Universal screening for thyroid disease SHOULD NOT be recommended before and during pregnancy.

Thyroid dysfunction in pregnancy is strongly associated with adverse maternal and foetal outcomes. The effects of treatment are less clear. There is ongoing discussion on whom to treat, when to treat and whether treatment is beneficial. Although universal screening for thyroid disease during pregnancy increases diagnosis and treatment of thyroid dysfunction, there is currently insufficient evidence demonstrating a positive effect of screening on maternal and foetal outcomes. We therefore, at present, recommend against universal screening for thyroid disease before and during pregnancy.

Frequency of thyroid function tests and examinations in participants of a population-based study.

BACKGROUND: Thyroid disorders are common in the adult German population. Little is known about guideline implementation in clinical practice and the prevalence of diagnostic procedures in ambulatory care. The study aims to investigate the use of thyroid hormone measurements, thyroid ultrasound, thyroid scintiscan and associated costs in ambulatory care at population level. METHODS: Data were derived from two independent population-based cohorts of the Study of Health In Pomerania (SHIP). Ambulatory billing data from the Association of Statutory Health Insurance Physicians Mecklenburg-Vorpommern were individually linked for the period 2002-2016 with SHIP data. The main outcomes were the frequency of outpatient ultrasound, scintiscan, serum TSH level measurement, free triiodothyronine (fT3) and free thyroxine (fT4) measurement, TSH-receptor-antibodies and microsomal antibodies measurement within 1 year and 3 years prior to the study entrance of the participants. Multinomial logistic regression models were used to assess the association of age, sex, thyroid medication intake and Charlson-Comorbidity-Index with frequency of TSH measurements and ultrasound examinations. RESULTS: A total of 5552 participants (47% male, median age 55) were included in the analysis. 25% (1409/5552) had a diagnosed thyroid disorder or treatment, 40% (2191/5552) had clinical findings based on ultrasound or laboratory testing in SHIP only and 35% (1952/5552) neither a coded thyroid disorder or clinical finding nor thyroid medication. In the total study population 30% (1626/5552) received at least one TSH measurement, 6.8% (378/5552) at least one thyroid ultrasound and 2.6% (146/5552) at least one scintiscan within the past year before the study examination. Tests were performed more frequently in patients with thyroid medication and coded thyroid disorders. Hence, this group caused the highest expenditures. CONCLUSIONS: Given the high prevalence of thyroid disorders, diagnostic and monitoring tests should be used rationally with regard to costs. TSH levels should be monitored regularly in patients on thyroid medication. A consensus on monitoring frequency and iteration of monitoring of morphological thyroid disorders with TSH and ultrasound and specific guideline recommendations are needed. TRIAL REGISTRATION: Versorgungsforschung Deutschland (VfD_17_003880).

Reducing waste: a guidelines-based approach to reducing inappropriate vitamin D and TSH testing in the inpatient rehabilitation setting.

Background: Laboratory overutilisation increases healthcare costs, and can lead to overdiagnosis, overtreatment and negative health outcomes. Discipline-specific guidelines do not support routine testing for Vitamin D and thyroid-stimulating hormone (TSH) in the inpatient rehabilitation setting, yet 94% of patients had Vitamin D and TSH tests on admission to inpatient rehabilitation at our institution. Our objective was to reduce Vitamin D and TSH testing by 25% on admission to inpatient Stroke, Spinal Cord Injury, Acquired Brain Injury and Amputee Rehabilitation units. Methods: A fishbone framework for root cause analysis revealed potential causes underlying overutilisation of Vitamin D and TSH testing. A series of Plan-Do-Study-Act (PDSA) cycles were introduced to target remediable factors, starting with an academic detailing intervention with key stakeholders that reviewed applicable clinical guidelines for each patient care discipline and the rationale for reducing admission testing. Simultaneously, computerised clinical decision support (CCDS) limited Vitamin D testing to specific criteria. Audit and feedback were used in a subsequent PDSA cycle. Frequency of Vitamin D and TSH testing on admission was the primary outcome measure. The number of electronic admission order caresets containing automatic Vitamin D and/or TSH orders before and after the interventions was the process measure. Rate of Vitamin D supplementation and changes in thyroid-related medication were the balancing measures. Results: After implementation, 2.9% of patients had admission Vitamin D testing (97% relative reduction) and 53% of patients had admission TSH testing (43% relative reduction). Admission order caresets with prepopulated Vitamin D and TSH orders decreased from 100% (n=6) to 0%. The interventions were successful; similar to previous literature, CCDS was more effective than education and audit and feedback interventions alone. The interventions represent >$9000 annualised savings.

