The survey design was based on standard multistage cluster
sampling methods, and field work procedures were made as
robust as possible. Assessment of iodine status was based on the
use of UIC, which is a well-established tool for monitoring
iodine status in national and regional surveys (14). Although we
found no evidence of widespread goiter in the 2 zones in which
we carried out the examinations, caution is needed in the
comparison of visible goiter with other prevalence data, which is
usually based on total, rather than grade 2, goiter (11).