Nursing Research Guide

Quantitative studies generate numerical data, or data that can be converted into numbers, to learn how many, how much, how often. Quantitative studies are often easier to locate, as the type of study usually appears in the title, and medical databases have built in filters to locate quantitative materials. Look for the following terms to signal a quantitative study, and make sure you familiarize yourself with the differences in study types and where they fall in the levels of evidence.

• A meta-analysis is a quantitative method, that combines all the results of all the studies into a single statistical analysis. A meta-synthesis does the same, but with qualitative studies.
• A systematic review asks a specific clinical question, performs a comprehensive literature search, and attempts to make practice recommendations based on well-done studies.
• A randomized controlled trial is a type of clinical study in which participants are randomly assigned to groups that receive one or more intervention/treatment (or no intervention).
• A quasi-experimental study is one where participants are not randomized but rather use pre-existing groups, or other non-random methods, to form groups.
• 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.
• A case-control study is concerned with the frequency and amount of exposure in subjects with a specific disease (cases) and people without the disease (controls).

• 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.

You can also use the filters in CINAHL (under Filters and Publication Type) and PubMed (on the left after search titled, Article Type). Engaging any of these filters will limit your results to just that type of study or material.

Qualitative studies use non-numeric data to understand the why and how of people's beliefs, experiences, attitudes, behavior and interactions. You will often see the following terms/titles used:

• Passive observation 
• Participant observation 
• In-depth interview 
• Focus group 
• Hospital or medical records

For MEDLINE/Pubmed recall this database uses what are called subject terms, labeled MeSH. 

In PubMed, you can use "Qualitative Research" or "Nursing Methodology Research" as a SUBJECT term. You can copy and paste this search string into the Pubmed search box along with your other keywords for your search connecting it with AND:

qualitative research [MeSH] OR qualitative[tiab]

You can also use the filters in PubMed, on the left after search titled, Article Type. Engaging any of these filters will limit your results to just that type of study or material.

CINAHL uses the CINAHL heading "Qualitative Studies" complemented by more detailed terms, including "Phenomenological Research" and "Focus Group," etc. You can use any of the Filters under the Advanced Search as well, and limit to the item type you want. 

For any database you can add the following search string to your other keywords preceded by the word "AND."

(qualitative OR ethnograph* OR phenomenol* OR ethnonurs* OR grounded theor* OR “purposive sample” OR hermeneutic* OR heuristic* OR semiotics OR lived experience* OR narrative* OR “life experiences” OR “cluster sample” OR “action research” OR “observational method” OR “content analysis” OR “thematic analysis” OR “constant comparative method” OR field stud* OR “theoretical sample” OR “discourse analysis” OR focus group* OR “ethnological research” OR ethnomethodolog* OR interview*)