We analyzed data from the 15% sample survey in the 2009 Population and Housing Census, the 3% sample in the 1999 national census, the 5% sample in the 1989 national census, and selected data from the 2008 Vietnam Household Living Standards Survey.
This resulted in a total of 342 houses, divided by the 30 census tracts selected for the study, resulting in a fraction of 11.4 houses per census tract.
To select the houses, considering the possibility of refusals, we added 30% of this sample size which comprised 342 houses, divided by the 30 census tracts selected for the study, resulting in a fraction of 11.4 houses per census tract.
After the removal of duplicates and genes with no curated protein sequences, a total of 479 genes from the Census were selected for the subsequent analysis.
The map in the right corner locates the four most vulnerable census tracts selected for the uncertainty and sensitivity analyses of the built environment.
We successfully linked 425 (99.8%) to the census and selected 3'350 sex- and age-matched controls.
All private households with permanent resident as of December 2011 in the 130 census tracts selected were listed.
Similarly, U.S. census tracts, selected to be relatively homogeneous for key sociodemographic indicators, may be a meaningful unit of analysis for some social and economic factors (Subramanian et al. 2005).
A three-stage sampling design was used with enumerator areas (one or more unified city blocks) based on the 2001 census survey selected at the first stage, households within the selected areas at the second stage and individuals within the households at the third stage.
Based on our community census, we selected a random sample of households in three of the following groups (target 30 per group): urban households that predominantly cook with clean fuels (i.e., LPG), rural households that predominantly cook with biomass fuels and have a chimney, and rural households that predominantly cook with biomass fuels but do not have a chimney.
