Disparities in postoperative opioid prescribing by race and ethnicity: an electronic health records-based observational study from Northern California, 2015-2020.

OBJECTIVES: To examine racial and ethnic disparities in postoperative opioid prescribing. DATA SOURCES: Electronic health records (EHR) data across 24 hospitals from a healthcare delivery system in Northern California from January 1, 2015 to February 2, 2020 (study period). STUDY DESIGN: Cross-sectional, secondary data analyses were conducted to examine differences by race and ethnicity in opioid prescribing, measured as morphine milligram equivalents (MME), among patients who underwent select, but commonly performed, surgical procedures. Linear regression models included adjustment for factors that would likely influence prescribing decisions and race and ethnicity-specific propensity weights. Opioid prescribing, overall and by race and ethnicity, was also compared to postoperative opioid guidelines. DATA EXTRACTION: Data were extracted from the EHR on adult patients undergoing a procedure during the study period, discharged to home with an opioid prescription. PRINCIPAL FINDINGS: Among 61,564 patients, on adjusted regression analysis, non-Hispanic Black (NHB) patients received prescriptions with higher mean MME than non-Hispanic white (NHW) patients (+ 6.4% [95% confidence interval: 4.4%, 8.3%]), whereas Hispanic and non-Hispanic Asian patients received lower mean MME (-4.2% [-5.1%, -3.2%] and - 3.6% [-4.8%, -2.3%], respectively). Nevertheless, 72.8% of all patients received prescriptions above guidelines, ranging from 71.0 to 80.3% by race and ethnicity. Disparities in prescribing were eliminated among Hispanic and NHB patients versus NHW patients when prescriptions were written within guideline recommendations. CONCLUSIONS: Racial and ethnic disparities in opioid prescribing exist in the postoperative setting, yet all groups received prescriptions above guideline recommendations. Policies encouraging guideline-based prescribing may reduce disparities and overall excess prescribing.

Cost analysis of reflexive versus selective molecular testing for indeterminate thyroid nodules.

BACKGROUND: Molecular testing is now commonly used to refine the diagnosis of indeterminate thyroid nodules. The purpose of this study is to compare the costs of a reflexive molecular testing strategy to a selective testing strategy for indeterminate thyroid nodules. METHODS: A Markov model was constructed to estimate the annual cost of diagnosis and treatment of a real-world cohort of patients with cytologically indeterminate thyroid nodules, comparing a reflexive testing strategy to a selective testing strategy. Model variables were abstracted from institutional clinical trial data, literature review, and the Medicare physician fee schedule. RESULTS: The average cost per patient in the reflexive testing strategy was $8,045, compared with $6,090 in the selective testing strategy. In 10,000 Monte Carlo simulations, diagnostic thyroid lobectomy for benign nodules was performed in 2,440 patients in the reflexive testing arm, compared with 3,389 patients in the selective testing arm, and unintentional observation for malignant nodules occurred in 479 patients in the reflexive testing arm, compared with 772 patients in the selective testing arm. The cost of molecular testing had the greatest impact on overall costs, with $1,050 representing the cost below which the reflexive testing strategy was cost saving compared with the selective testing strategy. CONCLUSION: In this cost-modeling study, reflexive molecular testing for indeterminate thyroid nodules enabled patients to avoid unnecessary thyroid lobectomy at an estimated cost of $20,600 per surgery avoided.

Patient experience with electronic health record-integrated postoperative telemedicine visits in an academic endocrine surgery program.

BACKGROUND: In response to the coronavirus 2019 pandemic, telemedicine use has increased throughout the United States. We aimed to measure patient experience with electronic health record-integrated postoperative telemedicine encounters following thyroid and parathyroid surgery. METHODS: In this preliminary study, adult patients receiving postoperative electronic health record-integrated telemedicine video encounters or standard in-person visits after thyroid or parathyroid surgery at a single institution were prospectively enrolled from November 2019 through May 2020. Patients with home zip codes 10 to 75 miles from the medical center were included. Patient experience was assessed using the Consumer Assessment of Health Care Providers and Systems Clinician & Group Visit Survey 2.0 and the Communication Assessment Tool. Top box analysis was performed, defined as the percentage of respondents who chose the most positive response score. RESULTS: The cohort consisted of 45 telemedicine and 32 in-person encounters. Both groups reported similar and excellent patient experience and satisfaction (9.7 of 10 for telemedicine vs 9.8 of 10 for in-person encounters, mean difference 0.02, 95% confidence interval, [-0.25 to 0.29]). Similar surgeon communication performance was observed (mean Communication Assessment Tool top box score 83% telemedicine vs 86% in-person, mean difference 3%, 95% confidence interval [-10% to 17%]). Nonlinear increases in monthly telemedicine encounter volume were observed within the section of endocrine surgery (3-fold increase) and the health system (125-fold increase) from November 2019 to May 2020. CONCLUSION: Patients who underwent cervical endocrine surgery reported similarly high rates of satisfaction and excellent surgeon communication following either telemedicine or in-person postoperative encounters. Electronic health record-integrated telemedicine for a subset of low-risk procedures can act as a suitable replacement for in-person encounters. A surge in telemedicine use, stimulated by the coronavirus 2019 pandemic, was experienced at our institution.

