Table 2:
Death and major cardiovascular events during the study period among people who experienced mild gastroenteritis (n = 414), severe gastroenteritis (n = 153) or no gastroenteritis (n = 331) during the Escherichia coli O157:H7 outbreak and among a control population (n = 11 263) from the surrounding communities
| Group | No. (%) | No. of events per 1000 person-years | Hazard ratio (95% confidence interval) | |
|---|---|---|---|---|
| Unadjusted | Adjusted* | |||
| Death or major cardiovascular event | ||||
| Residents of surrounding communities | 1115 (9.9) | 13.4 | 1.0 (ref) | 1.0 (ref) |
| Walkerton Health Study participants | ||||
| No gastroenteritis | 28 (8.5) | 11.4 | 0.85 (0.60–1.22) | 1.05 (0.72–1.53) |
| Mild gastroenteritis | 22 (5.3) | 6.9 | 0.52 (0.34–0.79) | 0.64 (0.42–0.98) |
| Severe gastroenteritis | 9 (5.9) | 7.9 | 0.60 (0.31–1.12) | 0.74 (0.38–1.43) |
| Major cardiovascular event (death censored) | ||||
| Residents of surrounding communities | 536 (4.8) | 6.5 | 1.0 (ref) | 1.0 (ref) |
| Walkerton Health Study participants | ||||
| No gastroenteritis | 8 (2.4) | 3.3 | 0.51 (0.25–1.01) | 0.61 (0.30–1.22) |
| Mild gastroenteritis | 13 (3.1) | 4.1 | 0.64 (0.37–1.10) | 0.75 (0.43–1.30) |
| Severe gastroenteritis | 6 (3.9) | 5.3 | 0.82 (0.37–1.81) | 1.04 (0.46–2.33) |
| Death (all causes) | ||||
| Residents of surrounding communities | 684 (6.1) | 8.1 | 1.0 (ref) | 1.0 (ref) |
| Walkerton Health Study participants | ||||
| No gastroenteritis | 20 (6.0) | 8.0 | 1.0 (0.64–1.55) | 1.29 (0.82–2.01) |
| Mild gastroenteritis | 10 (2.4) | 3.1 | 0.39 (0.21–0.71) | 0.52 (0.29–0.97) |
| Severe gastroenteritis | † | † | † | 0.39 (0.13–1.21) |
Adjusted for age, sex, neighbourhood income quintile, number of comorbidities, number of family physician visits in the 2 years before the outbreak, chronic obstructive pulmonary disease, diabetes, hypercholesterolemia and chronic kidney disease before the outbreak.
Not reported because of count data less than 6. With such low counts, there is a risk of reidentification using Institute for Clinical Evaluative Sciences data. This is under the agreement between the Institute for Clinical Evaluative Sciences and the privacy officer of Ontario.