Association of Insurance Expansion With Surgical Management of Thyroid Cancer.

Importance: To our knowledge, thyroid cancer incidence is increasing faster than any other cancer type and is currently the fifth most common cancer among women. While this rise is likely multifactorial, there has been scarce consideration of the effect of insurance statuses on the treatment of thyroid cancer.

Objective: We evaluate the association of insurance expansion with thyroid cancer treatment using the 2006 Massachusetts health reform, which serves as a unique natural experiment.

Design, Setting, and Participants: We used the Agency for Healthcare Research and Quality State Inpatient Databases to identify patients with government-subsidized or self-pay insurance or private insurance who were admitted to a hospital with thyroid cancer and underwent a thyroidectomy between 2001 and 2011 in Massachusetts (n = 8534) and 3 control states (n = 48 047). Difference-in-differences models were used to evaluate an association between the 2006 Massachusetts health care reform and thyroid cancer treatment, and participants were controlled for age, sex, comorbidities, and secular trends.

Main Outcomes and Measures: Change in the thyroidectomy rate for thyroid cancer treatment was the primary outcome evaluated.

Results: The Massachusetts cohort consisted of 6443 women (75.5%) and 2091 men (24.5%), of whom 6388 (79.6%) were white, 391 (4.9%) were black, 527 (6.6%) were Hispanic, 424 (5.3%) were Asian/Pacific Islander, 63 (0.8%) were Native American, and 228 (2.8%) were other. The participants from control states included 36 818 women (76.6%) and 11 229 men (23.4%), of whom 30 432 (65.5%) were white, 3818 (8.2%) were black, 6462 (13.9%) were Hispanic, 2591 (5.6%) were Asian/Pacific Islander, 211 (0.5%) were Native American, and 2947 (6.3%) were other. Before the 2006 Massachusetts insurance expansion, patients with government-subsidized or self-pay insurance had lower thyroidectomy rates for thyroid cancer in Massachusetts and the control states compared with patients with private insurance. The Massachusetts insurance expansion was associated with a 26% increased rate of undergoing a thyroidectomy (incident rate ratio, 1.26; 95% CI, 1.04-1.52; P = .02) and a 22% increased rate of neck dissection (incident rate ratio, 1.22; 95% CI, 1.07-1.37; P = .002) for treating cancer compared with control states.

Conclusions and Relevance: The 2006 Massachusetts health reform, which is a model for the Affordable Care Act, was associated with a 26% increased rate of thyroidectomy for treating thyroid cancer. Our study suggests that insurance expansion may be associated with increased access to the surgical management of thyroid cancer. Further studies need to be conducted to evaluate the effect of healthcare expansion at a national level.