group with serum T4 >200 nmol/L on all occa- sions T 4 ~ 2 0 0g, roup with serum T4 ~ 2 0 n0mol/L on all occa- sions bl, slope for period T4 ~ 2 0 n0mol/L b2, slope for period T4 >200 nmol/L The major objective of the national screening programs for CHT is the pr...