How to search for evidence to inform clinical decisions?
This summary is based on the article published in the Journal of the American Dental Association: A practical approach to evidence-based dentistry. How to search for evidence to inform clinical decisions (December 2014)
Romina Brignardello-Petersen, DDS, MSc; Alonso Carrasco-Labra, DDS, MSc, PhD(c); H. Austin Booth, MA, MIS; Michael Glick, DMD; Gordon H. Guyatt, MD, MSc; Amir Azarpazhooh, DDS, MSc, PhD, FRCD(C); Thomas Agoritsas, MD
Courtesy of the American Dental Association, you can access the full-text article for the next 3 months here (PDF)
Knowing how to search for evidence that can inform clinical decisions is a fundamental skill for the practice of evidence-based dentistry. There are many available types of evidence-based resources, characterized by their degrees of coverage of pre-appraised or summarized evidence at varying levels of processing, from primary studies to systematic reviews and clinical guidelines. The practice of evidence-based dentistry requires familiarity with these resources.
Purpose of the article
To describe the process of searching for evidence: defining the question, identifying the question’s nature and main components, and selecting the study design that best addresses the question.
Why is it Important to know how to search for the best current evidence?
Because of the increasing number of new treatments and studies that address their effectiveness, knowing how to search for and use the best current evidence is a fundamental skill in clinical practice.2, 3
Defining the question of interest
Framing the question is a key step in the process of searching for evidence to inform clinical decisions. (4)
There are two main types of questions that will determine an efficient and relevant search strategy: (4)
- Background questions are aimed at eliciting descriptive information concerning clinical conditions, diagnostic tests or treatments.
- Foreground questions are targeted questions about therapy and prevention, diagnosis, etiology and prognosis that directly inform clinical decision making.
The first step in formulating the question of interest is to identify the nature of the question, which is related directly to the type of evidence the search will target:
- Therapy or prevention to assess the effect of interventions on patient-important outcomes
- Harm or etiology, to evaluate how exposure to risk factors influences patient important outcomes
- Diagnosis to assess the performance of a test in differentiating between patients with and without a condition or disease
- Prognosis to estimate a patient’s future course of disease on the basis of prognostic factors
The second step is to identify the main components of the question:
- Population (the patients relevant to the question);
- Intervention (the treatment or prevention strategy or, possibly, the harmful exposure of interest);
- Comparison (the management strategy used as a reference against which to compare the intervention);
- Outcomes (the consequences of the intervention in which we are interested).
Which resources should we use to find evidence?
- The types of resources vary considerably in the level or extent to which they summarize the evidence. There are three levels of resources: summaries and guidelines, pre-appraised research, and non-pre-appraised research.
- Dentists should consider two main factors when choosing which type of resource to consult to inform evidence-based practice:
- The resource should be based on the current best evidence, should be both comprehensive yet specific enough to cover the question of interest (8) should be up to date relying on the most recent evidence, and should be available to the practitioner who wants to use it.