Measuring patient perceptions of surgeon communication performance in the treatment of thyroid nodules and thyroid cancer using the communication assessment tool.

BACKGROUND: Thyroid surgeons are offering their patients less aggressive diagnostic and therapeutic management strategies for thyroid nodules and low-risk thyroid cancer in an effort to decrease overdiagnosis and overtreatment of indolent disease. Explaining the rationale for less aggressive management plans requires physicians to be effective communicators. We aimed to assess the communication skills of thyroid surgeons with the Makoul Communication Assessment Tool and to identify risk factors for poor communication. METHODS: New adult patients with thyroid nodules or thyroid cancer presenting to a single tertiary-referral endocrine surgery clinic were enrolled from July 2018 through December 2019. Patients were administered the Communication Assessment Tool immediately after their clinical encounter. Outlier communication scores were identified, and clinical characteristics were compared between outlier and nonoutlier groups. RESULTS: A total of 107 patients completed the Communication Assessment Tool. Mean (standard deviation) total and top box scores were 67 (6) and 86% (29%), respectively. Twenty-five patients (23%) were in the low-outlier group, defined by a total score below 67.5/70 or top box score below 82.25%. Other race and non-Hispanic patients (versus white race) were more likely low outliers (odds ratio 3.58, P = .048). The lowest scoring Communication Assessment Tool item overall was "the doctor encouraged me to ask questions" (78.5% top box). CONCLUSION: We found communication to be perceived as excellent in the majority of patients; however, an opportunity for improvement was identified in 29% of participants. Significant differences in race and ethnicity between low outlier and nonoutlier communication score patients were observed, which warrants additional investigation. These findings support the utility of the Communication Assessment Tool in studying the effectiveness of communication improvement initiatives.

Cost Saving of Short Hospitalization Nonoperative Management for Acute Uncomplicated Appendicitis.

BACKGROUND: Nonoperative management (NOM) of uncomplicated appendicitis has gained recognition as an alternative to surgery. In the largest published randomized trial (Appendicitis Acuta), patients received a 3-d hospital stay for intravenous antibiotics; however, cost implications for health care systems remain unknown. We hypothesized short stay protocols would be cost saving compared with a long stay protocol. MATERIALS AND METHODS: We constructed a Markov model comparing the cost of three protocols for NOM of acute uncomplicated appendicitis: (1) long stay (3-d hospitalization), (2) short stay (1-d hospitalization), and (3) emergency department (ED) discharge. The long stay protocol was modeled on data from the APPAC trial. Model variables were abstracted from national database and literature review. One-way and two-way sensitivity analyses were performed to determine the impact of uncertainty on the model. RESULTS: The long stay treatment protocol had a total 5-y projected cost of $10,735 per patient. The short stay treatment protocol costs $8026 per patient, and the ED discharge protocol costs $6,825, which was $2709 and $3910 less than the long stay protocol, respectively. One-way sensitivity analysis demonstrated that the relative risk of treatment failure with the short stay protocol needed to exceed 6.3 (absolute risk increase of 31%) and with the ED discharge protocol needed to exceed 8.75 (absolute risk increase of 45%) in order for the long stay protocol to become cost saving. CONCLUSIONS: Short duration hospitalization protocols to treat appendicitis nonoperatively with antibiotics are cost saving under almost all model scenarios. Future consideration of patient preferences and health-related quality of life will need to be made to determine if short stay treatment protocols are cost-effective.

Selective use of Molecular Testing Based on Sonographic Features of Cytologically Indeterminate Thyroid Nodules: A Decision Analysis.

