US adults: smoking, weight and exercise
Version 0.1.0 · Licence CC-BY-4.0 · By OpenLifeModel contributors
Experimental: based on published evidence but not validated as a whole.
Adjusts US population mortality for three of the best-measured lifestyle factors: cigarette smoking (including the age you quit), body mass index and leisure-time exercise. Each effect comes from a large published study of all-cause mortality; the share of US adults in each group comes from NHANES.
Download us-lifestyle.olm.yaml · View on GitHub
Intended population
US adults aged roughly 25 to 80, without serious chronic disease. The source studies followed people in this range; effects at older ages are extrapolated.
Assumptions
- Baseline mortality is the SSA 2023 period life table: today's death rates, with no future improvement.
- Each factor's hazard ratio is constant over the rest of life. In reality the excess risk from high BMI shrinks with age (Global BMI Mortality Collaboration 2016), so effects at old age are probably overstated.
- Factors multiply. The exercise effect is adjusted for smoking and BMI and the smoking effect for adiposity, which limits double-counting; the BMI effect is not adjusted for exercise, so part of it may overlap.
- Hazard ratios are rescaled so that a person with the average US adult mix of each factor reproduces the baseline. The mix is for all adults aged 20 and over, not specific to your age and sex.
- Smoking risk for people who quit is taken from the age at which they quit; people who quit within the previous 5 years were counted as current smokers in the source study.
- Exercise means leisure-time activity only, not work or commuting.
Baseline
Period life table from age 0, for male and female. Source: Social Security Administration, Office of the Chief Actuary. Actuarial Life Table: Period Life Table, 2023, as used in the 2026 Trustees Report.
Personal factors
Method: proportional hazards, rescaled so that population-average exposure reproduces the baseline.
Smoking
| Level | Hazard ratio | Population share |
|---|---|---|
| Never smoked | 1 | 0.582 |
| Quit before 35 | 1 | 0.129 |
| Quit at 35–44 | 1.2 | 0.053 |
| Quit at 45–54 | 1.5 | 0.039 |
| Quit at 55+ | 1.7 | 0.029 |
| Quit, age unknown | 1.2 | 0 |
| Smoke now | 2.9 | 0.169 |
Source: Jha P, Ramasundarahettige C, Landsman V, et al. 21st-century hazards of smoking and benefits of cessation in the United States. N Engl J Med. 2013;368(4):341-350.
Body mass index
| Level | Hazard ratio | Population share |
|---|---|---|
| < 18.5 | 1.47 | 0.014 |
| 18.5 to < 25 | 1 | 0.249 |
| 25 to < 30 | 1.11 | 0.317 |
| 30 to < 35 | 1.44 | 0.219 |
| 35 to < 40 | 1.92 | 0.111 |
| ≥ 40 | 2.71 | 0.09 |
Source: The Global BMI Mortality Collaboration. Body-mass index and all-cause mortality: individual-participant-data meta-analysis of 239 prospective studies in four continents. Lancet. 2016;388(10046):776-786.
Exercise
| Level | Hazard ratio | Population share |
|---|---|---|
| < 1 | 1 | 0.457 |
| 1 to < 150 | 0.8 | 0.154 |
| 150 to < 300 | 0.69 | 0.118 |
| 300 to < 450 | 0.63 | 0.086 |
| 450 to < 800 | 0.61 | 0.11 |
| 800 to < 1500 | 0.61 | 0.055 |
| ≥ 1500 | 0.68 | 0.019 |
Source: Arem H, Moore SC, Patel A, et al. Leisure time physical activity and mortality: a detailed pooled analysis of the dose-response relationship. JAMA Intern Med. 2015;175(6):959-967.
Sources
- Social Security Administration, Office of the Chief Actuary. Actuarial Life Table: Period Life Table, 2023, as used in the 2026 Trustees Report. https://www.ssa.gov/oact/STATS/table4c6.html
- Jha P, Ramasundarahettige C, Landsman V, et al. 21st-century hazards of smoking and benefits of cessation in the United States. N Engl J Med. 2013;368(4):341-350. doi:10.1056/NEJMsa1211128
- The Global BMI Mortality Collaboration. Body-mass index and all-cause mortality: individual-participant-data meta-analysis of 239 prospective studies in four continents. Lancet. 2016;388(10046):776-786. doi:10.1016/S0140-6736(16)30175-1
- Arem H, Moore SC, Patel A, et al. Leisure time physical activity and mortality: a detailed pooled analysis of the dose-response relationship. JAMA Intern Med. 2015;175(6):959-967. doi:10.1001/jamainternmed.2015.0533
- National Center for Health Statistics. National Health and Nutrition Examination Survey, 2017-March 2020 prepandemic files (P_DEMO, P_BMX, P_SMQ, P_PAQ). Survey-weighted shares of adults aged 20 and over. https://wwwn.cdc.gov/nchs/nhanes/continuousnhanes/default.aspx?Cycle=2017-2020
Reference tests
4 test cases that any OLM implementation must reproduce. They run on every change to the code.