An extensive search on the major databases did not yield any previous report on the factors associated with LBW in Nepal based on the community based survey covering the entire country. An updated knowledge on the factors contributing the higher Gefitinib clinical trial prevalence of LBW will enable to design a better public health intervention and contribute in child survival in Nepal. This study aimed to (i) identify the factors associated with low birth weight and (ii) compare factors associated with low birth weight among under-five children between 2006 and 2011. Methods The Nepal Demographic and Health Surveys (NDHS) of 2006 and 2011 [8,13] were nationally representative cross sectional studies based on multistage cluster sampling conducted every five years.

In first stage, the primary sampling units (wards in rural and sub wards in urban areas) were selected. In second stage, households were selected by a random selection of households from the wards. Details of clustering, listing, and sample selection have been explained elsewhere (11, 12). The intended sample in the 2006 survey (12) was 8600 women aged 15-49 years. A total of 4397 men in 2006, aged 15-59 years were interviewed from every second selected household. The 2011 survey interviewed 12,674 women and 4,121 men (11). The response rate was 96% in 2006 and 95.3% in 2011. Three sets of internationally validated questionnaires were used to collect different levels of information: (i) household information�Ccovered information about all the members of the household; (ii) women��s information; and (iii) men��s information (11, 12).

This study utilised the 2006 and 2011child datasets that contained information on under-five children. The datasets contained information on the child, mother, father, and household characteristics necessary for further analysis. Only those cases with recorded birth weight were included in the analysis. Multiple births were excluded from the study as this have been reported to be a known risk factors of LBW and may mask the effect of other socio-demographic variables due to its stronger effect on birth weight [14,15]. The children without a recorded birth weight were also excluded from the analysis. Conceptual framework To conceptualise the analysis, we adapted the framework used by Dharmalingam et al. [16]. Figure 1 illustrates the potential causal link to LBW in Nepal.

In this framework, Dharmalingam et al. [16] suggested that LBW is directly or indirectly caused by three major factors: Underlying factors (maternal socio-demographic characteristics), Proximate factors (maternal characteristics such as body mass index, service use, birth interval, smoking, use of type of cooking fuel), and Gestational and foetal growth factors (sex of infants, AV-951 mothers age and parity). In our study, the selection of factors were based on previously published studies including Dharmalingam et al. [16] and others [7,17].