Abstract
Context:
As thyroid cancer incidence rises, more patients undergo thyroid surgery. Although postoperative complication rates have been reported in single institution studies, population-based data are limited.
Objective:
To determine thyroid cancer surgery complication rates and identify at-risk populations.
Design/Setting/Patients:
Using the Surveillance, Epidemiology, and End Results–Medicare database, we evaluated general complications within 30 days and thyroid surgery–specific complications within 1 year in 27,912 patients who underwent surgery for differentiated or medullary thyroid cancer between 1998 and 2011. Multivariable analyses of patient characteristics associated with postoperative complications were performed.
Main Outcome Measures:
General and thyroid surgery–specific complications.
Results:
Overall, 1820 (6.5%) patients developed general postoperative complications and 3427 (12.3%) developed thyroid surgery–specific complications. In multivariable analyses, general and thyroid surgery–specific complications were significantly higher in patients >65 years [odds ratio (OR), 2.61; 95% confidence interval (CI), 2.31 to 2.95; OR, 3.12; 95% CI, 2.85 to 3.42], those with a Charlson/Deyo comorbidity score of 1 (OR, 2.40; 95% CI, 1.66 to 3.49; OR, 1.88; 95% CI, 1.53 to 2.31) and ≥2 (OR, 7.05; 95% CI, 5.33 to 9.56; OR, 3.62; 95% CI, 3.11 to 4.25), and those with regional (OR, 1.18; 95% CI, 1.03 to 1.35; OR, 1.31; 95% CI, 1.19 to 1.45) or distant disease (OR, 2.83; 95% CI, 2.30 to 3.47; OR, 1.85; 95% CI, 1.54 to 2.21), respectively.
Conclusions:
The rates of thyroid cancer surgery complications are higher than predicted, and patients with older age, more comorbidities, and advanced disease are at greatest risk. Efforts to reduce complications are needed.
We evaluated general and thyroid surgery–specific complications. We found higher complication rates than expected; patients with older age, more comorbidities, and advanced cancer are at greatest risk.
The incidence of thyroid cancer is steadily increasing, with the rates for new thyroid cancer cases in the United States rising an average of 4.5% each year (1, 2). By 2030, thyroid cancer is expected to replace colorectal cancer as the fourth leading cancer diagnosis (3). Because thyroid cancer incidence is rising, and surgical resection is the mainstay of treatment of thyroid cancer patients (4), the number of thyroid surgeries is also increasing (5, 6).
Despite advances in surgical techniques that aim to minimize adverse patient effects, thyroid surgery still has risks (7–9). These include, but are not limited to, general postoperative complications, such as postoperative fever, infection, hematoma/hemorrhage, cardiopulmonary and thromboembolic events, and thyroid surgery–specific complications, such as hypoparathyroidism/hypocalcemia and vocal cord/fold paralysis. The long-term consequences of thyroid surgery–specific complications, including hypoparathyroidism, are often managed by nonsurgical specialists, such as endocrinologists (8, 10–14). Despite the increasing number of thyroid surgeries nationwide, population-based data on postoperative complication rates are limited, with most existing evidence reported from high-volume single-institution studies (10, 13, 15–17). Results from these studies may not be generalizable to the population at-large because most were conducted at high-volume centers, where thyroid surgery complication rates have been shown to be lower (18–20). Additionally, many of the existing studies did not solely focus on thyroid surgery for cancer, on identifying at-risk populations to target for directed interventions, or on allowing adequate follow-up to assess long-term thyroid surgery–specific complications.
To address this knowledge gap, we performed a large population-based study of patients who underwent surgery for differentiated follicular-derived (papillary, follicular, or Hürthle cell) or medullary thyroid cancer between 1998 and 2011 using the Surveillance, Epidemiology, and End Results (SEER)–Medicare database. In addition to examining the rates of both general and thyroid surgery–specific postoperative complications in these patients, we sought to identify at-risk groups who may benefit from interventions to reduce risks.
