7531 Evidence Based Medicine. Part II

The Protocol At the time of discharge, death, or month’s end, each patient was reviewed and consensus reached on: The primary diagnosis:  the disease, syndrome or condition most responsible for the patient’s admission to hospital Centre for Evidence-Based Medicine The Protocol (cont.) The Primary Intervention   the treatment or other manoeuvre that constituted our most important attempt to cure, alleviate, or care for the primary diagnosis traced into the literature to determine its basis in evidence – the Consultant’s “Instant Resource Book” – bibliographic data base searches Centre for Evidence-Based Medicine Primary Interventions were Classified by Level:  Evidence from Randomised Control Trials (better yet: systematic reviews of all relevant, high-quality RCTs)  Convincing non-experimental evidence (unnecessary & unethical to randomise)  Interventions without substantial evidence Centre for Evidence-Based Medicine Conclusions from E-B oriented General Medicine: 82% of our patients received evidencebased care.  treatments for 53% were justified by RCTs or systematic reviews of RCTs.  Of 28 relevant RCTs and SRs, 21 were accessible within seconds.  treatments for 29% were justified by convincing non-experimental evidence  Centre for Evidence-Based Medicine Evidence from RCTs  (53%) 36% had Cardiovascular diagnoses: » Ischaemic heart disease 17% » Heart failure 6% » Arrhythmia 2% » Thromboembolism 3% » Cerebrovascular 8% Centre for Evidence-Based Medicine Evidence from RCTs  (53%) 7% had taken poison  5% received chemotherapy or analgesia for cancer  3 % had gastrointestinal disorders  2% had obstructive airways disease Centre for Evidence-Based Medicine Convincing non-experimental evidence (29%) Infections 15%  Cardiac disorders 7%  Miscellany (non-compliance, drug reactions, bowel or bladder neck obstruction, dehydration, micturition syncope) 7%  Centre for Evidence-Based Medicine Interventions without substantial evidence (18%) Specific symptomatic and supportive care for mild poisoning, non-cardiac chest pain, viral (non-herpetic) meningitis, terminal CNS disease, confusion, and food poisoning.  Centre for Evidence-Based Medicine Better Outcomes for Patients When EBM Is Practised E-B practise vs. Outcome in stroke (US):  When cared for by E-B neurologists, patients were 44% more likely to receive warfarin, and much more likely to be placed in a stroke care unit,  And were 22% less likely to die in the next 90 days.  (Mitchell et al: stroke 1996;27:1937-43) Centre for Evidence-Based Medicine Centres for Evidence-Based Surgery  E-B General/Vascular Unit in Liverpool: » 95% received evidence-based Rx   24% Level 1 71% Level 2  E-B Paediatric Unit in Liverpool: » 77% received evidence-based Rx   11% Level 1 66% Level 2 Centre for Evidence-Based Medicine Worse Outcomes for Patients When EBM Is Not Practised:    In a city-wide study of E-B practise vs. Outcome in carotid stenosis: Generated E-B indications for endarterectomy and reviewed 291 pts. Found the surgical indications: » Appropriate in 33% »Questionable in 49% »Inappropriate in 18% Centre for Evidence-Based Medicine Worse Outcomes for Patients When EBM Is Not Practised Stroke or death within the next 30 days:  Expected (if left alone): 0.5%  Expected (if properly selected and operated): 1.5%  Observed among operated patients (2/3 operated for questionable or inappropriate reasons): >5%  Wong et al. Stroke 1997;28: 891-8. Centre for Evidence-Based Medicine Evidence-Based Ambulatory Paediatrics  54% of manoeuvres were evidencebased (“experts” had predicted <20%) » 77% of diagnostic manoeuvres » 67% of treatments » 59% of health promotion Centre for Evidence-Based Medicine Centres for Evidence-Based Psychiatry   In-Patients (Oxford) » 67% treated on the basis of RCTs Out-Patient » >80% received evidence-based Rx Centre for Evidence-Based Medicine Evidence-Based General Practice 122 consecutive consultations in a suburban (Leeds, UK) practice.  81% evidence-based: » 31% based on RCTs or overviews » 50% based on convincing non-experimental evidence » 19% without substantial evidence (Gill et al, BMJ 1996;312:819-21) Centre for Evidence-Based Medicine Can we get evidence to the bedside? Need it within seconds if it is to be incorporated into busy clinical rounds  Our initial attempts to bring the best evidence to a busy clinical team caring for 200+ admissions per month  Centre for Evidence-Based Medicine Searching for Evidence in the Month Before the Cart: Expected searches = 98  Identified searching needs = 72  Only 19 searches (26%) carried out.  Centre for Evidence-Based Medicine Contents of the Cart:     Infra-red simultaneous stethoscope with 12 remote receivers. Physical diagnosis text book and reprints (JAMA Rational Clinical Exam). Notebook computer, computer projector, and pop-out screen. Rapid printer. Centre for Evidence-Based Medicine Contents of the Cart (cont): Library Round-Trip = 7 min  125 summaries (1-3 pp) of evidence previously appraised and summarised by Side A teams (in the form of “Redbook” entries or Critically-Appraised Topics : “CATs”). Access Time to the “bottom line” = 12 sec. Centre for Evidence-Based Medicine CAN FIND THE CAT IN 12 SECONDS MIS WITH HYPERGLYCAEMIA BENEFIT FROM INTENSIVE INSULIN THERAPY. Clinical Bottom Line: Treating 9 hyperglycaemic MI patients iwth intensive insulin => 3 months will prevent one additional death over the next 3.4 years. Appraised by: Sackett; 24 October 1997 The Study: Non-blinded concealed randomised controlled trial with intention-to-treat. Swedish patients admitted with MI in the prior 24 hours with blood glucose >11 mmol/l with or without prior known diabetes. 50% thrombolysed; by discharge 80% given aspirin, 70% given beta-blockers, and 31% given ACE-inhibitors. Control group (N = 314; 314 analysed): Routine MI care (including aspirin and beta-blockers) but no (extra) insulin unless "clinically indicated" (43%, 45% and 49% on insulin at discharge, 3 months, and 1 year)). Experimental group (N = 306; 306 analysed): Routine MI care plus glucose+insulin infusion for =>24 hours and qid insulin for =>3 months (87%, 80% and 72% on insulin at discharge, 3 months, and 1 year). The Evidence: Outcome Time to CER EER RRR ARR NNT Outcome death (all 3.4 years 0.439 0.333 24% 0.106 9 patients) 95% 7% to 41% 0.030 to 0.182 5 to 34 Confidence Intervals: Comments: 1. Benefit greatest in low risk patients (< 70 y/o, no prior MI, no CHF, no digitalis Rx) not previously on insulin (RRR 46%; ARR 0.15; NNT 7). 2. PTCA and CABG done in 5% and 11% of controls and in 4% and 11% of intensive insulin patients. 3. Glucose 11.7 and 9.6 at 24 hours; 9 and 8.2 at discharge. 4. 97% of deaths were cardiovascular, and most of the mortality benefit was seen after discharge. Expiry date: October 1998 References: Malmberg K for the DIGAMI Study Group: Prospective randomised study of intensive insulin treatment on long term survival after acute myocardial infarction in patients with diabetes mellitus. BMJ 1997;314:1512-5. CAN OBTAIN THE BOTTOM LINE IN 2 SECONDS: MIS WITH HYPERGLYCAEMIA BENEFIT FROM INTENSIVE INSULIN THERAPY. Clinical Bottom Line: Treating 9 hyperglycaemic MI patients with intensive insulin => 3 months will prevent one additional death over the next 3.4 years. CAN READ THE EVIDENCE IN 2 MINUTES The Study: Non-blinded concealed randomised controlled trial with intention-to-treat. Swedish patients admitted with MI in the prior 24 hours with blood glucose >11 mmol/l with or without prior known diabetes. 50% thrombolysed; by discharge 80% given aspirin, 70% given beta-blockers, and 31% given ACE-inhibitors. Control group (N = 314; 314 analysed): Routine MI care (including aspirin and beta-blockers) but no (extra) insulin unless "clinically indicated" (43%, 45% and 49% on insulin at discharge, 3 months, and 1 year)). Experimental group (N = 306; 306 analysed): Routine MI care plus glucose+insulin infusion for =>24 hours and qid insulin for =>3 months (87%, 80% and 72% on insulin at discharge, 3 months, and 1 year). The Evidence: Outcome Time to Outcome CER 0.439 EER 0.333 RRR 24% 7% to 41% ARR 0.106 0.030 to 0.182 NNT 9 5 to 34 death (all patients) 95% Confidence 3.4 years Intervals: CAN STUDY THE ORIGINAL EVIDENCE FOR HOURS Reference: Malmberg K for the DIGAMI Study Group: Prospective randomised study of intensive insulin treatment on long term survival after acute myocardial infarction in patients with diabetes mellitus. BMJ 1997;314:1512-5. Contents of the Cart (cont): Library Round-Trip = 7 min  CD of Best Evidence Access Time to the “bottom line” = 26 sec.  CD of WinSPIRS (5-year clinical subsets) Access Time to useful abstract = 90 sec. (so used for filling Educational Rx after rounds)  CD of the Cochrane Library (used for filling Educational Rx after rounds) Centre for Evidence-Based Medicine Usefulness of the Cart:  81% of searches were for evidence that could affect diagnostic and/or treatment decisions. 90% of these searches were successful in finding useful evidence. *  Centre for Evidence-Based Medicine Of the successful searches (from the perspective of the most junior responsible team member):  52% confirmed diagnostic and/or management decisions 23% led to changes in existing decisions   25% led to additional decisions Centre for Evidence-Based Medicine Searching for Evidence in a 3day period after the Cart: Expected searches = 10  Identified searching needs = 41  Only 5 searches (12%) carried out.  Centre for Evidence-Based Medicine Can we get evidence to the bedside? Yes, and it will improve patient care.  But can we provide it in a less cumbersome form?  Centre for Evidence-Based Medicine EBM and Purchasing In harmony:  When we clinicians stop doing things that are useless or harmful When we use just-as-good but less expensive treatments, carers, and sites for care. Centre for Evidence-Based Medicine What we could save in Oxford by switching from: LASIX  frusemide: £ 90,000 simvastatin  cerivastatin: £ 500,000 TENORMIN  atenolol: £ 700,000 diclofenac  ibuprofen: £ 1,000,000 Total: £ 2,290,000  how many hips would these savings purchase? Centre for Evidence-Based Medicine EBM and Purchasing Still in harmony:  When we spend now to save later. Centre for Evidence-Based Medicine EBM and Purchasing In grudging collaboration:  Waiting lists, once we understand the opportunity costs of shortening them: » it’s not about money » it’s about what else we won’t be able to do if we shorten them Centre for Evidence-Based Medicine EBM and Purchasing In conflict:  When we identify so strongly with a dying patient’s short-term goals that we use resources that we know would “add more QALYs” if used for other patients. Centre for Evidence-Based Medicine