Table 4. PAFs for Population Counterfactuals.
| Population counterfactuals | Definition | PAF %, (95% CI)a |
|---|---|---|
| Weight loss | If those who maintained an obese BMI lost weight to an overweight BMI at midlife | 3.2 (1.6-4.9) |
| Weight maintenance-overweight | If those who gained weight from overweight to obese instead remained overweight between age 25 y and midlife | 2.3 (0.7-3.8) |
| Weight maintenance-normal | If those who gained weight from normal to obese instead remained normal between age 25 y and midlife | 2.2 (1.0-3.3) |
| Comprehensive prevention | If the total population had a normal BMI from age 25 y through midlife | 12.4 (8.1-16.5) |
Abbreviations: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); PAF, population-attributable fraction.
a
PAFs and related 95% CIs were calculated by the Stata punafcc package using the formula ∑pdi[(HRi − 1)/HRi], where pdi is the proportion of total incident deaths observed in the ith obesity progression category and HRi is the hazard ratio (HR) associated with that category. PAFs were calculated using pdi and HRi estimated from the entire sample. All HRi values were generated from Cox proportional hazards regression models adjusted for covariates (age at baseline, sex, race/ethnicity, educational level, nativity, and survey cycles) and postestimation analyses.