The score ranges from + 45 to -25. A score greater than 19 implies toxic hyperthyroidism, while a score less than 11 implies euthyroidism, A score between 11 and 19 is equivocal. Though arrived at by trial and error, it has shown a diagnostic accuracy of 85%.
Reference:
Kalra, S., Khandelwal, S. K., & Goyal, A. (2011). Clinical scoring scales in thyroidology: A compendium. Indian journal of endocrinology and metabolism, 15(Suppl 2), S89–S94. https://doi.org/10.4103/2230-8210.83332