THYROID FUNCTION COMMENTS – FOR AUTOVALIDATION GROUPS

Code / Comment / TSH / FT4 / FT3
T1 / Normal TSH supports euthyroidism. / 0.40 - 4.00 / Either no FT4
or 10 - 24 / Either no FT3
or 2.5 – 6.0
T2 / Normal TSH supports euthyroidism. Low FT4 may be attributable to drugs or non-thyroidal illness. / 0.40 - 4.00 / = 9 / Either no FT3
or 2.5 – 6.0
TSIXA / If the patient is not on thyroxine, the TSH suppression is unexplained and should be reviewed in clinical context. / <0.40 (test add FT4 and FT3 if not there) / 10 - <20 / 2.5 – 6.0
TSIXB / If the patient is not on thyroxine, consider subclinical hyperthyroidism.
Suggest review in clinical context and consider repeat TFT's in 3-6 months. / <0.40 - 0.1 / 20 – 24 / 2.5 – 6.0
TSIXC / If the patient is not on thyroxine, consider hyperthyroidism. Suggest review in clinical context and consider repeat TFT's in 3-6 months. / 0.1 / 20 - 24 / 2.5 – 6.0
T7 / Consistent with primary hypothyroidism. / >10 / <10 / Either no FT3
or < 2.5
T9 / Elevated TSH suggests propensity to primary hypothyroidism. Suggest monitor at least annual TFTs or sooner if clinically indicated. / 4 – 7 (if >4, test add FT4) / 10 - 15 / Either no FT3
or 2.5 – 6.0
T14 / Low FT4 may be attributable to drugs or non-thyroidal illness. Normal TSH supports euthyroidism, although secondary (pituitary) hypothyroidism should be considered. / 0.40 – 4.00 / <9 / Either no FT3
or 6.0
T15 / Consistent with hyperthyroidism. / <0.40 / >24 / Either no FT3
or 6.0
T18 / High FT3 in the presence of suppressed TSH and normal or low FT4 suggests either T3 ingestion or possible T3-toxicosis. / <0.40 / 10 / > 6.0

NB: &T6 removed and replaced with comments &TSIXA, &TSIXB and &TSIXC – April 2015 (job #9143)