DIAGNOSTIC GUIDELINES A Service for Clinicians and Patients


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DIAGNOSTIC GUIDELINES A Service for Clinicians and Patients

  1. 1. DIAGNOSTIC GUIDELINES A Service for Clinicians and Patients <ul><li>Mathias M. Müller </li></ul>BCLF Antalya 2007 BCLF Antalya 2007
  2. 2. LABORATORY MEDICINE <ul><li>OBJECTIVES </li></ul><ul><ul><li>Prevention - Risk assessment </li></ul></ul><ul><ul><li>Diagnosis of conditions and diseases </li></ul></ul><ul><ul><li>Monitoring of therapy - Follow-up of patients </li></ul></ul><ul><li>METHODS </li></ul><ul><ul><li>Chemical, physical, biochemical, immunological, molecular biological </li></ul></ul><ul><ul><li>Measurement procedures accurate and precise </li></ul></ul>
  3. 3. INTERESTS and EXPECTATIONS No mutual understanding No confidence in service When communicating with clinicians, one must think like a clinician R. H. Christenson 2007
  4. 4. DETECTION MONITORING INFANT ADULT ELDERLY wellness and fitness acute and chronic diseases PREVENTION inborn errors genetic disposition
  5. 5. HIERARCHY OF CLINICAL DECISIONS Decision Cost effectiveness Organizational impact Clinical impact Diagnostic Therapeutic Health outcome Diagnostic performance Technical performance C. Price 2000 To use a test ?
  6. 6. GUIDELINES systematic developed statements to assist practitioner (clinician) and patient decisions about appropriate healthcare decisions for specific clinical circumstances Field and Lohr 1990 <ul><li>Dissemination of best practice </li></ul><ul><li>Standardization of medical decisions </li></ul><ul><ul><li>Increased transparency </li></ul></ul><ul><ul><li>Better information of patients </li></ul></ul><ul><li>Improvement of patient outcome </li></ul><ul><li>Improve the transperancy and accountability </li></ul><ul><li>Basis in the training of professionals </li></ul><ul><li>Improvement in cost-effectiveness </li></ul>
  7. 7. QUESTIONS TO BE ASKED R. H. CHRISTENSON 2007 What is the interest, the diagnostic validity ? Sensitivity, specificity, predictive values, prognosis ? O: Outcome What is the standard procedure, the comparator ? R: Reference Which procedure or strategy is considered ? A: Assay What are the patient characteristics, conditions, symptoms, demographics ? C: Case QUESTIONS CARO
  8. 8. GUIDELINE DEVELOPMENT TOPIC SELECTION TARGET GROUP MULTIDISCIPLINARY DEVELOPMENT TEAM SCOPE OF GUIDELINE The diagnostic question SYSTEMATIC REVIEW of LITERATURE Critical Appraisal Skill Programme (CASP/NHS) Appraisal of Guidelines Research and Evaluation (AGREE) WRITING GUIDLINE RECOMMENDATIONS Synthesis of evidence Consultation, consensus, peer review GUIDELINE Presentation, dissemination, monitoring
  9. 9. GUIDELINE RESOURCES <ul><li>US National Guideline Clearing House: http: //www . guideline . gov </li></ul><ul><li>Finnish Medical Society: </li></ul><ul><li>http.//www.udate-software.com/publications/EBMG/default.html </li></ul><ul><li>National Academy of Clinical Biochemistry </li></ul><ul><li>http://www.nacb.org </li></ul><ul><li>Clinical Guidelines from other disciplines </li></ul>
  10. 10. QUALITY of REFERENCES Oosterhuis W. P. et al 2004 Statements of committees, expert opinions - reviews. IV Non-comparative studies. Descriptive studies - case reports. III Diagnostic trials or outcome studies of medium quality. Insufficient number of patients, case studies. II Double blind randomised controlled clinical/diagnostic trial or outcome study of good quality. Ib Metaanalysis of randomised trials or systematic reviews based on consistent level Ib studies. Ia
