Stata svy
The -svy- prefix command adjusts estimation commands to take a survey design into account.
Usage
The -svyset- command must be used first, to declare the survey design.
As an example:
use https://stats.idre.ucla.edu/stat/stata/faq/svysmall, clear svyset house [pweight = wt], strata(eth) svy: regress y x1 x2 x3
svy commands use t statistics with n - L df, where n is the number of PSUs and L is the number of first stage strata, rather than Z statistics. Following from this, the test command technically runs an adjusted Wald test.
svy estimation commands like regress use maximum pseudo-likelihood rather than ML.