Racial disparities in ankylosing spondylitis risk following tonsillectomy: a large-scale retrospective analysis

The objective was to investigate the association between tonsillectomy and subsequent ankylosing spondylitis (AS) risk, with particular emphasis on racial disparities in disease susceptibility.

A retrospective cohort study was conducted using de-identified electronic health records from approximately 120 million patients in the collaboration network in the United States. Patients diagnosed with tonsillar and adenoidal diseases between 2005 and 2023 were selected and divided into surgical and non-surgical cohorts. Propensity score matching (PSM) was employed to balance baseline differences and control for confounding factors, and statistical analyses were performed using Kaplan-Meier survival analysis and Cox proportional hazards models.

After PSM, 173,483 individuals were included in each cohort with well-balanced baseline characteristics. Overall, tonsillectomy did not significantly increase AS risk (HR = 1.26, 95% CI: 0.90-1.75, p = 0.210). Age- and sex-stratified analyses yielded consistent results. However, race-stratified analysis revealed that White individuals who underwent tonsillectomy had significantly elevated AS risk (HR = 1.80, 95% CI: 1.19-2.72, p = 0.005) and higher cumulative incidence compared to matched controls, a finding not observed in other racial groups.

This large-scale study identifies being of White ancestry as a significant effect modifier in the relationship between tonsillectomy and AS development. These findings warrant closer post-operative surveillance for AS symptoms in White patients undergoing tonsillectomy and further mechanistic research.