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Respiratory Care: Evidence Based Research

What is Evidence Based Medicine?

EBM is "the conscientious use of current best evidence in making clinical decisions about patient care". This original definition is attributed to this article by Sackett, et al.

What is Evidence Based Practice?

EBP is a method of effectively translating EBM into clinical practice using the best existing: evidence and research, knowledge of clinical experts, and patient preferences.

Why Conduct EBM Research?

Respiratory Therapists conduct Evidence-Based research to support Evidence-Based Practice because they want the best outcomes for their patients. 

The Focus = finding evidence of the best methods, interventions and practices
The Evidence = found in the most current professional research literature
The Goal = best outcomes for the patient


Content on this page has been adapted from Karen Delorey's work on Evidence Based Practice. Karen Delorey is a Librarian at Mass Bay CC.

Evidence Pyramid

This Evidence Hierarchy Pyramid is often used to graphically represent the quality of medical research. The higher on the pyramid the more comprehensive in scope is the research, and more rigorous the methodology and peer review. You should be looking for the highest level of research available in EBP.

You may not always find the highest level of study related to your research. In the absence of the best evidence, you need to consider moving down the pyramid.


Meta-Analysis: A meta-analysis is a review that combines the quantitative (numbers) results from different studies on a defined intervention in order to obtain a quantitative estimate of the overall effect of the particular intervention.  A meta-analysis produces a stronger conclusion than can be provided by any individual study.

Systematic Review: A systematic review tries to identify, appraise, select and synthesize all RCTs (randomized control trials) relevant to a specific clinical question.  Stringent guidelines are set in order to draw a conclusion about whether or not there is conclusive evidence about a specfic treatment or topic.

Randomized Control Trial: An RCT is a clinical trial in which the subjects are randomly distributed into groups that are either subjected to the experimental procedure (such as use of a certain rehabilitative treatment) or that serve as controls.  It is the research design considered to provide the most reliable evidence for evaluating the effectiveness of an intervention.

Cohort Study: A study designed to determine the relationship between a condition and a characteristic shared by some members of a group. The population selected is healthy at the beginning of the study. Some of the members of the group share a particular characteristic, such as cigarette smoking. The researcher follows the population group over a period of time, noting the rate at which a condition, such as lung cancer, occurs in the smokers and in the nonsmokers.

Case Control Study: A study where previously existing incidents of a medical condition are used in lieu of gathering new information. A group of patients with a particular disease or disorder, such as myocardial infarction, is compared with a control group of persons who have not had that medical problem. The two groups, matched for age, sex, and other personal data, are examined to determine which possible factor (e.g., cigarette smoking, coffee drinking) may account for the increased disease incidence in the case group.

Descriptive or Qualitative Study: A descriptive study is one in which information is collected without changing the environment (i.e. nothing is manipulated, no experiment is occurring). Sometimes these are referred to as correlational or observational studies. A descriptive study can provide information about the naturally occurring health status, behavior, attitudes or other characteristics of a particular group. Descriptive studies can involve a one-time interaction with groups of people (cross-sectional study) or a study might follow individuals over time (longitudinal study). These types of studies are often done before an experiment to know what specific things to manipulate and include in an experiment.

Finding Best Evidence - Library Databases

Cinahl Complete
This is a Library EBSCO database. From the Advanced Search screen scroll down and select the Evidence-Based Practice limiter:

Articles from evidence-based practice journals
Articles about evidenced-based practice
Research articles (including systematic reviews, clinical trials, meta-analyses)
Commentaries on research studies (applying practice to research)

 >You can limit your search to Meta-Analysis, Systematic Reviews, or Randomized Control Trials by selecting these formats in the Publication Box limiter.

Finding Best Evidence - PubMed Clinical Queries

PubMed Clinical Queries search on your topic and the center column will display evidence based research results. You may also want to review the first column Clinical Study Categories.

Practice Guidelines

Practice Guideline: Clinical Practice Guidelines are systematically developed statements designed to assist clinician and patient decisions about appropriate health care for specific clinical circumstances, and are based on rigorous review of the best evidence on a specific topic.

Best Evidence - The Cochrane Database of Systematic Reviews

The Cochrane Database of Systematic Reviews is the leading source of systematic reviews in health care.  The CDSR is one of seven databases in the Cochrane Library and is produced by the Cochrane Collaborative, the world's leading resource for evidence-based practice.

Cochrane reviews are indexed in Cinahl.