A Rational Request Behavior: The Development of Prediction Instruments regarding Thyroid Function Tests in Primary Care

F. M. H. M. Dupuits; P. Pop; A. Hasman; H. J. A. Schouten

doi:10.1055/s-0038-1634145

Methods of Information in Medicine, Table of Contents

Methods Inf Med 1999; 38(01): 31-36
DOI: 10.1055/s-0038-1634145

Original article

Schattauer GmbH

A Rational Request Behavior: The Development of Prediction Instruments regarding Thyroid Function Tests in Primary Care

Authors

F. M. H. M. Dupuits

¹Department of Medical Informatics, Maastricht University, The Netherlands
P. Pop

²Diagnostic Coordinating Center, University Hospital Maastricht, The Netherlands
A. Hasman

¹Department of Medical Informatics, Maastricht University, The Netherlands
H. J. A. Schouten

³Department of Methodology and Statistics, Maastricht University, Maastricht, The Netherlands

Abstract

Abstract:

A prospective study was performed to encourage a rational thyroid-stimulating hormone (TSH) test request behavior of physicians, using prediction instruments. The latter give direct feedback about request adequacy on the basis of pretest probabilities of hyperthyroidism using patients’ signs and symptoms. For instrument design, stepwise logistic regression was used on diagnostic data acquired through questionnaires, answered by 80 physicians and 668 patients for whom physicians requested a TSH test. Instruments were designed for clinical and subclinical hyperthyroidism and for clinical hyperthyroidism alone. Use of the instrument for clinical or subclinical hyperthyroidism on the selected group, at a 5% probability threshold, can result in a 37% reduction of unnecessary TSH test requests. With the instrument for clinical hyperthyroidism at a 5% probability threshold, the number of unnecessary test requests can be reduced by 57%. Therefore, it can be concluded that the instruments can determine TSH test request adequacy and encourage a rational TSH test request behavior of physicians at low pretest probability thresholds.

Keywords:

Hyperthyroidism - Medical Models - Prediction Instruments - Family Medicine

Full Text

References

REFERENCES
1 Crooks J, Murray IPC, Wayne EJ. Statistical methods applied to the clinical diagnosis of thyrotoxicosis. Quart J Med 1959; XXVIII (Suppl. 110) 211-34.
2 Crooks J, Wayne EJ, Robb RA. A clinical method of assessing the results of therapy in thyrotoxicosis. Lancet 1960; 20: 397-401.
3 Gurney C, Owen SG, Hall R, Roth M, Harper M, Smart GA. Newcastle thyrotoxicosis index. Lancet 1970; 2 7686 1275-8.
4 Wayne EJ. Clinical and metabolic studies in thyroid disease (The first of two Lumleian Lectures delivered before the Royal College of Physicians of London on April 14 and 16, 1959). Br Med J 1960; 2: 1-11.
5 Billewicz WZ, Chapman RS, Crooks J. et al. Statistical methods applied to the diagnosis of hypothyroidism. Quart J Med 1969; XXXVIII (Suppl. 150) 255-66.
6 Wayne EJ. Clinical and metabolic studies in thyroid disease (The second of two Lumleian Lectures delivered before the Royal College of Physicians of London on April 14 and 16, 1959). Br Med J 1960; 9: 78-90.
7 Bommer M, Eversmann T, Pickardt R, Leonhardt A, Naber D. Psychopathological and neuropsychological symptoms in patients with subclinical and remitted hyperthyroidism. Klin Wochenschr 1990; 68 (Suppl. 11) 552-8.
8 Mudde AH. Effects of Subclinical Hyperthyroidism on Bone and Heart [Doctoral Thesis at the Maastricht University]. Maastricht: University Press Maastricht (UPM); 1993
9 Ross DS, Neer RM, Ridgway EC, Daniels GH. Subclinical hyperthyroidism and reduced bone density as a possible result of prolonged suppression of the pituitary-thyroid axis with L-thyroxine. Am J Med 1987; 82: 1167-70.
10 Schlote B, Schaaf L, Schmidt R. et al. Mental and physical state in subclinical hyperthyroidism – Investigations in a normal working population. Biol Psych 1992; 32 (Suppl. 01) 48-56.
11 Wiersinga WM. Subclinical hypothyroidism and hyperthyroidism – I. Prevalence and clinical relevance. Neth J Med 1995; 46 (Suppl. 04) 197-204.
12 Lentner C. Geigy Scientific Tables – Volume 2: Introduction to Statistics, Statistical Tables, Mathematical Formulae . Basel: Ciba-Geigy Limited; 1982
13 Miller RG. The Jackknife – A review. Biometrika 1974; 61: 1-15.
14 Diamond GA, Forrester JS. Analysis of probability as an aid in the clinical diagnosis of coronary artery disease. N Engl J Med 1979; 300: 1350-8.
15 Aronson MD. Heterophil antibody in adults with sore throat-Frequency and clinical presentation. Ann Int Med 1982; 96: 505-8.
16 Griner PF. Cholelithiasis. In: Griner PF, Panzer RJ, Greenland P. eds. Clinical Diagnosis and the Laboratory: Logical Strategies for Common Medical Problems . Chicago: Chicago Year Book Medical Publishers; 1986: 247-55.
17 Bagchi N, Brown TR, Parish RF. Thyroid dysfunction in adults over age 55 years – A study in an urban US community. Arch Intern Med 1990; 150: 785-7.
18 Davies AB, Williams I, John R, Hall R, Scanlon MF. Diagnostic value of thyrotropin releasing hormone tests in elderly patients with atrial fibrillation. Br Med J 1985; 291: 773-6.
19 Finucane P, Rudra T, Church H. et al. Thyroid function tests in elderly patients with and without an acute illness. Age and Ageing 1989; 18: 398-402.
20 Francis T, Wartofsky L. Common thyroid disorders in the elderly. Postgrad Med 1992; 92 (Suppl. 03) 225-30 233-6.
21 Levy EG. Thyroid disease in the elderly. Med Clin North Am 1991; 75 1 – Special on Thyroid Diseases 151-67.
22 Sawin CT, Castelli WP, Hershman JM, McNamara P, Bacharach P. The aging thyroid – Thyroid deficiency in the Framing-ham study. Arch Intern Med 1985; 145: 1386-8.
23 Dupuits FMHM. The use of the Arden Syntax for MLMs in HIOS+, a decision support system for general practitioners in The Netherlands. Comp Biol Med 1994; 24 (Suppl. 05) 405-10.
24 Dupuits FMHM, Hasman A. Evaluation of a decision support system in a medical environment. Int J Bio-Med Comp 1995; 38: 155-65.
25 Dupuits FMHM, Hermsen JT, Oosterhuis WP, Winkens RAG. BODE, een transmuraal laboratoriumaanvraag informatiesys-teem. In: Sollet PCGM. ed. Symposiumverslag van het Electronisch Medisch Dossier Congres 1997 – Huisarts, Specialist en het Elektronische Medisch Dossier: ‘Werken aan transmurale zorg’ (EMD 97) . Rotterdam: Erasmus Universiteit Rotterdam; 1997: P113-P6.