Stability of thyroid function in older adults: the Birmingham Elderly Thyroid Study.

BACKGROUND: Thyroid function tests (TFTs) are among the most requested tests internationally. However, testing practice is inconsistent, and potentially suboptimal and overly costly. The natural history of thyroid function remains poorly understood. AIM: To establish the stability of thyroid function over time, and identify predictors of development of overt thyroid dysfunction. DESIGN AND SETTING: Longitudinal follow-up in 19 general practices in the UK. METHOD: A total of 2936 participants from the Birmingham Elderly Thyroid Study (BETS 1) with a baseline TFT result indicating euthyroid or subclinical state were re-tested after approximately 5 years. Change in thyroid-stimulating hormone (TSH), free thyroxine (FT4), and thyroid status between baseline and follow-up was determined. Predictors of progression to overt dysfunction were modelled. RESULTS: Participants contributed 12 919 person-years; 17 cases of overt thyroid dysfunction were identified, 13 having been classified at baseline as euthyroid and four as having subclinical thyroid dysfunction. Individuals with subclinical results at baseline were 10- and 16-fold more likely to develop overt hypothyroidism and hyperthyroidism, respectively, compared with euthyroid individuals. TSH and FT4 demonstrated significant stability over time, with 61% of participants having a repeat TSH concentration within 0.5 mIU/L of their original result. Predictors of overt hypothyroidism included new treatment with amiodarone (odds ratio [OR] 92.1), a new diagnosis of atrial fibrillation (OR 7.4), or renal disease (OR 4.8). CONCLUSION: High stability of thyroid function demonstrated over the 5-year interval period should discourage repeat testing, especially when a euthyroid result is in the recent clinical record. Reduced repeat TFTs in older individuals is possible without conferring risk, and could result in significant cost savings.

Analysis of current thyroid function test ordering practices.

RATIONALE: Current guidelines recommend thyroid stimulating hormone (TSH) alone as the best test to detect and monitor thyroid dysfunction, yet free thyroxine (FT4) and free triiodothyronine (FT3) are commonly ordered when not clinically indicated. Excessive testing can lead to added economic burden in an era of rising healthcare costs, while rarely contributing to the evaluation or management of thyroid disease. OBJECTIVE: To evaluate our institution's practice in ordering thyroid function tests (TFTs) and to identify strategies to reduce inappropriate FT4 and FT3 testing. METHODS: A record of all TFTs obtained in the San Antonio Military Health System during a 3-month period was extracted from the electronic medical record. The TFTs of interest were TSH, FT4, thyroid panel (TSH + FT4), FT3, total thyroxine (T4), and total triiodothyronine (T3). These were categorized based on the presence or absence of hypothyroidism. RESULTS: Between August 1 and October 31, 2016, there were 38 214 individual TFTs ordered via 28 597 total laboratory requests; 11 486 of these requests were in patients with a history of hypothyroidism. The number (percent) of laboratory requests fell into these patterns: TSH alone 14 919 (52.14%), TSH + FT4 7641 (26.72%), FT3 alone 3039 (10.63%), FT4 alone 1219 (4.26%), TSH + FT4 + FT3 783 (2.74%), and others 996 (3.48%); 36.0% of TFTs ordered were free thyroid hormones. Projected out to a year, using Department of Defense laboratory costs, $317 429 worth of TFTs would be ordered, with free thyroid hormone testing accounting for $107 720. CONCLUSION: Inappropriate ordering of free thyroid hormone tests is common. In an era of rising healthcare costs, inappropriate thyroid function testing is an ideal target for efforts to reduce laboratory overutilization, which in our system, could save up to $120 000 per year. Further evaluation is needed to determine strategies that can reduce excessive thyroid hormone testing.

Adoption of TSH Reflex algorithm in an Italian clinical laboratory.

