Searching for the evidence to support diagnosis and treatment reveals one important observation: Perhaps only 20% of what we do in medicine is supported by solid scientific evidence. The remaining 80% is based on, at best, reasonable assumptions based on our understanding of anatomy, biochemistry and physiology and, at worst, anecdote, dogma and myth. This Web page identifies some of these medical myths which have not withstood scrutiny. Note that most of these myths are debunked by clinical trials, rather than systematic analyses.

References:

• Paauw DS, Did we learn evidence-based medicine in medical school? Some common medical mythology, J Am Board Fam Pract 1999 Mar-Apr;12(2):143-9 - From PubMed 
• Emergency Medicine and Acute Care/Series 12 (1999) - By The Center for Medical Education, Inc. 
• Medical Mythology - An on-line lecture by Robert J. Flaherty, MD

General
Myth: Worried patients are reassured by normal test results.

Truth:

• Patients frequently are not reassured by a normal test result, and once anxiety develops, it may be difficult to completely eliminate. Reassuring patients when test results are normal: Review of McDonald IG et al, Opening Pandora's box: the unpredictability of reassurance by a normal test result. BMJ 1996:313:329-32 - Reviewed by POEMS/JFP 

Truth:

• The conclusions of review articles are strongly associated with the affiliations of their authors. Barnes DE, Bero LA, Why review articles on the health effects of passive smoking reach different conclusions, JAMA 1998 May 20;279(19):1566-70 - From PubMed 
• Our results demonstrate a strong association between authors' published positions on the safety of calcium-channel antagonists and their financial relationships with pharmaceutical manufacturers. Stelfox HT et al, Conflict of interest in the debate over calcium-channel antagonists, N Engl J Med 1998 Jan 8;338(2):101-6 - From PubMed 
• One of every three articles in our sample has at least one... author with a financial interest, and 15% of the authors in our sample have a financial interest relevant to one of their publications. Krimsky S et al, Scientific journals and their authors' financial interests: a pilot study, Psychother Psychosom 1998 Jul-Oct;67(4-5):194-201 - From PubMed 
• Clinical trials with positive results are published more frequently and more quickly than are those with negative results. Ioannidis JP, Effect of the statistical significance of results on the time to completion and publication of randomized efficacy trials. JAMA 1998 Jan 28;279(4):281-6 - From PubMed 

Truth:

• The severity of the patient's disability, not the occurrence of an adverse event or an adverse event due to negligence, was predictive of payment to the plaintiff. Brennan TA et al, Relation between negligent adverse events and the outcomes of medical-malpractice litigation. N Engl J Med 1996 Dec 26;335(26):1963-7 - From PubMed 

Truth:

• Guidelines published in the peer-reviewed medical literature during the past decade do not adhere well to established methodological standards. While all areas of guideline development need improvement, greatest improvement is needed in the identification, evaluation, and synthesis of the scientific evidence. Shaneyfelt TM et al, Are Guidelines Following Guidelines? The Methodological Quality of Clinical Practice Guidelines in the Peer-Reviewed Medical Literature, JAMA, 1999;281:1900-1905

Truth:

• A meta-analysis of  39 studies of the use of bed rest versus early mobilization for prevention and treatment of a variety of medical conditions showed bed rest to be at best not beneficial and at worst harmful. Allen C et al, Bed rest: a potentially harmful treatment needing more careful evaluation, Lancet 1999 Oct 9;354(9186):1229-33 - From PubMed 

Truth:

• In children and young people temperature measured at the axilla does not agree sufficiently with temperature measured at the rectum to be relied on in clinical situations where accurate measurement is important. Craig JV et al, Temperature measured at the axilla compared with rectum in children and young people: systematic review, BMJ 2000;320:1174-1178 ( 29 April ) 

Chest X-ray in older patients, smokers and travellers. 
Hemoglobin for anaemia. 
ESR for inflammatory infective or malignant disease. 
Liver function tests in blood. 
Renal function tests. 
Calcium in blood. 
Uric acid in blood. 
Glucose in blood. 
Cholesterol. 
HDL/LDL ratio. 
Mammography in women over 40 years. 
Ultrasound examination of the ovaries. 
Bone density in women. 
Resting ECG. 
Exercise ECG on a treadmill. 
Ultrasound examination of the aorta in men over 55 years. 
PSA in men over 50 years. 
Helicobacter pylori. 

• There is no scientific evidence supporting the value of these studies as screening tests in asymptomatic populations. Evidence-Based Journalism - Reviewed by Bandolier

Truth:

• James Bond's profound state of health may be due, at least in part, to compliant bartenders. Trevithick CC et al, Shaken, not stirred: bioanalytical study of the antioxidant activities of martinis, BMJ 1999;319:1600-1602

Allergy
Myth:  Oral antihistamines are the first-line treatment for allergic rhinitis.

