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

Abstract

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).

The course of thyroid nodules and thyroid volume over a time period of up to 10 years: a longitudinal analysis of a population-based cohort

“…Structural abnormalities of the thyroid gland, including nodules and goitre, are very common and often lead to repeated testing, including functional test, ultrasound follow-up and scintiscan, which may induce invasive procedures. Previous analyses of the SHIP cohort have shown that 6.8% (378/5552) of subjects had at least one ultrasound and 2.6% (146/5552) had at least one scintiscan within 1 year prior to the study examination based on billing data (20). The majority of structural abnormalities are asymptomatic, clinically irrelevant and malignancy developed in only a very small proportion (6,7).…”

“…Once a thyroid nodule is detected, a cascade of follow-up examinations with moderate sensitivity and even worse, low specificity, is recommended to exclude thyroid cancer. In clinical practice, ignoring findings or systematic follow-ups is common (20). Once follow-up examinations are started, there is uncertainty when to discontinue.…”

The future of diagnosis in general practice

“…For instance, around 10 million thyroid function tests are carried out each year in the UK with enormous variation in frequency across practices, 2 while in comparison about 30% of the adult German population have thyroid function taken in any one year. 3 This testing, arguably over-testing, is inextricably linked with diagnosis, and with over-diagnosis. For example, the median level of thyroid stimulating hormone (TSH) at which treatment is begun has fallen steadily to reach 7.9 mIU/l by 2009, 4 despite a dearth of evidence of benefit of treating patients with a TSH below 10 mIU/l.…”

Trends in thyroid function testing, neck ultrasound, thyroid fine needle aspiration, and thyroidectomies in North-eastern Italy

“…These studies would further increase the knowledge on the pathways to the diagnosis of thyroid cancer and other thyroid disorders, to differentiate clinically relevant diseases from those with no impact on mortality [ 19 , 49 ]. In addition, they would contribute to evaluate adherence to evolving guidelines [ 5 , 7 , 50 ] and they should be used to reduce unnecessary medicalization of patients [ 51 ] and unnecessary costs for the healthcare system [ 23 , 52 , 53 ].…”