Task: Answer Verification
Input (English): Question: Do normal limits for serum thyrotropin vary greatly depending on method?
Answer: Different normalization methods alter the normal limits greatly. However, in individuals without thyroid illness, thyroid hormone values are stable over a wide range of TSH levels including beyond the UNL for all methods. Indeed, there may be no true universal upper TSH cut-off level and clinical decision-making cannot rely on these calculated limits.
Output (English): yes