PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “THYROID FUNCTION TESTS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1987

Recent advances in routine thyroid function testing.

Thyroid function tests are one of the most common of endocrine laboratory investigations requested by general clinicians. The tests used therefore have to be efficient at identifying thyroid disease, monitoring treatment, and handling large numbers of tests. Recent advances in methodology have expanded both the range of in vitro thyroid function tests available and the techniques by which the well-established tests may be performed. This article reviews the methods and analytical and clinical performance of the routine tests currently available, concentrating particularly on the relatively new ones, and speculating on their role in strategies for the laboratory investigation of thyroid function.

Female↗
PubMed1984

Controversies in thyroid function testing.

Thyroid function tests can be abnormal in certain patients in the absence of thyroid dysfunction. All thyroid function tests can be affected in these patients, including the free thyroxine assays and free thyroxine index. Familiarity with the conditions affecting thyroid function tests is necessary to avoid incorrect diagnosis and unnecessary testing.

Female↗
PubMed1973

Discriminant value of thyroid function tests.

Different thyroid function tests permitted a final classification of 204 consecutive patients with suspected thyroid disorders into three populations (thyrotoxic, euthyroid, and hypothyroid). Linear discriminant analysis was applied to all test results (10 variates) on adjacent population pairs. Two invitro tests (serum protein bound iodine (P.B.I.) and tri-iodothyronine (T-3) uptake values) gave good separation of thyrotoxic from euthyroid patients and fairly good distinction of hypothyroid patients. If a (131)I uptake figure was then added to the in-vitro results most patients (95.5%), including thse initially classified as equivocal, were correctly diagnosed. Other tests, including clinical questionnaires, were poor discriminants.Two new techniques of utilizing the test data were devised. Firstly, the data from the two in-vitro tests were also displayed graphically, and oblique boundary lines derived from the discriminant functions gave better separation of patients than previously used limits or mathematical expressions of "free thyroxine." Secondly, a nomogram incorporating the best four discriminants was designed as a diagnostic aid and proved to be the best means of interpreting the tests.Discriminant analysis of this kind can be used in the interpretation of diagnostic tests in any branch of medicine, and it allows the best use to be made of the available data.

Diagnosis, Differential↗
PubMed1983

Effect of oral intake of thyroxine on results of thyroid function tests in patients receiving thyroid replacement therapy.

To investigate the effect of orally administered thyroxine on thyroid function tests, serial thyroid function tests were performed in 29 patients receiving maintenance thyroxine replacement therapy. The results showed that plasma thyroxine levels rose significantly in most subjects after an oral dose of thyroxine. The patients who had the largest rise had high basal levels and were taking a higher mean replacement dose of thyroxine. This increase may move a patient's thyroxine level from within the reference range to the abnormal range if blood is taken soon after thyroxine ingestion.

Administration, Oral↗
PubMed1997

The effects of modifying proficiency testing materials on thyroid function test results. A College of American Pathologists Ligand Assay Survey Study.

OBJECTIVE: To gain insight on the matrix effects, and possible clinical implications, resulting from diluting and concentrating proficiency testing survey material used for the measurement of thyroid function tests. DESIGN: To the standard set of five proficiency survey samples, three supplementary "Wildcard" samples were added. These additional samples were manufactured by overfilling and underfilling vials prior to lyophilization so as to vary the thyroxine-binding protein concentrations. Survey participants measured thyroxine, free thyroxine, and the triiodothyronine uptake and related tests on the Wildcard samples. In addition, free thyroxine indices were calculated. SETTING: The first mailing of the 1995 College of American Pathologists (CAP) Ligand Assay--Series 1 Survey. MAIN OUTCOME MEASURES: Results obtained from the regular set of survey samples and the Wildcard set were compared to values expected by the laws of conservation of matter and mass action. PARTICIPANTS: The approximately 2000 participants of the first mailing of the 1995 CAP Ligand Assay--Series 1 Survey. RESULTS: Numerous assays systems did not give the predicted results, including all of the single-step radioimmunoassays for free thyroxine and over three quarters of free thyroxine index determinations. CONCLUSIONS: Varying the dilution of proficiency survey material produced results that were not predicted by the laws of conservation of matter and of mass action. Although these observations may have been the result of matrix effects, one cannot rule out the possibility that certain thyroid assays may not work in clinical situations having abnormal thyroxine-binding protein concentrations.