Methods
Data source and study population
The SEER Program is a nationally representative population-based cancer registry sponsored by the National Cancer Institute (2). It currently comprises 20 sites and includes ∼28% of the US population (2). Data tracked by SEER include patient demographics, tumor characteristics, treatment, and outcomes information. In 1991, the SEER-Medicare database was created by combining the SEER patient records with Medicare reimbursement claims data, with successful linkage achieved for >90% of patients (21).
For the current study, the cohort consisted of all patients from the SEER-Medicare linked database who underwent surgery for differentiated thyroid cancer (papillary, follicular, or Hürthle cell histology) or medullary thyroid cancer between 1 January 1998 and 31 December 2011. Patients who did not undergo surgery for their thyroid cancer and patients with anaplastic thyroid cancer were excluded. A total of 27,912 patients were identified.
The study was exempt from the University of Michigan Institutional Review Board.
Measures
For our study cohort, the data included information on patient age (categorized as ≤65 and >65 years old), race, and ethnicity, as defined by the SEER database (white, black, and other; other including Hispanic, Asian, North American Native, and other). Measures of socioeconomic status included median household income, percentage of patients with only high school diploma and rural-urban continuum. Tumor characteristics included tumor histology (papillary, follicular, Hürthle cell, and medullary), tumor size (≤1, 1.1 to 2.0, 2.1 to 4.0, and >4.0 cm), and SEER stage at diagnosis (localized, regional, and distant). The type of thyroid cancer surgery (lobectomy or total thyroidectomy) and the presence or absence of lymph nodes resected were also included. The Charlson/Deyo comorbidity score was calculated using the validated Charlson/Deyo comorbidity score mapping table (Supplemental Data (101.6KB, docx) ) and categorized as 0, 1, and ≥2. Missing data on race (<2%), median household income (10.6%), percentage with no high school diploma (10.6%), rural-urban continuum (<2%), tumor size (7.5%), and lymph nodes resected (<2%) were excluded from the analyses. After exclusion of missing data, the total number of patients with a complete set of information was 22,867. All analyses were based on the 22,867 participants.
Using the International Classification of Diseases, Ninth Revision and Current Procedure Terminology codes from SEER-Medicare data, we obtained information on postoperative complications after thyroid cancer surgery in our cohort (Supplemental Data (101.6KB, docx) ). Postoperative complications were divided into general complications and thyroid surgery–specific complications. General complications were assessed in the first 30 days postoperatively and included postoperative fever; postoperative local complications, including infection and hemorrhage/hematoma; cardiopulmonary complications, including pneumonia, emergency intubation, or tracheostomy; and myocardial infarction and thromboembolic events, including pulmonary embolism and deep vein thrombosis. Thyroid surgery–specific complications were assessed between 31 days and 1 year postoperatively and included hypoparathyroidism/hypocalcemia and vocal cord/fold paralysis. Thyroid surgery–specific complications that were only present at 0 to 30 days postoperatively were excluded from the analyses (n = 12), thus avoiding inclusion of transient hypoparathyroidism and temporary voice abnormalities.
Statistical analyses
We generated descriptive statistics for our study cohort, including the frequency of general and thyroid surgery–specific postoperative complications. Univariate analyses were conducted to determine the association of patient characteristics with cardiopulmonary/thromboembolic complications, postoperative fever/local complications, hypoparathyroidism/hypocalcemia, and vocal cord/fold paralysis. Multivariable logistic regression was used to identify factors associated with general and thyroid surgery–specific complications. The χ2 test for linear trend was used to determine trends of general and thyroid surgery–specific postoperative complications according to SEER thyroid cancer stage, patient age, and Charlson/Deyo comorbidity score. All data were analyzed using R version 3.2.4 (R Foundation for Statistical Computing) and SAS version 9.3 (SAS Institute).
Results
Table 1 illustrates the demographic characteristics of the study cohort. Most patients were women (70.5%) and white (79.7%). A total of 47.6% of patients were >65 years. Most of the study population had papillary thyroid cancer (84.8%) with localized disease (63.9%). A total of 67.0% of the patients had a Charlson/Deyo comorbidity score ≥2. Overall, there was a higher than expected rate of postoperative complications compared with most previously published literature, both for general complications (6.5%) and for thyroid surgery–specific complications (12.3%).
