National trends in thyroid surgery and the effect of volume on short-term outcomes.

OBJECTIVES/HYPOTHESIS To characterize contemporary patterns of thyroid surgical care and the effect of volume status on surgical care and short-term outcomes. STUDY DESIGN Retrospective cross-sectional study. METHODS Discharge data from the Nationwide Inpatient Sample for 871,644 patients who underwent surgery for thyroid disease in 1993 through 2008 were analyzed using cross-tabulations and multivariate regression modeling. RESULTS Surgical cases increased from 364,288 in 1993 through 2000 to 507,356 in 2001 through 2008, with an increase in thyroid cancer surgical cases from 28% to 34%. Cases performed by high-volume surgeons increased from 12% in 1993 through 2000 to 25% in 2001 through 2008, whereas cases performed by very-low volume surgeons decreased from 51% to 34% (P < .001). Cases performed at high-volume hospitals increased from 14% in 1993 through 2000 to 29% in 2001 through 2008, whereas cases performed at very-low volume hospitals decreased from 46% to 33% (P < .001). High-volume surgeons were significantly more likely to perform total thyroidectomy (odds ratio [OR] = 1.4, P < .001) and had a lower incidence of recurrent laryngeal nerve injury (OR = 0.7, P = .024), hypocalcemia (OR = 0.7, P = .002), and in-hospital death (OR = 0.3, P = .004). High-volume hospital care was not associated with extent of surgery, postoperative morbidity, or mortality after adjusting for surgeon volume. After controlling for other variables, thyroid surgery in 2001 through 2008 was associated with an increase in cases performed by low-volume (relative risk ratio [RRR] = 1.5, P < .001), intermediate-volume (RRR = 1.7, P < .001), and high-volume surgeons (RRR = 2.1, P < .001), high-volume hospitals (RRR = 2.0, P = .008), total thyroidectomy (RRR = 2.1, P < .001), and neck dissection (RRR = 1.3, P = .016). CONCLUSIONS These data reflect changing trends in the surgical management of thyroid disease, with meaningful differences in the type of surgical care provided by high-volume surgeons.