Methods for categorisation and percentages of smokers and other covariates used
| Authors | Smoking | Other variables |
| Menotti et al 3 (2016) | Never (25.4%), ex (13.6%), current (61.0%) | Diet |
| Turi et al (2017) | Never, former, current | Age, SES, BMI |
| Etemadi et al (2014) | Never, quartiles of cigs/day | Age, ethnicity, urban, education, SES, opium use, body size, medical history |
| Huerta et al (2016) | Never (29.6%), former (29.6%), current (40.8%) | Age, education, body build, alcohol, diet, diabetes, hypertension, hyperlipidaemia |
| Wanner et al (2014) | Never (35.1%), former (23.7%), <20/d (17.0%), >20/d (24.2%) | Age, education, smoking, nutrition |
| Andersen et al (2000) | Never (12.2%), former (19.5%), 1–14 g/d (21.6%), 15–24 g/d (31.7%), >25 g/d (14.9%) | Age, systolic blood pressure, cholesterol, triglycerides, education |
| Petersen et al 6 (2012) | Never (33.9%), former (17.8%), daily (18.2%), heavy (30.1% | Age, education, alcohol, stress, lifting, leisure activity |
| Clays (2014) | Current smoker (yes/no) (45.5%) | Age, education, occupational class, BMI, cholesterol |
| Holterman (2012) | Never, former, current | Age, BMI, alcohol, social class, chronic disease |
| Krause et al 7 (2017) | Cigarettes/day (linear) | Age, income and many other variables |
| Richard et al. 1 (2015) | Never, former, current | Age, race, waist circumference, education, poverty index |
| Holtermann et al (2010) | Never (9.2%), former (23.2%), current (67.6%) | Age, BMI, blood pressures, alcohol |
| Chau et al (2015) | Never (35.5%), former (29.8%), current (34.6%) | BMI, education, total activity, cardiometabolic disease, marital status, diabetes, hypertension, asthma, family history of coronary disease |
| Harari et al (2015) | Current smoking (39.3%) | Age, SES, over-crowding at home, education, ethnicity, cholesterol, HDL, hypertension, blood lipids, glucose, uric acid, diabetes, coffee, alcohol, diet, shift work |
| Holtermann et al (2012) | Never, former, <15 g/day, >15 g/day | Age, alcohol, BMI, leisure activity, systolic pressure, diabetes, cholesterol, income |
| Stender et al (1993) | Cigarettes/day | Age, BMI, heart rate, alcohol |
| Hu et al (2014) | Current smoking (68.3%) | Age, BMI, marital status, job status, education, other physical activity, alcohol, hypertension, diabetes, blood pressures |
For details of references, see the online supplementry table S3.
BMI, body mass index; HDL, high-density lipoprotein; SES, socioeconomic status.