Cost effectiveness of intraoperative pathology examination during diagnostic hemithyroidectomy for unilateral follicular thyroid neoplasms

Abstract

Background: The use of intraoperative pathology examination (IPE) during diagnostic hemithyroidectomy for a follicular neoplasm is controversial. Although this service rarely alters intraoperative decision making, it does provide patients with the possibility of avoiding reoperation for completion thyroidectomy if malignancy is detected. We hypothesized diagnostic hemithyroidectomy with IPE for a unilateral follicular thyroid neoplasm diagnosed on fine-needle aspiration is not cost effective compared with diagnostic hemithyroidectomy alone.

Study design: Cost-effectiveness analysis with a Markov decision model was performed comparing diagnostic hemithyroidectomy without IPE, diagnostic hemithyroidectomy with IPE, and total thyroidectomy. Treatment outcomes and their probabilities were identified based on literature review. Costs were estimated using data from Medicare, the US Bureau of Labor Statistics, and the Nationwide Inpatient Sample. Sensitivity analysis and a 1,000-iteration Monte Carlo simulation were used to examine the uncertainty of cost, probability, and utility estimates in the model.

Results: Diagnostic hemithyroidectomy without IPE had an expected cost of US$7,665 and an effectiveness of 23.95 quality-adjusted life years and dominated both the IPE and total thyroidectomy strategies. Intraoperative pathology examination became cost effective during one-way sensitivity analysis if the sensitivity of IPE increased from 14.3% to 34.4%, the specificity increased from 98.6% to 99.8%, or the pretest probability of malignancy increased from 25% to 43%. Monte Carlo simulation demonstrated that the intraoperative pathology strategy was not cost effective in 92.7% of iterations.

Conclusions: Intraoperative pathology examination is not cost effective in the diagnosis of follicular thyroid neoplasms during diagnostic hemithyroidectomy. Improvements in both the sensitivity and specificity of this service would be needed to justify its use.

Keywords: FNA; FS; IPE; QALY; RLN; fine-needle aspiration; frozen section; intraoperative pathology examination; quality-adjusted life year; recurrent laryngeal nerve.