Table 1 Characteristics of Age at First Birth, the Ohsaki Cohort, Japan, 1995–2008
From: Age at first birth and long-term mortality for mothers: the Ohsaki cohort study
Age at first birth (years) | |||||
|---|---|---|---|---|---|
≤19 | 20–24 | 25–29 | ≥30 | p-value | |
No. of subjects | 498 | 13,607 | 5,625 | 894 | |
Age at baseline (%) | |||||
40–49 | 19.7 | 18.2 | 15.4 | 21.4 | <0.01 |
50–59 | 20.5 | 26.1 | 24.4 | 18.9 | |
≥ 60 | 59.8 | 55.7 | 60.2 | 59.7 | |
Average (SD) | 61.3 (11.4) | 60.0 (9.9) | 60.7 (9.6) | 60.3 (10.4) | <0.01 |
Number of births (%) | |||||
1 | 2.8 | 3.2 | 8.1 | 34.8 | <0.01 |
2 | 20.5 | 33.6 | 44.2 | 43.5 | |
3 | 28.3 | 36.5 | 31.1 | 15.2 | |
≥ 4 | 48.4 | 26.8 | 16.6 | 6.6 | |
Average (SD) | 3.9 (1.9) | 3.1 (1.3) | 2.6 (1.1) | 2.0 (1.0) | <0.01 |
Use of oral contraceptives (%) | |||||
No | 95.0 | 94.8 | 96.2 | 97.0 | <0.01 |
Yes | 5.0 | 5.2 | 3.8 | 3.0 | |
Green vegetables consumption (%) | |||||
≤ 1–2 times per month | 11.1 | 7.5 | 7.1 | 7.0 | <0.01 |
1–2 times per week | 29.2 | 25.5 | 25.9 | 29.1 | |
3–4 times per week | 36.3 | 36.5 | 35.8 | 32.1 | |
Almost every day | 23.5 | 30.5 | 31.2 | 31.8 | |
Carrot or pumpkin consumption (%) | |||||
≤ 1–2 times per month | 17.6 | 10.6 | 9.7 | 10.6 | <0.01 |
1–2 times per week | 32.8 | 32.0 | 29.9 | 33.7 | |
3–4 times per week | 32.6 | 36.9 | 38.2 | 32.5 | |
Almost every day | 17.1 | 20.4 | 22.2 | 23.2 | |
Orange consumption (%) | |||||
≤ 1–2 times per month | 11.6 | 8.2 | 8.9 | 10.8 | <0.01 |
1–2 times per week | 18.5 | 16.0 | 16.5 | 17.7 | |
3–4 times per week | 30.8 | 30.4 | 30.0 | 29.5 | |
Almost every day | 39.1 | 45.4 | 44.6 | 42.1 | |
Green tea consumption (%) | |||||
< 1 cup per day | 24.2 | 22.4 | 21.7 | 24.9 | 0.27 |
1–2 cups per day | 18.0 | 20.8 | 20.6 | 20.6 | |
3–4 cups per day | 20.1 | 23.1 | 23.6 | 22.6 | |
≥ 5 cups per day | 37.8 | 33.6 | 34.1 | 32.0 | |
Coffee consumption (%) | |||||
< 1 cup per day | 63.9 | 58.8 | 60.4 | 57.0 | <0.01 |
1–2 cups per day | 25.3 | 31.9 | 30.5 | 30.8 | |
3–4 cups per day | 5.1 | 6.7 | 6.3 | 7.8 | |
≥ 5 cups per day | 5.6 | 2.6 | 2.7 | 4.4 | |
Smoking status (%) | |||||
Current | 18.9 | 7.4 | 7.0 | 11.9 | <0.01 |
Former | 2.0 | 1.9 | 2.6 | 4.3 | |
Never | 79.0 | 90.8 | 90.4 | 83.9 | |
Alcohol consumption (%) | |||||
Current | 29.3 | 27.8 | 22.8 | 23.7 | <0.01 |
Former | 7.7 | 4.6 | 4.1 | 7.8 | |
Never | 63.1 | 67.6 | 73.1 | 68.5 | |
BMI at baseline in kg/m2 (%) | |||||
< 18.5 | 3.8 | 3.2 | 4.4 | 4.7 | <0.01 |
18.5–24 | 58.1 | 63.6 | 65.5 | 65.2 | |
≥ 25.0 | 38.0 | 33.2 | 30.1 | 30.1 | |
Average (SD) | 24.1 (3.4) | 23.9 (3.4) | 23.6 (3.4) | 23.5 (3.7) | <0.01 |
Increase in body weight since age 20 years (%) | |||||
< 10.0 kg | 70.5 | 76.1 | 77.8 | 74.3 | <0.01 |
≥ 10.0 kg | 29.6 | 23.9 | 22.2 | 25.7 | |
Average (SD) | 4.2 (11.1) | 3.5 (9.5) | 2.9 (9.6) | 3.7 (9.9) | <0.01 |
Walking duration (%) | |||||
< 1 h per day | 42.9 | 46.5 | 38.3 | 34.6 | <0.01 |
≥ 1 h per day | 57.1 | 53.5 | 61.7 | 65.4 | |
Sleeping time (hours per day) | |||||
Average (SD) | 7.6 (1.4) | 7.5 (1.2) | 7.4 (1.2) | 7.2 (1.2) | <0.01 |
Defecation frequency (%) | |||||
≥ 1 time per day | 70.7 | 74.0 | 73.6 | 70.3 | <0.01 |
1 time per 2–3 days | 24.4 | 23.7 | 24.2 | 26.0 | |
1 time per 4–5 days | 3.8 | 2.0 | 2.0 | 3.1 | |
≤ 1time per 6 days | 1.1 | 0.3 | 0.3 | 0.6 | |
Educational level (%) | |||||
Junior high school (<10 years) | 83.5 | 57.5 | 52.0 | 42.6 | <0.01 |
High school (10–12 years) | 14.9 | 36.3 | 36.2 | 41.5 | |
University or higher (≥13 years) | 1.6 | 6.2 | 11.8 | 16.0 | |
Ikigai (%) | |||||
Yes | 53.5 | 58.1 | 57.8 | 55.8 | <0.01 |
Uncertain | 38.8 | 37.8 | 37.7 | 39.6 | |
No | 7.7 | 4.1 | 4.6 | 4.6 | |
Perceived mental stress (%) | |||||
High | 17.2 | 17.6 | 17.6 | 23.2 | <0.01 |
Moderate | 64.1 | 66.1 | 66.3 | 58.3 | |
Low | 18.8 | 16.3 | 16.1 | 18.5 | |
History of hypertension (%) | |||||
Yes | 27.5 | 27.6 | 28.3 | 25.8 | 0.47 |
No | 72.5 | 72.5 | 71.8 | 74.2 | |
History of diabetes (%) | |||||
Yes | 8.8 | 5.0 | 5.3 | 5.3 | <0.01 |
No | 91.2 | 95.0 | 94.7 | 94.7 | |