Table 1.
Results of univariable analysis for food items with P value <0·2 and >40% cases exposed following an outbreak at a hotel, Norway, December 2012
| Food item | Exposed | Unexposed | RR | (95% CI) | P value | % cases exposed | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| Total | Cases | AR, % | Total | Cases | AR, % | |||||
| Scrambled eggs | 173 | 127 | 73·4 | 87 | 22 | 25·29 | 2·9 | (2·0–4·2) | <0·00 | 85·2 |
| Smoked trout | 114 | 84 | 73·7 | 234 | 115 | 49·15 | 1·5 | (1·3–1·8) | <0·00 | 42·2 |
| Cooked trout | 109 | 79 | 72·5 | 239 | 120 | 50·21 | 1·44 | (1·2–1·7) | <0·00 | 39·7 |
| Cured trout | 118 | 79 | 67 | 230 | 120 | 52·17 | 1·28 | (1·1–1·5) | 0·01 | 39·7 |
| Bread | 150 | 95 | 63·3 | 198 | 104 | 52·53 | 1·21 | (1·0–1·4) | 0·04 | 47·7 |
| Tap water | 245 | 147 | 60 | 96 | 47 | 48·96 | 1·23 | (0·98–1·5) | 0·06 | 75·8 |
| Cooked potatoes | 233 | 140 | 60·1 | 115 | 59 | 51·3 | 1·17 | (0·95–1·4) | 0·12 | 70·4 |
| Mashed rutabaga | 141 | 87 | 61·7 | 207 | 112 | 54·11 | 1·14 | (0·95–1·4) | 0·16 | 43·7 |
AR, Attack rate; RR, relative risk; CI, confidence interval.