BACKGROUND: Molecular diagnostics can allow some patients with indeterminate thyroid nodule cytopathology to avoid diagnostic hemithyroidectomy; however, the testing is costly. We hypothesized that molecular testing with the intention of preventing unnecessary diagnostic hemithyroidectomy would be cost-effective if this test was applied selectively based on sonographic risk of malignancy. METHODS: A Markov model was constructed depicting a 40-year-old patient with a cytologically indeterminate thyroid nodule. Molecular testing of fine needle aspiration material was compared to a strategy of immediate diagnostic hemithyroidectomy. Data from a single tertiary-referral health system were reviewed to estimate the outcomes of molecular testing of indeterminate nodules stratified by the American Thyroid Association sonographic classification system. Other outcome probabilities and their utilities were derived from literature review. Costs were estimated with Medicare reimbursement data. A $100,000/QALY threshold for cost-effectiveness was applied. Sensitivity analysis was employed to examine uncertainty in the model's assumptions. RESULTS: Of 123 patients who underwent molecular testing for indeterminate cytology, 12 (9.8%) were classified as high sonographic suspicion, 49 (40%) were intermediate suspicion, and 62 (50%) were low or very low suspicion. Molecular testing was only cost-effective when the pretest probability of a negative test was greater than 31%. The model was most sensitive to the cost of molecular testing and the quality adjustment factor for hypothyroidism. CONCLUSIONS: In hypothetical modeling, molecular testing is only cost-effective for cytologically indeterminate thyroid nodules with sonographic features that are intermediate or low suspicion for malignancy. In nodules with high sonographic suspicion, molecular testing is rarely negative and appears to add minimal value.

Derivation of a cost-saving screening strategy for asymptomatic primary hyperparathyroidism.

BACKGROUND: Our study seeks to find a cost-saving screening strategy in a primary care population for diagnosing primary hyperparathyroidism based on peak serum total calcium level, age, and patient sex. METHODS: Laboratory data resulting from primary care office visits at our institution between January 2016 through December 2017 to evaluate patients who had at least 1 episode of hypercalcemia (≥10.5 mg/dL). For each serum calcium threshold, we calculated the percentage of patients who were found to have an increased parathyroid hormone level (≥65 pg/mL). We determined whether net cost savings could be achieved by screening hypercalcemic patients given their probability of primary hyperparathyroidism and expected cost savings from fracture risk reduction, given their sex and age. RESULTS: From 155,350 unique patients in the study period, a total of 2,271 had a minimum of 1 hypercalcemic lab value. After exclusion criteria, there were 1,326 patients of whom 27.5% had a parathyroid hormone level checked. Cost savings was established at a screening threshold of 10.5 for all patients until age 66 years for men and 69 years for women. For men aged 67-68 y and women aged 70-71 years, the optimal screening threshold was 10.8 mg/dl. CONCLUSION: Cost savings can be achieved by screening hypercalcemic patients with a life expectancy exceeding 16 years, with varying thresholds based on age and sex.

Cost effectiveness of immediate biopsy versus surveillance of intermediate-suspicion thyroid nodules.

BACKGROUND: In an effort to reduce overdiagnosis of low-risk thyroid cancer, recent clinical guidelines increased the size-based biopsy thresholds for thyroid nodules. The cost-effectiveness of these guidelines is largely unknown. We hypothesized that ultrasound surveillance in lieu of immediate fine needle aspiration biopsy would be cost effective for a 1.0 cm thyroid nodule with American Thyroid Association Intermediate Suspicion sonographic features. METHODS: A Markov transition-state model was constructed to compare immediate fine needle aspiration versus ultrasound surveillance. Univariate and multivariate sensitivity analyses were used to examine the uncertainty of cost, probability, and utility estimates in the model. RESULTS: Ultrasound surveillance was $1,829 less costly and 0.016 quality-adjusted life years more effective than immediate fine needle aspiration. Immediate fine needle aspiration became cost effective when the probability of malignancy increased from 15% to 84% or the cost of ultrasound increased from $129 to $793. Immediate fine needle aspiration was cost-effective if the quality adjustment factor for observation following a benign fine needle aspiration result exceeded the quality adjustment factor for observation without a biopsy. CONCLUSION: Ultrasound surveillance is more cost-effective than immediate fine needle aspiration for 1.0 cm thyroid nodules with an intermediate-suspicion sonographic pattern. Additional investigation of health-related quality of life in patients undergoing fine needle aspiration or surveillance is necessary.

