Real Time Evidence Based Medicine

Questions arise all the time on the wards and as medical students, you frequently may wonder why we do things the way we do. Now is your chance to apply the literature to these questions and practice evidence rather than “expert” based medicine.

EBM Misconceptions

  • Takes too long
  • Requires expertise in statistics

Some common pitfalls in EBM

  • Unfocused questions
  • Trouble recognizing which literature best addresses the question s(e.g. when to use UpToDate vs. perform PubMed search)
  • Inefficient search strategies
  • Misapplication of the data (great article but doesn’t really answer your questions)

All the above can improve quickly with practice and that is the goal of this assignment.

Helpful resource: Users’ Guide to the Medical Literature published by JAMA. (access it through a UF computer or website.) The “tips” are particularly useful.

Recommended Approach for Patient Care

  • Keep a list of the questions that come up in the course of patient care.
  • Frame questions using PICO (Patient, Intervention, Comparison, Outcome) format.
  • Look up an article for at least one question a week that will help with patient care.
  • Read the article
  • Make a judgment about the article’s applicability, quality, limitations (Critical appraisal questions can help you identify its relevance and validity to your question. Dartmouth provides a nice list of these tools organized by study type. You are NOT required to fill out a critical appraisal form unless you find it helpful.)

Documentation (Optional)

You may find it helpful to write down your findings in this format to help organize your evaluation of the study. This approach is highly recommended if you are presenting the study to your team.
  1. One liner patient summary
  2. PICO question (use as much of PICO as you can)
  3. Citation (you can cut and paste form internet, doesn’t need to look pretty)
  4. Analysis– 2-3 sentence that includes:
    1.  Application to patient care
    2. One strength
    3. One concern.

Note: If you incorporated one of your questions into a write-up or progress note, then simply cut and paste that section as one of your entries.


1)  Mr. P is a 70 year old patient with left ventricular dysfunction with LVEF of 20%, atrial fibrillation and type 2 DM that presented with CHF exacerbation due to non-compliance to CHF medications.

PICO: Are the new oral anticoagulants such as rivaroxaban and dabigatan more effective than warfarin in reducing stroke in the elderly with atrial fibrillation?

According to this meta-analysis study, the new anticoagulants are more effective at reducing stroke and systemic embolism than the gold standard (warfarin) in the elderly. In addition, they didn’t pose a greater threat of bleeding compared to warfarin. This would be a good pharmacologic approach to those elderly individuals with a high CHADS2 score for stroke and risk of falling (risk to bleeding). Although the new anticoagulants are very good alternative to warfarin, this wasn’t applied to the care of our patient due to a history of recurrent fall episodes and renal impaired function. The article suggested extra caution should be taken in those individuals with renal impaired function since rivaroxaban and dabigatan have a renal elimination route. In addition, the study’s participants included patients younger than 70 years old while my patient was 72 year old. Therefore, the results of this study couldn’t be generalized to my patient.

Article: Sardar, P., Chatterjee, S., Chaudhari, S., and Lip, G (2014).New Oral Anticoagulants in Elderly Adults: Evidence from a Meta-Analysis of Randomized Trials. The American Geriatrics Society, 162, 857-864.

2) Summary: Mr. K is a 45 year old male presenting with wheezing and vomiting with a PMH of asthma and CHF admitted for asthma exacerbation. This patient was recently admitted in the past 1 month with same presentation. He revealed that he had increased snoring as well as epigastric pain that is exacerbated after eating spicy food.

PICO: Does untreated obstructive sleep apnea increases the odds of recurrent exacerbations more than untreated GERD in asthmatic patients?

The results of the study indicated that asthma exacerbations are associated with severe nasal sinus disease( Odds ratio: 3.7), gastro-esophageal reflux (odds ratio: 4.9) and recurrent respiratory infections( odds ratio: 3.7) and obstructive sleep apnea (OR: 3.4). The results of this study gave us insight into what treatment he needed to go home after discharge including omeprazole and education on how to use the nasal continuous positive airway pressure therapy. I believe that controlling those co-morbidities is essential to decrease the number of exacerbations and the increase quality of life. He is unemployed and doesn’t have insurance therefore controlling his asthma and treatment for his comorbidities will reduce his health care utilization and cost. The strengths of the study was the methodology of using a well defined control group well described in the study and limitation to my studies is that my patient had a immunocompromised illness compared to the patients studied in this group who only had one of the studied comorbidities.

