Table 2.
4-year changes in physical component scores (1992–2000 in NHS and 1993–2001 in NHSII) according to 4-year changes in plant-based diet indices (1990–1998 in NHS and 1991–1999 in NHSII)*
| Decrease ≥ 10 pt | Decrease 3 to 9 pt | Relatively stable (± 2 pt) | Increase 3 to 9 pt | Increase ≥ 10 pt | Changes/10-point increase in indices (95% CIs) | P | |
|---|---|---|---|---|---|---|---|
| Overall Plant-Based Diet Index (PDI) | |||||||
| Nurses’ Health study | |||||||
| Model 1 | −0.21 (−0.40, −0.01) | −0.14 (−0.25, −0.02) | 0.00 | 0.05 (−0.06, 0.17) | 0.15 (−0.05, 0.36) | 0.17 (0.09, 0.26) | <0.001 |
| Model 2 | −0.14 (−0.34, 0.06) | −0.10 (−0.21, 0.02) | 0.00 | 0.06 (−0.06, 0.17) | 0.19 (−0.02, 0.40) | 0.14 (0.05, 0.23) | 0.002 |
| Nurses’ Health study II | |||||||
| Model 1 | −0.10 (−0.28, 0.07) | −0.09 (−0.19, 0.02) | 0.00 | 0.02 (−0.09, 0.12) | −0.03 (−0.21, 0.14) | 0.07 (−0.01, 0.14) | 0.09 |
| Model 2 | −0.02 (−0.19, 0.15) | −0.05 (−0.16, 0.05) | 0.00 | 0.01 (−0.09, 0.11) | −0.07 (−0.24, 0.11) | 0.02 (−0.06, 0.09) | 0.63 |
| Pooled Results | |||||||
| Model 1 | −0.15 (−0.28, −0.02) | −0.11 (−0.19, −0.03) | 0.00 | 0.03 (−0.04, 0.11) | 0.05 (−0.09, 0.18) | 0.11 (0.06, 0.17) | <0.001 |
| Model 2 | −0.05 (−0.18, 0.08) | −0.07 (−0.15, 0.00) | 0.00 | 0.03 (−0.05, 0.11) | 0.04 (−0.09, 0.17) | 0.07 (0.01, 0.13)(14; 17; 48) † | 0.02 |
| Healthful Plant-Based Diet Index (hPDI) | |||||||
| Nurses’ Health study | |||||||
| Model 1 | −0.39 (−0.57, −0.20) | −0.12 (−0.24, −0.01) | 0.00 | 0.03 (−0.09, 0.15) | 0.16 (−0.05, 0.37) | 0.20 (0.11, 0.28) | <0.001 |
| Model 2 | −0.29 (−0.48, −0.10) | −0.12 (−0.24, −0.01) | 0.00 | 0.07 (−0.05, 0.19) | 0.31 (0.10, 0.52) | 0.22 (0.14, 0.30) | <0.001 |
| Nurses’ Health study II | |||||||
| Model 1 | −0.28 (−0.46, −0.11) | −0.06 (−0.17, 0.04) | 0.00 | 0.00 (−0.11, 0.11) | −0.09 (−0.26, 0.08) | 0.10 (0.02, 0.17) | 0.01 |
| Model 2 | −0.22 (−0.39, −0.05) | −0.04 (−0.15, 0.06) | 0.00 | 0.00 (−0.11, 0.10) | −0.11 (−0.28, 0.06) | 0.07 (−0.01, 0.14) | 0.08 |
| Pooled Results | |||||||
| Model 1 | −0.33 (−0.46, −0.20) | −0.09 (−0.17, −0.01) | 0.00 | 0.01 (−0.07, 0.09) | 0.01 (−0.12, 0.15) | 0.14 (0.09, 0.20) | <0.001 |
| Model 2 | −0.25 (−0.38, −0.13) | −0.08 (−0.16, 0.00) | 0.00 | 0.03 (−0.05, 0.11) | 0.06 (−0.07, 0.19)† | 0.13 (0.08, 0.19) † | <0.001 |
| Unhealthful Plant-Based Diet Index (uPDI) | |||||||
| Nurses’ Health study | |||||||
| Model 1 | −0.01 (−0.20, 0.18) | −0.11 (−0.23, 0.01) | 0.00 | −0.12 (−0.23, 0.00) | −0.25 (−0.43, −0.07) | −0.06 (−0.14, 0.02) | 0.14 |
| Model 2 | 0.16 (−0.04, 0.35) | −0.06 (−0.17, 0.06) | 0.00 | −0.10 (−0.22, 0.01) | −0.22 (−0.40, −0.04) | −0.11 (−0.18, −0.03) | 0.01 |
| Nurses’ Health study II | |||||||
| Model 1 | −0.11 (−0.27, 0.06) | −0.04 (−0.14, 0.07) | 0.00 | −0.05 (−0.16, 0.05) | −0.20 (−0.36, −0.03) | −0.03 (−0.11, 0.03) | 0.26 |
| Model 2 | −0.08 (−0.24, 0.08) | −0.03 (−0.13, 0.08) | 0.00 | −0.06 (−0.16, 0.05) | −0.16 (−0.32, 0.00) | −0.04 (−0.11, 0.02) | 0.21 |
| Pooled Results | |||||||
| Model 1 | −0.06 (−0.19, 0.06) | −0.07 (−0.15, 0.01) | 0.00 | −0.08 (−0.16, 0.00) | −0.22 (−0.34, −0.10) | −0.05 (−0.10, 0.00) | 0.07 |
| Model 2 | 0.02 (−0.11, 0.14) | −0.04 (−0.12, 0.04) | 0.00 | −0.08 (−0.16, 0.00) | −0.18 (−0.31, −0.06) | −0.07 (−0.12, −0.02) | 0.008 |
NHS, Nurses’ Health Study; NHS II, Nurses’ Health Study II.
Values were beta coefficients (95% CIs) in physical component scores. Pooled results were calculated with a fixed effects model.
The P value for Q-statistic for heterogeneity <0.05, indicating statistically significant heterogeneity between the NHS and the NHSII.
Model 1: Adjusted for age, race, baseline corresponding plant-based diet indices, baseline corresponding HRQoL scores, baseline BMI, and baseline and changes in each of smoking status, menopausal status and postmenopausal hormone use, NSAIDs use, multi vitamin use, marital status, working status, husband education, physical activity, alcohol intake, margarine intake, and total energy intake. For the NHS, models were additionally adjusted for educational attainment. For the NHSII, models were additionally adjusted for household income.
Model 2: Further adjusted for cardiovascular disease, cancer, respiratory disease, hypertension, hypercholesterolemia, diabetes, and weight change.