Truth:

• Intranasal corticosteroids produce significantly greater relief than oral antihistamines of nasal blockage, nasal discharge, sneezing, nasal itch, postnasal drip, and total nasal symptoms in allergic rhinitis. Weiner JM, Abramson MJ, Puy RM, Intranasal corticosteroids versus oral H1 receptor antagonists in allergic rhinitis: systematic review of randomised controlled trials, BMJ 1998 Dec 12;317(7173): 1624-9 - From PubMed  

Truth:

• For treatment of acute urticaria, the combination of cimetidine and diphenhydramine is more effective than diphenhydramine alone. Runge JW et al, Histamine antagonists in the treatment of acute allergic reactions. Ann Emerg Med 1992 Mar;21(3):237-42 - From PubMed 
• Chlorpheniramine plus cimetidine is more effective than chlorpheniramine alone for chronic urticaria. Bleehen SS et al, Cimetidine and chlorpheniramine in the treatment of chronic idiopathic urticaria: a multi-centre randomized double-blind study. Br J Dermatol 1987 Jul;117(1):81-8 - From PubMed 
• Our results indicate that cimetidine is efficacious as the initial treatment of acute urticaria and has less tendency toward sedation. Moscati RM, Moore GP, Comparison of cimetidine and diphenhydramine in the treatment of acute urticaria. Ann Emerg Med 1990 Jan;19(1):12-5 - From PubMed 

Truth:

• In patients with histories of penicillin allergy the incidence of cephalosporin reactions is minimally, if at all increased. Post-marketing studies of second and third generation cephalosporins showed no increase in allergic reactions in patients with penicillin allergy histories. Penicillin skin tests do not predict the likelihood of allergic reactions to cephalosporins in patients with histories of penicillin allergy. Anne S, Reisman RE, Risk of administering cephalosporin antibiotics to patients with histories of penicillin allergy. Ann Allergy Asthma Immunol 1995 Feb;74(2):167-70 - From PubMed 

Truth:

• A 10 d course of 40mg/d of prednisolone may be stopped abruptly in asthmatics. Tapering is unnecessary. O'Driscoll BR et al, Double-blind trial of steroid tapering in acute asthma, Lancet 1993 Feb 6;341(8841):324-7 - From PubMed 
• There was no difference in relapse rate between asthmatics receiving an 8-day tapering dose of prednisone and those receiving and 8-day non-tapering course of 40 mg/day prednisone. No patients had evidence of adrenal suppression from either dosing
  regimen. Cydulka RK et al, A pilot study of steroid therapy after emergency department treatment of acute asthma: is a taper needed? J Emerg Med 1998 Jan-Feb;16(1):15-9 - From PubMed
• Tapering of prednisone may not be needed in asthmatic patients. Verbeek PR et al, Nontapering versus tapering prednisone in acute exacerbations of asthma:a pilot trial, J Emerg Med 1995 Sep-Oct;13(5):715-9 - From PubMed 
• There is no need to reduce prednisolone gradually following recovery from an exacerbation of asthma, provided systemic corticosteroid treatment is continued until a satisfactory and stable PEF is achieved. Hatton MQ et al, A comparison of 'abruptly stopping' with 'tailing off' oral corticosteroids in acute asthma, Respir Med 1995 Feb;89(2):101-4 - From PubMed

Cardiology
Myth: Hypertensive urgency (diastolic BP>120 without evidence of CNS, cardiac, pulmonary, vascular or renal end-organ damage) requires rapid BP reduction, preferably by sublingual nifedipine.

Truth:

• Hypertensive urgency is generally treated over 24 to 48 hours in a closely monitored outpatient setting. Bales A, Hypertensive crisis. How to tell if it's an emergency or an urgency. Postgrad Med 1999 May 1;105(5):119-26, 130 - From PubMed 
• Patients with nonemergent hypertension do not always require immediate and aggressive pharmacological intervention in the Emergency Department setting and are best observed for a short period and then reassessed before beginning pharmacological therapy. Lebby T et al, Blood pressure decrease prior to initiating pharmacological therapy in nonemergent hypertension. Am J Emerg Med 1990 Jan;8(1):27-9 - From PubMed 
• A review of the literature revealed reports of serious adverse effects such as cerebrovascular ischemia, stroke, numerous instances of severe hypotension, acute myocardial infarction, conduction disturbances, fetal distress, and death resulting from the use of sublingual nifedipine. Given the seriousness of the reported adverse events and the lack of any clinical documentation attesting to a benefit, the use of nifedipine capsules for hypertensive emergencies and pseudoemergencies should be abandoned. Grossman E et al, Should a moratorium be placed on sublingual nifedipine capsules given for hypertensive emergencies and pseudoemergencies? JAMA 1996 Oct 23-30;276(16):1328-31 - From PubMed 