Table 1.
Demographic Characteristics of Thyroid Cancer Patients (N = 27,912) Based on SEER-Medicare Data Between 1998 and 2011a
| Characteristics | n (%) |
|---|---|
| Age (y) | |
| ≤65 | 14,625 (52.4) |
| >65 | 13,287 (47.6) |
| Sex | |
| Male | 8239 (29.5) |
| Female | 19,673 (70.5) |
| Race | |
| White | 22,256 (79.7) |
| Black | 2160 (7.7) |
| Other | 3302 (11.8) |
| Median household income | |
| <$35,000 | 12,947 (46.4) |
| $35,000–$59,999 | 10,126 (36.3) |
| ≥$60,000 | 1894 (6.8) |
| Percent of no high school degree | |
| <20% | 12,016 (43.1) |
| 20%–29% | 6100 (21.9) |
| ≥30% | 6851 (24.5) |
| Rural-urban continuum | |
| Metro | 24,077 (86.3) |
| Other | 3833 (13.7) |
| Histology | |
| Papillary | 23,655 (84.8) |
| Follicular | 2146 (7.7) |
| Hürthle cell | 1333 (4.8) |
| Medullary | 778 (2.8) |
| Stage | |
| Localized | 17,847 (63.9) |
| Regional | 8688 (31.1) |
| Distant | 1171 (4.2) |
| Unknown | 206 (0.7) |
| Tumor size (cm) | |
| ≤1 | 10,198 (36.5) |
| 1.1–2 | 6450 (23.1) |
| 2.1–4 | 5969 (21.4) |
| 4 | 3208 (11.5) |
| Surgery | |
| Lobectomy | 5455 (19.5) |
| Total thyroidectomy | 22,457 (80.5) |
| Lymph nodes resected | |
| No | 17,292 (62.0) |
| Yes | 10,518 (37.7) |
| Charlson/Deyo comorbidity score | |
| 0 | 5732 (20.5) |
| 1 | 3483 (12.5) |
| ≥2 | 18,697 (67.0) |
| General postoperative complications | |
| No | 26,092 (93.5) |
| Yes | 1820 (6.5) |
| Thyroid surgery–specific postoperative complications | |
| No | 24,485 (87.7) |
| Yes | 3427 (12.3) |
Missing data were excluded: race (<2%), median household income (10.6%), percent of no high school degree (10.6%), rural-urban continuum (<2%), tumor size (7.5%), and lymph nodes resected (<2%).
As shown in Fig. 1(a), 7.2% of patients with regional disease and 18.7% of patients with distant disease had general postoperative complications compared with 5.4% of patients with localized disease (P < 0.001). Regarding thyroid surgery–specific complications, these were present in 15.7% of patients with regional disease and in 22.9% of patients with distant disease compared with 9.9% of patients with localized disease (P < 0.001). Figure 1(b) shows that 10.2% of patients aged >65 years developed general postoperative complications compared with 3.2% of patients aged ≤65 years (P < 0.001), whereas 19.1% of patients aged >65 years developed thyroid surgery–specific complications compared with only 6.1% of patients aged ≤65 years (P < 0.001). Figure 1(c) demonstrates the rates of postoperative complications according to the Charlson/Deyo comorbidity score. A total of 2.4% of patients with a score of 1 and 9.0% of patients with a score ≥2 had general postoperative complications compared with 0.9% of patients with a score of 0 (P < 0.001). Additionally, a total of 6.9% of patients with a score of 1 and 15.9% of patients with a score ≥2 developed thyroid surgery–specific postoperative complications as compared with 3.7% of patients with a score of 0 (P < 0.001).
Figure 1.
(a) Postoperative complications according to SEER thyroid cancer stage. (b) Postoperative complications according to patient age (years). (c) Postoperative complications according to the Charlson/Deyo comorbidity score.
