Table 1. Demographic characteristics of the patients.

Demographic characteristics	N	%
Age, mean (SD) months	14 (15)	-
Gender
Male	184	61
Female	116	39
Ethnicity
Malay	263	87.7
Chinese	11	3.7
Indian	21	7
Breast fed ≥ 6mths	116	38.7
In out-of-home care	192
Number of children in household, median (IQR)	5(4,6)	-
Number of people in household, median (IQR)	3(3,4)	-
Number of people co-sleeping with child, median (IQR)	3 (3,4)	-
Father’s educationa
Low	216	72
High	84	28
Mother’s educationa
Low	200	66.7
High	100	33.3
Total income, Median (IQR)
Has a past history of lower respiratory tract infection	70	23
Exposed to ETS	143	47.7
Vaccinated against pneumococcal	26	8.7
Vaccinated against Hib	270	90.0
Vaccinated against Influenza	11	3.7
Weight z score, median (IQR)	-1.07 (-5.54 to 4.00).	-
Prior antibiotics before admission	87	29

^aLow education is defined as low if have diploma and less while high was defined higher than diploma