BACKGROUND: TSH Reflex is an automated diagnostic algorithm which follows the rule "If ... then", in which the initial determination of TSH is followed by the determination of fT4, and possibly of fT3, if TSH is not within the reference limits. The aim of our study was to evaluate the results of the introduction and implementation of the test "TSH Reflex", which started in late 2013 in the hospital of Grosseto, comparing the requests of thyroid hormones for external patients, in 2012, 2014 and 2015. METHODS: In our study we analyzed the number of thyroid tests prescribed in 2012, 2014 and 2015 and we calculated the increase in prescription of "TSH Reflex" from 2014 to 2015; the prescriptive appropriateness, after the introduction of the "TSH Reflex", through the ratios TSH/FT4, TSH/FT3 and the ratio "TSH Reflex"/TSH. Finally we calculated the total spending for the reagents in 2012, 2014 and 2015 and the consequent savings in euros (the costs of the reagents did not change during that time). RESULTS: Requests for TSH decreased by 4.6% in 2014, compared to 2012 and by 5.4% in 2015 compared to 2014, with a 9.8% reduction in 2015 compared to 2012. The requests for FT4 decreased by 11.5%, comparing 2014 with 2012, by 5.3% comparing 2015 with 2014, with a 16.2% reduction in 2015 compared to 2012. The requests for FT3 decreased by 13.3% in 2014 compared to 2012 and by 8.4% in 2015 compared to 2014, with a 20.6% reduction in 2015 compared to 2012. The appropriateness, evaluated the indicator TSH/FT4, increased by 7.6%, comparing 2014 with 2012, and remained unchanged in 2015. In 2012 71,134 euros were spent, 63,998 euros in 2014, 60,055 euros in 2015, resulting in a saving of € 11,079 in 2015 compared to 2012. The spending for "TSH Reflex" should be subtracted (1,964 Euros in 2015) from the previous savings. CONCLUSIONS: The improvement of the efficiency and the prescriptive appropriateness was better in 2014, the first year of implementation of the "TSH Reflex". The overall assessment suggests that the 2014 results are attributable to the letters that general practitioners received in December 2013, with a temporary increase of the use of the test. We need further analyses with the same indicators in order to assess the possibility of additional improvements in the future.

Monitoring Thyroid Function in Patients on Levothyroxine. Assessment of Conformity to National Guidance and Variability in Practice.

With demand for endocrine tests steadily increasing year-on-year, we examined thyroid function test (TFT) frequencies in patients on levothyroxine replacement therapy to assess the effect of initial TFT results and request source on TFT re-testing interval. All TFTs performed by the Clinical Biochemistry Departments at the Salford Royal Hospital (2009-2012; 288 263 requests from 139 793 patients) and University Hospital of North Midlands (2011-2014; 579 156 requests from 193 035 patients) were extracted from the laboratory computer systems. Of these, 54 894 tests were on 13 297 patients confirmed to be on levothyroxine therapy in the test cohort (Salford) and 67 298 requests on 11 971 patients in the confirmatory cohort (North Midlands). In the test cohort, median TFT re-testing interval in the total group was 19.1 weeks (IQR 9.1-37.7 weeks), with clearly defined peaks in TFT re-testing evident at 6 and 12 months and a prominent broad peak at 1-3 months. Median re-test interval was much lower than recommended (52 weeks) for those with normal TFTs at 31.3 weeks (30.6 weeks for the confirmatory cohort). Where thyroid-stimulating hormone (TSH) was elevated and free thyroxine (fT4) was below the reference range, re-test interval was much longer than is recommended (8 weeks) at 13.4-17.6 weeks (7.1-23.4 weeks in the confirmatory cohort), as was the interval when TSH was below and fT4 was above the normal range, at 16.7-25.6 weeks (27.5-31.9 weeks in the confirmatory cohort). Our findings show that the majority of TFT requests are requested outside recommended intervals and within-practice variability is high. A new approach to ensuring optimum monitoring frequency is required. Direct requesting from the clinical laboratory may provide one such solution.

Effectiveness of interventions to reduce ordering of thyroid function tests: a systematic review.

