The Decade in Clinical Thyroid Disease: An Analysis of Published Literature.

Background: The purpose of this study was to assess the current status of the clinical thyroidology literature using bibliographic analysis. Methods: The subject "clinical thyroidology" was divided into six broad topics: iodine deficiency/iodine nutrition, hypothyroidism, hyperthyroidism/thyrotoxicosis, thyroiditis/autoimmune thyroid disease, thyroid nodules/multinodular goiter, and thyroid cancer. Using Scopus, an online bibliographic searching tool, this study sought to examine the trends in the publication of clinical thyroid disease-related research articles over the decade from 2006 through the end of 2015. Citation counts were also retrieved for individual research papers in order to find papers that might have had a bigger impact on clinical practice. Review articles, guidelines, and editorials were excluded. Results: A total of 19,055 articles were published in the broad area of clinical thyroid disease. The largest proportion was in the topic of thyroid cancer, accounting for >30% of the total. The numbers of papers published annually on thyroid nodules and thyroid cancer increased progressively over the decade. The largest proportion of clinical thyroid publications emanated from the United States, and the majority of papers were published in subspecialty journals. Within each clinical thyroid topic, the most highly cited papers published from 2006 to 2015 were identified, and outliers-that is, papers that had been cited far more often that others in the topic-were also identified. The most highly cited paper in all of clinical thyroidology was a 2006 study describing the increase in thyroid cancer incidence in the United States (JAMA 295: 2164-2167). Most of the highly cited clinical papers were case series or cohort studies, rather than randomized controlled trials. Conclusions: The number of papers in clinical thyroid disease is expanding rapidly, with >1000 papers published annually over the last decade. Research papers on thyroid nodules and cancer accounted for 51% of all clinical thyroid disease-related papers. More randomized controlled trials have been published in the last few years, portending a bright future for clinical thyroidology.