Table 1.

Summary of HCHS/SOL Sample Design Features

Sampling Stage	Sampling Unit and Frame Source(s)	Stratification and Stratum Allocation	Random Selection Method in Each Stratum
1	Sampling unit: Block group (BG) as defined for the 2000 Census Frame: List of BGs created from the designated community area at the site, defined in each stratum as a set of contiguous BGs.	Explicit strata formed by crossclassification of: (i) “high”/“low” categories according to % Hispanic among total population in 2000 and (ii) “high”/“low” socio-economic status as measured by % of the population with at least a high school education. One or more special strata were defined in a subset of sites to target specific population subgroups. Disproportionately higher BG sampling rates for strata in the “high” % Hispanic category; proportionate allocation to “high” and “low” SES categories within each % Hispanic category	Simple random sampling
2	Sampling Unit: Household address Frame source: US Postal Service listing of addresses available through MSG- Genesys	Explicit strata formed by whether/not the occupant has an Hispanic surname Disproportionately higher address sampling rate for Hispanic surname addresses; uniform stratum-specific address sampling rates among sample BGs	Simple random sampling