Nursing

Acquire - Find your Resources

You need to find resources for your question.

• Browse the Internet for general or background information.
• Look for books at your library.
• Check out research databases.

As you gather your resources, jot down the biographical information (author, title, place/date of publication, publisher, page numbers, URLs and your date of access).

Quantitative Research

Quantitative research is used to generate numerical data or data that can be converted into numbers. Study types that are used in the health field include:  

Qualitative Research

Qualitative research is used to explore and understand people's beliefs, experiences, attitudes, behaviour and interactions. It generates descriptive, non-numerical data.  Qualitative research methods include:

Mixed Methods

A research study does not have to be exclusively quantitative or qualitative. Many studies will use a combination of both types of research.

Case Control Studies

Case control studies are studies in which patients who already have a specific condition are compared with people who do not have the condition. The researcher looks back to identify factors or exposures that might be associated with the illness. They often rely on medical records and patient recall for data collection. These types of studies are often less reliable than randomized controlled trials and cohort studies because showing a statistical relationship does not mean than one factor necessarily caused the other.

Case Series / Case Report

Case series and Case reports consist of collections of reports on the treatment of individual patients or a report on a single patient. Because they are reports of cases and use no control groups to compare outcomes, they have little statistical validity.

Cohort Studies

Cohort studies identify a group of patients who are already taking a particular treatment or have an exposure, follow them forward over time, and then compare their outcomes with a similar group that has not been affected by the treatment or exposure being studied. Cohort studies are observational and not as reliable as randomized controlled studies, since the two groups may differ in ways other than in the variable under study.

Retrospective Cohort (or Historical Cohort)

Follows the same direction of inquiry as a cohort study. Subjects begin with the presence or absence of an exposure or risk factor and are followed until the outcome of interest is observed. However, this study design uses information that has been collected in the past and kept in files or databases. Patients are identified for exposure or non-exposures and the data is followed forward to an effect or outcome of interest.

Randomized Controlled Trials (RCTs)

Carefully planned experiments that introduce a treatment or exposure to study its effect on real patients. They include methodologies that reduce the potential for bias (randomization and blinding) and that allow for comparison between intervention groups and control (no intervention) groups. A randomized controlled trial is a planned experiment and can provide sound evidence of cause and effect.

Systematic Review

Focus on a clinical topic and answer a specific question. An extensive literature search is conducted to identify studies with sound methodology. The studies are reviewed, assessed for quality, and the results summarized according to the predetermined criteria of the review question.

Meta-Analysis

Thoroughly examines a number of valid studies on a topic and mathematically combine the results using accepted statistical methodology to report the results as if it were one large study.

Cross-Sectional Studies

Describe the relationship between diseases and other factors at one point in time in a defined population. Cross-sectional studies lack any information on the timing of exposure and outcome relationships and include only prevalent cases. They are often used for comparing diagnostic tests. Studies that show the efficacy of a diagnostic test are also called prospective, blind comparison to a gold standard study. This is a controlled trial that looks at patients with varying degrees of an illness and administers both diagnostic tests — the test under investigation and the “gold standard” test — to all of the patients in the study group. The sensitivity and specificity of the new test are compared to that of the gold standard to determine potential usefulness.

Double Blind Method

A double blind study is one in which neither the patient nor the physician knows whether the patient is receiving the treatment of interest or the control treatment.

 For example, studies of treatments that consist essentially of taking pills are very easy to do double blind - the patient takes one of two pills of identical size, shape, and color, and neither the patient nor the physician needs to know which is which.

 A double blind study is the most rigorous clinical research design because, in addition to the randomization of subjects which reduces the risk of bias, it can eliminate the placebo effect which is a further challenge to the validity of a study.

All images are based on examples from SUNY Downstate Medical Research Library of Brooklyn from their Evidence-Based Medicine Course - check out Sorting Out EBM Study Types.

Image from UT Health San Antonio, School of Nursing: Evidence-Based Practice: Study Design

The definition of EBM states the importance of obtaining the "best available evidence." The evidence pyramid is a hierarchy which ranks the health information resource/study design with the highest quality and least bias from top to bottom. This hierarchy is helpful to guide evidence acquisition (literature searching).

When it comes to prioritizing the evidence in any specific situation, clinicians will need understand the nuances of the evidence (reviews, studies) obtained. It is not uncommon for lower levels of evidence on the hierarchy to provide better evidence that those sitting above: a hot-off the-press large RCT over an older meta analysis containing small studies.  

Grey literature can be described as any information produced outside of traditional publishing channels--essentially anything besides articles published in scholarly journals. Grey Literature refers to a body of materials that cannot be found easily through conventional channels such as publishers.

Grey literature can include, but is not limited to: pre-prints, reports, white papers, theses, conference proceedings, technical specifications and standards, technical and commercial documentation, and government documents. For this reason, grey literature can be difficult to systematically search for and evaluate.

Grey Literature is a potential useful source of material, if you are prepared to do the extra work to use it.   Typically grey literature has to be searched using multiple tools.  The links below contain links to specific sites and search tools to find grey literature.

Google Scholar is a sub set of the Google web search engine that indexes the full text and metadata of scholarly literature.  It supports a large number of publishing formats and disciplines.  A great deal of grey literature sits on freely accessible academic servers.
https://scholar.google.ca/

Grey Matters, from From CADTH, is a tool for searching health-related grey literature.
https://www.cadth.ca/resources/finding-evidence/grey-matters

This is a good starting point produced by the University of Illinois at Chicago.
http://researchguides.uic.edu/c.php?g=252186&p=1684970

A similar resource from New York University.
http://guides.nyu.edu/greylithealth