OBJECTIVES: To evaluate the effectiveness of behaviour changing interventions targeting ordering of thyroid function tests. DESIGN: Systematic review. DATA SOURCES: MEDLINE, EMBASE and the Cochrane Database up to May 2015. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: We included studies evaluating the effectiveness of behaviour change interventions aiming to reduce ordering of thyroid function tests. Randomised controlled trials (RCTs), non-randomised controlled studies and before and after studies were included. There were no language restrictions. STUDY APPRAISAL AND SYNTHESIS METHODS: 2 reviewers independently screened all records identified by the electronic searches and reviewed the full text of any deemed potentially relevant. Study details were extracted from the included papers and their methodological quality assessed independently using a validated tool. Disagreements were resolved through discussion and arbitration by a third reviewer. Meta-analysis was not used. RESULTS: 27 studies (28 papers) were included. They evaluated a range of interventions including guidelines/protocols, changes to funding policy, education, decision aids, reminders and audit/feedback; often intervention types were combined. The most common outcome measured was the rate of test ordering, but the effect on appropriateness, test ordering patterns and cost were also measured. 4 studies were RCTs. The majority of the studies were of poor or moderate methodological quality. The interventions were variable and poorly reported. Only 4 studies reported unsuccessful interventions but there was no clear pattern to link effect and intervention type or other characteristics. CONCLUSIONS: The results suggest that behaviour change interventions are effective particularly in reducing the volume of thyroid function tests. However, due to the poor methodological quality and reporting of the studies, the likely presence of publication bias and the questionable relevance of some interventions to current day practice, we are unable to draw strong conclusions or recommend the implementation of specific intervention types. Further research is thus justified. TRIAL REGISTRATION NUMBER: CRD42014006192.

[Cost-effectiveness analysis of universal screening for thyroid disease in pregnant women in Spain]. / Análisis coste-efectividad del cribado universal de la enfermedad tiroidea en mujeres embarazadas en España

OBJECTIVE: To assess the cost-effectiveness of universal screening for thyroid disease in pregnant women in Spain as compared to high risk screening and no screening. METHODOLOGY: A decision-analytic model comparing the incremental cost per quality-adjusted life year (QALY) of universal screening versus high risk screening and versus no screening. was used for the pregnancy and postpartum period. Probabilities from randomized controlled trials were considered for adverse obstetrical outcomes. A Markov model was used to assess the lifetime period after the first postpartum year and account for development of overt hypothyroidism. The main assumptions in the model and use of resources were assessed by local clinical experts. The analysis considered direct healthcare costs only. RESULTS: Universal screening gained .011 QALYs over high risk screening and .014 QALYS over no screening. Total direct costs per patient were €5,786 for universal screening, €5,791 for high risk screening, and €5,781 for no screening. Universal screening was dominant compared to risk-based screening and a very cost-effective alternative as compared to no screening. Use of universal screening instead of high risk screening would result in €2,653,854 annual savings for the Spanish National Health System. CONCLUSIONS: Universal screening for thyroid disease in pregnant women in the first trimester is dominant in Spain as compared to risk-based screening, and is cost-effective as compared to no screening (incremental cost-effectiveness ratio of €374 per QALY). Moreover, it allows diagnosing and treating cases of clinical and subclinical hypothyroidism that may not be detected when only high-risk women are screened.

Assessment of thyroid function during first-trimester pregnancy: what is the rational upper limit of serum TSH during the first trimester in Chinese pregnant women?

CONTEXT: Guidelines of the American Thyroid Association (ATA) proposed that the upper limit of the TSH reference range should be 2.5 mIU/L in first trimester, but the reported ranges in China are significantly higher. OBJECTIVE: Our objective was to establish a rational reference range of serum TSH for diagnosis of subclinical hypothyroidism in the first trimester of pregnant women in China. DESIGN: We screened 4800 pregnant women in the first trimester and 2000 women who planned to become pregnant and evaluated 535 pregnant women in follow-up visits during the second and third trimester. RESULTS: Median concentrations of serum TSH decreased significantly from the seventh week of gestation. The median of TSH from 4 to 6 weeks was significantly higher than from 7 to 12 weeks (2.15 [0.56-5.31] mIU/L vs 1.47 [0.10-4.34] mIU/L, P<.001); however, there was no significant difference compared with nonpregnant women (2.07 [0.69-5.64] mIU/L; P=.784). The median of free T4 was not significantly altered in the first trimester. The prevalence of subclinical hypothyroidism in the 4800 pregnant women was 27.8% on the diagnostic criteria of TSH>2.5 mIU/L and 4.0% using the reference interval derived by our laboratory (0.14-4.87 mIU/L).Additionally, of 118 pregnant women who had serum TSH>2.5 mIU/L in the first trimester, only 30.0% and 20.3% of them at the 20th and 30th week of gestation had TSH>3.0 mIU/L. CONCLUSIONS: The reference range for nonpregnant women can be used for the assessment of pregnant women at 4 to 6 weeks of gestation. The upper limit of serum TSH in the first trimester was much higher than 2.5 mIU/L in Chinese pregnant women.

