Prevalence of Thyroid Nodules in China: A Health Examination Cohort-Based Study

Thyroid nodules are a common clinical problem and some are potentially cancerous; however, little is known about the prevalence of thyroid nodules in China. The objective of this study was to investigate the prevalence of thyroid nodules in a healthy Chinese population. We reviewed electronic medical records of 13,178,313 participants from 30 provinces and regions who received health examinations and underwent thyroid ultrasound at Meinian Onehealth Healthcare in 2017. Among them, 6,192,357 were excluded based on predefined criteria. All thyroid nodules were diagnosed by ultrasonography, and standardized protocols were adopted for data collection, quality control, and data management. A total of 6,985,956 participants (mean age: 42.1 ± 13.1 years) were included in this study. The overall prevalence of thyroid nodules was 36.9% (95% CI, 35.7%-38.1%; age- and sex-standardized prevalence 38.0% [95% CI, 37.0%-39.1%]). The prevalence of thyroid nodules in females (44.7% [95% CI, 43.4%-45.9%], age-standardized prevalence: 45.2% [95% CI, 44.1%-46.4%]) was significantly higher than that in males (29.9% [95% CI, 28.8%-31.0%], age-standardized prevalence 31.2% [95% CI, 30.1%-32.2%]; < 0.001). The prevalence of thyroid nodules decreased from