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A Critical Look at Diagnostic Criteria: Time for a Change? Hasan Yazici Istanbul University.

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Presentation on theme: "A Critical Look at Diagnostic Criteria: Time for a Change? Hasan Yazici Istanbul University."— Presentation transcript:

1 A Critical Look at Diagnostic Criteria: Time for a Change? Hasan Yazici Istanbul University

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3 Plan ● A broken ankle ● Issues with ISBD (Behçet) criteria ● The EULAR/ACR criteria for RA: an issue in validation ● Thought barriers ● Perhaps…

4 Ottowa Ankle Rules sensitivity ~ 100%, specificity ~ 40% IG Stiell et al. Ann Emerg Med, 1992

5 The Ottowa Ankle Rules ● They were not directly about diagnosing, they were about when we should get a radiograph to help us diagnose an ankle fracture in the relevant setting. ● They avoided many unnecessary radiographs but all necessary radiographs were taken.

6 Blink The Power of Thinking Without Thinking The Getty Kouros Malcolm Gladwell (2005)

7 from: Blink (M. Gladwell ) A computer-derived protocol to aid in the diagnosis of emergency room patients with acute chest pain. L. Goldman et al. N Eng J Med, 1982 To determine whether data available to physicians in the emergency room can accurately identify which patients with acute chest pain are having myocardial infarctions, we analyzed 482 patients at one hospital. Using recursive partitioning analysis, we constructed a decision protocol in the format of a simple flow chart to identify infarction on the basis of nine clinical factors. In prospective testing on 468 other patients at a second hospital, the protocol performed as well as the physicians. Moreover, an integration of the protocol with the physicians' judgments resulted in a classification system that preserved sensitivity for detecting infarctions, significantly improved the specificity (from 67 per cent to 77 per cent, P less than 0.01) and positive predictive value (from 34 per cent to 42 per cent, P = 0.016) of admission to an intensive-care area. The protocol identified a subgroup of 107 patients among whom only 5 per cent had infarctions and for whom admission to non-intensive-care areas might be appropriate. This decision protocol warrants further wide- scale prospective testing but is not ready for routine clinical use 7

8 MI prediction rules L Goldman et al. N Engl J Med, Unstable angina 2. Basilar rales 3. BP<10 mmHg

9 The Cook County MI Prediction Rules ● They were not directly about diagnosing, they were about when we should send a patient to CCU when we suspected MI in the relevant setting. ● They avoided many unnecessary admissions to CCU but those patients who really needed the CCU got there.

10 1010 EULAR/ACR Vasculitis Criteria Group (2008) “Perhaps the most robust criteria pertain to Behçet’s disease, where international colloboration has led to a validated proposal effective for both clinical and research purposes.” “The challange of producing validated diagnostic criteria for these heterogeneous diseases that are suitable for use in clinical research as a classification tool, is a formidable one. However, as the international community has examplified with Behçet’s disease, it is achievable.”

11 Plan ● A broken ankle ● Issues with ISBD (Behçet) criteria ● The EULAR/ACR criteria for RA: an issue in validation ● Thought barriers ● Perhaps

12 1212 International Study Group Diagnostic Criteria (Lancet, 1990) Oral ulcers (~100%) + Two of below: a.Genital ulcers (80%) b.Skin lesions (80%) c.Eye lesions (50 %) d.Pathergy (50 %)

13 1313 Hunder GG. The Use and Misuse of Classification and Diagnostic Criteria for Complex Diseases. Ann Intern Med, 1998

14 1414 International Study Group Diagnostic Criteria (Lancet, 1990) Oral ulcers (~100%) + Two of below: a.Genital ulcers (80%) b.Skin lesions (80%) c.Eye lesions (50 %) d.Pathergy (50 %) Classification

15 1515 International Study Group Diagnostic Criteria (Lancet, 1990) Oral ulcers (~100%) + Two of below: a.Genital ulcers (80%) b.Skin lesions (80%) c.Eye lesions (50 %) d.Pathergy (50 %) Classification ?

