American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Jun 2013
ReviewStudy design and "evidence" in patient-oriented research.
Individual studies in patient-oriented research, whether described as "comparative effectiveness" or using other terms, are based on underlying methodological designs. A simple taxonomy of study designs includes randomized controlled trials on the one hand, and observational studies (such as case series, cohort studies, and case-control studies) on the other. A rigid hierarchy of these design types is a fairly recent phenomenon, promoted as a tenet of "evidence-based medicine," with randomized controlled trials receiving gold-standard status in terms of producing valid results. ⋯ This essay presents an argument in support of a more balanced approach to evaluating evidence, and discusses representative examples from the general medical as well as pulmonary and critical care literature. The simultaneous consideration of validity (whether results are correct "internally") and generalizability (how well results apply to "external" populations) is warranted in assessing whether a study's results are accurate for patients likely to receive the intervention-examining the intersection of clinical and methodological issues in what can be called a medicine-based evidence approach. Examination of cause-effect associations in patient-oriented research should recognize both the strengths and limitations of randomized trials as well as observational studies.
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Am. J. Respir. Crit. Care Med. · Jun 2013
Comparative StudyInfluence of previous use of inhaled corticoids on the development of pleural effusion in community-acquired pneumonia.
Previous use of inhaled corticosteroids (ICS) in patients with chronic obstructive pulmonary disease has been associated with increased risk of community-acquired pneumonia. However, ICS have been associated with fewer pneumonia complications and decreased risk of pneumonia-related mortality. ⋯ Prior treatment with ICS in a population of patients with different respiratory chronic disorders who develop pneumonia is associated with lower incidence of parapneumonic effusion.