Table 3.
Association of Secondhand Smoke Exposure and Stroke among All Participants and Never and Former Smokers
| Any Stroke | Secondhand smoke exposure (>1 hour/week over past year) | |||||
|---|---|---|---|---|---|---|
| No. of Events | Model 1 Unadjusted | Model 2 a | Model 3 b | Model 4 c | Model 5 d | |
| HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | ||
| Overall e | 428 | 1.16 (0.93, 1.44) | 1.31 (1.03, 1.65) | 1.30 (1.02, 1.67) | 1.31 (1.02, 1.69) | 1.27 (0.98, 1.64) |
| Never smokers | 217 | 1.07 (0.77, 1.48) | 1.32 (0.94, 1.87) | 1.28 (0.84, 1.84) | 1.28 (0.89, 1.86) | 1.17 (0.80, 1.72) |
| Former smokers f | 211 | 1.22 (0.91, 1.63) | 1.30 (0.94, 1.80) | 1.33 (0.95, 1.87) | 1.36 (0.96, 1.93) | 1.37 (0.97, 1.95) |
| Ischemic Stroke | Secondhand smoke exposure (>1 hour/week over past year) | |||||
|---|---|---|---|---|---|---|
| No. of Events | Model 1 Unadjusted | Model 2 a | Model 3 b | Model 4 c | Model 5 d | |
| HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | ||
| Overall e | 352 | 1.13 (0.89, 1.44) | 1.29 (1.00, 1.68) | 1.29 (0.98, 1.69) | 1.28 (0.97, 1.69) | 1.21 (0.91, 1.61) |
| Never smokers | 184 | 1.11 (0.78, 1.57) | 1.63 (0.94, 1.98) | 1.32 (0.89, 1.96) | 1.31 (0.87, 1.95) | 1.17 (0.77, 1.78) |
| Former smokersf | 168 | 1.15 (0.82, 1.60) | 1.25 (0.87, 1.79) | 1.27 (0.87, 1.86) | 1.26 (0.85, 1.87) | 1.26 (0.85, 1.87) |
| Hemorrhagic Stroke | Secondhand smoke exposure (>1 hour/week over past year) | |||||
|---|---|---|---|---|---|---|
| No. of Events | Model 1 Unadjusted | Model 2 a | Model 3 b | Model 4 c | Model 5 d | |
| HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | HR (95% CI) | ||
| Overall e | 50 | 1.04 (0.55, 2.00) | 0.84 (0.38, 1.85) | 0.86 (0.39, 1.91) | 0.94 (0.42, 2.09) | 0.95 (0.42, 2.12) |
| Never smokers | 23 | 0.81 (0.28, 2.39) | 0.89 (0.29, 2.72) | 0.94 (0.31, 2.89) | 1.04 (0.34, 3.24) | 1.03 (0.33, 3.22) |
| Former smokers f | 27 | 1.18 (0.52, 2.69) | 0.80 (0.26, 2.45) | 0.77 (0.25, 2.37) | 0.84 (0.27, 2.61) | 0.89 (0.28, 2.76) |
HR, hazard ratio
Model 2: Adjusted for demographics (age, race, sex, age*race), SES factors (education [<high school vs. >high school] and income [<$35,000 vs. >$35,000]).
Model 3: Adjusted for demographics, SES factors, and Framingham Stroke Risk Score factors (diabetes, cardiovascular disease history, atrial fibrillation, current antihypertensive medication use, systolic blood pressure [SBP] and left ventricular hypertrophy).
Model 4: Adjusted for demographics, SES factors, Framingham Stroke Risk Score factors, and C-reactive protein (CRP).
Model 5: Adjusted for demographics, SES factors, Framingham Stroke Risk Score factors, BMI and lifestyle/behavioral factors (physical activity [none vs. >1 time per week], and weekly alcohol consumption [ever vs. never]).
Overall models 3–5 also adjusted for smoking history (former vs. never).
Models 3–5 for former smokers adjusted for pack years smoked.