Subclinical hypothyroidism: a comparison of strategies to achieve adherence to treatment guidelines.
BACKGROUND
Subclinical hypothyroidism is an entity based on the laboratory findings of a raised serum thyrotrophin (TSH) concentration and a normal free thyroxine (FT(4)) concentration. Patients with subclinical hypothyroidism who also have anti-thyroid peroxidase (TPO) antibodies have a higher conversion to overt hypothyroidism than those without, and treatment with thyroxine is recommended.


METHODS
We audited anti-TPO assay requests within two NHS Trust hospitals, against consensus standards, to ascertain whether a cascade approach to anti-TPO testing and direct advice leads to more appropriate prescribing of thyroxine in general practice.


RESULTS
Our data show that where anti-TPO status was automatically tested for and clear advice for treatment given, >85% of patients were treated according to the standard required by the consensus document, with >90% of those recommended to be commenced on thyroxine actually doing so. In contrast, where anti-TPO was not routinely assessed, treatment was started in 46% of patients, without clear evidence that this was appropriate.


CONCLUSIONS
In order to better advise clinicians and in accordance with the agreed protocol, laboratory-generated cascade testing for anti-TPO antibodies should be an integral part of the investigation of subclinical hypothyroidism, and reports should contain appropriate interpretation and advice.
Lock
R J
RJ
Immunology and Immunogenetics, North Bristol NHS Trust, Southmead Hospital, Bristol BS10 5NB, UK.
Marden
N A
NA
Kemp
H J
HJ
Thomas
P H
PH
Goldie
D J
DJ
Gompels
M M
MM
D000906:Antibodies / Q000032:analysis; D019983:Guideline Adherence; D006801:Humans; D007037:Hypothyroidism / Q000150:complications / Q000628:therapy*; D007453:Iodide Peroxidase / Q000276:immunology; D007755:Laboratories, Hospital / Q000592:standards; D017410:Practice Guidelines as Topic; D013960:Thyroid Function Tests / Q000592:standards; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood / Q000627:therapeutic use
D000906:Antibodies; D013972:Thyrotropin; D007453:Iodide Peroxidase; D013974:Thyroxine