Ma et al. BMC Public Health 2012, 12:568 http://www.biomedcentral.com/1471-2458/12/568 Table 2 Main characteristics of the cohort Characteristic n Child age Visit 1 (6-month-old) Visit 2 (12-month-old) Visit 3 (18-month-old) Child gender [n (%)] Male Female Breastfeeding [n (%)] Visit 1 (6-month-old) Visit 2 (12-month-old) Visit 3 (18-month-old) Child nutritional status Length-for-age z score Visit 1 (6-month-old) Visit 2 (12-month-old) Visit 3 (18-month-old) Weight-for-age z score Visit 1 (6-month-old) Visit 2 (12-month-old) Visit 3 (18-month-old) Weight-for-length z score Visit 1 (6-month-old) Visit 2 (12-month-old) Visit 3 (18-month-old) Mother’s pre-pregnancy height (cm) Mother’s pre-pregnancy weight (kg) Mother’s pre-pregnancy BMI (kg/m2) Caregiver’s schooling years [n (%)] ≦12y >12y Annual household income [n (%)] ≦RMB 60 thousand per year RMB 60-150 thousand per year >RMB 150 thousand per year aMean ± SD (all such values). 180 180 180 79 101 88 12 3 180 180 180 180 180 180 180 180 180 180 180 180 75 105 56 81 43 result 5.85 ± 0.44 a 12.13 ± 0.29 18.12 ± 0.27 43.89 56.11 48.89 6.67 1.67 0.58 ± 0.80 0.43 ± 0.88 0.41 ± 0.91 0.83 ± 0.78 0.70 ± 0.74 0.65 ± 0.80 0.76 ± 0.88 0.70 ± 0.77 0.62 ± 0.82 161.61 ± 4.24 55.64 ± 8.02 21.30 ± 2.93 41.67 58.33 31.11 45.00 23.89 food consistency changed with infants receiving more semi-solid and solid food. The percentage of infants in the high feeding frequency category moved from 89.44% to 100% between Visit 1 and Visit 3. Dietary diversity and food group frequency also changed in a positive direction. The percentage of infants with high category rose from 63.33% to 90.00% and from 46.11% to 98.33%, respectively, over the study period. Page 5 of 9 Table 3 Distribution of the CS-ICFI components at different time points Components score Visit 1 Visit 2 Visit 3 [n(%)] [n(%)] [n(%)] P value a Breastfeeding Yes Food consistency Feeding frequency Food group frequency Low High Low High Low High Low High 0/+1 +2 0/+1 0/+1 +2/+3 0/+1 +2 Dietary diversity aChi-square test. +2/+3 161 (89.44) 126 (70.00) 180 (100.00) 88 (48.89) 12 (6.67) 3 (1.67) <0.0001 105 (58.33) 79 (43.89) 10 (5.56) <0.0001 75 (41.67) 101 (56.11) 170 (94.44) 19 (10.56) 54 (30.00) 0 (0.00) <0.0001 97 (53.89) 1 (0.56) 3 (1.67) <0.0001 83 (46.11) 179 (99.44) 177 (98.33) 66 (36.67) 9 (5.00) 18 (10.00) <0.0001 144 (63.33) 171 (95.00) 162 (90.00) Association between CS-ICFIs and LAZ, WAZ and WLZ at Visit 3 The CS-ICFI at Visit 1 (6-month-old) was positively associated with child LAZ, WAZ and WLZ (beta = 0.160, P = 0.029; beta = 0.191, P = 0.009 and beta = 0.176, P = 0.020, respectively) at Visit 3(18-month-old). Fur- thermore, the CS-ICFI at Visit 3 was also positively asso- ciated with child LAZ (beta = 0.176, P = 0.016) at Visit 3. However, there was no significant association between the CS-ICFI at Visit 2(12-month-old) and LAZ, WAZ and WLZ at Visit 3 after adjustment for confounders by a linear regression model (Table 4). Table 4 Association between CS-ICFIs and LAZ, WAZ and WLZ at Visit 3 CS-ICFIs LAZ WAZ Visit 1 (6-month-old) Beta a 0.160 0.191 WLZ 0.176 Visit 2 (12-month-old) Visit 3 (18-month-old) Std.Error P value b Beta a Std.Error P value b Beta a Std.Error P value b 0.042 0.029 -0.071 0.079 0.326 0.176 0.073 0.016 0.037 0.009 0.011 0.072 0.884 0.042 0.070 0.585 0.040 0.020 0.065 0.074 0.387 -0.066 0.074 0.398 aStandardized partial regression coefficient. bAssociation between CS-ICFI and LAZ, WAZ and WLZ at each time point. adjusted for child sex and age, birth weight, mother’s pre-pregnancy height and annual household income using a linear regression model.