  11. 11. STARD (Standards for reporting diagnostic accuracy) - a checklist P. M. Bossuyt et al. 2003 Time frame, number and group of probands, time of measurements, treatment of probands Study design Clinical application Conclusion Cross tabulaton of results (reference, test), analytical and diagnostic acuracy between groups of probands, ROC-curves, Box-Whiskers plot. Results Methods for reporting diagnostic validities, comparisons between groups, test reproducibility Statistical methods Technical, analytical specifications (linearity, cut-off levels, uncertainty, bias, etc) Test method Description of standard and rationale for comparison. Reference standard Demographic description, inclusion and exclusion criteria, symptoms, data collection criteria. Probands Diagnostic accuracy between tests or across patient groups Introduction
  12. 12. THE DIAGNOSTIC PROCESS PATIENT CARE <ul><li>PREANALYTICS </li></ul><ul><li>Diagnostic strategy </li></ul><ul><li>Test selection/request </li></ul><ul><li>Patient factors </li></ul><ul><li>Sample collection </li></ul><ul><li>POSTANALYTICS </li></ul><ul><li>Laboratory report </li></ul><ul><li>Interpretation </li></ul><ul><li>Effect on patient </li></ul><ul><li>Clinical consultation </li></ul><ul><li>ANALYTICS </li></ul><ul><li>Sample preparation </li></ul><ul><li>Measurement </li></ul><ul><li>Result verification </li></ul>
  13. 13. ESSENTIALS IN DIAGNOSTIC GUIDELINES <ul><li>PREANALYTICS </li></ul><ul><ul><li>Prevalence of condition </li></ul></ul><ul><ul><li>Usefulness of a test </li></ul></ul><ul><ul><ul><li>Diagnostic validities </li></ul></ul></ul><ul><ul><li>Diagnostic algorithm </li></ul></ul><ul><ul><li>Patient preparation </li></ul></ul><ul><ul><ul><li>Timing / frequency of testing </li></ul></ul></ul><ul><ul><ul><li>Type / handling of specimen </li></ul></ul></ul><ul><ul><li>Biological variation </li></ul></ul>Oosterhuis W. P. et al 2004
  14. 14. <ul><li>ANALYTICS </li></ul><ul><ul><li>Validated measurement procedure </li></ul></ul><ul><ul><li>Analytical characteristics </li></ul></ul><ul><ul><ul><li>Detection limits, sensitivity, specificity </li></ul></ul></ul><ul><ul><ul><li>Interferences </li></ul></ul></ul><ul><ul><ul><li>Quality assurance: bias, imprecision </li></ul></ul></ul><ul><ul><li>Laboratory requirements </li></ul></ul><ul><ul><ul><li>Turnaround time </li></ul></ul></ul><ul><ul><ul><li>Qualification, competence </li></ul></ul></ul><ul><ul><ul><li>Costs </li></ul></ul></ul>ESSENTIALS IN DIAGNOSTIC GUIDELINES
  15. 15. <ul><li>POSTANALYTICS </li></ul><ul><ul><li>Reference ranges </li></ul></ul><ul><ul><li>Medical decision limits </li></ul></ul><ul><ul><li>Diagnostic validities </li></ul></ul><ul><ul><ul><li>Sensitivity, specificity </li></ul></ul></ul><ul><ul><ul><li>Predictive values </li></ul></ul></ul><ul><ul><ul><li>Likelihood, ROC analysis </li></ul></ul></ul><ul><ul><li>Interpretation of results </li></ul></ul><ul><ul><ul><li>Intra-individual variation </li></ul></ul></ul><ul><ul><ul><li>Critical limits </li></ul></ul></ul>ESSENTIALS IN DIAGNOSTIC GUIDELINES
  16. 16. DATABASE RESOURCES for the Development / Appraisal of a Guideline <ul><li>AGREE: Appraisal of guidelines: http://www.agreecollaboration.org </li></ul><ul><li>AHRQ: Agency for healthcare research and quality: http://www.ahrq.gov/ </li></ul><ul><li>CASP/NHS: Critical appraisal skill programme of the national health service: http://www.phru.nhs.uk/casp/casp.htm </li></ul><ul><li>Cochrane: Methods working group on systematic review of screening and diagnostic tests: www.cochrane.org/cochrane/sadtdoc1.htm </li></ul><ul><li>US National Guideline Clearing House: http://www.guideline.gov </li></ul><ul><li>IFCC C-EBLM: Committee on evidence based laboratory medicine database: www.ckchmb.nl/ifcc </li></ul>
