NURS B444/445 Managing Health and Illness Across Care Environments

While searching for research, it may be tricky to distinguish one study from another. The graphic above illustrates the hierarchy of evidence synthesis or different types of research papers. Here's a quick blurb about each:

• Systematic Review   Is an article that collects all possible studies related to a given topic and design, and reviews and analyzes the results. This is a time consuming method of analyzing research, which means there might not be a systematic review for your topic; however, if you do find a systematic review, it's a wonderful way to identify multiple articles on a singular topic.

• Meta-Analysis  Differs from a systematic review in that it uses statistical methods on estimates from two or more different studies to summarize the results of the studies. Meta-analyses can be helpful when seeking precise estimates of the effects of health care or particular intervention. 

• Randomized Controlled Trials  RCT's include a randomized group of patients in an experimental group and a control group. These groups are followed up for the variables/outcomes of interest.

• Case-Control Study  Involves identifying patients who have the outcome of interest (cases) and control patients without the same outcome, and looking to see if they had the exposure of interest.

• Cohort Study  Identifies two groups (cohorts) of patients, one which did receive the exposure of interest, and one which did not, and following these cohorts forward for the outcome of interest.

• Cross-Sectional Studies   Observational studies that analyze data from a population at a single point in time. They are often used to measure the prevalence of health outcomes, understand determinants of health, and describe features of a population.

• Case Series & Expert Opinion   Case series is a group of case reports involving patients who were given similar treatment. Case reports and case series usually contain demographic information about the patient(s), such as age, gender, etc. Case series are uncontrolled. Expert opinions can include information from committee reports or other "voices of authority"; these types of resources are at the bottom of the hierarchy because both case series and expert opinions can be biased by the author's experience or opinions and there is no control of confounding factors.

What is PICO?

PICO stands for:

• Population (or patient or problem)

  • What are the characteristics of the patient or population?

• Intervention

  • What is the intervention under consideration for this patient or population?

    • Drug, surgical intervention, therapy, etc.

• Comparison

  • What is the alternative to the intervention?

    • a different drug or placebo

  • Note: It's possible that you won't have a comparison in your research question

• Outcome

  • What are the related outcomes?

    • Improvement in quality of life or minimizing adverse effects?

PICO Question 

A patient is scheduled for a cesarean section and is nervous about having staples in their stomach. They fear that the staples will not close their wound properly and have heard from a friend about other possible complications such as the wound separating and becoming infected. The patient is interested in sutures, as they think it will reduce the possibility of complications. 

Example PICO

• P: Pregnant people undergoing c-section

• I: Staples

• C: Sutures

• O: Fewer complications (such as wounds separating and infection)

Searching with PICO

When searching for the best evidence, it's important to ensure you're capturing the key concepts; in this case, it's best to start broad and then narrow the search as you go. The search concept you start with will rarely be the final one you end up with, so trust the process and don't be afraid to add, remove, or change terms as you go.

Let's practice with the example above:

• P: "cesarean section" OR "c-section"

AND

• I: staples

AND

• C: sutures

Plugging those topics into PubMed looks like this and produced the following results:

Hierarchy of Evidence

Connecting what we've learned about the hierarchy of evidence, you can use filters in databases to access high caliber research quickly. Here are the article type filters that are in PubMed for this particular search: