For some of your NURS classes, you'll have to evaluate if the research articles you find match the specific criteria your professor wants. You may be asked to find specific study types, or to identify the dependent and independent variables in a study. The pages of this guide describe some basic categories of articles or variables you might have to find or identify. Click on each page to learn more about how to recognize and differentiate these types of articles.
It's important to remember that these categories are not necessarily exclusive of each other. For example, a study can be a primary study, observational, retrospective, and longitudinal all at once. But also not every category will be relevant to every study.
Primary v. Secondary
This is a primary article. The title identifies it as a randomized controlled trial, and an RCT is only ever a primary article type. Learn more here.
Observational v. Experimental
This is an experimental study. Notice that the abstract says "patients were recruited...then randomly assigned to two groups." In an observational study the researchers can't control whether or not patients are exposed to the intervention or independent variable, so if these groups were assigned this makes it an experimental study where researchers control who receives the intervention. Learn more here.
Cross Sectional v. Longitudinal
This is a longitudinal study. Researchers checked in with study participants three times: "immediately, 1 month, and 3 months." This means it's a longitudinal study which follows participants over a period of time, rather than a cross sectional study which measures participants once. Learn more here.
Dependent Variable(s)
The dependent variable is "adherence to treatment in hemodialysis patients." This is what is being measured in the study and what the researchers want to determine if education will effect. It depends on that patient education. Learn more here.
Independent Variable(s)
The independent variable is "the patient education program and nurse led telephone follow up." This is what is expected to cause a change in patient adherence to treatment. Learn more here.
Prospective v. Retrospective
This study is neither! Learn more here.
This abstract is excerpted from Arad, M., Goli, R., Parizad, N., Vahabzadeh, D., & Baghaei, R. (2021). Do the patient education program and nurse-led telephone follow-up improve treatment adherence in hemodialysis patients? A randomized controlled trial. BMC nephrology, 22(1), 119. https://doi.org/10.1186/s12882-021-02319-9 CC-BY 4.0
Opinion/Commentary
These pieces are where readers of the journal provide their opinion on recent articles or issues in the field. These readers are usually experts, and often they cite other studies and data to back up their points of view. However, these are not studies and they typically are not subjected to the peer review process.
Theory
Nursing theory is when an expert proposes a novel way of understanding events, environments, actions related to nursing. It offers a way of understanding why something is happening, or how things ought to be done. While these theories develop from years of nursing experience, observation, and research, they aren't studies themselves. Eventually, these theories are tested and applied in primary studies.
Conference Abstracts
Have you ever found a source that appears to only be an abstract and nothing more? You probably came across a conference abstract. It describes a talk or poster given at a conference, but there's often no full text to be had. Although like a primary study, these often describe the methodology and results of a study the authors conducted, they don't provide enough information for them to be a good source for you to use in your papers for a class.
Research Protocol
Research protocols describe a study that is being planned but hasn't actually been performed yet. These protocols provide a valuable way for researchers to document their processes and get feedback on their proposed study design, but the study itself hasn't been conducted yet.
