Information Retrieval for Evidence-based Practice

1. Information Retrieval for Evidence-based Practice Fall 2001 Suzanne Bakken, RN, DNSc, FAAN School of Nursing & Department of Medical Informatics Columbia University

2. Definition • Information retrieval (IR) is the science and practice of identification and efficient use of recorded media

3. Information Retrieval and Analysis • Indexing (using standardized terminology and other methods) • Query formulation • Retrieval • Evaluation and refinement

4. Relevance • Recall - ratio of number of documents retrieved and relevant to number of relevant documents in database (sensitivity) • Precision - ratio of relevant documents retrieved to total number of documents retrieved (positive predictive value)

5. User-defined Relevance • Information content of document • Provision of references to other sources of information • Subjective qualities • Situational aspects - clinical vs. student

6. Types of Clinical Decisions • Diagnostic reasoning - differential diagnosis • Decisions related to actions - involve risk: cost, time, morbidity, mortality, discomfort • Diagnostic tests - treatment-threshold • Screening • Management (including prevention) - medications, surgery, education, watchful waiting

7. General Search Strategy for EBP Information Retrieval Clinical problem Define searchable question Select most likely resource Design search strategy Summarize the evidence yield Poor Apply the evidence Select another resource

8. General Search Strategy for EBP Information Retrieval Clinical problem Define searchable question Select most likely resource Design search strategy Summarize the evidence yield Poor Apply the evidence Select another resource

9. Define Searchable Question • Background question – general (who, what, where, when, why, and how) • Foreground question – patient-specific knowledge questions

10. Informatics Support for Background Questions at CPMC • Generic queries – Medline Button/ InfoButton • Is [laboratory test] indicated in [disease or syndrome]? • What is the drug of choice for [disease or syndrome]? • Supported through the Medical Entities Dictionary (the MED), the concept-oriented terminology

12. Elements of Well-built Foreground Questions • Patient or problem being addressed • “Intervention” (natural or therapeutic) being considered • Comparison intervention being considered, where relevant • Outcome of interest

13. Selecting a Diagnostic Test • In patients with heart failure, how accurate is the bedside test for post-Valsalva systolic overshoot in predicting left ventricular function? • Problem • Intervention • Comparison intervention • Outcome

14. Determining Prognosis • In an elderly woman with coronary heart disease, by how much does the appearance of heart failure shorten her life? • Problem • Intervention • Comparison intervention • Outcome

15. Selecting Therapy • In coronary patients who develop heart failure on ibuprofen, would simple drug withdrawal plus diuretics suffice or should they be offered an angiotensin-converting enzyme (ACE) inhibitor as well, in order to alleviate the heart failure? • Problem • Intervention • Comparison intervention • Outcome

16. Selecting Secondary Prevention Measures • In patients with heart failure, would long-term ACE inhibitor therapy prevent recurrences and improve the quality of life? • Problem • Intervention • Comparison intervention • Outcome

17. Informatics Support for Background Questions at CPMC • MED • Query matching • In the context of the particular application, what is the closest generic question? • Matches displayed to user and user may add more information then query is passed to multimedia search process • Query refinement • Additional information can be added (e.g., age) if search results are not satisfactory