Table 1 Characteristics of participants regarding history of dog/cat ownership (N = 73,936)
Variable | Dog and/or cat ownership | |||
|---|---|---|---|---|
Non-ownership | Infant-period ownership (until 6 months of age) | Current ownership (at 3 years of age) | Long-term ownership (until 6 months and at 3 years of age) | |
N = 57,264 | N = 7,715 | N = 1,295 | N = 7,762 | |
Maternal age at delivery (years) | 32 (28, 35) | 30 (26, 34) | 30 (26, 34) | 31 (28, 35) |
Maternal age group, n (%) | ||||
< 35 years | 40,986 (71.6) | 6,073 (78.7) | 1,031 (79.6) | 5,554 (72.5) |
≥ 35 years | 16,728 (28.4) | 1,641 (21.3) | 264 (20.4) | 2,108 (27.5) |
Pre-pregnancy BMI (kg/m2) | 20.4 (19.1, 22.3) | 20.5 (19.1, 22.5) | 20.7 (19.1, 22.7) | 20.6 (19.1, 22.7) |
Pre-pregnancy BMI group, n (%) | ||||
Underweight (BMI < 18.5) | 9,338 (16.3) | 1,221 (15.8) | 204 (15.8) | 1,200 (15.7) |
Normal weight (BMI 18.5–24.9) | 42,503 (74.3) | 5,679 (73.6) | 943 (72.9) | 5,563 (72.7) |
Overweight (BMI 25.0–29.9) | 4,248 (7.4) | 606 (7.9) | 101 (7.8) | 664 (8.7) |
Obese (BMI ≥ 30.0) | 1,144 (2.0) | 207 (2.7) | 46 (3.6) | 223 (2.9) |
Highest level of maternal education, n (%) | ||||
< 16 years | 1,749 (3.1) | 381 (5.0) | 88 (6.9) | 471 (6.2) |
16 to < 19 years | 15,982 (28.2) | 2,668 (35.0) | 469 (36.9) | 2,717 (35.9) |
≥ 19 + years | 39,008 (68.7) | 4,570 (60.0) | 713 (56.1) | 4,379 (57.9) |
Annual household income a, n (%) | ||||
< 2,000,000 JPY | 2,181 (4.0) | 478 (6.6) | 107 (8.6) | 430 (5.9) |
2,000,000–3,999,999 JPY | 14,911 (27.2) | 2,395 (32.9) | 430 (34.7) | 2,273 (31.3) |
4,000,000–5,999,999 JPY | 19,729 (36.0) | 2,464 (33.9) | 385 (31.1) | 2,468 (34.0) |
6,000,000–7,999,999 JPY | 10,496 (19.2) | 1,123 (15.4) | 194 (15.7) | 1,205 (16.6) |
≥ 8,000,000 JPY | 128 (8.1) | 817 (12.2) | 122 (9.9) | 890 (12.2) |
Marital status, n (%) | ||||
Married | 55,033 (96.9) | 7,140 (93.6) | 1,208 (94.6) | 7,168 (94.3) |
Single | 1,429 (2.5) | 430 (5.6) | 54 (4.2) | 373 (4.9) |
Divorced | 333 (0.6) | 58 (0.8) | 15 (1.2) | 56 (0.7) |
Widowed | 8 (0.0) | 3 (0.0) | 0 (0.0) | 1 (0.0) |
Body weight gain during pregnancy (kg) | 10.1 (7.9, 12.4) | 10.6 (8.2, 13.0) | 10.7 (8.5, 13.0) | 10.5 (8.1, 13.0) |
Parity, n (%) | ||||
Primiparous | 22,231 (39.7) | 3,783 (50.4) | 433 (34.3) | 3,510 (47.1) |
Multiparous | 33,697 (60.3) | 3,727 (49.6) | 828 (65.7) | 3,938 (52.9) |
Cesarean section at delivery, n (%) | ||||
No | 46,678 (81.9) | 6,345 (82.6) | 1,069 (82.9) | 6,106 (80.0) |
Yes | 10,331 (18.1) | 1,338 (17.4) | 220 (17.1) | 1,528 (20.0) |
Male, n (%) | 29,121 (50.9) | 3,921 (50.8) | 651 (50.3) | 3,919 (51.1) |
Gestational age (weeks) | 39 (38, 40) | 39 (38, 40) | 39 (38, 40) | 39 (38, 40) |
