Finding relevant literature is important when searching, but it isn't the only factor. Evaluating the currency and strength of the articles you find is just as important. When you are searching for answers to a clinical question or for research, outdated or weak evidence can lead to poor and even harmful decisions. Instead, aim for current, high-quality literature that reflects the best available knowledge in your field.
Knowledge and best practices evolve quickly in healthcare. An intervention considered best practice one year may be outdated or even harmful just a few years later. Conversely, a new treatment might not appear in literature older than two years, but could now be the gold standards. Without careful consideration for your field's standards of currency, you could place too much weight on outdated literature, or even miss the newest information in a sea of older articles.
Standards of currency are the parameters that determine whether an article are considered up-to-date, or current. They vary between disciplines, especially between biomedical information and areas like the humanities. For clinical information, a 5-year window is often a good starting point, though you may need to expand to 10 years if relevant literature is limited.
Be cautious about excluding older studies that are considered landmarks or foundational. If a study continues to influence current practice or guidelines, it may still be considered current even if it's older than your usual standard.
Levels of evidence help you assess the strength and ability of an article to answer a clinical question. Standards for evidence vary by discipline. In clinical fields, systematic reviews, meta analyses, and randomized controlled trials (RCTs) are often considered the highest levels of evidence. They're well suited for answering clinical questions or for inclusion in a research project. In contrast, qualitative studies usually rank lower, though they may still offer valuable insights.
It's important to remember that a lower level of evidence doesn't necessarily mean that an article is low quality or irrelevant. Different study types serve different purposes, and their relevance depends on your question.
Stillwell SB, Fineout-Overholt E, Melnyk BM, & Williamson KM. (2010). Evidence-based practice, step by step: searching for the evidence. AJN American Journal of Nursing, 110(5), 41–47. https://doi.org/10.1097/01.NAJ.0000372071.24134.7e
Most databases have a variety of filters you can apply to refine your results. They are most often located on the left side of the search results screen.
Available filters and their functionality vary from database to database. Many databases offer the ability to narrow your results by:
You can plan ahead for which filters you plan to use by considering concepts like the standards of currency for your field or acceptable levels of evidence for your project. Filters like language and population may not be necessary to apply immediately.
For this project, we define "current" literature as publications from the last 5 years, and we only want high levels of evidence. So we'd use the following limiters or filters, subject to change depending on what the database offers:
In this scenario, we would likely not need to filter by age/population - it's unlikely that there will be pediatric patients in the mix since healthcare workers are always, to our knowledge, adults. If we applied the age/population filter, we might accidentally eliminate results about nurses for pediatric patients, which may be relevant! We also would not add the language filter right off the bat, only when it's necessary.