Purpose: Our objective was to estimate the cost-effectiveness of systematic calcitonin (CT) measurement in a fictive population of patients with thyroid nodule greater than 1 cm to detect sporadic medullary thyroid carcinoma (SMTC) versus the reference screening strategy recommended in our national guidelines.
Method: A Markov model was used to estimate life-time discounted costs and effectiveness of two screening strategies in a cohort of 50-year-old patients with thyroid nodule. In the reference strategy, CT measurement was performed in patients meeting criteria for surgery on the basis of clinical signs or of the results of fine-needle aspiration (FNA). In the second strategy, routine CT measurement was performed in all patients with thyroid nodule. In both strategies, hormonal measurement, ultrasonography and FNA were performed according to our national guidelines and patients with high basal CT underwent a pentagastrin stimulation test. Then, patients underwent surgery appropriate or not to the type of carcinoma (i.e, differentiated thyroid carcinoma or SMTC) or nodule follow-up. A systematic review of the literature examined the positive predictive value for each test, the efficacy of the procedures, their probabilities of adverse events. Costs (Euros 2008) were estimated from the health insurance perspective. Sensitivity analyses were performed on variables such as age, basal and stimulated CT thresholds, probabilities of complications and costs. The outcome measure was the cost per life-year gained.
Result: For the base-case, both strategies provided approximately the same life expectancy (i.e, 19.7 and 19.8). The routine CT measurement is more expensive 1892 euros vs 1570 euros and does not seem to provide a gain in life expectancy. Multiple sensitivity analyses were performed to check the robustness of the model.
Conclusion: Thyroid nodule is a frequent disease. However, thyroid carcinoma especially SMTC is rare. A preoperative detection of SMTC is useful to determine the appropriate surgery to improve chances of recovery but the target population to screen remain to determine. Currently, we do not confirm the results of a study by Cheung (2008) that used a decision tree to evaluate the cost-effectiveness of routine CT measurement in all detected thyroid nodules and concluded that it would be cost-effective. However, the systematic review of the literature revealed an important lack of epidemiological data of the outcomes of the current medical practices.
Candidate for the Lee B. Lusted Student Prize Competition