Table 3.
Univariate and Multivariate Logistic Regression Analysis: Risk Factors Among Transmission vs Nontransmission Households, Kaiser Permanente Northwest, April 2014–September 2016
| Household, No. (%) | Univariate Analysis | Multivariate Analysis | ||||
|---|---|---|---|---|---|---|
| Transmission (n = 209) | Nontransmission (n = 361) | OR (95% CI) | P Valuea | aOR (95% CI) | P Value | |
| Household characteristics | ||||||
| Household size | ||||||
| Median (range) | 4 (2–7) | 3 (2–10) | ||||
| Members ≥3 | 187 (89) | 245 (68) | 4.0 (2.5–6.6) | <.001 | 2.1 (1.1–4.5) | .043 |
| Household income, $ | ||||||
| ≤75 000 | 86 (41) | 155 (43) | 1 [Reference] | |||
| >75 000 | 93 (45) | 147 (41) | 1.1 (.8–1.7) | .487 | … | |
| Unknown | 22 (11) | 45 (12) | 0.9 (.5–1.6) | .666 | … | |
| Refused | 8 (4) | 14 (4) | 1.0 (.4–2.6) | .949 | … | |
| Primary case characteristics | ||||||
| Age, y | ||||||
| <5 | 102 (56) | 129 (36) | 3.2 (2.0–5.3) | <.0001 | 2.4 (1.4–4.1) | .002 |
| 5–17 | 35 (19) | 40 (11) | 3.5 (1.9–6.4) | <.0001 | 3.5 (1.8–6.8) | <.001 |
| 18–64 | 29 (16) | 116 (32) | 1 [Reference] | |||
| ≥65 | 15 (8) | 74 (21) | 0.8 (.4–1.6) | .550 | 1.2 (.5–2.7) | .693 |
| Exposuresb | ||||||
| Travel outside US | 4 (2) | 13 (4) | 0.5 (.2–1.6) | .244 | … | |
| Dine at a restaurant/fast food/vendor | 145 (70) | 257 (72) | 0.9 (.6–1.3) | .611 | … | |
| Contact with a diapered children/adult | 133 (65) | 156 (44) | 2.3 (1.6–3.3) | <.001 | 1.9 (1.3–2.9) | .003 |
| Consume food at potluck/event | 61 (30) | 141 (31) | 0.9 (.7–1.4) | .775 | … | |
| Contact with person at nursing home | 14 (7) | 29 (8) | 0.8 (.4–1.6) | .540 | … | |
| Contact with children in day care/nursery | 106 (51) | 134 (38) | 1.7 (1.2–2.4) | .002 | … | |
| Type of viral pathogen detected | ||||||
| Norovirus | 127 (61) | 174 (48) | 1.7 (1.2–2.4) | .004 | 2.0 (1.3–3.0) | <.001 |
| Rotavirus | 23 (11) | 46 (12) | 0.9 (.5–1.5) | .604 | … | |
| Astrovirus | 22 (11) | 58 (16) | 0.6 (.4–1.0) | .069 | … | |
| Sapovirus | 43 (21) | 94 (26) | 0.7 (.5–1.1) | .142 | … | |
Abbreviations: aOR, adjusted odds ratio; OR, odds ratio.
a P < .2 was included in the multivariate analysis.
bIn the 7 days prior to symptom onset.