Table 3 Personal factors influencing EBF rates until 6 months postpartum in Japan.

Social demographic factors

Age of the mother^e (by year)

0.984

(0.981–0.987)

0.957

(0.953–0.961)

Household income^b (n = 74,424)

Less than 4 million yen

Reference

Reference

4–6 million yen

1.117

(1.079–1.157)

1.022

(0.980–1.066)

Greater than 6 million yen

1.156

(1.114–1.199)

1.049

(0.998–1.102)

Mother’s level of education^b (n = 79,533)

Middle/High school graduate

Reference

Reference

Vocational school/ Community college graduate

1.285

(1.243–1.328)

1.188

(1.138–1.240)

College/University graduate or higher

1.535

(1.476–1.596)

1.322

(1.253–1.395)

Father’s level of education^b (n = 79,066)

Middle/High school graduate

Reference

Reference

Vocational school/Community college graduate

1.213

(1.169–1.259)

1.079

(1.031–1.129)

College/University graduate or higher

1.342

(1.298–1.387)

1.104

(1.057–1.154)

Mother’s employment status^b (n = 79,277)

Full‐time

Reference

Reference

Self‐employed or its assistant

0.956

(0.881–1.038)

1.074

(0.972–1.186)

Temporary staff

0.741

(0.648–0.849)

0.863

(0.733–1.015)

Housewife or on leave

1.163

(1.125–1.202)

1.045

(1.000–1.092)

Part‐time/Side job/Commission

0.848

(0.811–0.887)

0.954

(0.902–1.009)

Unemployed

0.724

(0.632–0.830)

0.927

(0.777–1.107)

Other

0.790

(0.707–0.882)

0.852

(0.746–0.972)

Marital status^a (n = 79,685)

Married

Reference

Reference

Unmarried

0.718

(0.661–0.780)

0.997

(0.889–1.119)

Divorced/widowed

0.500

(0.412–0.606)

0.683

(0.523–0.892)

Maternal lifestyle factors

Daily calorie intake^b (per 1000 kcal)

1.020

(1.001–1.039)

0.995

(0.971–1.019)

Drinking habits^b (n = 79,355)

None

Reference

Reference

Stopped before pregnancy

1.068

(1.023–1.115)

1.039

(0.988–1.094)

Stopped after discovering pregnancy

0.910

(0.881–0.940)

0.967

(0.930–1.006)

Continued during pregnancy

0.918

(0.838–1.006)

0.995

(0.892–1.110)

Smoking habits^c (n = 79,851)

None

Reference

Reference

Stopped before pregnancy

0.960

(0.927–0.995)

1.016

(0.973–1.061)

Stopped after discovering pregnancy

0.666

(0.637–0.696)

0.796

(0.751–0.842)

Continued during pregnancy

0.434

(0.395–0.477)

0.557

(0.496–0.627)

Exercise habits^b (n = 79,704)

No exercise habits

Reference

Reference

At least 10 min of exercise (walking) weekly

1.12

(1.082–1.158)

1.074

(1.031–1.118)

Household pet^d (n = 80,194)

Absent

Reference

Reference

Present

0.817

(0.79–0.845)

0.907

(0.870–0.946)

Factors related to maternal behavior during nursing

Experience of child’s condition worsening during breastfeeding^c (n = 79,200)

Absent

Reference

Reference

Present

1.107

(1.002–1.224)

1.144

(1.014–1.290)

Activities of the mother during nursing^c (n = 79,143)

Looked into the eyes of and talked with child

Reference

Reference

Often watch TV or a DVD

1.014

(0.974–1.056)

0.954

(0.910–1.001)

Reading newspapers or magazines

1.394

(1.170–1.662)

1.130

(0.924–1.381)

Used cellphones or a PC

1.148

(1.087–1.212)

1.101

(1.031–1.175)

Did housework

0.405

(0.227–0.724)

0.420

(0.203–0.868)

Something other than the above

1.500

(1.391–1.617)

1.136

(1.039–1.242)