Table 4.
Parameter and OR estimates for multivariate logistic regression models
| Cohort | Subgroup | N | Variable | Lag | Estimate | SE | p Value | OR | Lower CL | Upper CL |
|---|---|---|---|---|---|---|---|---|---|---|
| Calgary | ||||||||||
| Main | Whole | 12 066 | NO2 | 1 | 0.0452 | 0.0194 | 0.0199 | 1.046 | 1.007 | 1.087 |
| Female | Whole | 3875 | NO2 | 1 | 0.0709 | 0.0342 | 0.0381 | 1.073 | 1.004 | 1.148 |
| Female | NSTEMI | 1728 | PM2.5 | 0 | –0.0627 | 0.0319 | 0.0489 | 0.939 | 0.882 | 1.000 |
| Agecat1 | Dysrhythmia | 585 | PM2.5 | 1 | –0.1285 | 0.0589 | 0.0292 | 0.879 | 0.784 | 0.987 |
| Agecat2 | Whole | 6736 | CO | 1 | 0.0264 | 0.0130 | 0.0428 | 1.027 | 1.001 | 1.053 |
| Agecat2 | Whole | 6736 | NO | 1 | 0.0324 | 0.0139 | 0.0193 | 1.033 | 1.005 | 1.061 |
| Agecat2 | Whole | 6736 | NO2 | 1 | 0.0734 | 0.0260 | 0.0047 | 1.076 | 1.023 | 1.132 |
| Edmonton | ||||||||||
| Main | Diabetes | 2825 | PM2.5 | 3 | 0.0532 | 0.0247 | 0.0314 | 1.055 | 1.005 | 1.107 |
| Main | Dysrhythmia | 1935 | PM2.5 | 0 | –0.0616 | 0.0312 | 0.0480 | 0.940 | 0.885 | 0.999 |
| Agecat1 | Whole | 4613 | PM2.5 | 1 | 0.0397 | 0.0192 | 0.0391 | 1.040 | 1.002 | 1.080 |
| Agecat1 | Diabetes | 1039 | PM2.5 | 1 | 0.0836 | 0.0423 | 0.0485 | 1.087 | 1.001 | 1.181 |
Data were calculated for an IQR increase of CO (0.27 mg/m3), NO (26.3 µg/m3), NO2 (21.9 µg/m3), O3 (26.7 µg/m3), PM2.5 (7.1 µg/m3) in the Calgary study, or of CO (0.27 mg/m3), NO (20 µg/m3), NO2 (23.8 µg/m3), O3 (30 µg/m3), PM2.5 (7.8 µg/m3) in the Edmonton study. Frequency of NSTEMI was based on the period 1 April 2002 to 31 March 2010; frequency of other subgroups was based on the period 1 April 1999 to 31 March 2010.
Agecat1, age <65; Agecat2, age ≥65; CL, 95% confident level; N, number of first-time hospitalisations for acute myocardial infarction; NSTEMI, non-ST segment elevation myocardial infarction; PM, particulate matter.