Faculty peer reviewed
With Thanksgiving behind us, hopefully we have all had a chance to ruminate on the flurry of changes to cancer screening guidelines and the public reaction they generated. This week the NEJM has published a series of perspectives that not only detail the rationale for those changes but also provide a guide for their interpretation in order to facilitate advice for concerned patient populations.(1,2,3) They also address some of the missteps in framing discussions for the public. Together they emphasize the role public and private communication has on the perception of medicine and, consequently, how beliefs are shaped.With all the talk of guidelines, we turn to those for the diagnosis of pulmonary embolism (PE). Despite widespread, well-delineated, and validated evidence-based guidelines to direct a noninvasive, diagnostic testing for PE, Roy et. al. in the Annals of Internal Medicine, cites fewer than 25% of patients are managed according to these guidelines.(4) As a result, they conducted a randomized trial in 20 French emergency departments that provided physicians with handheld computers containing a clinical decision-support system (CDSSs). These devices “recommended” the least invasive of the appropriate diagnostic tests after calculating post-test probabilities based on test results at each step of the diagnostic work-up. They were compared to a control grouip that received educational tools (posters and pocket cards). The authors found the proportion of patients who received appropriate diagnostic work-ups was greater during the trial than in the pre-intervention period in both groups, but the increase was greater in the CDSS group. Furthermore, those in the computer-based guidelines group used fewer tests to reach a validated diagnostic decision.
In a related study published in Archives of Internal Medicine, Hall et. al. published a retrospective, cross-sectional study that reviewed 589 pulmonary catscan-angiograms (CTA) that were ordered in the emergency department of a tertiary care hospital.(5) They reported a remarkably low (9%) prevalence of PE possibly due to an inappropriate diagnostic evaluation strategy, in which patients were sent directly to CTA. Interestingly, a third of CTAs revealed an alternative explanation for the patients’ symptoms; half of which were present in the admission chest radiograph,. Moreover, the CTAs ordered were more than twice as likely to show an incidental finding such as a pulmonary nodule or adenopathy rather than a PE. These incidental findings then required further evaluation. The authors argue for higher yield indications for CTA during assessments of acute pulmonary symptoms in the emergency department. Interestingly, the two studies illustrate similar concepts behind the recent changes in recommendations for screening mammography, such as maximizing clinician efficiency, avoiding excessive diagnostic testing, minimizing patients’psychosocial stress, and decreasing the economic implications for the healthcare system.
In another evaluation of guidelines, Olasveengen et. al. published a prospective, randomized control trial to determine whether removing intravenous drug administration from an ACLS protocol would improve survival to hospital discharge after an out-of-hospital cardiac arrest.(6) As a basis for their study, the authors cited a large, retrospective study that found epinephrine administration to be an independent predictor of poor outcome and its near-universal use. Compared to those patients who received out-of-hospital ACLS with IV drug administration to those without, the rate of survival to hospital discharge, survival with favorable neurological outcome, and survival at 1 year were not statistically significant (10.5% v. 9.2%, 9.8% v. 8.1%, and 10% v. 8%, respectively). However, there was a higher rate of short-term survival (i.e., hospital admission with return of spontaneous circulation) after IV drug administration. The authors note the majority of patients that died after initial successful resuscitation in both groups had severe cerebral damage and emphasize the importance of improving brain-directed post-resuscitation treatment for improving long-term survival. Thus, one could argue, these ALCS guidelines with the current state of medicine may have the unintended consequence of causing an additional burden on intensive care units rather than providing an additional opportunity for meaningful recovery.
In the Lancet, Konstam et. al. sought to maximize the clinical benefits stemming from the recommended use of angiotensin receptor blockers (ARB’s)to reduce morbidity or mortality in patients with heart failure and reduced left-ventricular ejection fraction.(7) Their randomized, multinational double-blinded trial contained over 3,800 patients with heart failure of NYHA Class II-IV, left-ventricular ejection fraction 40% or less, and intolerance to ACE. Patients were randomized to either 50 mg. or 150 mg. of losartan daily. After about 4.5 years of follow-up, 150mg of losartan reduced the rate of death or admission for heart failure. Not surprisingly, the rates of hypotension, hyperkalemia, and renal failure were greater with 150mg of losartan than 50mg; however, medication discontinuation occurred with similar frequency to that in previous investigations of ARBs.
These last two studies demonstrate the tools physicians use on a daily basis to reexamine guidelines, maximize efficacy, and discover shortcomings. Usually much of this work remains “behind the scenes” as most patients are not explicitly aware that their doctor is translating medical recommendations to benefit the individual while minimizing harm. Unfortunately, the role of the clinician is often omitted when guidelines are released via mass media. As a result, the public is left alone to draw conclusions perhaps without essential information, or, at worst, misinformation. Is this what leads to polarizing controversies? Could this be mitigated with improved communication of the science behind recommendations?
Our own Dr. Danielle Ofri raises additional concerns in her eloquent account of the emotional epidemiology of H1N1 Influenza vaccination in the NEJM.(8) She describes the evolution of the public psyche after H1N1’s introduction and calls for clinicians to affect both emotional as well as disease epidemiology. Surely this is no easy feat. Fortunately we, as physicians, routinely engage in a dialogue with our patients to address their anxieties and determine treatments best suited for them as individuals. With any luck, these conversations may alleviate our patients concern, confusion, and frustration-perhaps another reason to give thanks.
Dr. Ecker is a 2nd year resident in internal medicine at NYU Medical Center.
Peer reviewed by Neil Shapiro MD, Editor in Chief, Clinical Correlations
1. Partridge AH, Winer EP. On Mammography-More Agreement Than Disagreement. NEJM 2009; Nov 25 [Epub ahead of print].
2. Truog, RD. Screening Mammography and the “R” Word. NEJM 2009; Nov 25 [Epub ahead of print].
3. Sawaya GF. Cervical-Cancer Screening-New Guidelines and the Balance between Benefits and Harms. NEJM 2009; Nov 25 [Epub ahead of print].
4. Roy, PM, et. al. A Computerized Handheld Decision Support System to Improve Pulmonary Embolism Diagnosis. Ann Int Med 2009; 151(10): 677-86.
5. Hall EB, et. al. The Prevalence of Clinically Relevant Incidental Findings on Chest Computed Tomographic Angiograms Ordered to Diagnose Pulmonary Embolism. Arch Intern Med 2009; 169(21): 1961-5.
6. Olasveengen TM, et. al. Intravenous Drug Administration During Out-of-Hospital Cardiac Arrest. JAMA 2009; 302(20): 2222-9.
7. Konstam MA, et. al. Effects of High-Dose versus Low-Dose Losartan on Clinical Outcomes in Patients with Heart Failure (HEAAL Study): A Randomized, Double-Blind Trial. Lancet 2009; 374: 1840-48.
8. Orfi D. The Emotional Epidemiology of H1N1 Influenza Vaccination. NEJM 2009; Nov 25 [Epub ahead of print].