Gene Expression Classifier vs Targeted Next-Generation Sequencing in the Management of Indeterminate Thyroid Nodules.

Context: Molecular testing has reduced the need for diagnostic hemithyroidectomy for indeterminate thyroid nodules. No studies have directly compared molecular testing techniques. Objective: Compare the diagnostic performance of Afirma Gene Expression Classifier (GEC) with that of ThyroSeq v2 next-generation sequencing assay. Design: Parallel randomized trial, monthly block randomization of patients with Bethesda III/IV cytology to GEC or ThyroSeq v2. Setting: University of California, Los Angeles. Participants: Patients who underwent thyroid biopsy (April 2016 to June 2017). Intervention: Testing with GEC or ThyroSeq v2. Main Outcome Measure: Molecular test performance. Results: Of 1372 thyroid nodules, 176 (13%) had indeterminate cytology and 149 of 157 eligible indeterminate nodules (95%) were included in the study. Of nodules tested with GEC, 49% were suspicious, 43% were benign, and 9% were insufficient. Of nodules tested with ThyroSeq v2, 19% were mutation positive, 77% were mutation negative, and 4% were insufficient. The specificities of GEC and ThyroSeq v2 were 66% and 91%, respectively (P = 0.002); the positive predictive values of GEC and ThyroSeq v2 were 39% and 57%, respectively. Diagnostic hemithyroidectomy was avoided in 28 patients tested with GEC (39%) and 49 patients tested with ThyroSeq v2 (62%). Surveillance ultrasonography was available for 46 nodules (45 remained stable). Conclusions: ThyroSeq v2 had higher specificity than Afirma GEC and allowed more patients to avoid surgery. Long-term surveillance is necessary to assess the false-negative rate of these particular molecular tests. Further studies are required for comparison with other available molecular diagnostics and for newer tests as they are developed.

Risk Factors Associated With Reoperation and Disease-Specific Mortality in Patients With Medullary Thyroid Carcinoma.

Importance: The association of initial neck dissection with recurrence in medullary thyroid carcinoma (MTC) has not been evaluated on a population level to date. Objective: To elucidate risk factors associated with reoperation in MTC and disease-specific mortality. Design, Setting, and Participants: A retrospective analysis was performed of hospital data obtained from the California Cancer Registry and the Office of Statewide Health Planning and Development from January 1, 1999, through December 31, 2012. The dates of the analysis were January 1, 1999, to December 31, 2012. A population-based sample of 953 patients with MTC was identified. Patients who underwent thyroid surgery and had a minimum postoperative follow-up of 2 years (n = 609) were included in the analysis. Exposure: Initial neck dissection in MTC. Main Outcomes and Measures: Recurrent MTC leading to reoperation and disease-specific mortality. Results: Of the 609 patients with MTC who underwent thyroid surgery, the mean (SD) patient age at diagnosis was 52.6 (17.5) years, and 60.8% (n = 370) of the patients were female. The mean (SD) tumor size was 2.8 (2.0) cm. Although initial central neck dissection is recommended by published MTC guidelines, only 35.5% (216 of 609) of patients underwent central neck dissection at the time of the initial thyroidectomy. The rate of reoperation was 16.3% (99 of 609), and the median time to reoperation was 6.4 months. The presence of lymph node metastasis increased the risk of reoperation (hazard ratio [HR], 3.43; 95% CI, 2.00-5.90), while central and lateral neck dissection performed at the initial operation was protective (HR, 0.53; 95% CI, 0.30-0.93). In patients who underwent reoperation, 45.5% (45 of 99) were disease free at a median follow-up of 7.7 years. Five-year disease-specific mortality for the entire cohort was 13.5% (82 of 609). Independent risk factors for disease-specific mortality included older age (HR, 1.36 per decade; 95% CI, 1.17-1.59), tumor size greater than 2 cm (HR, 2.83; 95% CI, 1.08-7.44 for >2 to 4 cm and HR, 2.89; 95% CI, 1.09-7.71 for >4 cm), and regional (HR, 4.77; 95% CI, 2.29-9.94) and metastatic (HR, 21.08; 95% CI, 9.90-44.89) disease. Reoperation was not associated with increased mortality. Conclusions and Relevance: Lymph node dissection may decrease recurrence leading to reoperation for patients with MTC. Reoperation is a viable strategy to achieve long-term disease-free survival in appropriately selected patients. Central neck dissection remains underused.

