Abstract
Objective: We aimed to improve our new simple, low-cost method for detecting overt thyroid dysfunction using a set of routine tests during the general health check-up called "Ningen Dock", with no TSH measurement.
Methods: In this study, screening was conducted on a total of 9,816 Japanese (4,355 with no overlaps) undergoing a health check-up at JR Sendai Hospital from July 2008 to December 2011. The existing procedure comprised 5 routine tests (alkaline phosphatase (ALP), serum creatinine (S-Cr), total cholesterol (TC), lactate dehydrogenase (LDH) and red cell count (RBC)) and we investigated further refinements to it such as (1) including heart rate in hyperthyroid screening, (2) correcting for the effect of dosing in examinees taking cholesterol-lowering agents, (3) considering characteristics of time series variation in routine tests.
Results: 89 examinees were suspected of having thyroid dysfunction by our screening and 11 of them were actually confirmed to do so by blood thyroid hormone measurements. None of them had complained of any illness. The implementation of (1) - (3) above was successful in decreasing both false negatives and false positives.
Conclusions: The usefulness of our new method for screening patients with overt thyroid dysfunction through a set of routine tests conducted during Ningen Dock without thyroid hormone measurement was further confirmed. We also verified that refinements to our screening method, such as adding heart rate, including the influence of dosing and considering characteristics of time series variation of routine tests, were very effective.
