Distribution of subjects regarding age group in the intervention and in the control group Age group (month) Intervention (n1,%) Control (n2,%) Total (n,%) p 0-< 12 3 (42.9) 4 (57.1) 7 (4.3) 0.35 12-<24 12 (35.5) 22 (64.7) 34 (20.7) 24-<36 23 (53.5) 20 (46.5) 43 (26.2) 36-<48 24 (54.2) 22 (45.8) 46 (28.0) 48-<60 20 (58.8) 14 (41.2) 34 (20.7) Total 82 82 164 Remarks: In both intervention and control group, we found that subjects concentrated in age groups 12-<24 and 48-<60 months with the rate 20.7%, 26.2%, 28.0%, and 20.7%.