Table 2.

Study characteristics and outcome measured for two cardiovascular conditions (coronary artery diseases and hypertension)

Publication (author, year, country, journal, study design)	Outcome (definition, ascertainment, activity level classification for RRadj)	Exposure (leisure-time PA and PI: definition, measurement, categorisation)	Study details (age, total number of participants, study sample, data collection year, number of follow-up years)	Confounders
Coronary artery disease
Grau et al,45 2010, Spain, Preventive Medicine, prospective cohort study.	Definition: non-fatal and fatal events (acute myocardial infarction, angina pectoris or death). Ascertainment: non-fatal cardiovascular events ascertained by telephone questionnaire and medical record review, fatal cardiovascular events ascertained and identified from regional and national mortality registers. Activity level classification for RRadj: light-intensity (≤4.0 METs), moderate-intensity (4.5–5.5 METs) and heavy-intensity (≥6.0 METs) leisure-time PA.	Definition: sedentary (average weekly EE in moderate-intensity to vigorous-intensity leisure-time PA <1000 kcal). Measurement: trained interviewer used validated Spanish version of Minnesota Leisure Time Physical Activity Questionnaire during the previous year. Categorisation: light-intensity (≤4.0 METs), moderate-intensity (4.5–5.5 METs), heavy-intensity (≥6.0 METs) leisure-time PA.	Pe source: 18–75 years old, n=3734 participants (n=1802 men and n=1932 women), Spain, 1996–2012. RRadj source: 35–74 years old, n=3734 participants (n=1802 men and n=1932 women), prospective cohort study, Spain, 2005, follow-up time: 10 years (average 6.9 years).	Age, sex, hypertension, LDL cholesterol, HDL cholesterol, diabetes and smoking.
Hypertension
Paffenbarger et al,44 1983, USA, American Journal of Epidemiology, prospective cohort study.	Definition: systolic blood pressure >160 mm Hg. Ascertainment: self-reported, physician-diagnosed hypertension. Activity level classification for RRadj: stair-climbing (<50 or >50), block-walking (<5 or >5), leisure-time sport (none, light, moderate and vigorous intensity), PA index (<2000 or >2000 kcal/week).	Definition: stair-climbing (<50), block-walking (<5) and absence of vigorous-intensity leisure-time sport, PA index (<2000 kcal/week) Measurement: PA index was computed as EE in kcal/week from current self-reported PA levels mainly in three types of activities: stair-climbing (number of steps), block-walking (number of blocks) and leisure-time sports (light, moderate and vigorous intensity). Categorisation: stair-climbing (<50 or >50), block-walking (<5 or >5) and leisure-time sport (none, light, moderate and vigorous intensity), PA index (<2000 or >2000 kcal/week).	Pe source: 35–74 years old, n=14 998 men, mailed questionnaire, 1962–1972, USA, >70% response rate. RRadj source: 35–74 years old, n=14 998 men, prospective cohort study, USA, 1962–1972, follow-up time: 6–10 years.	Adjusted for a variety of important confounders or intermediary factors including age, BMI and family history.
Suka et al,27 2002, Japan, Environmental Health and Preventive Medicine, prospective cohort study.	Definition: systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg. Ascertainment: initiation of antihypertensive therapy or systolic blood pressure ≥140 mm Hg using annual health examination and questionnaire. Activity level classification for RRadj: active (regular exercise) and inactive (no regular exercise).	Definition: no regular exercise (<20 min, 2 days/week)*. Measurement: annual health questionnaire. Categorisation: active (regular exercise) and inactive (no regular exercise).	Pe source: 30–59 years old, n=6306 men, annual health questionnaire, 1991–1998, Japan. RRadj source: 30–59 years old, n=6306 men, prospective cohort study, Japanese, 1991–1998, follow-up time: 7 years.	Age, BMI, blood pressure, glucose intolerance and alcohol intake.

*Personal communication with the author.

BMI, body mass index; EE, energy expenditure; HDL, high-density lipoprotein; LDL, low-density lipoprotein; METs, metabolic equivalents; PA, physical activity; PI, physical inactivity; P_e, prevalence of exposure; RR_adj, adjusted relative risk.