Results of the univariate analyses of patient characteristics associated with specific general and thyroid surgery–specific postoperative complications are shown in Table 2. Older age (>65 years), a higher Charlson/Deyo comorbidity, and more advanced stage were all significantly associated with higher rates of all distinct general (Table 2) and thyroid surgery–specific complications (Table 2).
Table 2.
Patient Characteristics Associated With Postoperative Complications
| Clinical Factors | Cardiopulmonary/Thromboembolic Complications |
Postoperative Fever/Local Complications |
||
|---|---|---|---|---|
| n (%) | P Valuea | n (%) | P Valuea | |
| General postoperative complications | ||||
| Age (y) | ||||
| ≤65 | 332 (2.3) | 192 (1.3) | ||
| >65 | 1119 (8.4) | <0.001 | 444 (3.3) | <0.001 |
| Charlson/Deyo comorbidity score | ||||
| 0 | 33 (0.6) | 25 (0.4) | ||
| 1 | 67 (1.9) | 25 (0.7) | ||
| ≥2 | 1351(7.2) | <0.001 | 586 (3.1) | <0.001 |
| Stage | ||||
| Localized | 737 (4.1) | 373 (2.1) | ||
| Regional | 513 (5.9) | 195 (2.2) | ||
| Distant | 193 (16.5) | <0.001 | 63 (5.4) | <0.001 |
| Hypoparathyroidism/Hypocalcemia |
Vocal Cord/Fold Paralysis |
|||
|---|---|---|---|---|
| n (%) | P Valuea | n (%) | P Valuea | |
| Thyroid surgery–specific complications | ||||
| Age (y) | ||||
| ≤65 | 743 (5.1) | 204 (1.4) | ||
| >65 | 1810 (13.6) | <0.001 | 948 (7.1) | <0.001 |
| Charlson/Deyo comorbidity score | ||||
| 0 | 164 (2.9) | 55 (1.0) | ||
| 1 | 202 (5.8) | 51 (1.5) | ||
| ≥2 | 2187 (11.7) | <0.001 | 1046 (5.6) | <0.001 |
| Stage | ||||
| Localized | 1448 (8.1) | 420 (2.4) | ||
| Regional | 932 (10.7) | 568 (6.5) | ||
| Distant | 158 (13.5) | <0.001 | 150 (12.8) | <0.001 |
P values were calculated based on χ2 test for linear trend.
Based on multivariable analysis (Table 3), rates of general and thyroid surgery–specific postoperative complications were significantly higher in patients aged >65 years [odds ratio (OR), 2.61; 95% confidence interval (CI), 2.31 to 2.95; OR, 3.12; 95% CI, 2.85 to 3.42], those with a Charlson/Deyo comorbidity score of 1 (OR, 2.40; 95% CI, 1.66 to 3.49; OR, 1.88; 95% CI, 1.53 to 2.31) or ≥2 (OR, 7.05; 95% CI, 5.33 to 9.56; OR, 3.62; 95% CI, 3.11 to 4.25), and those with regional (OR, 1.18; 95% CI, 1.03 to 1.35; OR, 1.31; 95% CI, 1.19 to 1.45) or distant disease (OR, 2.83; 95% CI, 2.30 to 3.47; OR, 1.85; 95% CI, 1.54 to 2.21), respectively. Additionally, rates of thyroid surgery–specific postoperative complications were significantly higher in patients undergoing total thyroidectomy compared with lobectomy (OR, 1.59; 95% CI, 1.41 to 1.80) and in patients undergoing lymph node resection compared with those who did not (OR, 1.43; 95% CI, 1.31 to 1.57). Although in univariate analysis patients with medullary thyroid cancer were significantly more likely to have general (P = 0.036) and thyroid surgery–specific postoperative complications (P = 0.005) compared with patients with well-differentiated thyroid cancer, in the fully adjusted model there was no significant difference.
Table 3.
