The findings suggest that at the individual level neither
dietary methods nor spot urine samples provide adequate
accuracy in the assessment of 24-h urinary sodium relative
to the gold standard of measured 24-h urinary sodium.
However group mean errors from both dietary methods
(FFQ and modified 24-h dietary recall, a novel method that
can be completed in under 20 minutes) were small and
random and compare favourably with those from spot
urine samples in this population.