Truth:

• There is persuasive evidence supporting a favorable effect of beta-blockade on ejection fraction and the combined risk of death and hospitalization for heart failure. Lechat P et al, Clinical effects of beta-adrenergic blockade in chronic heart failure: a meta-analysis of double-blind, placebo-controlled, randomized trials. Circulation 1998 Sep 22;98(12):1184-91 - From PubMed 
• In patients with congestive heart failure, b-blockers reduce mortality, hospitalization, and heart transplantation and improve left ventricular ejection fraction. Avezum A et al,  Beta-blocker therapy for congestive heart failure: a systematic overview and critical appraisal of the published trials. Can J Cardiol. 1998 Aug;14:1045-53 - From the ACP Journal Club 

Continuing Education
Myth: Conventional continuing education is an effective way to change physician behavior and patient coutcome.

Truth:

• Dissemination-only strategies, such as conferences or the mailing of unsolicited materials, demonstrate little or no changes in health professional behavior or health outcome. No magic bullets: a systematic review of 102 trials of interventions to improve professional practice - Reviewed by the CMA-CPG Database 
• Printed educational materials have, at best, a small effect on  improvement of practice behavior of health professionals and on patient outcomes. Audit and feedback and conferences/workshops do not appear to produce substantial changes in practice. Educational outreach visits and opinion leaders may be somewhat more effective, although the evidence is sparse. It is unclear to what extent the effects of any of the interventions may be worth the costs involved. Printed educational materials to improve the behaviour of health care professionals and patient outcomes - Reviewed by  Cochrane 
• There is little evidence that Clinical Practice Guidelines are effective in improving patient outcomes in primary care. Even when the change was statistically significant, it was usually modest. The effects of clinical practice guidelines on patient outcomes in primary care: a systematic review - Reviewed by DARE 
• The evidence shows serious deficiencies in the adoption of Clinical Practice Guielines in practice. Davis DA, Taylor-Vaisey A, Translating guidelines into practice. A systematic review of theoretic concepts, practical experience and research evidence in the adoption of clinical practice guidelines. CMAJ 1997 Aug 15;157(4):408-16 - From PubMed 

Endocrinology
Myth: Sliding-scale insulin therapy is effective and appropriate therapy for managing diabetes in the hospital.

Truth:

• Sliding-scale insulin therapy is less effective than
  preventive therapy in the management of hospitalized diabetic patients, resulting in more hyperglycemia and longer hospital stays. Gearhart JG et al, Efficacy of sliding-scale insulin therapy: a comparison with prospective regimens, Fam Pract Res J 1994 Dec;14(4):313-22 - From PubMed
• Although sliding scale insulin regimens are prescribed for the majority of inpatients with diabetes, they appear to provide no benefit; in fact, when used without a standing dose of intermediate-acting insulin, they are associated with an increased rate of hyperglycemic episodes. Queale WS et al, Glycemic control and sliding scale insulin use in medical inpatients with diabetes mellitus, Arch Intern Med 1997 Mar 10;157(5):545-52 - From PubMed 

Truth:

• There is good evidence that giving sodium bicarb in severe DKA (pH: 6.90 to 7.15) is of no significant benefit. DKA doesn't benefit from NaHCO3 - Reviewed by CATS/CEBM 
• Studies have failed to demonstrate accelerated reduction of blood ketone levels, elevation of pH, or a beneficial effect on survival with bicarbonate therapy in many acodotic states, and may have significant adverse effects. Graf H, Arieff AI, The use of sodium bicarbonate in the therapy of organic acidosis, Intensive Care Med 1986;12(4):285-8  - From PubMed
• Adjunctive bicarbonate is unnecessary and potentially disadvantageous in severe pediatric DKA. Green SM et al, Failure of adjunctive bicarbonate to improve outcome in severe pediatric diabetic ketoacidosis. Ann Emerg Med 1998 Jan;31(1):41-8 - From PubMed 

Truth:

• It is safe and convenient to inject insulin
  through clothing. Fleming DR et al, The safety of injecting insulin through clothing. Diabetes Care 1997 Mar;20(3):244-7 - From PubMed

Truth:

• Lipid-modifying dosages of niacin can be safely used in patients with diabetes. Niacin therapy may be considered as an alternative to statin drugs or fibrates for patients with diabetes in whom these agents are not tolerated or fail to sufficiently correct hypertriglyceridemia or low HDL-C levels.- Elam MB et al,  Effect of Niacin on Lipid and Lipoprotein Levels and Glycemic Control in Patients With Diabetes and Peripheral Arterial Disease: The ADMIT Study: A Randomized Trial. JAMA 2000 Sept 13; 1263-70 

Hematology/Oncology
Myth: Vitamin B12 deficiency must be treated with parenteral cyanocobalamin.

Truth:

• In cobalamin deficiency, 2 mg of cyanocobalamin administered orally on a daily basis was as effective as 1 mg administered intramuscularly on a monthly basis and may be superior. Kuzminski AM et al, Effective treatment of cobalamin deficiency with oral cobalamin, Blood 1998 Aug 15;92(4):1191-8 

Truth:

• The serum ferritin performed dramatically better than any other diagnostic test or combination tests for iron deficiency. Guyatt GH et al, Laboratory diagnosis of iron-deficiency anemia: an overview. J Gen Int Med 1992; 7:145-153 - Reviewed by POEMS/JFP  

Obstetrics/Gynecology
Myth: Prenatal care clearly improves pregnancy outcome.

Truth:

• Current evidence (a meta-analysis of 50 studies  involving 669,876 women) does not satisfy the criteria necessary to establish that prenatal care definitively improves birth outcomes. Does prenatal care improve birth outcomes?: a critical review - Reviewed by DARE   
• Prenatal care has not been demonstrated to improve birth outcomes conclusively. Fiscella K, Does prenatal care improve birth outcomes? A critical review, Obstet Gynecol 1995 Mar;85(3):468-79 - From PubMed 

Truth:

• Women taking oral contraceptives and long term antibiotics had a small but statistically insignificant increased risk of pregnancy. Overall OC failure rates were no higher than expected for OC users.  OCP failure and oral antibiotics: Review of Helms SE et al, Oral contraceptive failure rates and oral antibiotics. J Am Acad Dermatol 1997;36:705-10s - Reviewed by POEMS/JFP  
• Most of the available data do not indicate any major reduction in the efficacy of OCPs with concurrent common antibiotic use. Burroughs KE et al, Antibiotics and oral contraceptive failure, JAMA 2000 Jan, 9: 81-82 

Truth:

Accuracy of home pregnancy tests in the hands of the user is low, with a sensitivity range of 53-82% and a specificity range of 52-75%. This means that for every four women who are pregnant and self-test, one will have a negative result. For every four women who are not pregnant and self test, one will have a positive result. Bastian LA et al, Diagnostic efficiency of home pregnancy test kits. A meta-analysis, Arch Fam Med 1998 Sep-Oct, 7(5): 465-9  - Reviewed by Bandolier

Ophthalmology
Myth: Corneal abrasions should be covered by an eye patch to improve healing and decrease pain. 

Truth:

• Eye patching was not found to improve healing rates or reduce pain in patients with corneal abrasions. Given the theoretical harm of loss of binocular vision and possible increased pain, we recommend the route of harmless nonintervention in treating corneal abrasions. Flynn CA et al, Should we patch corneal abrasions? A meta-analysis. J Fam Pract 1988; 47: 264-70 - From PubMed 

Orthopedics
Myth: Isolated sternal fractures are associated with serious thoracic and intrathoracic trauma and require hospital admission.

Truth:

• Sternal fractures, without evidence of other organ trauma, are benign and do not require special treatment or an expensive work-up. It is possible that the seat belt and the sternal fracture absorb a substantial part of the energy transfer, and prevent greater damage. Roy-Shapira A et al, Sternal fractures: a red flag or a red herring? J Trauma 1994 Jul;37(1):59-61 - From PubMed 
• There may be no need to admit patients with isolated sternal fractures solely for observation if their initial clinical condition is satisfactory and there are no abnormalities identified by an anteroposterior chest radiograph and electrocardiography. Jackson M, Walker WS, Isolated sternal fracture: a benign injury? Injury 1992;23(8):535-6 - From PubMed 
• The outcome of patients with an isolated sternal fracture and a normal ECG is very good. Routine admission and cardiac monitoring do not appear to be warranted in this subset of patients with a sternal fracture. Wright SW, Myth of the dangerous sternal fracture. Ann Emerg Med 1993 Oct;22(10):1589-92 - From PubMed 

Truth:

• There is clinically significant overlap in the erythrocyte sedimentation rate, temperature, and WBC count in children with septic arthritis of the hip versus transient synovitis of the hip. All children with an irritable hip without a clearly identified source who have an erythrocyte sedimentation rate of more than 20 mm/hr or a temperature of more than 37.5 C should be considered for diagnostic hip aspiration. Del Beccaro MA et al, Septic arthritis versus transient synovitis of the hip: the value of screening laboratory tests. Ann Emerg Med 1992 Dec;21(12):1418-22 - From PubMed 

Truth:

