Table 3.
Association between optimism and change in AHEI-2010 score between baseline and year 1 in the WHI Diet Modification Clinical Trial by trial arm, race/ethnicity, age, and smoking
| Subgroup | AHEI | Optimism score at baseline
|
P trend1,2 | ||
|---|---|---|---|---|---|
| Tertile 1 (low) scores 6–22 | Tertile 2 (middle) scores 23–25 | Tertile 3 (high) scores 26–30 | |||
|
Stratified by Trial Arm
| |||||
| Intervention (n = 13,645) | |||||
| Baseline (mean ± SD) | 42.1 ± 9.4 | 43.3 ± 9.4 | 44.3 ± 9.8 | < 0.001 | |
| Year 1 (mean ± SD) | 43.8 ± 9.1 | 44.8 ± 9.0 | 45.7 ± 9.2 | ||
| Change (95% CI)2 | 1.36 (1.15–1.57) | 1.52 (1.32–1.72) | 1.77 (0.53–2.01) | 0.014 | |
| Control (n = 20,242) | |||||
| Baseline (mean ± SD) | 42.2 ± 9.5 | 43.3 ± 9.5 | 44.1 ± 9.7 | < 0.001 | |
| Year 1 (mean ± SD) | 42.7 ± 9.4 | 44.1 ± 9.6 | 44.9 ± 9.7 | ||
| Change (95% CI)2 | 0.32 (0.15–0.49) | 0.82 (0.66–0.98) | 1.01 (0.81–1.20) | < 0.001 | |
| Test for interaction3, P = 0.014 | |||||
| Stratified by race/ethnicity (Intervention arm only) | |||||
| NHW (n = 11,380) | |||||
| Baseline (mean ± SD) | 42.2 ± 9.4 | 43.5 ± 9.4 | 44.7 ± 9.8 | < 0.001 | |
| Year 1 (mean ± SD) | 43.8 ± 9.1 | 44.9 ± 9.0 | 45.9 ± 9.2 | ||
| Change (95% CI)2 | 1.26 (1.02–1.49) | 1.38 (1.17–1.60) | 1.62 (1.36–1.88) | 0.045 | |
| Black (n = 1,311) | |||||
| Baseline (mean ± SD) | 40.1 ± 9.1 | 40.7 ± 9.1 | 41.8 ± 9.4 | 0.146 | |
| Year 1 (mean ± SD) | 42.4 ± 8.9 | 43.4 ± 9.1 | 44.4 ± 9.3 | ||
| Change (95% CI)2 | 2.10 (1.42–2.79) | 2.58 (1.87–3.29) | 2.98 (2.20–3.75) | 0.105 | |
| Hispanic (n = 402) | |||||
| Baseline (mean ± SD) | 39.5 ± 8.7 | 42.6 ± 8.9 | 42.0 ± 9.5 | 0.142 | |
| Year 1 (mean ± SD) | 42.2 ± 8.1 | 45.0 ± 8.3 | 44.7 ± 7.5 | ||
| Change (95% CI)2 | 2.11 (1.06–3.16) | 3.13 (1.85–4.40) | 2.95 (1.33–4.58) | 0.326 | |
| Asian (n = 345) | |||||
| Baseline (mean ± SD) | 47.6 ± 8.9 | 46.5 ± 10.1 | 43.0 ± 7.9 | 0.005 | |
| Year 1 (mean ± SD) | 48.8 ± 8.8 | 47.0 ± 8.8 | 45.2 ± 8.7 | ||
| Change (95% CI)2 | 1.65 (0.54–2.76) | 0.31 (–0.99–1.62) | 1.07 (–0.98–3.12) | 0.357 | |
| Stratified by age (Intervention arm only) | |||||
| Age 50–59 y (n = 4,835) | |||||
| Baseline (mean ± SD) | 41.5 ± 9.6 | 42.7 ± 9.5 | 43.6 ± 9.8 | 0.001 | |
| Year 1 (mean ± SD) | 43.7 ± 9.2 | 44.7 ± 9.2 | 45.5 ± 9.3 | ||
| Change (95% CI)2 | 2.04 (1.68–2.39) | 1.99 (1.64–2.35) | 2.13 (1.73–2.53) | 0.747 | |