16 1616 International Study Group Diagnostic Criteria (Lancet, 1990) Oral ulcers (~100%) + Two of below: a.Genital ulcers (80%) b.Skin lesions (80%) c.Eye lesions (50 %) d.Pathergy (50 %) Classification & Diagnostic

17 ISBD Criteria for Behçet’s Disease (Lancet, 1990)

18 ISBD Criteria for Behçet’s Disease (Lancet, 1990) L Goldman et al. N Engl J Med 1982

19 ISBD Criteria-Methods I ● Information on 914 patients with diagnosed BS were collected from 12 centers. ● Of these, the clinical features of only those with oral ulcers (n= 887) were compared with those among 97 patients with other inflammatory diseases and oral ulcers. ● The criteria were initially formulated among a 60% sample of the BS pool and the criteria were later validated among the 40% sample.

20 ISBD Criteria-Methods II ● The expected weight of evidences (Turing) calculated for each disease feature in the training sample. ● From these the new disease criteria were formed. ● These were validated among the validation sample (the randomly chosen 40% sample)

21 ISBD Criteria-Methods II ● The expected weight of evidences (Turing) calculated for each disease feature in the training sample. ● From these the new disease criteria were formed. ● These were validated among the validation sample (the randomly chosen 40% sample)

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24 2424 The Meaning of Fulfilling the ISBD Criteria (sensitivity = 90%; specificity =95%) ● Criteria + (+LR) : 0.90/ = 18 x pre-test odds ● Criteria - (-LR) : /0.95 = 0.10 x pre-test odds

25 2525 The Meaning of Fulfilling the ISBD Criteria (sensitivity = 90%; specificity =95%) ● Criteria + (+ LR) : 0.90/ = 18 x pre-test odds ● Criteria - (- LR) : /0.95 = 0.10 x pre-test odds

26 Issues with the ISBD criteria ● Did the comparator group represent conditions that usually come into the differential diagnosis of BS? ● The trouble with the validation group: - randomly chosen from the initial set ● The trouble with the control group: - lack of patients with CNS or major vessel disease ● What will be the pre-test odds of having BS in the setting in which these criteria will be used? ● What will be the pre-test odds of having one of the comparator diseases in the setting in which these criteria will be used? ● What will be the pre-test odds of having yet undefined diseases in the setting these criteria will be used?

27 Plan ● A broken ankle ● Issues with ISBD (Behçet) criteria ● The EULAR/ACR criteria for RA: an issue in validation ● Thought barriers ● Perhaps

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34 Validation vs.Total Group 34 Total includes data from the validation groups includes data from

35 In brief: ● We have problems in making good validation groups for our classification/diagnostic criteria. ● Perhaps this is due to the near impossibility of formulating such control groups.

36 Plan ● A broken ankle ● Issues with ISBD (Behçet) criteria ● The EULAR/ACR criteria for RA: an issue in validation ● Thought barriers ● Perhaps…

37 Thought Barriers I. The misconception of trying to avoid circularity in criteria making II. Promise of an universal diagnostic criteria, somehow different from classification criteria, to come III. A lack of appreciation of pre and post test (criteria) odds IV. A lack of appreciation that we begin to diagnose from a certain symptom or sign V. A lack of consideration of whether we have to diagnose and when we do what do we plan to do with our diagnosis VI. A lack of appreciation that there are diseases that are yet to be defined. VII. A lack of consideration that we should perhaps involve our patients in naming and what we plan to do with their diagnosis (es)

38 Thought Barriers I. The misconception of trying to avoid circularity in criteria making II. Promise of an universal diagnostic criteria, somehow different from classification criteria, to come III. A lack of appreciation of pre and post test (criteria) odds IV. A lack of appreciation that we begin to diagnose from a certain symptom or sign V. A lack of consideration of whether we have to diagnose and when we do what do we plan to do with our diagnosis VI. A lack of appreciation that there are diseases that are yet to be defined. VII. A lack of consideration that we should perhaps involve our patients in naming and what we plan to do with their diagnosis (es)

39 Circular Reasoning ● All diagnoses/classifications - even when specific histology/microbiology are involved - are based on definitions and thus have some circularity. ● However circular reasoning is only present when the conclusion is nothing more than a reiteration of the premise (s) of the reasoning.

40 Circular Reasoning Present ● Our rheumatology unit does not make a diagnosis of RA unless 3 months pass after the onset of symptoms. ● Among 300 patients with inflammatory arthritis seen in our clinic within 3 months, the arthritis went away by symptomatic therapy in 120 patients. ● It was interesting to note that there were no patients with RA among these 120 patients.