• The application of skin traction to patients with fractures of the upper femur is time-consuming and provided no advantage with respect to pain suffered, analgesia required, frequency of pressure sores or ease of operation. Anderson GH et al, Preoperative skin traction for fractures of the proximal femur. A randomised prospective trial. J Bone Joint Surg Br 1993 Sep;75(5):794-6 - From PubMed 
• skin traction offered no benefits in pain control for the patient and therefore should not be used routinely. Needoff M et al, Preoperative traction for hip fractures in the elderly: a clinical trial. Injury 1993 May;24(5):317-8 - From PubMed 
• Traction should not be administered routinely to patients awaiting operation for hip fracture. Finsen V et al, Preoperative traction in patients with hip fractures. Injury 1992;23(4):242-4 - From PubMed 

Truth:

• No statistical difference was found in the speed of recovery when clavicle fractures were treated by either a figure-of-eight bandage or broad arm sling. Stanley D, Norris SH, Recovery following fractures of the clavicle treated conservatively. Injury 1988 May;19(3):162-4 - From PubMed 
• Treatment with a simple sling caused less discomfort and perhaps fewer complications than with the figure-of-eight bandage. The functional and cosmetic results of the two methods of treatment were identical and alignment of the healed fractures was unchanged from the initial displacement. Andersen K et al, Treatment of clavicular fractures. Figure-of-eight bandage versus a simple sling. Acta Orthop Scand 1987 Feb;58(1):71-4 - From PubMed 

Truth:

• Bed rest is not an effective treatment for acute low back pain and may delay recovery. Advice to stay active and to continue ordinary activities results in a faster return to work, less chronic disability, and fewer recurrent problems. Waddell G et al, Systematic reviews of bed rest and advice to stay active for acute low back pain. Br J Gen Pract 1997 Oct;47(423):647-52  - From PubMed 
• Among patients with acute low back pain, continuing ordinary activities within the limits permitted by the pain leads to more rapid recovery than either bed rest or back-mobilizing exercises. Malmivaara A et al, The treatment of acute low back pain--bed rest, exercises, or ordinaryactivity?N Engl J Med 1995 Feb 9;332(6):351-5 - From PubMed 

Otolaryngology
Myth:  Antibiotics should be used to treat acute otitis media (AOM) in children.

Truth:

• Antibiotics provide a real but small benefit in AOM in children. As most cases will resolve spontaneously, this poses a difficult decision for clinicians when weighed against the possible adverse reactions. Antibiotic versus placebo for acute otitis media in children - Reviewed by  Cochrane  
• Antimicrobial drugs have a modest but significant impact on the primary control of AOM. Clinical efficacy of antimicrobial drugs for acute otitis media: metaanalysis of 5400 children from  thirty-three randomized trials - Reviewed by DARE 
• Six of every seven children with AOM either do not need antibiotics for primary control or will not respond to antibiotic therapy. Antibiotics for Acute Otitis Media - Reviewed by Bandolier 
• Early treatment of AOM with antibiotics can reduce the severity of pain, but the majority of children will feel better in 24 hours with or without antibiotics. Withholding antibiotic treatment while following closely with adequate analgesia is acceptable for children aged 2 years or older without a high fever or severe pain. Antibiotics for acute otitis media: Review of Del Mar C et al, Are antibiotics indicated as initial treatment for children with acute otitis media? A meta-analysis. BMJ 1997;314:1526-29 - Reviewed by POEMS/JFP  
• No statistically significant difference was found between antibiotic-treated children and controls under two years of age with AOM, judged on the basis of clinical improvement within seven days The current high prescription rates of antibiotics among children under two years of age with acute otitis media are not sufficiently supported by evidence from published trials. Damoiseaux RA et al, Antibiotic treatment of acute otitis media in children under two years of age: evidence based? Br J Gen Pract 1998 Dec;48(437):1861-4 - From PubMed 

Truth:

• No specific antibiotic is likely to be helpful in most cases of AMS. Antibiotics for acute maxillary sinusitis: Review of de Bock GH et al, Antimicrobial treatment in acute maxillary sinusitis: A meta-analysis. J Clin Epidemiol 1997;50:881-890 - Reviewed by POEMS/JFP 
• Patients with more severe signs and symptoms of AMS may benefit from an antibiotic, while those with less severe findings may do as well without one. Antibiotics for acute maxillary sinusitis in adults: Review of Stalman W et al, Maxillary sinusitis in adults: an evaluation of placebo-controlled double-blind trials. Family Practice 1997; 14(2):124-129s - Reviewed by POEMS/JFP  
• This study supports the expectant management of  patients suspected of having AMS. Antibiotic therapy benefits few, if any, of these patients, and expectant management does not increase the risk of developing sinusitis relapses or chronic sinusitis. Amoxicillin in acute maxillary sinusitis: Review of Van Buchem FL et al, Primary-care- based randomised placebo-controlled trial of antibiotic treatment in acute maxillary sinusitis. Lancet 1997;349:683-7 - Reviewed by POEMS/JFP  
• Amoxycillin compared with placebo did not improve the cure rate, the proportion of patients with greatly decreased symptoms, or the rates of relapse or chronic symptoms. Amoxicillin did not improve the clinical course of acute maxillary sinusitis in primary care  - Reviewed by Evidence-Based Medicine 