Medically underserved girls receive less evaluation for short stature.

OBJECTIVE: To determine if gender is associated with diagnostic evaluation by primary care pediatricians caring for children with growth-faltering. PATIENTS AND METHODS: This was a retrospective study of children who were attending 4 urban pediatric primary care practices affiliated with a tertiary pediatric hospital. Growth-faltering was defined as height at the <5th percentile or a z-score decrease of ≥ 1.5 SDs before 18 months of age or ≥ 1 SD thereafter. For each child, height z score, age, gender, race, insurance, diagnostic tests, and subspecialist appointments were examined. RESULTS: Of 33 476 children, 3007 had growth-faltering (mean height: -1.5 ± 1.0 vs 0.3 ± 0.9 SDs in those without growth-faltering). Boys comprised 53% of the growth-faltering group (vs 51% of the nonfaltering group; P < .01). Among children with growth-faltering, 2.8% had endocrinology appointments (vs 0.8% of others; P < .0001) and 6% had gastroenterology appointments (vs 1.5% of others; P < .0001). Subspecialty care was not associated with gender. Pediatricians ordered diagnostic tests for a significantly greater proportion of children with growth-faltering than others. In multivariate analysis of height z score among children with growth-faltering, tests for chromosomes (1.4% of short girls vs 0.4% of short boys; P < .005) and growth hormone/insulin-like growth factor axis (0.9% of short girls vs 1.8% of short boys; P < .05) were associated with gender. Thirty-five percent of the girls for whom chromosome testing was performed were 12 years old or older. CONCLUSIONS: Patterns in diagnostic testing of children with growth-faltering by their pediatricians may lead to underdiagnosis of Turner syndrome and growth hormone deficiency among girls.

[Overutilization of clinical biochemical analyses?]. / Overrekvirering av laboratorieanalyser i medisinsk biokjemi.

BACKGROUND: A pilot study was conducted in order to highlight the possibly unnecessary requisitioning of biochemical analyses in a Norwegian hospital. MATERIAL AND METHODS: The following parameters from consecutive patients and focusing repeated testing were included in the study: i) serum protein electrophoresis (30 patients), ii) thyroid function tests in serum (43 patients), iii) prothrombin time test (PT-INR) (30 patients), iv) haemoglobin (30 patients) and v) an analysis package of 13 single tests designed for the primary investigation of "acute abdomen" (30 patients). Criteria for correct and incorrect requisitioning were defined. RESULTS: 69% of the acute abdomen test package requisitions were incorrect, although single tests within the package may have been justified. 17% of PT-INR and 15% of haemoglobin tests were superfluous, while nearly all serum protein electrophoresis and thyroid analyses were not unnecessarily repeated. INTERPRETATION: The study demonstrated a clear possibility for reducing financial as well as labour costs by correct requisitioning of biochemical analyses, without loss to the quality of diagnostic service and treatment.

Assessment of hypothyroidism in patients with chronic heart failure.

STUDY OBJECTIVE: To determine whether appropriate thyroid function measurements were being conducted in patients receiving care at a multidisciplinary heart failure clinic. DESIGN: Retrospective chart review. SETTING: University-affiliated outpatient clinic. PATIENTS: One hundred ninety-three patients with heart failure. INTERVENTION: Patients enrolled in the heart failure clinic at the Medical University of South Carolina from January 2000-April 2003 were identified. Their medical records were reviewed for demographics, New York Heart Association (NYHA) functional classification, laboratory data, and date of most recent heart failure clinic appointment. MEASUREMENTS AND MAIN RESULTS: The records of 193 patients (43% women) were reviewed. Overall and subgroup analyses were performed based on patient characteristics such as presence of thyroid-stimulating hormone (TSH) level, interval since last heart failure clinic appointment, presence of thyroid replacement therapy, amiodarone use, NYHA functional class, and attending physician. Of the 193 patients, 77 (40%) had appropriate TSH monitoring, whereas 10 (32%) of 31 patients receiving amiodarone had appropriate monitoring. Forty-four (27%) patients not receiving amiodarone had no record of a TSH level. In 22 patients (11%), hypothyroidism was diagnosed and treated, whereas 16 patients (8%) had an abnormal TSH level but received no therapy. CONCLUSION: Forty percent of the 193 patients at this outpatient heart failure clinic received appropriate TSH monitoring. An opportunity exists for protocol implementation and education of pharmacists, nurse practitioners, and physicians concerning appropriate thyroid function monitoring in the heart failure population.