Individualizing Surgery in Papillary Thyroid Carcinoma Based on a Detailed Sonographic Assessment of Extrathyroidal Extension.

BACKGROUND: Lobectomy may be sufficient for patients with intrathyroidal papillary thyroid carcinomas (PTC) <4 cm without nodal metastasis. Based on the 2015 American Thyroid Association guidelines, a strategy using ultrasound to identify appropriate candidates for lobectomy was implemented. METHODS: Patients with Bethesda V or VI cytology who underwent surgery for PTC (January 2016 to May 2017) were retrospectively reviewed. Eligibility for lobectomy was based on both tumor (unilateral, intrathyroidal tumors ≤3 cm in size) and non-tumor (history of hypothyroidism, radiation exposure, etc.) characteristics. A detailed sonographic assessment of extrathyroidal extension (ETE) included surgeon-performed evaluation of thyroid capsular distortion, a long interface between tumor and thyroid capsule, irregular or indistinct tumor margins abutting the thyroid capsule, or a tracheal footprint. RESULTS: Of 141 patients with PTC, 35 (25%) patients were candidates for lobectomy, and 105 (75%) patients were not candidates for lobectomy because of non-tumor (n = 46) or tumor (n = 59) characteristics. Of the 35 patients who were candidates for lobectomy, 27 had sonographic ETE on detailed assessment. Total thyroidectomy was performed in 23 patients, while thyroid lobectomy was performed in 12 patients. Total thyroidectomy was indicated based on final histopathology in 15 patients (ETE, aggressive histology, vascular invasion, or cervical metastasis). Histopathologic ETE was present in 13 of these 15 patients and was the only indication for total thyroidectomy in the remaining eight patients. Positive and negative predictive values for the prediction of ETE based on detailed sonographic assessment were 52% and 100%, respectively. In comparison to a strategy of routine total thyroidectomy, a detailed sonographic assessment of ETE reduced the rate of potentially avoidable total thyroidectomy from 57% to 31%. CONCLUSIONS: Patients with PTC who are potential candidates for lobectomy often require total thyroidectomy based on microscopic ETE detected on surgical pathology. A detailed sonographic assessment of ETE can reliably rule out microscopic ETE, reducing the rate of potentially avoidable total thyroidectomy.

NONOPERATIVE MANAGEMENT OF DIFFERENTIATED THYROID CANCER IN CALIFORNIA: A POPULATION-LEVEL ANALYSIS OF 29,978 PATIENTS.

OBJECTIVE: There has been increasing interest in active surveillance of papillary thyroid microcarcinoma. The objective of this study was to characterize the incidence and outcomes of nonoperatively managed differentiated thyroid cancers (DTCs) in California. METHODS: Biopsy-proven DTCs from the California Cancer Registry were linked to data from the California Office of Statewide Health Planning and Development (2004-2012). Low-risk tumors were defined as localized disease measuring <4 cm without extrathyroidal extension, nodal involvement, or distant metastasis. RESULTS: Of 29,978 patients with DTC, 318 (1.1%) were managed nonoperatively. Compared to operatively managed patients, patients managed nonoperatively were older with more comorbidities, larger tumors (mean size, 2.9 cm vs. 2.0 cm), and an increased rate of distant metastasis (20.4% vs. 3.4%). Independent predictors of nonoperative management included increasing age, larger tumor size, papillary histology, and distant metastases. Of 10,795 patients with low-risk tumors, 161 (1.5%) were managed nonoperatively, with tumor size as follows: <1 cm (15.5%), 1 to 2 cm (50.3%), >2 to 3 cm (24.3%), and >3 to 4 cm (9.9%). There were no disease-specific deaths in the low-risk, nonoperative group (median follow-up [interquar-tile range], 21.3 [5.7 to 51.1] months). The proportion of patients managed nonoperatively remained relatively stable over the study period (mean increase 0.1% per year, P = .09). All P values were <.05 unless otherwise stated. CONCLUSION: The vast majority of patients with DTCs are treated surgically, suggesting active surveillance is rarely practiced in California. Although follow-up was limited, no disease-specific mortality in nonoperatively managed, low-risk DTCs was observed. ABBREVIATIONS: CCI = Charlson Comorbidity Index; CCR = California Cancer Registry; CI = confidence interval; DTC = differentiated thyroid cancer; FTC = follicular thyroid carcinoma; HCC = Hürthle cell carcinoma; IQR = interquartile range; mPTC = papillary thyroid micro-carcinoma; OR = odds ratio; OSPHD = Office of Statewide Health Planning and Development; PTC = papillary thyroid carcinoma.

