On the Probability of Correct Diagnosis by Pulmonary Function Tests

• DOI: 10.1136/thx.14.4.300
• Publication Date: 2008-12-13T02:52:56Z
• Authors: R. J. Shephard; M. E. Turner
• Keywords: Respiration; Probability; Respiratory Function Tests

For many years, chest physicians have cherished the hope that respiratory physiologists wiU devise an effective and simple test to distinguish normal from abnormal subjects.The limitations of well- established tests gained increasing recogni- tion, this has led a rapid multiplication in number procedures.Patients are commonly subjected battery 10 or more tests, but all too clear separation is still not obtained.One difficulty tenuous relationship between procedures fundamental characteristics system.Multi- variate statistical techniques such as factor analysis (Gilson Hugh-Jones, 1955; Shephard, Turner, Williams, unpublished) discriminant func- tion now beginning explore problem, it becomes better understood may be possible specific individual system, describing disease states terms alterations these characteristics.Factor formid- able undertaking, been suggested immediate future efficient use existing data could obtained by applying analysis.Instead relying upon intuitive inspection laboratory sheet, results weighted combined manner maximizes difference subjects those suffering under study.Factor also produces combination tests; however, criterion weighting involves maximizing variation value rather than discrimination.A general discussion objectives, similarities, differences analysis, function other multivariate given Kendall (1957).Discriminant used Gilson Hugh-Jones (1955) assessing degree emphysema coalworkers.and Becklake, du Preez, Lutz (1958) study Witwatersrand gold-miners.The purpose present paper examine critically technique with reference examples similar carried out us.