Truth:

•  Receiving a prescription for an antibiotic was not associated with increased patient satisfaction. Physicians should spend time explaining the nature of a particular illness and their choice of treatment, rather than relying on antibiotic prescriptions to generate satisfaction. Antibiotic use and patient satisfaction: Review of Hamm RM et al, Antibiotics and respiratory infections: Are patients more satisfied when expectations are met? J Fam Pract 1996;43:56-62 - Reviewed by POEMS/JFP  
• Failure to provide expected antimicrobials did not affect satisfaction. Mangione-Smith R et al, The relationship between perceived parental expectations and pediatrician antimicrobial prescribing behavior, Pediatrics 1999 Apr;103(4 Pt 1):711-8 - From PubMed 
• Fulfilment of patient expectations for an antibiotic was not associated with higher satisfaction: Himmel W et al, Are patients more satisfied when they receive a prescription? The effect of patient expectations in general practice. Scand J Prim Health Care 1997 Sep;15(3):118-22 - From PubMed    

Truth:

• Pain relief was greater and more rapid in patients treated with betamethasone as an adjuvant therapy in acute exudative pharyngitis. Marvez-Valls EG et al, The role of betamethasone in the treatment of acute exudative pharyngitis. Acad Emerg Med 1998 Jun;5(6):567-72  - From PubMed 
• In patients with severe, acute exudative pharyngitis, single-injection dexamethasone adjuvant compared with placebo resulted in statistically and clinically significant improvement, as evidenced by more rapid onset and greater degree of pain relief. O'Brien JF et al, Dexamethasone as adjuvant therapy for severe acute pharyngitis. Ann Emerg Med 1993 Feb;22(2):212-5  - From PubMed 
• Patients treated with intramuscular or oral dexamethasone had significant relief of pain (relative to baseline) compared to patients who were given placebo. Wei J et al, Efficacy of single-dose dexamethasone as adjuvant therapy for acute pharyngitis. Laryngoscope 2000 Jan; 112:87-93 - From PubMed 

Truth:

• In a setting with adherent patients, children with sore throats should generally get throat cultures in lieu of rapid streptococcus antigen tests. Tsevat J et al,  Management of sore throats in children: a cost-effectiveness analysis. Arch Pediatr Adolesc Med 1999 Jul;153(7):681-8 - Reviewed by POEMS/JFP   

Pain Control 
Myth:  Propoxyphene plus acetaminophen (Darvocet) is a more powerful pain reliever than acetaminophen (paracetamol, Tylenol) alone.

Truth:

• In both head to head and indirect comparisons of paracetamol and the combination (of paracetamol plus proposyphene), the combination was no  better than paracetamol on its own. Li Wan Po A, Zhang WY, Systematic overview of co-proxamol to assess analgesic effects of addition of dextropropoxyphene to paracetamol, BMJ 1997, 315: 1565-71 

Truth:

• Blood cultures are uncommonly positive in outpatients diagnosed with pneumonia, and when positive, they resulted in no changes in clinical management. Hickey RW et al, Utility of blood cultures in pediatric patients found to have pneumonia in the emergency department. Ann Emerg Med 1996 Jun;27(6):721-5 - From PubMed 
• Few blood cultures were positive for likely infecting organisms in adult patients with community acquired pneumonia without defined underlying risk factors. In this group of patients, blood cultures may have limited clinical utility and questionable cost-effectiveness. Chalasani NP et al, Clinical utility of blood cultures in adult patients with community-acquired pneumonia without defined underlying risks. Chest 1995 Oct;108(4):932-6 - From PubMed 
• Routine blood cultures taken at the time of diagnosis of nosocomial pneumonia fail to alter therapy. Chendrasekhar A, Are routine blood cultures effective in the evaluation of patients clinically diagnosed to have nosocomial pneumonia? Am Surg 1996 May;62(5):373-6 - From PubMed 

Truth:

• A MDI with a spacer for the administration of albuterol was an effective alternative to a nebuliser in children with acute asthma and resulted in both shorter treatment time spent in the emergency department and fewer side effects. A metered-dose inhaler with a spacer was more effective than a nebuliser in children with acute asthma - Reviewed by Evidence-Based Medicine  
• MDIs with accessory devices are at least as effective as nebulizers for treating acute asthma in children. : MDI for acute asthma in children: Review of Amirav I, Newhouse MT. Metered-dose inhaler accessory devices in acute asthma. Arch Pediatr Adolesc Med 1997;151:876-882 - Reviewed by POEMS/JFP 
• An MDI with a holding chamber produced outcomes that were at least equivalent to nebuliser delivery of beta-agonists in acute asthma. Comparison of holding chambers and nebulisers for beta-agonists in acute asthma  - Reviewed by Cochrane 

Truth:

• Of 9,599 sets of radiographs interpreted confidently by the emergency physicians, there were 11 clinically significant discordant interpretations (0.1%). The standard practice of radiologists' review of all ED radiographs may not be justifiable. Lufkin KC et al, Radiologists' review of radiographs interpreted confidently by emergency physicians infrequently leads to changes in patient management. Ann Emerg Med 1998 Feb;31(2):202-7 - From PubMed 
• Radiograph interpretations by pediatric emergency physicians were generally accurate, and no adverse outcomes occurred as a result of misinterpretation. Clinical assessment probably assisted these physicians in interpreting the radiographs of high-risk patients. Simon HK et al, Pediatric emergency physician interpretation of plain radiographs: Is routine review by a radiologist necessary and cost-effective? Ann Emerg Med 1996 Mar;27(3):295-8 - From PubMed 
• Routinely reviewing every radiologic study did not affect patient outcome in an outpatient clinic with low prevalence of disease. Knollmann BC et al, Assessment of joint review of radiologic studies by a primary care physician and a radiologist. J Gen Intern Med 1996 Oct;11(10):608-12 - From PubMed 
• Family physicians correctly interpreted 92.4% of the radiographic studies in their offices. Their accuracy with extremity films (96.0%) was significantly higher than their accuracy with chest films (89.3%). Family physicians were more likely to correctly interpret normal films (95.2%) than abnormal ones (85.9%). Thirty-five percent of the cases in which there were differences between family physician and radiologist interpretations were correctly interpreted by family physicians. Bergus GR et al, Radiologic interpretation by family physicians in an office practice setting. J Fam Pract 1995 Oct;41(4):352-6 - From PubMed 
• Because the two interpretations were accurate and not statistically different, interpretation of orthopedic films by a radiologist seems to be an unnecessary expense. Turen CH et al, Comparative analysis of radiographic interpretation of orthopedic films: is there redundancy? J Trauma 1995 Oct;39(4):720-1 - From PubMed 
• In an emergency room stting, when 12,083 interpretations by emergency or family physicans  were compared with those by radiologists, there was an overall discrepancy rate of 1.1 percent. Warren JS et al, Correlation of emergency department radiographs: results of a quality assurance review in an urban community hospital setting. J Am Board Fam Pract 1993 May-Jun;6(3):255-9 - From PubMed 

Truth:

• Comparison radiographs of the uninjured elbow did not improve diagnostic accuracy in elbow trauma in the pediatric emergency department. Chacon D et al, Use of comparison radiographs in the diagnosis of traumatic injuries of the elbow. Ann Emerg Med 1992 Aug;21(8):895-9 - From PubMed 
• Comparison radiographs of the UE were not useful in improving diagnostic accuracy in elbow trauma. Kissoon N et al, Evaluation of the role of comparison radiographs in the diagnosis of traumatic elbow injuries. J Pediatr Orthop 1995 Jul-Aug;15(4):449-53 - From PubMed 

Surgery
Myth: Giving narcotics to a patient with a possible acute abdomen might mask the signs and make it difficult to make a diagnosis.

Truth:

• Early administration of opiate analgesia to patients with acute abdominal pain can greatly reduce their pain. This does not interfere with diagnosis, which may even be facilitated despite a reduction in the severity of physical signs. Attard AR et al, Safety of early pain relief for acute abdominal pain, BMJ 1992 Sep 5;305(6853):554-6 - From PubMed
• When compared with saline placebo, the administration of morphine sulfate to patients with acute abdominal pain effectively relieved pain and did not alter the ability of physicians to accurately evaluate and treat patients. Pace S, Burke TF, Intravenous morphine for early pain relief in patients with acute abdominal pain, Acad Emerg Med 1996 Dec;3(12):1086-92  - From PubMed 
• Physical examination does change after the administration of analgesics in patients with acute abdominal pain, but no adverse events or delays in diagnosis were attributed to the administration of analgesics. LoVecchio F et al, The use of analgesics in patients with acute abdominal pain, J Emerg Med 1997 Nov-Dec;15(6):775-9 - From PubMed

Myth:  The rectal exam is an essential part of the abdominal examination in assessing possible appendicitis.

