Table 2.
Association between smoking status and change in health-related quality of life measures over 3 years among postmenopausal women with multiple sclerosis in the Women's Health Initiative Observational Study.
| Exposure | ΔPhysical component score (3-year baseline) | ΔMental component score (3-year baseline) | ||||
|---|---|---|---|---|---|---|
| Mean change (standard deviation) |
β-Coefficient | Mean change (standard deviation) |
β-Coefficient | |||
| Crude | Adjusted1
(95% confidence interval) |
Crude | Adjusted1
(95% confidence interval) |
|||
| Smoking history | ||||||
| Never smokers | −0.65 (8.6) | Ref. | Ref | −0.84 (12.1) | Ref. | Ref. |
| Ever smokers | −1.10 (9.5) | −0.45 | 0.05 (−3.3 to 3.4) |
0.12 (11.5) | 0.96 | 0.25 (−4.1 to 4.6) |
| Former smokers | −0.74 (9.1) | −0.10 | 1.67 (−4.0 to 7.3) |
−0.25 (11.2) | 0.59 | −1.82 (−5.9 to 9.5) |
| Current smokers | −2.97 (11.7) | −2.33 | −0.90 (−6.7 to 4.9) |
2.08 (13.4) | 2.91 | 1.80 (−9.3 to 5.6) |
| Age started smoking (years) | ||||||
| <20 | −1.25 (9.6) | 1.25 | 1.64 (−7.0 to 10.3) |
−0.93 (11.4) | −10.03 | −10.45 (−19.1 to −1.8) |
| 20 to 24 | −0.58 (9.0) | 1.93 | 2.33 (−6.9 to 11.6) |
0.72 (11.2) | −8.37 | −8.9 (−18.2 to 0.3) |
| 25 or older | −2.51 (12.3) | Ref. | Ref. | 9.09 (12.4) | Ref. | Ref. |
| Cigarettes smoked (per day) | ||||||
| <15 | −1.73 (8.3) | Ref. | Ref. | 0.71 (10.3) | Ref. | Ref. |
| 15 or more | −0.46 (10.7) | 1.64 | 1.32 (−2.9 to 5.5) |
−0.47 (12.7) | −1.07 | −1.16 (−6.7 to 4.4) |
| Years smoked regularly | ||||||
| <30 | −1.89 (8.8) | Ref. | Ref. | 1.12 (10.6) | Ref. | Ref. |
| 30 or more | −0.12 (11.1) | 1.77 | 2.41 (−2.0 to 6.8) |
−1.89 (13.3) | −3.01 | −3.29 (−9.1 to 2.6) |
| Number of smoking pack-years | ||||||
| <10 | −1.65 (8.2) | Ref. | Ref. | −0.05 (11.2) | Ref. | Ref. |
| 10 to 29 | −2.31 (9.0) | −0.14 | −1.55 (−6.0 to 2.9) |
2.89 (10.1) | 3.19 | 3.85 (−2.0 to 9.7) |
| 30 or more | 1.21 (9.9) | 3.10 | 2.41 (−4.5 to 9.3) |
−4.15 (13.9) | −2.48 | −3.49 (−12.5 to 5.5) |
| Age quit smoking (years) | ||||||
| <40 | −2.94 (8.9) | Ref. | Ref. | 1.79 (10.8) | Ref. | Ref. |
| 40 or older | 0.46 (9.9) | 2.62 | 3.46 (−1.3 to 8.2) |
−2.82 (11.9) | −4.94 | −4.44 (−10.8 to 1.9) |
1Adjusted for the following baseline confounders: age, education, race/ethnicity, years since menopause, alcohol use, depression, and body mass index. Bonferroni corrections applied to confidence intervals to adjust for multiple comparisons.