  17. 17. RATING of GUIDELINE RECOMMENDATIONS Oosterhuis W. P. et al 2004 Advise of experts D Not supported by sufficient level I or II studies C Supported by at least 2 level II studies B Supported by one Ia level systematic review or at least 2 level Ib studies A
  18. 18. MI - Which Test ? I. A. KATZ 1998
  19. 19. Diagnostic Validties 6 hours from onset of symptomes J. ZIMMERMAN et al. CC 1999
  20. 20. Diagnostic Validties 18 hours from onset of symptomes J. ZIMMERMAN et al. CC 1999
  21. 21. Troponin I - Assay Performance F. S. APPLE et al. AmHJ 2002
  22. 22. ESC - ACC - MI DIAGNOSTIC GUIDELINE (Redefinition)
  23. 23. Ventricular Dysfunction Natriuretic Peptides proANP 1-126 proBNP 1-108  -ANP 99-126 active t/2 2.5 min NTproANP 1-98 1-30 31-67 79-98 NTproBNP 1-76 t/2 60-120 min BNP 77-108 active t/2 20 min Volume overload Myocardial wall tension Natriuresis - Diuresis Vasodilatation
  24. 24. Natriuretic Peptides Left Ventricular Dysfunction Hammerer-Lercher et al. 2001 CCA LVEF < 55% LVEF < 40 %
  25. 25. NATRIURETIC PEPTIDES in heart function assessment <ul><li>Assessment of cardiac conditions </li></ul><ul><li>Screening of NYHAN I patients </li></ul><ul><li>Diagnosis of left ventricular dysfunction </li></ul><ul><li>Diagnosis of heart failure </li></ul><ul><li>Diagnosis of ventricular hypertrophy </li></ul><ul><li>Prognosis of myocardial infarction </li></ul><ul><li>Diagnosis of essential hypertension </li></ul>C. J. BURDBURY et al HSQ Scotland 2005 S. K. JAMES et al. Circulaton 2003
  26. 26. ÖGLMKC: DIAGNOSTIC GUIDELINE OF THYREOD FUNCTION <ul><li>Investigation of </li></ul><ul><ul><li>Newborn (screening) </li></ul></ul><ul><ul><li>Asymptomatic adults > 50 a </li></ul></ul><ul><li>family history of thyreoidea dysfunction </li></ul><ul><li>patients in hospitals </li></ul><ul><li>before exposure to Jodide </li></ul><ul><ul><li>Symptomatic adults Hypothyreosis ? </li></ul></ul><ul><ul><li>Hyperthyreosis ? </li></ul></ul><ul><ul><li>Autoimmun disease ? </li></ul></ul><ul><ul><li>Infertility </li></ul></ul><ul><ul><li>Post Partum </li></ul></ul><ul><ul><li>Depression, demenzia </li></ul></ul><ul><ul><li>Abnormal lipids </li></ul></ul><ul><li>1st Diagnostic test: TSH </li></ul><ul><ul><li>TSH within reference range - euthyreosis </li></ul></ul><ul><ul><li>TSH > 3.0 mU/L - hypothyreosis </li></ul></ul><ul><ul><li>TSH < 3.0 mU/L - hyperthyreosis </li></ul></ul>C. BIEGLMAYER et al. 2007
  27. 27. 1 Clinical Diagnosis 2 Control after 3 months Control after 2 months Clinical Diagnosis 3 1 - medication 2 - T3/T4 medication 3 - Initial phase of thyreostatic therapy 4 - sec. Hyperthyreosis, hormone resistance
  28. 28. Thyroid function tests: Reference ranges for adults
  29. 29. Thyroid function tests: Reference ranges for children Age
  30. 30. ÖGLMKC: WG: Laboratorians, Clinicians (endocrinology, internal medicine, nuclear medicine, practitionare). Databases: References: 1. - 35 - 1990 - 2004
  31. 31. Thyroid function tests in serious diseases DISEASED RECOVERY DEMERS AND SPENCER NACB 2002
  32. 32. Thyroid function tests during medication CLINICS Thyreostatics Intermediate phase Intermediate phase Normal TSH/FT4 Equilibrium Diagnostic Test Referencerange Months DEMERS AND SPENCER NACB 2002
  33. 33. SCREENING for DIAGNOSIS of DYSLIPIDAEMIA Cardiovascular Risk Population (Family History CVD, smoker, hypertension, diabetes, obese FLP: Fasting lipids (TG, Chol, HDL-Chol)
  34. 34. SCREENING for DIAGNOSIS of DYSLIPIDAEMIA Not Cardiovascular Risk Population
  35. 35. WHAT IS A GOOD GUIDELINE ? A good guideline is one that leads to improved outcomes in patients. Needs to be based on evidence Needs to be used (implemented) Needs to be regularly assessed, and updated
  36. 36. A lot of work !