The screening programme for congenital hypothyroidism in Greece: evidence of iodine deficiency in some areas of the country.

Newborn screening for Congenital Hypothyroidism, using TSH measurement in dried blood spots, was started in Greece in 1979. A total of 1,274,000 neonates have been screened and 377 cases of Congenital Hypothyroidism were detected, for an incidence of 1:3370. Employing a cut-off point of 30 mU/L of TSH in whole blood, 0.3% of the infants were recalled for repeat examination. The sensitivity of the screening test was 0.99 and the predictive value of a positive test 0.1. The frequency of "false positive" cases in the different geographic regions of Greece showed wide variation between the south and the north areas of the country. We suggest that these differences reflect the degree of iodine deficiency in the population and may be used as an epidemiological indicator of this deficiency.