Multivariable Analysis of Patient Characteristics Associated With Postoperative Complications After Thyroid Cancer Surgery
| Clinical Factors | General Complications | Thyroid Surgery–Specific Complications |
|---|---|---|
| Age (y) | ||
| ≤65 (REF) | 1.00 | 1.00 |
| 65 | 2.61 (2.31–2.95) | 3.12 (2.85–3.42) |
| Sex | ||
| Male (REF) | 1.00 | 1.00 |
| Female | 0.90 (0.80–1.01) | 1.34 (1.22–1.47) |
| Race | ||
| White (REF) | 1.00 | 1.00 |
| Black | 1.42 (1.17–1.71) | 1.07 (0.90–1.26) |
| Other | 0.86 (0.72–1.02) | 1.03 (0.91–1.16) |
| Median household income | ||
| <$35,000 (REF) | 1.00 | 1.00 |
| $35,000–$59,999 | 0.83 (0.72–0.93) | 1.05 (0.94–1.16) |
| ≥$60,000 | 0.68 (0.52–0.87) | 1.03 (0.96–1.23) |
| Percent with no high school degree | ||
| <20% (REF) | 1.00 | 1.00 |
| 20%–29% | 1.04 (0.90–1.20) | 1.06 (0.95–1.19) |
| ≥30% | 1.09 (0.93–1.28) | 1.11 (0.98–1.26) |
| Rural-urban continuum | ||
| Metro (REF) | 1.00 | 1.00 |
| Other | 0.95 (0.80–1.12) | 1.09 (0.96–1.24) |
| Histology | ||
| Papillary (REF) | 1.00 | 1.00 |
| Follicular | 0.87 (0.71–1.07) | 0.75 (0.63–0.89) |
| Hürthle cell | 0.88 (0.69–1.12) | 0.71 (0.58–0.87) |
| Medullary | 1.00 (0.73–1.33) | 1.05 (0.83–1.31) |
| Stage | ||
| Localized (REF) | 1.00 | 1.00 |
| Regional | 1.18 (1.03–1.35) | 1.31 (1.19–1.45) |
| Distant | 2.83 (2.30–3.47) | 1.85 (1.54–2.21) |
| Unknown | 0.51 (0.08–1.68) | 1.34 (0.57–2.75) |
| Tumor size (cm) | ||
| ≤1 (REF) | 1.00 | 1.00 |
| 1.1–2 | 0.97 (0.83–1.13) | 1.00 (0.90–1.12) |
| 2.1–4 | 1.02 (0.87–1.20) | 1.06 (0.94–1.19) |
| 4 | 1.48 (1.24–1.76) | 1.23 (1.07–1.41) |
| Surgery | ||
| Lobectomy (REF) | 1.00 | 1.00 |
| Total thyroidectomy | 0.84 (0.73–0.96) | 1.59 (1.41–1.80) |
| Lymph nodes resected | ||
| No (REF) | 1.00 | 1.00 |
| Yes | 1.06 (0.93–1.20) | 1.43 (1.31–1.57) |
| Charlson/Deyo comorbidity score | ||
| 0 (REF) | 1.00 | 1.00 |
| 1 | 2.40 (1.66–3.49) | 1.88 (1.53–2.31) |
| ≥2 | 7.05 (5.33–9.56) | 3.62 (3.11–4.25) |
Values are OR (95% CI).
Abbreviation: REF, reference.
Discussion
In this large sample of patients from our population-based study, we found that overall the rates of complications after thyroid cancer surgery are much higher than expected relative to previously reported data from most existing single-institution studies (10, 13, 15–17). We found that older patients, patients with one or more comorbid conditions, and those with regional or distant disease are at increased risk for both general and thyroid surgery–specific postoperative complications.
General postoperative complications after thyroid cancer surgery have not been widely studied. The significantly high rates of general postoperative complications seen in older patients, patients with comorbidities, and those with regional or distant disease noted in our study are concerning for these at-risk populations. Most existing single-institution and multicenter studies on general complications after thyroid surgery focused on rates of postoperative hemorrhage/hematoma, which have ranged between 0.3% and 2.1% (13, 14, 22–25). Increased age and the presence of comorbidities were found to be significant risk factors for pulmonary, cardiac, and infectious complications in a prior population-based study that had a 30-day postoperative follow-up (26), a finding also confirmed in our study. However, contrasting with our study, none of the existing studies on general postoperative complications focused on patients with thyroid cancer or additionally addressed thyroid surgery–specific complications.
