A Danish study on inequalities in health spanning 14 years finds the probability of a patient getting a thyroid stimulating hormone (TSH) test within 30 days of seeing a general practitioner, is higher among patients with a primary or high school education, but the probability of getting treatment is higher among those with advanced degrees.
The study was first published January 29 in Clinical Endocrinology.
The study included all citizens 25 years old and older from the greater Copenhagen area between 2001 and 2015 (9,390,052 person-years). Researchers examined the relative risks associated with education levels, an annual thyroid stimulating hormone (TSH) measurement test, and initiation of treatment.
Approximately 19% of the study population had a thyroid stimulating hormone measurement test. Those with a primary or high school education were more likely to be tested (relative risk 1.16; 95% CI, 1.15-1.16) second to those with vocational education. But individuals with a bachelor’s degree or higher were more likely to receive treatment despite having lower TSH scores (relative risk 1.11; 95% CI, 1.06-1.12). “The probability of treatment initiation was highest following thyroid stimulation hormone measurements in persons with longer education for lower levels of thyroid stimulation hormone and slightly higher for higher levels of TSH,” the authors wrote.
Education was not found to be a determinant of TSH levels, but whether a TSH test was conducted did increase slightly in patients who had vocational education or a four-year degree.
For patients with a TSH level of less than 5 mIU/L RR, treatment initiation ranged between 0.47 (95%CI 0.39-0.57) for those with a primary or secondary education; and, 0.78 (95%CI 0.67-0.91) for those patients with a vocational education. For TSH 5-10 mIU/L there were no statistically significant difference in treatment rates. For TSH levels greater than 10 mIU/L the relative risk was 1.07 (95% CI 1.02-1.12) for primary and secondary education and 1.08 (95% CI 1.03-1.13) for patients with vocational education.
The authors noted the possibility of overtreatment for patients with a TSH of 5-10 mIU/L. This is contrary to treatment guidelines that suggest limiting TSH treatment to patients with a history of thyroid cancer or patients planning pregnancy.
The probability of treatment was highest among patients with at least a four-year degree.
Patients who were among the least educated generally ranked higher on the six-index Charlson comorbidity index. They also saw their general practitioner more frequently than the other two patient groups.
A limitation of this study was the lack of data regarding symptoms, fT4, fT3, and anti-TOP to evaluate specific indications for thyroid stimulating hormone measurement and therapeutic management.
The researchers concluded that their study “warrants further studies to elucidate the motivation for treatment initiation with low and normal TSH to prevent overtreatment.”
Møllehave LT, Jacobsen RK, Linneberg A, et al. Influence of educational level on test and treatment for incident hypothyroidism. Published online January 29, 2021. Clin Endocrinol (Oxf). doi:10.1111/cen.14429