Gestational age category, n (%) | ||||
< 37 weeks | 2,541 (4.4) | 291 (3.8) | 53 (4.1) | 338 (4.4) |
37–41 weeks | 54,488 (95.3) | 7,387 (96.0) | 1,235 (95.5) | 7,293 (95.3) |
≥ 42 weeks | 128 (0.2) | 17 (0.2) | 5 (0.4) | 20 (0.3) |
Birth weight (g) | 3,030 (2,786, 3,282) | 3,035 (2,786, 3,288) | 3,064 (2,800, 3,300) | 3,028 (2,786, 3,284) |
Birth weight category, n (%) | ||||
< 1,500 g | 262 (0.5) | 23 (0.3) | 3 (0.2) | 28 (0.4) |
1,500–2,499 g | 4,167 (7.3) | 506 (6.6) | 93 (7.2) | 589 (7.7) |
2,50–3,999 g | 52,214 (91.4) | 7,093 (92.2) | 1,183 (91.6) | 6,974 (91.2) |
≥ 4000 g | 485 (0.8) | 67 (0.9) | 12 (0.9) | 57 (0.8) |
Initial feeding habit at 1 month of age, n (%) | ||||
Exclusively breastfeeding (reference) | 31,652 (57.1) | 3,899 (52.3) | 671 (53.4) | 3,841 (51.9) |
Partially breastfeeding | 21,971 (39.7) | 3,287 (44.0) | 522 (41.6) | 3,214 (40.5) |
Formula feeding | 1,782 (3.2) | 276 (3.7) | 63 (5.0) | 352 (4.8) |
Started solid baby food at 6 months of age, n (%) | ||||
No | 41,399 (72.4) | 5,982 (77.7) | 1,007 (78.2) | 5,900 (77.2) |
Yes | 15,759 (27.6) | 1,714 (22.3) | 281 (21.8) | 1,744 (22.8) |
Kaup index at 3 years of age (kg/m2) | 15.9 (15.2, 16.8) | 16.0 (15.2, 16.8) | 16.0 (15.2, 16.8) | 15.9 (15.2, 16.8) |
Maternal smoking at 3 years of age, n (%) | ||||
No | 52,113 (91.7) | 6,662 (87.4) | 1,059 (82.9) | 6,510 (85.9) |
Yes | 4,713 (8.3) | 960 (12.6) | 219 (17.1) | 1,068 (6.4) |
Partner smoking at 3 years of age, n (%) | ||||
No | 36,855 (66.0) | 4,240 (57.0) | 636 (51.2) | 4,104 (55.4) |
Yes | 18,988 (34.0) | 3,197 (43.0) | 605 (48.8) | 3,309 (44.6) |
Wearing a diaper during sleep at 3 years of age, n (%) | ||||
No | 8,052 (14.1) | 1,057 (13.7) | 192 (14.8) | 970 (12.7) |
Yes | 4,9136 (85.9) | 6,647 (86.3) | 1,102 (85.2) | 6,682 (87.3) |
Attendance at preschool or childcare facility (daycare center/nursery) at 3 years of age, n (%) | ||||
No | 20,400 (36.8) | 2,524 (33.8) | 408 (32.8) | 2,696 (36.2) |
Yes | 35,106 (63.2) | 4,949 (66.2) | 835 (67.2) | 4,743 (63.8) |
Daily hours playing outside during summer after becoming 2 years of age, n (%) | ||||
Almost none | 1,141 (2.0) | 122 (1.6) | 21 (1.7) | 183 (2.4) |
< 1 h | 13,566 (24.2) | 1,690 (22.5) | 294 (23.3) | 1,704 (22.8) |
1–3 h | 37,202 (66.4) | 5,040 (67.2) | 821 (65.2) | 4,932 (66.0) |
≥ 3 h | 4,089 (7.3) | 653 (8.7) | 124 (9.8) | 655 (8.8) |
Daily hours playing outside during winter after becoming 2 years of age, n (%) | ||||
Almost none | 5,756 (10.4) | 776 (10.5) | 115 (9.3) | 780 (10.6) |
< 1 h | 24,667 (44.6) | 3,351 (45.2) | 549 (44.3) | 3,216 (43.6) |
1–3 h | 23,317 (42.1) | 3,074 (41.4) | 525 (42.3) | 3,139 (42.5) |
≥ 3 h | 1,624 (2.9) | 217 (2.9) | 51 (4.1) | 243 (3.3) |