TSH test

[Guest guest]

Sheila,

You wrote:

>

> ...Any change you can find that paper again Chuck?

It's not quite what I remembered. The conclusion is that FT4 is more

" cost effective " than TSH for patients that are already hospitalized.

Plus, it is a bit dated. The generation 3 tests for both are more

precise now.

C Spencer, A Eigen, D Shen, M Duda, S Qualls, S Weiss and J Nicoloff,

" Specificity of sensitive assays of thyrotropin (TSH) used to screen for

thyroid disease in hospitalized patients, " _Clinical Chemistry_, Vol 33,

1391-1396, 1987.

Thyrotropin (TSH) concentrations were measured in 1580 hospitalized

patients and 109 normal persons. Using the mean +/- 3 SD limits of the

log values for the controls (0.35-6.7 milli-int. units/L), the

proportion of abnormal TSH results in the hospitalized patients was

17.2%. TSH was undetectable (less than 0.1 milli-int. unit/L) in 3.1% of

patients, suggesting hyperthyroidism, and high (greater than 20

milli-int. units/L) in 1.6%, suggesting hypothyroidism. On follow-up of

329 patients, 62% with abnormal TSH (less than 0.35 or greater than 6.7

milli-int. units/L) and 38% with normal TSH concentrations, only 24% of

those with undetectable TSH had thyroid disease: 36% of them were being

treated with glucocorticoids and 40% had nonthyroidal illness (NTI).

Although half the patients with TSH greater than 20 milli-int. units/L

had thyroid disease, 45% of patients had high TSH values associated with

NTI. TSH concentrations usually returned towards normal when patients'

therapy with glucocorticoids was discontinued or they recovered from

NTI. TSH test sensitivity appeared good when the mean +/- 3 SD limits of

the reference population were used, i.e., no cases of hyper- or

hypothyroidism, as identified by free thyroxin index (FT4I), were

missed. However, TSH test specificity was inferior to that of the FT4I

test (90.7% vs 92.3%), although specificity could be improved to 97.0%

if the wider TSH reference limits of 0.1 to 20 milli-int. units/L were

used--limits considered pathological if applied to outpatients.

Evidently, different reference intervals for TSH are needed for

hospitalized and nonhospitalized patients. We conclude that a " sensitive

TSH assay " is not a cost-effective thyroid screening test for

hospitalized patients as compared with the FT4I.

http://www.clinchem.org/cgi/content/abstract/33/8/1391

[Guest guest]

Re: TSH test

Sheila,You wrote:> > ...Any change you can find that paper again Chuck?It's not quite what I remembered. The conclusion is that FT4 is more "cost effective" than TSH for patients that are already hospitalized. Plus, it is a bit dated. The generation 3 tests for both are more precise now.C Spencer, A Eigen, D Shen, M Duda, S Qualls, S Weiss and J Nicoloff,"Specificity of sensitive assays of thyrotropin (TSH) used to screen for thyroid disease in hospitalized patients," _Clinical Chemistry_, Vol 33, 1391-1396, 1987.Thyrotropin (TSH) concentrations were measured in 1580 hospitalized patients and 109 normal persons. Using the mean +/- 3 SD limits of the log values for the controls (0.35-6.7 milli-int. units/L), the proportion of abnormal TSH results in the hospitalized patients was 17.2%. TSH was undetectable (less than 0.1 milli-int. unit/L) in 3.1% of patients, suggesting hyperthyroidism, and high (greater than 20 milli-int. units/L) in 1.6%, suggesting hypothyroidism. On follow-up of 329 patients, 62% with abnormal TSH (less than 0.35 or greater than 6.7 milli-int. units/L) and 38% with normal TSH concentrations, only 24% of those with undetectable TSH had thyroid disease: 36% of them were being treated with glucocorticoids and 40% had nonthyroidal illness (NTI). Although half the patients with TSH greater than 20 milli-int. units/L had thyroid disease, 45% of patients had high TSH values associated with NTI. TSH concentrations usually returned towards normal when patients' therapy with glucocorticoids was discontinued or they recovered from NTI. TSH test sensitivity appeared good when the mean +/- 3 SD limits of the reference population were used, i.e., no cases of hyper- or hypothyroidism, as identified by free thyroxin index (FT4I), were missed. However, TSH test specificity was inferior to that of the FT4I test (90.7% vs 92.3%), although specificity could be improved to 97.0% if the wider TSH reference limits of 0.1 to 20 milli-int. units/L were used--limits considered pathological if applied to outpatients. Evidently, different reference intervals for TSH are needed for hospitalized and nonhospitalized patients. We conclude that a "sensitive TSH assay" is not a cost-effective thyroid screening test for hospitalized patients as compared with the FT4I.http://www.clinchem.org/cgi/content/abstract/33/8/1391No virus found in this incoming message.

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[Guest guest]

Oh - what a shame. Thanks anyway Chuck.

Sheila

It's not quite what I remembered. The conclusion is that FT4 is more "cost effective" than TSH for patients that are already hospitalized. Plus, it is a bit dated. The generation 3 tests for both are more precise now.C Spencer, A Eigen, D Shen, M Duda, S Qualls, S Weiss and J Nicoloff,"Specificity of sensitive assays of thyrotropin (TSH) used to screen for thyroid disease in hospitalized patients," _Clinical Chemistry_, Vol 33, 1391-1396, 1987.

.. No virus found in this incoming message.

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[Guest guest]

I've just come across an interesting article,and have tried to mail it

to the group (an excerpt from Clinical chemistry).

I'm not very 'puter literate, so it may or may not arrive, and may or

may not have my ID on it (e-mail addy)

At present am in a state of total dismay and feel I'm just ramming my

head into a brick wall, with regards to endo's and doc's, but am going

to take time out and recover, and will be back with a vengeance. If

necessary I will insist on seeing a psych, just to prove I've not got

my head on back to front.

Sorry, rambling - frustrated, tired etc etc...

A

[Guest guest]

Hi jennyA,

Yes article did arrive! Interesting.

I know the feeling I gave up with NHS years ago.

Subject: TSH test

I've just come across an interesting article,and have tried to mail it

to the group (an excerpt from Clinical chemistry).

Sorry, rambling - frustrated, tired etc etc...

A

------------------------------------

TPA is not medically qualified. Consult with a qualified medical

practitioner before changing medication.

[Guest guest]

Hi Angel, please would you send us the link to this Abstract so

we can check it ourselves.

Luv - Sheila

Hi all, PUBMED=

evaluation of usefulness of a sensitive immunoradiometric assay for

thyroid stimulating hormone as a first-line thryoid function test in an

unselected patient population. ericsson ub, femlund p,

thorell jl.

scand j clin invest 1987 may;47(3):215-21.

A new sensitive immunoraddiometric assay for serum thyroid stimulating hormone

(TSH)was applied to 1627 consecutive patients from four large clinics at malmo

general hospital, in whom a thyroid function disorder was suspected. the final

diagnoses were taken from the patients` charts at a follow-up 1-2 years after

the primary evaluation. if only those patients without thyroid disease were

used as a reference population, the 5th percentile was 0.8mlu/l.

when this cutoff limit was applied to the unselected patient population, the

TSH assay had a high sensitivity for the diagnosis of hyperthyroidism((96%)

a lower specificity (64%) and a low predictive value (10%). therefore, in the

majotity of patients (72%) the sensitive TSH assay CANNOT BE USED ALONE TO

DEFINE THYROID FUNCTION.

this is for hyperthyroidism so could also apply for hypothyroidism.???

so much for the sensitivity of blood

tests.

regards angel.