Table 1 Characteristics of pertussis cases and controls (N = 391)
Controls (n = 261) | Cases (n = 130) | P value* | |
|---|---|---|---|
Age at case index date, years | 0.90 | ||
Median (IQR) | 13.1 (10.7–15.1) | 13.1 (10.9–14.9) | |
Mean (SD) | 12.2 (3.9) | 12.2 (3.8) | |
Sex, no. (%) | 1.00 | ||
Male | 143 (54.7) | 71 (54.6) | |
Female | 118 (45.3) | 59 (45.4) | |
Ethnicity, no. (%) | 0.76 | ||
Hispanic/Latino | 3 (1.1) | 1 (0.8) | |
American Indian/Alaska Native | 3 (1.1) | 0 | |
Asian | 0 | 2 (1.6) | |
Native Hawaiian/Pacific Islander | 4 (1.5) | 0 | |
White | 200 (76.7) | 105 (80.4) | |
Unknown | 51 (19.6) | 22 (17.2) | |
Ethnicity, no. (%) | 0.51 | ||
Nonwhites | 10 (3.9) | 3 (2.3) | |
Whites | 200 (76.7) | 105 (80.8) | |
Unknown | 51 (19.4) | 22 (16.9) | |
Maternal educational level, no. (%) | 0.40 | ||
High school or less | 16 (6.2) | 10 (7.7) | |
Some college | 29 (11.1) | 19 (14.6) | |
College graduate | 23 (8.8) | 13 (10) | |
Graduate degree or greater | 18 (6.9) | 5 (3.9) | |
Unknown | 175 (67.0) | 83 (63.8) | |
Paternal educational level, no. (%) | 0.19 | ||
High school or less | 8 (3.1) | 7 (5.4) | |
Some college | 20 (7.7) | 13 (10.0) | |
College graduate | 17 (6.5) | 2 (1.5) | |
Graduate degree or greater | 23 (8.8) | 9 (6.9) | |
Unknown | 193 (74.0) | 99 (76.2) | |
HOUSES index in z-score | 0.82 | ||
Median (IQR) | −0.30 (−2.28–2.25) | −0.43 (−2.00–2.36) | |
Mean (SD) | 0.05 (3.68) | 0.09 (3.29) | |
HOUSES index in quartiles | 0.91 | ||
First (lowest SES) | 63/252 (25.0) | 24/111 (21.6) | |
Second | 60/252 (23.8) | 29/111 (26.1) | |
Third | 61/252 (24.2) | 28/111 (25.2) | |
Fourth (highest SES) | 68/252 (27.0) | 30/111 (27.0) | |
Up-to-date status of pertussis vaccination, no. (%) | 0.10 | ||
Not up to date | 32 (12.3) | 23 (17.7) | |
Up to date | 216 (82.8) | 102 (78.5) | |
Unknown | 13 (4.9) | 5 (3.8) | |
Smoking status, no. (%) | 0.84 | ||
Non-smoking | 75 (28.7) | 39 (30) | |
Smoking | 34 (13.0) | 18 (13.8) | |
Unknown | 152 (58.3) | 73 (56.2) | |
Comorbid conditions at index date, no. (%)a | 1.00 | ||
Yes | 6 (2.3) | 3 (2.3) | |
No | 255 (97.7) | 127 (97.7) | |