Table 1 Description of explanatory variables included in the analysis, NFHS-4 (2015–16)

 Place of residence

Coded as 1 = Urban, 2 = Rural

 Caste

Coded as 1 = Scheduled Castes, 2 = Scheduled Tribes, 3 = Other Backward Classes, 4 = Others

 Religion

Coded as 1 = Hindu, 2 = Muslim, 3 = Others

 Maternal education

Coded as 1 = Illiterate/Primary, 2 = Secondary, 3 = Higher

 Father’s education

Coded as 1 = Illiterate/Primary, 2 = Secondary, 3 = Higher

 Maternal age

Self-reported ages coded as 1 = 15–24, 2 = 25–34, 3 = 35–49 years

 Maternal BMI

BMI was calculated from height and weight of the mother as per WHO standards: 1 = Underweight, 2 = Normal, 3 = Overweight/obese

 Access to mass media

Measured from frequency of reading newspapers/magazines, listening radio and watching television: 1 = No, 2 = Yes

 Household size

Classified as 1 = Less than 6, 2 = Above 6

 Wealth quintile

Access to household assets including dwelling characteristics, categorized into 5 quintile: 1 = Poorest, 2 = Poorer, 3 = Middle, 4 = Richer, 5 = Richest

 Region

Regions of residence as provided by NFHS: 1 = North, 2 = Central, 3 = East, 4 = Northeast, 5 = West, 6 = South

 Age of child

Self-reported ages coded as 1 = 0–11, 2 = 12–23, 3 = 24–35, 4 = 36–47, 5 = 48–59 months

 Sex of child

1 = Male, 2 = Female

 Birth order

Categorized into 3 groups: 1 = 1, 2 = 1–3, 3 = 4+

 Birth weight

Classified as 1 = < 2.5 kg (low birth weight), 2 = ≥2.5 kg (normal)

 Availability of toilet facility

Coded as 1 = No facility, 2 = Facility

 Sources of drinking water

Coded as 1 = Improved, 2 = Unimproved

 Child stool disposal

Coded as 1 = Not safe, 2 = Safe

 Main floor materials

Coded as 1 = Dirt, 2 = Non-dirt

 Main roof materials

Coded as 1 = Thatch, 2 = Concrete/metal