A COMPARISON OF WAYNE’S AND BILLEWICZ CLINICAL SCALES TO THYROID FUNCTION TEST IN THE ASSESSMENT OF SURGICAL PATIENTS WITH GOITRE IN JOS UNIVERSITY TEACHING HOSPITAL
BACKGROUND: Surgeons managing goitre need to determine thyroid function status and ensure
euthyroidism to prevent peri-operative thyroid storm and myxoedema coma, in addition to
determining the underlying pathology.
Thyroid function is most commonly determined by thyroid function test (TFT). Wayne’s and
Billewicz scales may be useful guides for selective TFT.
AIM: To compare Wayne’s and Billewicz scales to TFT in the determination of thyroid function of
surgical patients with goitre in JUTH.
METHODOLOGY: Data was collected prospectively from consecutive surgical patients with goitre
in JUTH, during the study period. Wayne’s and Billewicz scales were evaluated against TFT using Mcnemar’s Chi square. Their sensitivity, specificity, accuracy, positive and negative predictive values were determined. The AUROC and optimal cut-off values to guide selective TFT were determined from ROC curves. The level of significance was pre-set at 5%
RESULT: During the period of this study, from November 2019 to December 2020, 52 patients were recruited but 51 patients completed the study.
Mcnemar’s chi square test yielded a p-value of 0.5 for difference between Wayne’s scale and TFT and 1 for difference between Billewicz scale and TFT.
The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and
accuracy of Wayne’s scale were 85.7%, 100%, 100%, 94.7% and 96% respectively. There was an area of 0.92 under its ROC curve with p-value of 0.0000 and optimal cutoff value of >11.
The specificity, NPV and accuracy of Billewicz scale were 100%, 97.3% and 97.3% respectively. Lack of true overt hypothyroidism made sensitivity and PPV unreliable. There was an area of 0.82 under its ROC curve with p-value of 0.26 and an optimal cut-off value of >-53.