Primary Hyperparathyroidism: Effects on Bone Health.

Primary hyperparathyroidism (PHPT) is the most common cause of chronic hypercalcemia. With the advent of routine calcium screening, the classic presentation of renal and osseous symptoms has been largely replaced with mild, asymptomatic disease. In hypercalcemia caused by PHPT, serum parathyroid hormone levels are either high, or inappropriately normal. A single-gland adenoma is responsible for 80% of PHPT cases. Less frequent causes include 4-gland hyperplasia and parathyroid carcinoma. Diminished bone mineral density and nephrolithiasis are the major current clinical sequelae. Parathyroidectomy is the only definitive treatment for PHPT, and in experienced hands, cure rates approach 98%.

Parathyroidectomy for asymptomatic primary hyperparathyroidism: A revised cost-effectiveness analysis incorporating fracture risk reduction.

BACKGROUND: Recent data demonstrate decreased fracture risk after operation for asymptomatic primary hyperparathyroidism. We performed a revised cost-effectiveness analysis comparing parathyroidectomy versus observation while incorporating fracture risk reduction. METHODS: A Markov transition-state model was created comparing parathyroidectomy and guideline-based medical observation for a 60-year-old female patient with mild asymptomatic primary hyperparathyroidism. Costs were estimated using published Medicare reimbursement data. Treatment strategy outcomes, including risk of fracture, were identified by literature review. Quality adjustment factors were used to weight treatment outcomes. A threshold of $100,000/quality-adjusted life year was used to determine cost-effectiveness. Sensitivity analyses and Monte Carlo simulation were performed to examine the effect of uncertainty on the model. RESULTS: Parathyroidectomy was the dominant strategy (less costly and more effective) with an incremental cost savings of $1,721 and an incremental effectiveness of 0.185 quality-adjusted life years. Parathyroidectomy remained dominant when the relative risk reduction of fracture after operation was ≥14%, the cost of fracture was ≥$7,600, or the probability of recurrent laryngeal nerve injury was <12.5%. Monte Carlo simulation showed parathyroidectomy was cost-effective in 995/1,000 hypothetical patients. CONCLUSION: When fracture risk reduction is considered, parathyroidectomy for mild asymptomatic primary hyperparathyroidism is the dominant strategy when compared to observation.

Cost-Effectiveness of Long-Term Every Three-Year Versus Annual Postoperative Surveillance for Low-Risk Papillary Thyroid Cancer.

BACKGROUND: Patients with low-risk papillary thyroid cancer (PTC) who demonstrate an excellent response to initial therapy have a 2% recurrence rate and 100% disease-specific survival within 10 years. Thus, annual surveillance may be excessive. We hypothesized that less frequent postoperative surveillance in these patients is cost effective. METHODS: A Markov discrete time state transition model was created to compare postoperative surveillance tapered to 3-year intervals after 5 years of annual surveillance versus conventional annual surveillance in low-risk PTC patients with negative neck ultrasound and stimulated thyroglobulin less than 2 ng/mL 1 year postoperatively. Outcome probabilities, utilities, and costs were determined via literature review, the Medicare Physician Fee Schedule, and Healthcare Cost and Utilization Project data. Sensitivity analyses were performed to assess areas of uncertainty. RESULTS: The cost of annual surveillance was $5,239 per patient and yielded 22.49 quality-adjusted life-years (QALYs). The 3-year strategy cost $2,601 less, but also yielded 0.01 less QALYs. Thus, the incremental cost per QALY of annual surveillance was $260,100. Probabilistic sensitivity analysis demonstrated that less frequent surveillance was more cost effective in 99.98% of 10,000 simulated patients. One-way sensitivity analysis revealed that annual surveillance would be cost effective if the total cost of neck ultrasound could be reduced to $23 or less. CONCLUSION: Extending postoperative surveillance to 3-year intervals after 5 years of annual surveillance in patients with low-risk PTC with excellent response to therapy is more cost effective than annual surveillance.