Data Collection↗
PubMed1983

Thyroid function tests in thyroid and nonthyroid disease.

Modern day evaluation of thyroid disorders requires a combination of accurate clinical judgement and reliable, sensitive, and specific thyroid functions tests. Principle among the latter are thyroxine (T4) 3, 5, 3'-triiodothyronine (T3), and thyroid-stimulating hormone (TSH). Also playing an important role in special situations are free thyroxine, an assessment of bound and unbound thyroid-binding globulin, TRH stimulation, long-acting thyroid stimulator (LATS), antibodies to thyroid hormone and to thyroid receptors. Basic to interpretation of these tests in the clinical setting is a comprehension of the relationship of the hypothalamus, the pituitary, and the thyroid gland as well as a knowledge of the peripheral metabolism of thyroxine and triiodothyronine. The role of each of these laboratory tests in the evaluation of hyper- and hypometabolic states, their alteration in nonthyroid and other endocrine disorders, and the effects of environmental and physiological factors on these tests are reviewed.

Adult↗
PubMed1987

Determination of thyroxine, triiodothyronine, and cortisol changes during simultaneous adrenal and thyroid function tests in healthy dogs.

Changes in thyroxine (T4), triiodothyronine (T3), and cortisol during a combined adrenal (dexamethasone suppression/adrenocorticotrophic hormone response test) and thyroid function tests (thyroid-stimulating hormone [TSH] response test) were determined in 20 healthy hospitalized pet dogs. The effect of dexamethasone on T4 and T3 changes was evaluated during a simultaneous TSH response/dexamethasone suppression adrenocorticotrophic hormone response test. Greater ranges in basal cortisol concentrations and slower changes after dexamethasone was administered were observed in healthy pet dogs kenneled in a hospital setting than those reported for conditioned laboratory dogs. Pet dogs were observed to demonstrate cortisol suppression more reliably at 4 hours than at 2 hours after dexamethasone was administered. Dexamethasone had no effect on the response to TSH as assessed by T4 and T3 assays, thus supporting the validity of combining adrenal and thyroid response tests in a 5-hour period.

Adrenal Cortex Function Tests↗
PubMed1993

Thyroid function tests. Application of newer methods.

Thyroid function tests are often used to diagnose thyroid disease. Free thyroxine estimates and second- and third-generation assays for serum thyrotropin have simplified and enhanced the accuracy of thyroid function testing. All thyroid function tests have limitations and cannot be used in isolation of the clinical setting. Used appropriately, however, thyroid function tests are an invaluable aid in determining a patient's thyroid status.

Humans↗
PubMed2003

Reducing the number of T3 orders in the Paris hospital network: towards better appropriatness of thyroid function test prescription.

In vitro thyroid function tests are among the most frequently prescribed laboratory procedures. Serum triiodothyronine (T3) tests are seldom necessary as a first-level measurement. Our objectives were to measure the proportion of T3 measurements relative to all in vitro thyroid function tests in a large hospital network and to investigate the contributions of various interventions to change prescribers'behavior. We performed two cross-sectional surveys in 1995 and 1998 in the 50 Paris University hospitals. Questionnaires were mailed to the heads of the 30 laboratories performing thyroid function tests. One-month orders of free and total thyroxine, free and total T3 and thyrotropin were recorded; changes in T3 measurement orders between the two periods were estimated and association with interventions were expressed as odds ratios and 95% confidence intervals. Twenty-five heads of laboratory responded to both surveys. In 1995, T3 measurements constituted 21% of in vitro thyroid function test ordering, which seems to us exceedingly high. The decrease in T3 measurement ordering observed in 1998 (15% of thyroid function test ordering) was independently associated with multiple behavioral changes: educational interventions, structured test form use and year of prescription.

Humans↗