Table 5.
Birth Certificate Compared with Interview for Maternal Industrial Sectors of Work During First Trimester
| Women employed outside home according to both sourcesa | |||||||
| North American Industry Classification System (NAICS) industrial sector | Number (%) misclassified as homemaker or student on vital record | Number by interview | Number by birth certificateb | Number by both sources | Sensitivity (%) (95% CI) | Specificity (%) (95% CI) | Kappa |
| Manufacturing | 4 (22.2) | 14 | 15 | 12 | 85.7 (60.3 – 97.5) | 98.6 (96.2 – 99.6) | 0.82 |
| Wholesale & retail trade | 25 (36.8) | 42 | 40 | 35 | 83.3 (69.8 – 92.4) | 97.3 (94.1 – 99.0) | 0.82 |
| Finance & insurance | 4 (18.2) | 17 | 17 | 16 | 94.1 (74.3 – 99.7) | 99.5 (97.7 – 99.9) | 0.94 |
| Professional, scientific, & technical services | 4 (28.6) | 10 | 9 | 7 | 70.0 (38.0 – 91.7) | 99.1 (97.0 – 99.9) | 0.73 |
| Administration & support; waste management | 8 (38.1) | 12 | 11 | 7 | 58.3 (30.2 – 82.8) | 98.1 (95.6 – 99.4) | 0.59 |
| Educational services | 8 (21.1) | 29 | 27 | 24 | 82.8 (65.8 – 93.4) | 98.5 (95.9 – 99.6) | 0.84 |
| Health care & social assistance | 10 (15.4) | 52 | 53 | 48 | 92.3 (82.5 – 97.5) | 97.2 (93.8 – 98.9) | 0.89 |
| Accommodation & food services | 31 (67.4) | 15 | 16 | 13 | 86.7 (62.5 – 97.7) | 98.6 (96.2 – 99.6) | 0.83 |
| Public administration | 5 (20.8) | 19 | 14 | 13 | 68.4 (45.5 – 86.1) | 99.5 (97.7 – 99.9) | 0.77 |
aMothers who were listed as homemaker, student or unemployed are excluded in these analyses. Only industrial groups with 10 or more workers are shown in Table.
bOne missing each for manufacturing, finance and insurance, administrative support, and educational services sectors. Three missing for health care and social assistance sectors.