Alternative sequences of thyrotropin and free thyroxine assays for routine thyroid function testing. Quality and cost.

BACKGROUND: Current guidelines and practices for thyroid function testing are strongly affected by the usually higher patient billing charges and Medicare reimbursement for thyrotropin (TSH) vs free thyroxine (FT4) tests, despite their comparable direct costs. OBJECTIVE: Due to recently reduced laboratory costs, to reexamine the effectiveness and cost of alternative test sequences. METHODS: Alternative test sequences involve using the TSH test first, followed, if the TSH test result is abnormal, by the FT4 test; the FT4 test first, followed by the TSH test; and doing both tests together. We applied these strategies to consecutive patients referred for any thyroid function test to a health maintenance organization, a multispecialty fee-for-service group, a military hospital, and a commercial laboratory. Effectiveness was determined from a literature review. The cost was determined from direct costs and the distribution of diagnostic categories. RESULTS: The TSH and FT4 tests have similar sensitivities for detecting clinical hyperthyroidism and hypothyroidism. The TSH test detects subclinical function, and it monitors thyroxine treatment better; the FT4 test detects central hypothyroidism, and it monitors rapidly changing function better. Direct costs for both were equal, but charges for the TSH test were higher. The average direct cost per patient, starting with the FT4 test, was $4.61; starting with the TSH test, $5.90; and starting with both tests together, $6.50. Medicare reimbursements correlated poorly with costs. CONCLUSIONS: Starting with the TSH test and reflexing to the FT4 test provides a better first-line all-purpose sequence than the reverse. In managed care settings, the slightly higher direct cost of this approach is offset by greater clinical effectiveness. In fee-for-service settings, cost differences can be nearly eliminated by equalizing TSH and FT4 charges to reflect current direct-cost realities. Obtaining both tests together overcomes the disadvantages of each at a slightly higher direct cost.

An informatics-based chronic disease practice: case study of a 35-year computer-based longitudinal record system.

The authors present the case study of a 35-year informatics-based single subspecialty practice for the management of patients with chronic thyroid disease. This extensive experience provides a paradigm for the organization of longitudinal medical information by integrating individual patient care with clinical research and education. The kernel of the process is a set of worksheets easily completed by the physician during the patient encounter. It is a structured medical record that has been computerized since 1972, enabling analysis of different groups of patients to answer questions about chronic conditions and the effects of therapeutic interventions. The recording process and resulting studies serve as an important vehicle for medical education about the nuances of clinical practice. The authors suggest ways in which computerized medical records can become an integral part of medical practice, rather than a luxury or novelty.

The case for restructuring health care in the United States: the Hawaii paradigm.

Health care in the United States is plagued by many problems. This includes excessive specialization with too few generalists, burdensome bureaucratic federal rules and regulations, and outlandish malpractice awards--all contributing to costs of care that exceeds all other nations. Cost has erroneously been identified as the cause of the problem rather than being one of many results of a failing system. Rather than repetitive unsuccessful efforts to tinker with cost as the cause, it makes far more sense to design and build a better structure of health care including expanding the existing biomedical model into a broader biomedical-psychosocial model. Hawaii, with virtually 100% of its population insured, is closer to this model than most states. It also manages to be ranked the healthiest state with one of the lowest health care costs in the nation.

The superiority of antimicrosomal over antithyroglobulin antibodies for detecting Hashimoto's thyroiditis.

BACKGROUND: Antimicrosomal (anti-M) and antithyroglobulin (anti-Tg) antibodies are commonly measured together to detect Hashimoto's thyroiditis. Since this nearly doubles the cost of testing for one antibody, we wished to determine whether significant diagnostic loss would occur if the two tests were replaced by anti-M alone. METHODS: Both tests were performed in 2030 consecutive patients referred by general internists and endocrinologists. RESULTS: With a positive result defined as either test being positive at a 1:100 dilution, anti-M was much more sensitive than anti-Tg. Anti-M was positive in 99% (823/831) of all patients with positive tests, while anti-Tg was positive in 36% (302/831). Anti-M was the only positive test in 64% of all patients with positive tests, while anti-Tg was the only positive test in 1%. With a cutoff point of 1:400 dilution, the results were similar. CONCLUSIONS: Anti-M alone appears sufficient to detect autoimmune thyroid disease at about one half the cost of routinely performing both anti-M and anti-Tg studies. The widespread practice of performing both tests increases the cost without an offsetting diagnostic gain.

Painful subacute thyroiditis in Hawaii.

