<p>Thyroid Function Assessment Using a Cost-Effective and Time-Efficient Testing Algorithm New Thyroid Function Screening Cascade Bronson Laboratory Services introduces a new laboratory testing cascade for Nonhospitalized patients the initial screening and diagnosis of Not on thyroid replacement thyroid disease in nonhospitalized Without known or patients. suspected pituitary disease The cascade uses an algorithmic approach beginning with thyroid stimulating hormone (TSH). Further tests are performed automatically, at an TSH additional charge, as illustrated in this flowchart:</p><p>Borderline Normal TSH High TSH Low TSH low TSH 0.27-4.2 >4.2 mlU/L <0.10 mIU/L 0.1-0.26 mlU/L mlU/L</p><p>Free T4 No further Suspect Suspect to evaluate testing Hypo- Hyper- for unless thyroidism thyroidism possible clinically Hyper- indicated thyroidis m</p><p>Free T4 and Free T4 Thyroid peroxidas e antibodie s</p><p>Monitoring Patients on Thyroid Replacement The complete thyroid screening fT4 2.0 cascade is not designed for monitoring fT4 <2.0 ng/dL patients receiving thyroid replacement ng/dL therapy. For monitoring, TSH and/or free or greater T4 should be ordered individually. Patients on a stable dose of thyroid medication may be monitored with TSH Total T3 Consistent alone. After initiating thyroid replace- to evaluate with ment therapy or changing dosage, for primary free T4 levels should be followed until possible T3 Hyper- TSH levels stabilize (3-6 weeks). toxicosis thyroidism </p>