Factors Affecting Thyroid Cancer in Patients with Thyroid Nodules Using Logistic Regression in Interval Censored Data

[Background]Thyroid nodules in the majority of cases are symptom-free; but, their clinical significance is due to being differentiated from malignancy. The outbreak of thyroid cancer (TC) is gradually soaring because of lifestyle turning into westernization in developing nations such as Iran. Thus, the current research has been performed pursuing the goal to identify the most critical risk factors in the thyroid cancerous individuals with thyroid nodules in northern Iran during a decade.[Methods]This study is of historical cohort type. A total of 33,530 files of the patients referring to the medical clinic through 2003 to 2013 have been examined and 1,817 thyroid nodule afflicted patients have been diagnosed and the data about these patients includes 70 recorded variables The data have been analyzed by logistic regression in interval Censored data at significance level 0.05 applying SPSS and Strata software.[Results]A total of 1 594 (87.7%) of the patients consist of women in the mean age bracket 41.07 ± 13.81. Also, the mean age of those with TC is 38.15 ± 13.52. Among the most significant factors identified in thyroid malignancies in the patients with thyroid nodules, we can note severe obesity, bilateral nodules, abnormal thyroid stimulating hormone (TSH) and T4 hormones, phosphorus, calcium, and thyroglobulin.[Conclusions]Regarding the incidence raise of TC, it is required to identify the malignancy risk factors. It is recommended to carry out some studies on the role of abnormal T4 hormone, phosphorus, calcium, and thyroglobulin in thyroid malignancies in the patients suffering from thyroid nodules.