# Table 4 Univariate and multivariable logistic regression for determinants of whether or not MBF for the first 6 months

6-month mostly breastfeeding rate N (%) Univariate analysis Multivariable Logistic Regression
Non-MBF MBF P value 95% CI for OR
(N = 662) (N = 1138) (T = 1800) OR Lower Upper P value
Infant born before/during lockdown? 1800 (100)    0.003
born before lockdown   479 (39.1) 746 (60.9)   ref
born during lockdown   184 (31.9) 392 (68.1)   1.43 1.08 1.90 0.012
Maternal age (years)a 1764 (98) 31.8 ± 4.3 31.2 ± 4.1 0.000 0.96 0.93 0.99 0.011
Total years of maternal full-time education 1769 (98.3) 15.4 ± 2.5 15.3 ± 2.6 0.620 1.02 0.96 1.07 0.618
Household annual income in CNY 1417 (78.7)    0.781
< 200,000   239 (37.2) 404 (62.8)   ref
200,000-300,000   161 (39.2) 250 (60.8)   0.94 0.69 1.29 0.700
> 300,000   135 (37.2) 228 (62.8)   1.36 0.96 1.93 0.089
Maternal social class b 1706 (94.8)    0.233
IV & V   185 (35.1) 342 (64.9)   ref
III   197 (35.6) 357 (64.4)   1.08 0.76 1.53 0.666
I & II   247 (39.5) 379 (60.5)   0.77 0.55 1.07 0.113
Building living c 1627 (90.4)    0.204
Bungalow   5 (55.6) 4 (44.4)   ref
T apartment without garden   79 (33.5) 157 (66.5)   3.82 0.66 22.13 0.134
T apartment with garden   119 (33.2) 239 (66.8)   4.75 0.83 27.16 0.080
B apartment no garden   83 (36.4) 145 (63.6)   3.67 0.64 21.21 0.146
B apartment with garden   302 (39.4) 465 (60.6)   2.82 0.50 15.84 0.240
Villa with garden   9 (30) 21 (70)   3.53 0.50 25.18 0.208
whether had support from families/friends after birth 1797 (99.8)    0.360
No   36 (41.4) 51 (58.6)   ref
Yes   625 (36.5) 1086 (63.5)   1.95 1.06 3.59 0.032
Enough infant feeding support? 1784 (99.1)    0.053
not enough   23 (50) 23 (50)   ref
enough   628 (36.1) 1111 (63.9)   1.44 0.69 3.03 0.334
Enough support with own health? 1686 (93.7)    0.060
not enough   68 (43.3) 89 (56.7)   ref
enough   548 (35.8) 982 (64.2)   1.42 0.90 2.24 0.135
Contact with a health professional (/week) 1776 (98.7)    0.050
Never   428 (38.9) 673 (61.1)   ref
1–3 times/week   183 (34.3) 351 (65.7)   1.05 0.77 1.43 0.759
4+ times/week   43 (30.3) 99 (69.7)   1.12 0.65 1.94 0.684
Discuss health issues in mothers’ group online (/week) 1778 (98.8)    0.040
Never   305 (39.9) 459 (60.1)   ref
1–3 times/week   251 (35.6) 455 (64.4)   1.23 0.91 1.68 0.177
4+ times/week   99 (32) 210 (68)   1.66 1.09 2.53 0.019
Mode of delivery 1796 (99.8)    0.000
Vaginal   387 (33.4) 772 (66.6)   ref
Caesarean   275 (43.1) 363 (56.9)   0.77 0.59 1.01 0.059
whether COVID impacted birth location 1782 (99)    0.584
Yes   41 (34.5) 78 (65.5)   ref
No   615 (37) 1049 (63)   1.67 0.96 2.90 0.067
COVID impact on purchasing daily necessities 1785 (99.2)    0.355
Moderate-great impact   294 (35.6) 532 (64.4)   ref
Little or no impact   362 (37.7) 598 (62.3)   0.80 0.61 1.04 0.096
1. Notes: MBF Mostly breastfeeding, CI confidence interval, DL mothers who delivered during the lockdown, BL mothers who delivered before the lockdown. Factors controlled for included maternal socio-economic status (education, income, social class), living conditions, cohabitation with family members (“Who did you live with during the lockdown?”), gestational age, health advice-seeking behaviour (“Frequency of discussing with health professionals/chatting in breastfeeding support group”), support (“Did you receive enough support from health professionals/family members?”), and the impact of the COVID-19 lockdown on maternal daily life
2. a Younger maternal age as reference
3. b Class IV&V mainly refer to manual labor jobs which don’t require high education experience; Jobs in class III & II require certain training, certifications, licenses and degree to qualify; Jobs in class I involve professional careers which require advanced degree, high-end skills or expertise
4. c T-apartment is a type of apartment building with around ten residents live in each floor; and B-apartment is a type of apartment with less than three residents live in each floor