| Age 60–65 y (n = 4,898) | |||||
| Baseline (mean ± SD) | 42.2 ± 9.3 | 43.1 ± 9.2 | 44.3 ± 9.8 | 0.002 | |
| Year 1 (mean ± SD) | 43.6 ± 9.0 | 44.8 ± 8.9 | 45.8 ± 9.0 | ||
| Change (95% CI)2 | 1.08 (0.73–1.43) | 1.65 (1.31–1.98) | 1.92 (1.52–2.32) | 0.002 | |
| Age 66–79 y (n = 3,912) | |||||
| Baseline (mean ± SD) | 42.6 ± 9.3 | 44.4 ± 9.4 | 45.3 ± 9.8 | < 0.001 | |
| Year 1 (mean ± SD) | 44.0 ± 9.0 | 45.0 ± 8.9 | 46.0 ± 9.3 | ||
| Change (95% CI)2 | 0.85 (0.47–1.24) | 0.80 (0.43–1.17) | 1.15 (0.69–1.61) | 0.382 | |
| Stratified by smoking (Intervention arm only) | |||||
| Never smoker (n = 7,082) | |||||
| Baseline (mean ± SD) | 41.5 ± 9.2 | 42.9 ± 9.4 | 43.4 ± 9.6 | < 0.001 | |
| Year 1 (mean ± SD) | 43.2 ± 8.9 | 44.5 ± 8.9 | 45.0 ± 9.0 | ||
| Change (95% CI)2 | 1.43 (1.14–1.72) | 1.75 (1.47–2.02) | 1.82 (1.50–2.15) | 0.076 | |
| Past smoker (n = 5,686) | |||||
| Baseline (mean ± SD) | 43.1 ± 9.5 | 44.2 ± 9.4 | 45.5 ± 10.0 | < 0.001 | |
| Year 1 (mean ± SD) | 44.8 ± 9.2 | 45.4 ± 9.1 | 46.7 ± 9.3 | ||
| Change (95% CI)2 | 1.28 (0.95–1.62) | 1.25 (0.93–1.56) | 1.71 (1.34–2.09) | 0.115 | |
| Current smoker (n = 877) | |||||
| Baseline (mean ± SD) | 40.4 ± 9.1 | 41.4 ± 8.9 | 44.3 ± 9.7 | 0.001 | |
| Year 1 (mean ± SD) | 42.3 ± 9.1 | 42.9 ± 8.7 | 45.0 ± 9.5 | ||
| Change (95% CI)2 | 1.34 (0.56–2.12) | 1.43 (0.55–2.31) | 1.80 (0.72–2.88) | 0.527 | |
Categories of optimism modeled as an ordinal variable
Adjusted predictions calculated from linear regression models adjusted for baseline AHEI, age (continuous), race/ethnicity (American Indian or Alaskan Native, Asian or Pacific Islander, black or African-American, Hispanic/Latina, non-Hispanic white, other), education (≤ high school, any post-secondary, ≥ college), family income (< $20k, $20 to < 35k, $35 to < 50k, $50 to < 75k, ≥ $75k), attended 1+ religious service per week (yes, no), history of diabetes treatment (yes, no), current hypertension treatment (yes, no), high cholesterol requiring pills (ever, never), current smoking (yes, no), physical activity (< 2.5, ≥ 2.5 MET-hr/wk), hormone replacement therapy use (never, former, current), waist circumference (< 88, ≥ 88 cm), BMI (< 30, ≥ 30 kg/m2), and depression score (< 0.009, 0.009–0.06, > 0.06).
Likelihood ratio test for interaction between optimism (tertile) and trial arm on change in AHEI