Previously reported overall rates of thyroid surgery–specific postoperative complications varied significantly, ranging between 0.4% and 7.4% in single-institution studies (16, 27, 28). One study from Brazil reported an overall thyroid surgery–specific complication rate as high as 18.0%, but only 25% of the patients included had thyroid cancer (17). No prior studies evaluated rates of thyroid surgery–specific complications in patients with distant disease, whereas our finding of rates up to 22.9% in patients with distant disease is alarming.
More specifically, vocal cord/fold paralysis rates have been reported between 0.2% and 3.9% in single-institution and multicenter studies (10, 13–16, 23, 25). These studies had variable follow-up with the longest postoperative follow-up being 6 months. The only previous population-based study on vocal cord paralysis used SEER-Medicare data from 1991 to 2009 in patients who underwent total thyroidectomy for well-differentiated thyroid cancer, and found that 9.5% of surgeries were complicated by vocal fold paralysis (29), compared with rates of 2.4% to 12.8% in our study. However, this prior study only included patients who underwent a total thyroidectomy and not a lobectomy, and the median follow-up for this prior study was 5.6 months. Our population-based study focused on describing vocal cord/fold paralysis rates after any thyroid cancer surgery between 31 days and a year postoperatively to more accurately depict rates of permanent vocal cord/fold paralysis (30). We also identified populations at risk for thyroid surgery–specific complications.
Regarding permanent hypoparathyroidism rates, these varied between 0.1% and 8.8% in prior single-institution studies (10, 12–16, 23, 25, 31). A population-based study from South Korea using nationwide claims focused on the incidence of permanent hypocalcemia in patients who underwent total thyroidectomy plus or minus central neck dissection for thyroid cancer (12). The follow-up was 1 year, and rates of permanent hypocalcemia were as high as 5.4%. In this other study, permanent hypocalcemia was assumed in patients who had calcium prescriptions filled for >80% of the 1 year after surgery, with the mean amount of daily calcium >1000 mg. This method may be problematic because patients who were prescribed calcium for different indications other than hypoparathyroidism may have also been captured and falsely included in the cohort. Conversely, our methods differed because we measured both hypoparathyroidism and hypocalcemia in the SEER-Medicare claims, recognizing that providers may bill with either of these diagnoses for the same issue.
Although prior high-volume single-institution studies have demonstrated safety for thyroid operations (16, 23, 27), we showed that on a population level with long-term follow-up, clinical outcomes vary and postoperative complication rates appear to be higher than previously reported. The discrepancy may be explained by the fact that most prior publications have been limited to data from high-volume centers with experienced surgeons, who may have more favorable outcomes than low-volume surgeons. Even though it is widely accepted that high-volume surgeons have lower rates of incomplete resection, lower rates of compromised outcomes, and lower costs (19, 20, 32, 33), earlier studies have shown that low-volume surgeons perform a disproportionate number of thyroid surgeries (19, 34). Thus, because our study is population-based, it is probable that both low- and high-volume surgeons were performing thyroid cancer surgeries; therefore, this may account for the higher postoperative complication rates. It is also possible that previous single-institution studies may have been underpowered to identify accurate postoperative complication rates, may have been confounded by referral biases, and may have had inadequate length of follow-up. In addition, several of the existing studies based postoperative complication rates on surgeon report, which may have led to underreporting of complications. Because permanent hypoparathyroidism/hypocalcemia and vocal cord paralysis are often diagnosed and managed by physicians other than the operating surgeon, our study method of using claims data with follow-up to a year is likely a more accurate assessment of the true incidence of these complications.