Between 1960 and 1982 we prospectively studied 269 patients with painful subacute thyroiditis to determine the demographic characteristics, seasonality, and natural course of the disease. The mean age for all patients was 37.1 years. The female:male ratio was 6.7:1. At the first visit, disease was bilateral in 69%. No epidemic or seasonal pattern was identified. The mean duration of thyroid tenderness was 2.2 months and that of palpable thyroid lumps was 2.8 months. This time difference, sometimes lasting many months, left a painfree "window" during which the palpable hard residual mass of subacute thyroiditis may be confused with other thyroid problems, especially cancer.

Optimal iodine-131 dose for eliminating hyperthyroidism in Graves' disease.

Since hypothyroidism is commonplace after treatment of Graves' disease with radioiodine, the goal should be cure of hyperthyroidism rather than avoidance of hypothyroidism. To find the optimal dose to accomplish cure, we treated 605 patients with stepwise increasing doses of 3, 4, 5, 6, 8, and 10 mCi, analyzing the relationship of dose, age, sex, gland weight, and thyroidal uptake to cure. Estimates of cure at doses above 10 mCi were made from the literature. Cure was directly related to dose between 5 and 10 mCi. There was no significant relationship between cure and age (chi-square, p = 0.74), sex (chi-square, p = 0.12), and 24-hr uptake if over 30% (chi-square for slope, p greater than 0.10). Cure and gland weight had an inverse relationship (chi-square for slope, 0.01 less than p less than 0.02). We concluded that the optimal 131I dose for curing hyperthyroidism is approximated by starting with 10 mCi and increasing it for unusually large glands or for special patient circumstances.

Management of primary hypothyroidism.

Primary hypothyroidism is a common condition requiring lifelong treatment and monitoring. The type and amount of thyroid hormone replacement, selection of laboratory tests, and timing of office visits are all important for optimizing patient well-being and reducing the costs of medical care. The aim of treatment is to bring the patient to the euthyroid state. Currently this is defined as a normal serum concentration of TSH by recently developed sensitive and specific immunometric assays, and is accomplished by titrating the dose of levothyroxine and changing it not more often than at 4- to 6-week intervals. As an indicator of euthyroidism, the sensitive TSH assay has advantages over tests of serum T4, FT4I, T3, FT4, and TSH by RIA because it is independent of TBG changes that result from pregnancy, birth-control pills, and estrogen replacement, is not spuriously elevated by the levothyroxine treatment itself, and is the only test that detects both subclinical hypothyroidism and subclinical hyperthyroidism. Additional serum tests are not usually necessary but have advantages under special circumstances. Once the optimal replacement dose is determined, monitoring can be done yearly or even bi-yearly, depending on the adequacy of patient education and patient compliance.

Graves' disease. Influence of age on clinical findings.

To determine the influence of age on the signs and symptoms of hyperthyroidism we prospectively examined 880 patients and matched them by age, sex, race, and visit date with similarly examined euthyroid control subjects. Many signs and symptoms showed little change with age until after the fifth decade of life when they began to decrease gradually. Findings that increased with age were weight loss and atrial fibrillation, while those that decreased most markedly with age were increased appetite and weight gain. The diagnosis is more difficult as age progresses because there are fewer findings and because the significance of those present may not be appreciated. Identification of the most sensitive and specific signs and symptoms in each age decade should improve the early detection of hyperthyroidism.

Importance of calf vein thrombophlebitis.

Fifty-four patients with phlebogram-proven deep vein thrombophlebitis limited to the tibial and popliteal veins were studied for evidence of pulmonary embolism, both symptomatic and silent. All but two patients were symptomatic of either phlebitis or embolism. Pulmonary embolism, as judged by lung scan defects with V-Q imbalance, changing serial scans, or positive pulmonary angiograms were found in 50%. Popliteal thrombi had an embolism incidence of 66%, whereas tibial thrombi had a 33% incidence. Emboli from the popliteal veins were more extensive than were tibial emboli. Forty-five percent of all emboli were silent. Bilateral phlebitis was accompanied by a 75% incidence of pulmonary embolism. Emboli from tibial veins were minor in five of nine instances, but three instances involved 20% or more of total lung volume and one involved over 40% of total lung volume. These results support the belief that popliteal thrombophlebitis merits anticoagulant therapy. They also suggest caution in the management of tibial vein phlebitis. Objective tests are recommended to monitor for pulmonary embolism and for propagation of the thrombus before deciding to withhold anticoagulants in tibial thrombophlebitis.