Characteristics of 5867 participants with a pertussis test result between December 2009 and March 2013
| Characteristic | No. (%)* | |
|---|---|---|
| Pertussis-positive cases n = 486 | Pertussis-negative controls n = 5381 | |
| Age, yr, mean ± SD | 7.7 ± 5.7 | 5.0 ± 5.0 |
| Age | ||
| 3–11 mo | 80 (16.5) | 1268 (23.6) |
| 1–3 yr | 100 (20.6) | 1794 (33.3) |
| 4–6 yr | 52 (10.7) | 891 (16.6) |
| 7–13 yr | 165 (34.0) | 988 (18.4) |
| 14–21 yr | 89 (18.3) | 440 (8.2) |
| Birth year | ||
| 1992–1996 | 49 (10.1) | 340 (6.3) |
| 1997–2000 | 110 (22.6) | 517 (9.6) |
| 2001–2004 | 93 (19.1) | 569 (10.6) |
| 2005–2008 | 75 (15.4) | 1435 (26.7) |
| 2009–2012 | 159 (32.7) | 2520 (46.8) |
| Sex, male | 235 (48.4) | 2764 (51.4) |
| Neighbourhood income quintile | n = 478 | n = 5314 |
| 1 (lowest) | 90 (18.8) | 1121 (21.1) |
| 2 | 87 (18.2) | 954 (18.0) |
| 3 | 95 (19.9) | 997 (18.8) |
| 4 | 87 (18.2) | 1162 (21.9) |
| 5 (highest) | 119 (24.9) | 1080 (20.3) |
| Rural residence | n = 484 116 (23.9) | n = 5360 869 (16.2) |
| Year of test | ||
| 2009 | < 6 (< 1) | 82 (1.5) |
| 2010 | 35 (7.2) | 1087 (20.2) |
| 2011 | 63 (12.9) | 1083 (20.1) |
| 2012 | 366 (75.3) | 2648 (49.2) |
| 2013 | 20 (4.1) | 481 (8.9) |
| Any complex chronic medical condition | 9 (1.9) | 262 (4.9) |
| Health care use in previous year | ||
| ≥ 2 emergency department visits | 123 (25.3) | 2070 (38.5) |
| ≥ 1 hospital admission | 89 (18.3) | 1796 (33.4) |
| ≥ 8 physician office visits | 140 (28.8) | 2916 (54.2) |
Note: SD = standard deviation.
↵* Unless stated otherwise.