Article: Brinke,A., Sterk, P., Masclee, Spinhoven, P., schidmt, J., Zwinderman, A., Rabe, K., and Bel, E. Risk factors of frequent exacerbations in difficult-to-treat asthma.2005. European Respiratory Journal. 26:812-818

3) Consideration: On rounds; we discussed the often co-morbid conditions of obesity; sleep apnea; hypertension; joint disease and type two diabetes mellitus. Several of our patients have been diagnosed with sleep apnea; but it seems as if many of them do not use their CPAP machines on a regular basis; if at all. On 5/16 I helped admit a patient with sleep apnea who reported poor adherence with using his CPAP machine. In addition to a diagnosis of sleep apnea; the patient also has a history of hypertension and several severe cardiovascular events.

PICO: In patients with both obstructive sleep apnea and systemic hypertension; will regular use of a CPAP machine to treat their sleep apnea lead to an improvement in their hypertension?

Article: JACQUELINE F. FACCENDA; THOMAS W. MACKAY; NICHOLAS A. BOON; and NEIL J. DOUGLAS “Randomized Placebo-controlled Trial of Continuous Positive Airway Pressure on Blood Pressure in the Sleep Apnea–Hypopnea Syndrome”; American Journal of Respiratory and Critical Care Medicine; Vol. 163; No. 2 (2001); pp. 344-348. doi: 10.1164/ajrccm.163.2.2005037

The study supports the conjecture that nocturnal hypoxemia predisposes to higher blood pressures and also ultimately hypertension. With CPAP; there was a reduction in hypoxic events overnight; as well as a lower diastolic blood pressure. Although the reduction in hypertension was small; there can be a significant reduction in cardiovascular morbidity and mortality with even this small change. The study excluded people on anti-hypertensive medications; which helped limited confounding variables. However; my patient was already on anti-hypertensives; which may limit the applicability of the study to my patient.

4) “Does antibiotic treatment of asymptomatic pyuria/bacteriuria in an elderly male patient with a catheter reduce occurrence of symptomatic infection compared to non-treatment?”

Nicolle LE. Catheter-Related Urinary Tract Infection: Practical Management in the Elderly. Drugs Aging (2014) 31:1–10, DOI 10.1007/s40266-013-0089-5.

According to this study, acquisition of bacteriuria from an indwelling catheter is 3-7% per day with a mature biofilm forming along most chronic indwelling catheters within 2 weeks. Neither bacteriuria nor pyuria correlates with symptomatic infections which require one or more of: temperature greater than 37.9C, new costovertebral angle tenderness, new onset rigors, or delirium. Treatment of asymptomatic bacteriuria in elderly patient with a chronic indwelling catheter in this study did not show a decrease in frequency of symptomatic infection, but instead caused subsequent urine cultures to contain organisms of increased antibiotic resistance. Therefore there are no benefits and some harms associated with treatment of asymptomatic bacteriuria and urine cultures should not be sent unless symptomatic.

One of the strengths of the article comes from its incorporation of data from multiple studies including a prospective randomized comparative trial which is of higher value than simple observational studies. In addition, this article is extremely useful from a physician’s perspective as it discusses each aspect of a CAUTI from bacterial cause to diagnosis to treatment. Based on the information, I recommended that our asymptomatic patient with pyuria and bacteriuria have his catheter removed for a trial period to reduce possible morbidity related to its use. As there were no symptoms yet, a urine culture should not be sent and no antibiotics should be administered. Instead the patient should be monitored for development of UTI symptoms. Of note, the article primarily discusses results for patients with long term catheter use while our patient required a catheter for only a short period of time which may or may not influence the applicability of the data.