Table 2. Demographics of paediatric cancer cases and controls.
| Cases (n=459) | Controls (n=1135) | P-value | |
|---|---|---|---|
| Age at first chest image (years, s.d.) | 9.42 (5.91) | 5.57 (5.65) | <0.0001 |
| Age at diagnosis | 8.19 (5.91) | — | |
| Gender a | |||
| Female | 182 (40.3%) | 494 (43.6%) | 0.23 |
| Male | 270 (59.7%) | 639 (56.4 %) | |
| Ethnicity a | |||
| African-American | 7 (3.5%) | 111 (12.8%) | <0.001 |
| Asian | 9 (4.5%) | 30 (3.5%) | |
| Caucasian | 173 (84.6%) | 627 (72.7%) | |
| Hispanic/Latino | 7 (3.5%) | 50 (5.8%) | |
| Other | 8 (4.2%) | 45 (5.2%) | |
| Residence | |||
| Local (MN resident) | 302 (67.4%) | 1108 (97.9%) | <0.0001 |
| Non-local | 146 (32.6%) | 24 (2.1%) | |
| Indications for chest X-ray in controls a | |||
| Asthma or shortness of breath | — | 187 (16.5%) | |
| Bronchitis | — | 256 (22.5%) | |
| Chest pain | — | 105 (9.3%) | |
| Possible pneumonia | — | 416 (36.7%) | |
| Trauma | — | 46 (4.0%) | |
| Other | — | 122 (10.8%) | |
a
Sex was missing for 2 controls and 7 cases, ethnicity is missing for 272 controls and 254 cases, and indications for chest X-ray were missing in 2 controls.