Table 1. Characteristics of cases and controls.
| Cases | Controls | p-value | |
|---|---|---|---|
| N (%) | N (%) | ||
| Sex | 0.067 | ||
| Male | 21 (39%) | 225 (52%) | |
| Female | 33 (61%) | 207 (48%) | |
| Age | 0.998 | ||
| 15–24 mo | 6 (11%) | 48 (11%) | |
| 3–4 y | 7 (13%) | 59 (14%) | |
| 5–6 y | 9 (17%) | 67 (16%) | |
| 7–8 y | 26 (48%) | 214 (50%) | |
| 9–10 y | 6 (11%) | 44 (10%) | |
| Major chronic condition | 0.487 | ||
| No | 47 (87%) | 360 (83%) | |
| Yes | 7 (13%) | 72 (17%) | |
| Other persons in the household | 0.124 | ||
| 1 | 4 (7%) | 41 (9%) | |
| 2 | 5 (9%) | 96 (22%) | |
| 3 | 24 (44%) | 164 (38%) | |
| 4+ | 21 (39%) | 131 (30%) | |
| Migrant parents | 0.019 | ||
| No | 42 (78%) | 384 (89%) | |
| Yes | 12 (22%) | 48 (11%) | |
| Visits to the pediatrician | 0.050 | ||
| 0 | 3 (6%) | 73 (17%) | |
| 1–5 | 30 (56%) | 239 (55%) | |
| 6+ | 21 (39%) | 120 (28%) | |
| Doses of varicella vaccine | < 0.001 | ||
| 0 | 48 (89%) | 257 (59%) | |
| 1 | 5 (9%) | 112 (26%) | |
| 2 | 1 (2%) | 63 (15%) | |
| Doses of measles-mumps-rubella vaccine | 0.766 | ||
| 0 | 2 (4%) | 26 (6%) | |
| 1 | 14 (26%) | 103 (24%) | |
| 2 | 38 (70%) | 303 (70%) | |
| Total | 54 (100%) | 432 (100%) |