Therapeutic drug monitoring of mood stabilizers in Medicaid patients with bipolar disorder.

OBJECTIVE: The authors' goal was to determine the extent and pattern of blood serum monitoring of mood stabilizers in Medicaid patients with bipolar disorder. METHOD: Data were drawn from a Medicaid medical claims data set from Pittsburgh and the surrounding region. The authors identified bipolar patients using lithium, valproate, and carbamazepine (N = 718) and then examined the patient demographic, diagnostic, and service use variables associated with therapeutic drug monitoring. RESULTS: A substantial proportion of lithium users (36.5%), valproate users (42.4%), and carbamazepine users (42.2%) with bipolar disorder diagnoses did not receive therapeutic drug level testing during the 12-month study period. Carbamazepine users who were male or in the 30-49-year age range were significantly less likely to be tested for serum drug level. Lithium users who did not receive partial-hospitalization psychiatric services and valproate users who received mental health case management were also less likely to be tested for serum drug level. Over one-half of the lithium users (54.1%) did not receive thyroid function tests, and few (4.2%) received renal function tests. Patients who did receive tests for serum drug level were likely to receive the other recommended tests. CONCLUSIONS: Many Medicaid patients with bipolar disorder received no therapeutic drug monitoring. Patient sociodemographic characteristics contributed little to explaining this omission, although some types of service utilization were related to rates of serum drug level testing.

[Thyroid hormone determination at the Public Assistance Hospital of Paris: ordering, costs and opinions of physicians qualified in endocrinology]. / Les dosages hormonaux thyroïdiens à l'Assistance Publique-Hôpitaux de Paris: prescriptions, coût et opinions des médecins qualifiés en endocrinologie.

OBJECTIVES: To determine the distribution of orders for hormonal tests assessing thyroid function in a hospital setting. To collect the opinion of physicians specialized in endocrinology concerning free triodothyronine (FT3) assessment. METHODS: Using a cross-sectional survey numbers of free thyroxine (FT4), total T4 (TT4), FT3, total T3 (TT3), and TSH tests were collected from the heads of laboratory assessing thyroid function in June 95 at the Assistance Publique-Hôpitaux de Paris (AP-HP). Cost for these tests was estimated. The physicians of the AP-HP specialized in endocrinology were asked through a questionnaire for circumstances justifying FT3 test ordering. RESULTS: Twenty-eight laboratories (93%) responded: 28455 measurements (TSH: 43%, FT4: 33%, TT4: 2%, FT3: 20%, TT3: 2%) were performed and were valued at 3.4 million French Francs. Proportions of T4 (36%) and T3 (20%) tests were lower in hospitals with an inpatient department of endocrinology than in hospitals with an outpatient clinic with specialists in endocrinology (T4: 36%; T3: 27%) or with no endocrinology unit (T4: 33%, T3: 27%); proportion of TSH tests was higher in hospitals with an inpatient endocrinology unit (respectively 44%, 40%, 32%). Forty-two endocrinologists (76%) from 21 departments answered. Follow-up of treatment with amiodarone and euthyroid sick syndrome were considered the only conditions justifying FT3 test ordering. CONCLUSION: Though the opinion of physicians specialized in endocrinology was not uniform regarding recommendations for TT3 or FT3 tests as a first-line measurement, the cost of these tests has been estimated at 650 thousand Francs for a month at the AP-HP.

A rational request behavior: the development of prediction instruments regarding thyroid function tests in primary care.

A prospective study was performed to encourage a rational thyroid-stimulating hormone (TSH) test request behavior of physicians, using prediction instruments. The latter give direct feedback about request adequacy on the basis of pretest probabilities of hyperthyroidism using patients' signs and symptoms. For instrument design, stepwise logistic regression was used on diagnostic data acquired through questionnaires, answered by 80 physicians and 668 patients for whom physicians requested a TSH test. Instruments were designed for clinical and subclinical hyperthyroidism and for clinical hyperthyroidism alone. Use of the instrument for clinical or subclinical hyperthyroidism on the selected group, at a 5% probability threshold, can result in a 37% reduction of unnecessary TSH test requests. With the instrument for clinical hyperthyroidism at a 5% probability threshold, the number of unnecessary test requests can be reduced by 57%. Therefore, it can be concluded that the instruments can determine TSH test request adequacy and encourage a rational TSH test request behavior of physicians at low pretest probability thresholds.

