AMA Guides® Newsletter - Issue Archive

Articles

1. Evidence-Based Medicine: Determining Quality of Randomized Controlled Trials

   Melissa Cheng

   Pages 3–5

   DOI: 10.1001/amaguidesnewsletters.2014.JulAug01

   Abstract

   Evidence-based medicine is based on evidence gathered by randomized controlled trials (RCTs), which are considered the “gold standard” of research studies. Users of the medial literature must be able to read critically and evaluate RCTs. The present article uses the standards of the American College of Occupational and Environmental Medicine (ACOEM) practice guidelines in evaluating RCTs according to 11 criteria; these criteria follow those used by the Cochrane Collaboration in their evidence-based reviews. Well-written articles present their randomization schemes to create comparable groups, and studies must be controlled for co-interventions; in a double-blind trial, the co-interventions would be used equally in both groups, and treatment allocations should be concealed. Readers should ask if the study had acceptable compliance; that is, were patients doing what they were asked, and was the dropout rate acceptable (typically, less than 20%)? RCTs should be analyzed by an intention-to-treat analysis that includes all study subjects who were randomized, not just those who completed the study. Having high internal validity ensures a more accurate study that can be reproduced by others, so readers may ask if results are likely to be affected by observational bias, confounding, or chance variation. Readers can determine external validity by assessing study participants according to inclusion and exclusion criteria and baseline characteristics.
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2. Evidence-Based Medicine, Treatment Guidelines, and Literature Search Web Resources

   Christopher R. Brigham

   Pages 6–6

   DOI: 10.1001/amaguidesnewsletters.2014.JulAug02

   Abstract

   Cardiopulmonary exercise stress testing (CPET) provides objective data to assess cardiac and pulmonary impairment. This article discusses changes in the CPET section of the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides). The explanation of CPET in the AMA Guides, Sixth Edition, adds a single word, “static,” that significantly effects how this test should be conducted. Routine pulmonary function tests (PFTs) provide information about a person's ability to breathe, eg chronic obstructive pulmonary disease or asthma can stratify the severity of these diseases; they do not measure the ability of the lungs or heart to provide adequate oxygenation to metabolizing tissues. Static tests of lung function are the norm when diagnosing asbestosis, and the typical abnormalities seen are restriction, some airflow obstruction, and a diminished diffusing capacity. These abnormalities correlate linearly with the degree of abnormality found radiographically. In individuals with unexplained shortness of breath with exertion or fatigue that is not easily explained in the medical records, a CPET will allow secure diagnosis of causation. Thus CPET is a powerful tool to explain shortness of breath with exertion or fatigue, and CPET has a role in the impairment rating process of all individuals with interstitial lung diseases and in selected individuals with unexplained symptoms.
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3. Cardiopulmonary Exercise Stress Testing – an Update

   Stephen L. Demeter

   Pages 7–10

   DOI: 10.1001/amaguidesnewsletters.2014.JulAug03

   Abstract

   This article updates one published in The Guides Newsletter in January/February 1998 and reflects changing legislation in the workers’ compensation area and also in motor accident compensation. In the various Australian state and federal jurisdictions, impairment rating has become an important component of independent medical examinations, and in many areas, impairment guides have been adopted as a mandatory tool for assessing permanent impairment. For example, in the mid-1990s the state of Victoria established use of the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fourth Edition, as the sole tool for evaluating impairment and continues to use this edition to the present time. Despite the publication of the AMA Guides, Fifth Edition, in 2000, the Motor Accidents Authority in New South Wales (NSW) continues to use the fourth edition, supplemented with the NSW Motor Accidents Authority Guidelines. In November 2001, Tasmania adopted the same guidelines that were being used by the NSW Motor Accidents Authority. Despite publication of the AMA Guides, Sixth Edition, in 2007, there has remained a general reticence in Australia to progress to use of this latest edition either as stand-alone impairment rating tools or an underpinning of the purpose-developed impairment guidelines already in place. A large number of Australian medical assessors have become used to the model based on the NSW WorkCover Guides for the Evaluation of Permanent Impairment, which interprets the AMA Guides, Fifth Edition.
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4. The AMA Guides Use in Australia

   Dwight K. Dowda

   Pages 10–11

   DOI: 10.1001/amaguidesnewsletters.2014.JulAug04