Thyroid surgeries by high-volume hospitals, surgeons increased in recent years

Gourin CG. Arch Otolaryngol Head Neck Surg. 2010;136:1191-1198.

Issue: February 2011

Extensive thyroid surgery procedures performed by high-volume surgeons and at high-volume hospitals, particularly total thyroidectomy and neck dissection, increased significantly between 1990 and 2009, according to recent data.

Between 1990 and 2009, there were 1,064 ablative surgical procedures for thyroid disease performed at 51 hospitals in Maryland. The annual average increased from 943 cases during 1990 to 1999 to 1,184 cases during 2000 to 2009. Researchers conducted a cross-sectional analysis of all patients who underwent these procedures (mean age, 49.7 years).

The number of procedures performed by high-volume surgeons rose considerably from 15.7% during the first decade to 30.8% during the second decade (OR=3.69; 95% CI, 3.41-3.99). Additionally, the number of high-volume surgeons increased from five to eight during the study period. However, the proportion of cases dropped from 40.9% to 21.8% among low-volume surgeons between 1990 and 2009.

High-volume surgeons were more likely to perform total thyroidectomy (OR=2.5; 95% CI, 2.29-2.73) and neck dissection (OR=1.86; 95% CI, 1.52-2.27), as compared with intermediate- and low-volume surgeons. They were also less likely to perform surgery with an initial diagnosis of thyroid cancer (OR=0.89; 95% CI, 0.81-0.98), according to the results.

Similarly, procedures performed at high-volume hospitals increased from 11.9% from 1990 to 1999 to 22.7% from 2000 to 2009 (OR=3.46; 95% CI, 3.17-3.77). Again, the number of procedures performed at low-volume hospitals decreased, from 37% to 20.4%.

Data show that patients were also less likely to experience complications related to thyroid surgical procedures when receiving care from a high-volume surgeon or at a high-volume hospital. Specifically, incidences of surgery-related recurrent laryngeal nerve injury (OR=0.46; 95% CI, 0.32-0.69) and postoperative hypocalcemia (OR=0.49; 95% CI, 0.41-0.57) were lower for high-volume surgeons.

When the researchers compared results from 1990 to 1999 with results from 2000 to 2009, they found that patients were significantly more likely to undergo surgery by high-volume surgeons and at high-volume hospitals in recent years. In addition, total thyroidectomy and neck dissection were more common after 1999. Despite the increase in surgical cases, thyroid cancer-related procedures declined from 2000 to 2009.

“These data suggest that given the observed relationship between volume and outcome the temporal trend of fewer surgical procedures performed by low-volume providers seems appropriate,” the researchers wrote. “However, a significant proportion of surgical procedures are still performed at low-volume facilities and by low-volume surgeons and, thus, increased efforts by professional societies to export the surgical excellence of high-volume surgeons through educational efforts and adoption of best practices may improve outcomes for low-volume providers.”

Disclosures: The researchers report no relevant financial disclosures.

The paper describes patterns of thyroid surgery in one state. The authors conclude that more thyroid surgery is being performed after 2000 than in the decade before. In addition, most thyroid surgery is being performed for non-malignant disease. High-volume surgeons perform thyroidectomy most commonly for benign disease. Risks such has hypocalcemia and recurrent laryngeal nerve injury were higher among low-volume surgeons.

Limitations of this study are as follows:

1. Lack of generalizability: The paper only focuses on one state: Maryland. Caution should be used to extrapolate on a national level.

2. The study is based solely on claims data. Claims data can lead to misclassification. For example, a case may present to surgery with a benign diagnosis code but may be malignant on final pathology. It is unclear how such cases would be classified in this analysis. Likewise, complications occurring during the initial hospitalization may not be coded as hypocalcemia or recurrent laryngeal nerve injury. In addition, if the patient did not get admitted for these conditions, his or her complication may not be captured in these data.

3. The surgical volume stratification is a bit misleading in that the high-volume surgeons included any surgeon who performed more than three thyroidectomies in one year. Thus, there appears to be a wide variation of volume in the upper tertile, and the sensitivity of volume/outcomes relationship may be less than optimal.

In short, this paper does introduce the concept of volume based thyroid surgery, and suggests that high-volume surgeons and high-volume hospitals are associated with fewer complications of hypocalcemia and recurrent laryngeal nerve injury as captured in claims data.

- Amy Y. Chen, MD, MPH, FACS

Associate Professor, Otolaryngology-Head and Neck Surgery

Emory University

Disclosures: Dr. Chen reports no relevant financial disclosures.

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