Thyroid Screening Recommendations
Physician organizations such as the American College of Physicians and the US Preventive Services Task Force do not recommend screening the general adult population for occult thyroid disease because it has a low yield and is not cost effective. However, they do recommend selective testing of women aged 50 years and older with nonspecific symptoms and all women over 60 years. The College of American Pathologists recommends ordering a TSH for the following patient populations:
- Women over 50 years of age who seek medical care
- All patients entering a geriatric unit at admission and at least every 5 years thereafter
- Any adult aged 50 years or older with any complaints other than minor transitory ailments
- All adults with newly discovered dyslipidemia.
Among adults over age 50, it is estimated that unsuspected hypothyroidism will be found in up to 7 men and 18 women per 1000 persons tested. In addition, about five of 1000 older women will be found to have unsuspected hyperthyroidism. In the geriatric population, in whom symptoms are often difficult to attribute to any single etiology, up to 40 cases of thyroid disease will be found per 1000 persons tested.
Detection and treatment of early thyroid disease offers three potential health benefits. First, progression to overt hypothyroidism, which develops at a rate of 5 to 25% per year in patients with anti-thyroid antibodies, may be prevented. Second, serum cholesterol levels in patients with hypercholesterolemia induced by thyroid failure may be reduced by treatment with levothyroxine. Third, unrecognized symptoms of thyroid hormone deficiency that diminish quality of life and consume medical resources may be reversed much sooner. Based on these potential benefits, a recent study concluded that measuring serum TSH at the periodic health examination in adults over the age of 35 years was as cost effective as other widely accepted preventive medical practices such as screening for hypertension (JAMA. July 24/31, 1996; 276: 285-92).Repeating TSH measurements at 5 year intervals was most cost effective.
