Table 3 Ischemic stroke incidence rate ratios by severity and subtype associated with increases in outdoor NO 2 concentration in the South London Stroke Register study area, 1995-2007
Stroke category | n | Rate ratio (95% CI) | |||
|---|---|---|---|---|---|
Category by tertile | |||||
Per IQR (3.2ug/m3) increase | Low | Intermediate | High | ||
Oxford classification | |||||
TACI | 473 | 1.03 (0.93-1.14) | 1 | 1.10 (0.88-1.38) | 1.06 (0.84-1.34) |
PACI | 762 | 1.01 (0.93-1.09) | 1 | 1.04 (0.87-1.24) | 1.07 (0.90-1.28) |
POCI | 362 | 1.01 (0.90-1.13) | 1 | 1.07 (0.82-1.39) | 1.07 (0.83-1.39) |
LACI | 860 | 0.98 (0.91-1.06) | 1 | 1.06 (0.89-1.25) | 1.07 (0.91-1.27) |
TOAST classification* | |||||
Large artery atherosclerosis | 136 | 1.07 (0.90-1.28) | 1 | 0.96 (0.63-1.46) | 1.03 (0.68-1.56) |
Cardioembolism | 371 | 1.05 (0.94-1.17) | 1 | 1.08 (0.83-1.40) | 1.16 (0.90-1.50) |
Small vessel occlusion | 376 | 0.95 (0.84-1.07) | 1 | 1.21 (0.94-1.56) | 1.09 (0.84-1.42) |
NIHSS severity** | |||||
NIHSS = <6 | 541 | 0.96 (0.87-1.06) | 1 | 1.12 (0.91-1.38) | 1.06 (0.86-1.32) |
NIHSS >6 | 510 | 1.05 (0.95-1.15) | 1 | 1.07 (0.86-1.34) | 1.14 (0.91-1.42) |
Clinical severity | |||||
Mild | 1285 | 1.06 (1.00-1.12) | 1 | 1.10 (0.96-1.26) | 1.22 (1.06-1.40) |
Severe | 1207 | 0.95 (0.89-1.01) | 1 | 1.04 (0.91-1.20) | 0.94 (0.81-1.09) |