Description of perinatal, sociodemographic and medical factors in the Quebec Birth Cohort on Immunity and Health, Canada, 1970–2014
| Study population (n=400 520) | Appendectomy (n=17 205) | No appendectomy (n=383 315) | ||||
| n (%) | Mean (SD) | n (%) | Mean (SD) | n (%) | Mean (SD) | |
| Sex | ||||||
| Male | 205 923 (51.4) | 9479 (55.1) | 196 444 (51.2) | |||
| Female | 194 597 (48.6) | 7726 (44.9) | 186 871 (48.8) | |||
| Birth weight (grams) | 3240 (508) | 3260 (507) | 3239 (508) | |||
| Missing data | 33 | 1 | 32 | |||
| Gestational age (weeks)* | 39.2 (1.7) | 39.2 (1.7) | 39.2 (1.7) | |||
| Missing data | 7 | 1 | 6 | |||
| Median family income (dollars)† | 41 616 (8749) | 41 236 (8403) | 41 634 (8764) | |||
| Area of residence in 1987‡ | ||||||
| Urban | 270 835 (68.1) | 11 120 (64.8) | 259 715 (68.3) | |||
| Rural | 126 637 (31.9) | 6040 (35.2) | 120 597 (31.7) | |||
| Missing data | 3048 | 45 | 3003 | |||
| Social deprivation in 1987§ | ||||||
| Most privileged | 84 421 (22.2) | 3788 (23.1) | 80 633 (22.2) | |||
| Privileged | 77 242 (20.3) | 3529 (21.5) | 73 713 (20.3) | |||
| Moderately privileged | 82 102 (21.6) | 3530 (21.5) | 78 572 (21.6) | |||
| Deprived | 73 012 (19.2) | 3034 (18.5) | 69 978 (19.3) | |||
| Most deprived | 63 018 (16.6) | 2516 (15.3) | 60 502 (16.6) | |||
| Missing data | 20 725 | 808 | 19 917 | |||
| Material deprivation 1987§ | ||||||
| Most privileged | 66 460 (17.5) | 2537 (15.5) | 63 923 (17.6) | |||
| Privileged | 77 412 (20.4) | 3340 (20.4) | 74 072 (20.4) | |||
| Moderately privileged | 77 982 (20.5) | 3405 (20.8) | 74 577 (20.5) | |||
| Deprived | 77 407 (20.4) | 3437 (21.0) | 73 970 (20.4) | |||
| Most deprived | 80 534 (21.2) | 3678 (22.4) | 76 856 (21.1) | |||
| Missing data | 20 725 | 808 | 19 917 | |||
| Appendicitis (with or without appendectomy) | 27 303 (6.8) | 16 888 (98.2) | 10 415 (2.7) | |||
| Other diseases of appendix¶ | 1066 (0.3) | 807 (4.7) | 259 (0.1) | |||
| Inflammatory bowel disease | 3679 (0.9) | 123 (0.7) | 3556 (0.9) | |||
| Crohn’s disease | 2545 (0.6) | 112 (0.7) | 2433 (0.6) | |||
| Ulcerative colitis | 1134 (0.3) | 11 (0.1) | 1123 (0.3) | |||
Compilation based on data from the Government of Québec, Institut de la statistique du Québec, 2017 Institut de la statistique du Québec is not responsible for compilations or interpretation of results.
*Weeks of amenorrhea.
†Based on census data according to the first three digits of the postal code of residence in 1991.
‡Based on the second digit of residential postal code.17
§Based on material and social deprivation indices, using the six-digit postal code of residence in 1987.18
¶Appendicular colic, appendicular mucocele and sphacele, appendicular cyst, other.