Truth:

• Abdominal signs were better predictors of appendicitis than rectal examination. If patients presenting with pain in the right lower quadrant of the abdomen are tested for rebound tenderness then rectal examination does not give any further diagnostic information. Dixon JM et al, Rectal examination in patients with pain in the right lower quadrant of the abdomen, BMJ 1991 Feb 16;302(6773):386-8 - From PubMed 
• These findings call into question the need for routine rectal examination in children with suspected appendicitis. Dunning PG, Goldman MD, The incidence and value of rectal examination in children with suspected appendicitis, Ann R Coll Surg Engl 1991 Jul;73(4):233-4 - From PubMed 

Truth:

• In critically ill surgical patients with fever, leukocytosis, or other septic parameters, routine ordering of blood cultures is not cost-effective, rarely alters or provides therapeutic direction, and appears not to affect mortality. Henke PK, Polk HC Jr, Efficacy of blood cultures in the critically ill surgical patient. Surgery 1996 Oct;120(4):752-8; discussion 758-9 - From PubMed 
• In no case of peri-operative fever did a positive blood culture have a measurable effect on reducing patient morbidity or mortality. Neither the magnitude of the absolute leukocyte count nor the maximum temperature at the time of phlebotomy predicted a positive blood culture. Theuer CP et al, Are blood cultures effective in the evaluation of fever in perioperative patients? Am J Surg 1991 Dec;162(6):615-8; discussion 618-9  - From PubMed 

Truth:

• Of 217 patients with bright red hematochezia, 181 bled from the distal 60 cm of the colon, 20 had more proximal lesions (including eight with cancer), and 16 had no lesion found on colonoscopy. Fine KD et al,  Comparison of the color of fecal blood with the anatomical location of gastrointestinal bleeding lesions: potential misdiagnosis using only flexible sigmoidoscopy for bright red blood per rectum. Am J Gastroenterol 1999 Nov;94(11):3202-10 - From PubMed 

Truth:

With the possible exception of patients with acute myocardial infarction and unstable angina, patients with hemoglobin levels between 7-9 g/dl had equal survival to those with hemoglobin levels between 10-12 g/dl. Hebert PC et al, A multicenter, randomized controlled clinical trial of transfusion requirements in critical care. NEJM 1999 Feb 11; 340: 409-417 - From PubMed  

Urology
Myth: Blood cultures help guide the treatment of pyelonephritis. 

Truth:

• Whereas urine cultures are useful in directing antibiotic therapy in patients with the discharge diagnosis of acute pyelonephritis and support a change in therapy in 5% of cases, blood cultures results did not lead to changes in antibiotic therapy. Thanassi M, Utility of urine and blood cultures in pyelonephritis. Acad Emerg Med 1997 Aug;4(8):797-800 - From PubMed 
• Blood cultures are rarely clinically useful and seldom vary from urine culture results. McMurray BR et al, Usefulness of blood cultures in pyelonephritis. Am J Emerg Med 1997 Mar;15(2):137-40 - From PubMed 

Truth:

• Quick, complete emptying of the obstructed bladder is safe, simple, and effective and is recommended as the optimal method for decompressing the obstructed urinary bladder. Nyman MA et al, Management of urinary retention: rapid versus gradual decompression and risk of complications. Mayo Clin Proc 1997 Oct;72(10):951-6 - From PubMed 

Truth:

• Extensive evaluation appears unnecessary for young men with bacteriuria who respond to antimicrobial therapy. Krieger JN et al, Urinary tract infections in healthy university men. J Urol 1993 May;149(5):1046-8 - From PubMed 

Truth:

• For the treatment of UTI in symptomatic young women, the following strategies are listed in order of decreasing cost-effectiveness:
  • Most cost-effective (least expensive) strategy:
    • Empirical treatment of symptomatic women
  • Less cost-effective (more expensive) strategy:
    • Treatment based on full urinalysis
    • Treatment with office culture to confirm sensitivity
    • Treatment with reference lab culture to confirm sensitivity
    • Treatment after office culture results available
    • Treatment after reference lab results available
  • Least cost-effective (most expensive) strategy:
    • Treatment based on dipsticks
  Office management of suspected UTI: Review of Barry HC et al, Evaluation of suspected urinary tract infection in ambulatory women: A cost-utility analysis of office-based strategies. J Fam Pract 1997;44:49-60 - Reviewed by POEMS/JFP  
• Similarly: Fenwick EA et al, Management of urinary tract infection in general practice: a cost- effectiveness analysis. Br J Gen Pract 2000 aug; 50(457): 635-9 - From PubMed  
• This approach has been validated in practice. Saint S et al, The effectiveness of a clinical practice guideline for the management of presumed uncomplicated urinary tract infection in women, Am J Med, 1999; 106 (6): 636-641 - From PubMed