Y tế cộng đồng - Đánh giá chứng cứ từ nghiên cứu test chẩn đoán

Nội dung text: Y tế cộng đồng - Đánh giá chứng cứ từ nghiên cứu test chẩn đoán

1. www.cebm.net ĐÁNH GIÁ CHỨNG CỨ TỪ NGHIÊN CỨU TEST CHẨN ĐOÁN CEBM Course April 2013 Matthew Thompson Reader, Dept Primary Care Health Sciences Director, Oxford Centre for Monitoring and Diagnosis Deputy Director, Centre for Evidence Based Medicine
2. www.cebm.net
3. ◼ 2/3 malpractice claims against GPs in UK ◼ 40,000-80,000 US hospital deaths from misdiagnosis per year ◼ Diagnosis uses <5% of hospital costs, but influences 60% of decision making
4. On the menu this morning ◼ Tests have multiple roles ◼ Making sense of the in health care numbers ..! (sensitivity, ◼ Basic anatomy of specificity etc) diagnostic accuracy ◼ Not just accuracy – other studies outcomes of diagnostic ◼ Biases in diagnostic tests studies ◼ Systematic reviews of ◼ Tests don’t in themselves diagnostic tests make people better ◼ Useful books and articles ◼ Evaluating new tests
5. “Diagnosis” means lots of things - tests can have many roles
6. Role Description Examples Confirming or Used to confirm (“rule in”) or Normal blood pressure excluding a exclude (“rule out”) particular measurement to exclude diagnosis diagnoses. Most tests will be hypertension. better at one than the other. Raised cardiac troponins May vary between different to confirm cardiac clinical settings / different ischaemia spectrum of disease Triage An initial test in a clinical Blood pressure and heart Roles of pathway, which usually rate in initial triage of directs the need (or not) for patients with multiple diagnostic further (usually more trauma to identify those invasive) testing. Ideal triage with possible shock. tests in test is usually fairly rapid, D-dimer to screen for and should not miss any presence of pulmonary health patients (i.e. minimise false embolism in patients who negatives) have shortness of breath care Monitoring Tests that are repeated at Haemoglobin A1c to periodic intervals in patients monitor glucose control in with chronic conditions, or in patients with diabetes. those receiving certain Anticoagulation tests for treatments, in order to patients taking oral assess efficacy of anticoagulants (warfarin). interventions, disease HIV viral load and CD4 progression, or need for count changes in treatment Prognosis Provides information on CT scanning in patients disease course or with known ovarian progression, and individual cancer to determine the response to treatment stage Screening Detecting conditions or risk Mammography screening factors for conditions in for breast cancer. people who are apparently Cholesterol testing to asymptomatic. detect persons at greater risk of cardiovascular disease.
7. Roles of a new test ◼ Replacement – new replaces old ◼ E.g., CT colonography for barium enema ◼ Triage – new determines need for old ◼ E.g., B-natriuretic peptide for echocardiography ◼ Add-on – new combined with old ◼ ECG and myocardial perfusion scan Bossuyt et al BMJ 2006;332:1089–92
8. Evaluating genomic tests from bench to bedside: a practical framework. Lin, Thompson, et al. BMC something in press Table 1: Multiple clinical roles of genetic tests in clinical practice Type Purpose Definition Examples Detection or exclusion of a Fecal DNA to screen for characteristic or disease in colorectal cancer, SRY genotype Screening asymptomatic persons to determine fetal sex in first- trimester Rule in or rule out conditions in Lynch syndrome testing in Diagnostic symptomatic persons patients with colorectal cancer, CFTR testing in patients with Diagnosis suspected cystic fibrosis, Factor V Leiden or prothrombin gene testing in patients with thromboembolic disease Risk of future disease or Cardiogenomic profile in order to morbidity from disease in people assess risk of future Risk assessment without the disease cardiovascular disease, BRCA testing in women at high risk for breast cancer Prediction Predicting outcomes in people Oncotype DX panel to assess with disease prognosis in women with early Prognosis stage breast cancer , BRCA testing in women with breast cancer Determine, predict, or monitor CYP2C19 gene to predict response and/or adverse effects response to clopidigrel in patients Treatment selection or Treatment of treatment with acute coronary syndrome or monitoring percutaneous coronary intervention (PCI)
9. Basic anatomy of Diagnostic Accuracy studies
10. Defining the clinical question: PICO or PIRT ◼ Patient/Problem ◼ How would I describe a group of patients similar to mine? ◼ Index test ◼ Which test am I considering? ◼ Comparator or Reference Standard ◼ What is the best reference (gold) standard to diagnose the target condition? ◼ Outcome .or .Target condition ◼ Which condition do I want to rule in or rule out?