There are two steps you can take to plan your research before actually going to a database that will
State your research idea as a clinical question, which should be specific and answerable:
example: How effective is the use of mouth guards in reducing mild traumatic brain injury incidence in high school athletes?
Check that your question is indeed a "clinical question" by checking to see that it contains three or four specific variables known as PICO:
here is the same clinical question in PICO format:
P | ("high school athletes" OR "youth athlete") AND "traumatic brain injury" |
I | "mouth guard" |
C | n/a |
O | reduction |
You will notice that the Population box above has two variables with an all-caps AND connecting them. This is a Boolean command phrase, and will tell the database that both terms are required. Similarly, the Boolean command OR tells the database that you'll accept articles that contain either "high school athletes" or "youth athlete". Remember that when you use an OR command you need to isolate whatever concepts you're OR-ing together in their own set of parentheses.
You'll also see that some words have quotation marks around them. This tells the database that the words "high school athletes" are a phrase that have to appear together in order for you to want an article in your results list. If you had not placed these three words inside quotation marks, the database would retrieve articles that had the word "school" by itself, "high" by itself, or "athletes" by itself, and those articles would most likely not be relevant to you.
Charting your question as a PICO tells you what pieces of the search phrase you need to include in your search phrase when you search a database. All you need to do now is combine the pieces correctly, using Boolean commands AND, OR, and NOT.
Above, you see that the search boxes function the same as a parentheses sets. These parentheses work exactly like parentheses in a math equation, and tell the database in what order to apply your Boolean commands AND, OR, and NOT. You can use parentheses in any database to structure your search phrase, including Google!
In addition to clarifying the population, intervention or exposure, and outcome, it is productive to label the nature of the question that you are asking. There are 5 fundamental types of clinical questions:
Therapy: determining the effect of interventions on patient-important outcomes (symptoms, function, morbidity, mortality, and costs)
Harm: ascertaining the effects of potentially harmful agents (including therapies from the first type of question) on patient-important outcomes
Differential diagnosis: in patients with a particular clinical presentation, establishing the frequency of the underlying disorders
Diagnosis: establishing the power of a test to differentiate between those with and without a target condition or disease
Prognosis: estimating a patient's future course
Clarifying Your Question. In: Guyatt G, Rennie D, Meade MO, Cook DJ. eds. Users' Guides to the Medical Literature: A Manual for Evidence-Based Clinical Practice, 3rd ed. McGraw-Hill; Accessed April 30, 2021.