[The clinical and echographic assessment of thyroid function and structure in patients with a chronic inflammatory intestinal disease]. / Valutazione clinica ed ecografica della funzione e della struttura tiroidee in pazienti con malattia infiammatoria cronica intestinale.

In Crohn's disease (CD) and in ulcerative colitis (UC) data about possible thyroid involvement are lacking. We studied thyroid morphology and function in 41 patients affected by active inflammatory bowel disease (IBD) (14 UC; 27 CD) before (all) and 45 and 90 days after onset of therapy (23/41), and in 60 normal control subjects. At each time, the following tests were performed: thyroid sonography, hormonal and immunological assays. A statistically significant increase of thyroid volume was found in IBD compared to control subjects, more frequently in CD (70.4%) than in UC (14.3%). Parenchymal structure was inhomogeneous (88.4% CD; 15.4% UC) with increased frequency compared to control subjects (12.7%). Hormone assays demonstrated increased FT4 values in UC (64.3%) and decreased T4 values in CD (51.8%). Patients affected with IBD showed an increased frequency of anti-thyroglobulin and anti-thyroid peroxidase antibodies. Such abnormalities subsided only partially after therapy. Our data suggest that in IBD there is a frequent thyroid involvement with morphological, hormonal, and immunological abnormalities.

Are thyroid function tests too frequently and inappropriately requested?

In spite of data supporting the use of the serum thyrotropin (TSH) concentration as the best test to detect abnormal thyroid function, measurement of circulating thyroid hormones with or without a serum TSH continues to be frequently requested to evaluate thyroid function. We have analyzed how combinations of thyroid function tests were ordered by referring physicians and the results of the tests in order to offer some suggestions as to how to use thyroid function tests in a cost effective manner. During 1995, 19,181 inpatient and outpatient requests (45,865 different tests) for thyroid function tests were received by the laboratory of a 1600 bed University Hospital in Parma, Italy. The following tests were carried out: T4, free T4, T3, free T3 and TSH. Serum TSH values below and above the normal range were considered to reflect abnormal thyroid function i.e. hyperthyroidism, or hypothyroidism including subclinical disease independent of the results of the other tests. Combinations of ordered tests and the percent of the total for each combination were: TSH+T4+T3 (56%), TSH+FT4+FT3 (14%), TSH (12%), TSH+FT4 (9%), TSH+T4 (1%), TSH+T4+T3+FT4+FT3 (5%), others (3%). The T4+T3+TSH panel (10,780 requests) had normal serum TSH values in 80.6% and the FT4+ FT3+TSH panel (2,590 requests) had normal TSH values in 73.2%. Elevated serum TSH concentrations were observed more frequently in hospitalized than in ambulatory patients (9.7% vs 7.4% p<0.001). T3 (elevated serum T3, normal T4 and low TSH concentrations) and T4 (elevated serum T4, normal T3 and low TSH concentrations) toxicosis were observed in 8.1% and 9.4%, respectively, of the requested test (NS). FT3 and FT4 toxicosis, defined as for T3 and T4 toxicosis, were observed in 7.5% and 4.9%, respectively (NS). The low T3 and low FT3 syndrome in hospitalized patients was present in 1.6% and 2.3% of the requests, respectively (NS). The low T4+low T3 and low FT4+low FT3 syndrome was present in only 0.3% and 0.2%, respectively, of the requests. Our study shows that a) in hospitalized patients thyroid function tests were requested in 20% of the patients and only one in 14 of these patients at the highest could have abnormal thyroid function, as indicated by abnormal TSH value b) FT4 (or T4) is as useful as FT3 (or T3) in the diagnosis of hyperthyroidism, c) in hospitalized patients the low T3 syndrome was far less common than that reported in the literature, probably due to the lower severity of illness, d) panels which include T3 and FT3 are not justified, and e) serum TSH alone is the most appropriate initial thyroid function test.