/day=5
MET-hour/week: total MET-hour/week summed up and stratified into quartiles
  • *Data downloaded from https://biolincc.nhlbi.nih.gov/home/ (accessed 7 January 2018);

  • BMI, body mass index; CVD, cardiovascular disease; HDL, high-density lipoprotein; ICD, international classification of diseases; MET, metabolic equivalents; MPA, moderate physical activity; MVPA, moderate and vigorous physical activity; NDI, national death index; PAR-Q, physical activity readiness questionnaire; VPA, vigorous physical activity.