The results of our study show that older adults and patients with comorbid conditions are a vulnerable population and need special consideration, particularly regarding perioperative and postoperative care. This finding is corroborated by previous population-based studies that also found increased age conferring higher risk for postoperative complications in patients undergoing thyroid surgery (26, 35). This is especially important because rehospitalization among elderly patients with thyroid cancer after thyroid surgery has been proven to be prevalent and costly, especially in those with complications during their initial hospital stay (36). Additionally, postoperative complications in this population can have substantial adverse effects on long-term quality of life (26, 37). We also showed that thyroid cancer patients with regional or distant disease constitute another at-risk patient population. Furthermore, although these data identified at-risk groups, with some groups having complication rates close to 20%, the postoperative complication rates in low-risk groups were also higher than previously reported because up to 6.4% of patients with localized disease had thyroid surgery–specific complications.
Consistent with previous studies, we also found that more extensive surgery (i.e., total thyroidectomy vs lobectomy, lymph nodes resected vs not resected) correlated with increased rates of thyroid surgery–specific postoperative complications (8, 10–14). This outcome is important and should weigh into treatment decisions for all thyroid cancer patients, but especially for the low-risk thyroid cancer patients where unnecessary extensive surgery could confer more harm than benefit. This is reflected by a recent shift in thyroid cancer guidelines advocating for lobectomy instead of total thyroidectomy as an option for patients with low-risk thyroid cancer (4).
Strengths of this study include the population-based setting with longitudinal follow-up, the large sample size, and the inclusion of an extensive list of postoperative complications. Additionally, we assessed thyroid surgery–specific complications between 31 days and 1 year after surgery and excluded those with a diagnosis exclusively in the first month postoperatively, therefore focusing on permanent hypoparathyroidism/hypocalcemia and vocal cord/fold paralysis. Our study is also unique in that it focuses on identifying vulnerable patients who would most benefit from risk-reduction interventions. However, our study also has limitations. Similar to previous studies using population-based data, diagnosis and procedure codes from health care claims were used in our study, and we recognize that data from large administrative databases may inherently be subject to errors in coding, sampling, and reporting bias. Additionally, because Medicare includes mostly older patients, our findings may not be as applicable to a younger population, and may partially explain the higher event rate compared with prior studies. Finally, because we only included patients with thyroid cancer, results of this study may not be generalizable to patients undergoing thyroid surgery for benign indications.
In summary, despite the aforementioned limitations, our comprehensive population-based study on surgical risks has important implications for both patients and physicians. Postoperative complications are not uncommon, with many of the thyroid surgery–specific complications primarily managed by nonsurgical specialists, such as endocrinologists, involved in the patients’ long-term care. Given the risks, in select patients, such as those with low-risk thyroid cancer, less aggressive surgical approaches may be appropriate (4, 38). In addition, evidence-based quality initiatives should be implemented to improve thyroid cancer surgical care and minimize postoperative complications in vulnerable populations. Our study combined with prior work suggests that there may be a need for interventions to improve referral of at-risk patients to high-volume surgeons, especially when more extensive resection is needed or advanced disease is suspected, and to improve patient care by eliminating obstacles to appropriate patient referrals (39). For example, adopting a risk-based selective referral process of thyroid cancer patients to high-volume thyroid surgeons may offer a high-yield opportunity to improve patient outcomes in the long term. Additionally, there is a need for both physician and patient education. Physician education efforts should focus on effectively training low-volume surgeons to adopt best-practice strategies, minimize practice variation, and implement early recognition and prompt initial management of postoperative complications. Patients should also be adequately educated on possible thyroid surgery risks and complications and be encouraged to participate in shared decision-making.
Acknowledgments
The authors thank Brittany Gay, who assisted with manuscript formatting and review.
M.P. is funded by the National Institute on Aging of the National Institutes of Health under Award K08 AG049684 and a Career Development Pilot Grant from the Cancer Control and Population Sciences Program at the University of Michigan. M.R.H. is funded by Grant R01 CA201198 from the National Cancer Institute and Grant R01HS024512 from the Agency for Healthcare Research and Quality. The Punya Foundation for Thyroid Cancer Research also provided support for this project. The content is solely the responsibility of the authors and does not necessarily represent official views of the National Institutes of Health or Agency for Healthcare Research and Quality.
Disclosure Summary: The authors have nothing to disclose.
Footnotes
- CI
- confidence interval
- OR
- odds ratio
- SEER
- Surveillance, Epidemiology, and End Results.
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