41 Circular Reasoning Absent ● Our unit defines RA as symmetrical polyarthritis of unknown cause which lasts at least 3 months and involves at least 2/3 joint groups, consisting of MCP’s, wrists or MTP’s. ● Among 1000 new patients seen in our clinic within a year 490 satisfied this definition. ● Almost a half of the new patients we see in a year has RA.

42 In brief: ● Coming to a conclusion unaware that the conclusion reached was inescapable is “circular reasoning”. ● To search for and find what has been defined is NOT circular reasoning.

43 JF Fries Arch Intern Med, 1984

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45 Thought Barriers I. The misconception of trying to avoid circularity in criteria making II. Promise of an universal diagnostic criteria, somehow different from classification criteria, to come III. A lack of appreciation of pre and post test (criteria) odds IV. A lack of appreciation that we begin to diagnose from a certain symptom or sign V. A lack of consideration of whether we have to diagnose and when we do what do we plan to do with our diagnosis VI. A lack of appreciation that there are diseases that are yet to be defined. VII. A lack of consideration that we should perhaps involve our patients in naming and what we plan to do with their diagnosis (es)

46 The promise of diagnostic criteria to come

47 JF Fries et al. Arthritis Rheum, 1994

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49 Why Not an Universal Diagnosis/Classification Scheme ?

50 ● There are different reasons why we diagnose or classify. ● There are differences in disease presentation depending on: ● Frequency ● Subspecialty ● Geography ● Disease course ● Yet undefined diseases

51 51 Causes of Uveitis (%) in Japan* & USA** Japan (3060) USA (1237) Idiopathic B27 assoc Sarcoidosis JRA SLE Behçet HIV02.4 * H Goto et al. Jpn J Ophtalmol, 2007; ** A Rodriquez et al. Arch Ophthalmol, 1996

52 Thought Barriers I. The misconception of trying to avoid circularity in criteria making II. Promise of an universal diagnostic criteria, somehow different from classification criteria, to come III. A lack of appreciation of pre and post test (criteria) odds IV. A lack of appreciation that we begin to diagnose from a certain symptom or sign V. A lack of consideration of whether we have to diagnose and when we do what do we plan to do with our diagnosis VI. A lack of appreciation that there are diseases that are yet to be defined. VII. A lack of consideration that we should perhaps involve our patients in naming and what we plan to do with their diagnosis (es)

53 5353 The Meaning of Fulfilling the ISBD Criteria (sensitivity = 90%; specificity =95%) ● Criteria + (+ LR) : 0.90/ = 18 x pre-test odds ● Criteria - (- LR) : /0.95 = 0.10 x pre-test odds

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55 Thought Barriers I. The misconception of trying to avoid circularity in criteria making II. Promise of an universal diagnostic criteria, somehow different from classification criteria, to come III. A lack of appreciation of pre and post test (criteria) odds IV. A lack of appreciation that we begin to diagnose from a certain symptom or sign V. A lack of consideration of whether we have to diagnose, and when we do, what do we plan to do with our diagnosis VI. A lack of appreciation that there are diseases that are yet to be defined. VII. A lack of consideration that we should perhaps involve our patients in naming and what we plan to do with their diagnosis (es)

56 Thought Barriers I. The misconception of trying to avoid circularity in criteria making II. Promise of an universal diagnostic criteria, somehow different from classification criteria, to come III. A lack of appreciation of pre and post test (criteria) odds IV. A lack of appreciation that we begin to diagnose from a certain symptom or sign V. A lack of consideration of whether we have to diagnose, and when we do, what do we plan to do with our diagnosis VI. A lack of appreciation that there are diseases that are yet to be defined. VII. A lack of consideration that we should perhaps involve our patients in naming and what we plan to do with their diagnosis (es)

57 JF Fries et al. Arthritis Rheum, 1994

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59 Plan ● A broken ankle ● Issues with ISBD (Behçet) criteria ● The EULAR/ACR criteria for RA: an issue in validation ● Thought barriers ● Perhaps…

60 Perhaps… ● …. we can begin to be concerned more about having “rules” or “guidelines” about “what to do” with our patients rather than naming them. ● …for Behçet’s and similar conditions (other primary vasculitides?) we can tailor our diagnostic criteria to subspecialty. H Yazici et al. Arthritis Rheum, 2008 ● …we can honestly tell our patients that in many instances we should start treating them without a definate diagnosis AND they might also have a yet undefined disease. ● …we can re-name the new EULAR/ACR criteria for RA “Guidelines for initiating methotrexate treatment in new onset inflammatory joint disease”

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