Control rate of hyperthyroidism and its associated factors after prolonged use of anti-thyroid drugs in a hospital setting, Northwest Ethiopia

Abstract

Hyperthyroidism is increased synthesis and secretion of thyroid hormones by the thyroid gland resulting in thyrotoxicosis. The modality of therapy for hyperthyroidism includes anti-thyroid drugs, radioiodine and surgery. Anti-thyroid drugs are the only available therapy for hyperthyroid patients in developing world as radioiodine is inaccessible and surgical set up does not exist as required. The aim of this study was to determine the magnitude and predictors of uncontrolled hyperthyroidism among hyperthyroid patients after prolonged anti-thyroid drug use. An institutional-based cross sectional study was conducted at the University of Gondar hospital, Northwest Ethiopia, between April 1, 2022 and October 31, 2022. A consecutive sampling method was used to recruit 317 study subjects. Data were collected through a pre-designed questionnaire. Patients were interviewed to obtain socio-demographic data and relevant medical information. Laboratory analyses were done based on the follow up protocol. Data were entered into EPI Info version 4.6.0.0 (EPI Info, Atlanta) and analyzed in STATA version 14 (Stata Corp LP, Texas, USA). Binary logistic regression model was used to identify variables associated with uncontrolled hyperthyroidism among hyperthyroid patients. P value < .05 was used to declare significant association. A total of 317 patients with hyperthyroidism were included in the study. The median age of the study subjects was 45 years (IQR 36-55 years). Most (95%) of the study participants were females. Toxic multi-nodular goiter was the most common cause of hyperthyroidism (92%), followed by toxic adenoma (5%) and Graves' disease (2%). On multivariate binary logistic regression, large goiter size (AOR: 3.163, 95% CI [1.333-7.506]), severe disease (AOR: 2.275, 95% CI [1.060-4.880]), infrequent iodinated salt intake (AOR: 3.668, 95% CI [1.245-10.802]), and poor adherence to anti-thyroid drug (AOR:15.724, 95% CI [5.542-44.610]) were statistically significant with uncontrolled hyperthyroidism at 12 months of anti-thyroid drug intake. A quarter of patients with hyperthyroidism didn't achieve euthyroid state after 12 months of anti-thyroid drug use. The identified predictors for non-euthyroid state were large goiter size, severe disease, infrequent iodinated salt intake, and poor adherence to anti-thyroid drug.