When searching for evidence-based information, one should select the highest level of evidence possible--systematic reviews or meta-analyses. Systematic reviews, meta-analyses, and critically-appraised topics/articles have all gone through an evaluation process: they have been "filtered." Information that has not been critically appraised is considered "unfiltered."
As you move up the pyramid, however, fewer studies are available; it's important to recognize that high levels of evidence may not exist for your clinical question. If this is the case, you'll need to move down the pyramid if your quest for resources at the top of the pyramid is unsuccessful.
- Meta-Analysis: A systematic review that uses quantitative methods to summarize the results.
- Systematic Review: Authors have systematically searched for, appraised, and summarised all of the medical literature for a specific topic.
- Critically Appraised Topic: Authors evaluate and synthesize multiple research studies.
- Critically Appraised Articles: Authors evaluate and synopsize individual research studies.
- Randomized Controlled Trials: 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.
- 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.
- Case-Control Study: Identifies patients who have the outcome of interest (cases) and control patients without the same outcome, and looks for exposure of interest.
- Background Information/Expert Opinion: Handbooks, encyclopedias, and textbooks often provide a good foundation or introduction and often include generalized information about a condition. While background information presents a convenient summary, often it takes about three years for this type of literature to be published.
- Animal Research/Lab Studies: Information begins at the bottom of the pyramid: this is where ideas and laboratory research takes place. Ideas turn into therapies and diagnostic tools, which then are tested with lab models and animals.
Use the TRIP database to find unfiltered and filtered information sources online.
Greenhalgh, Trisha. How to Read a Paper: the Basics of Evidence Based Medicine. London: BMJ, 2000.
Glover, Jan; Izzo, David; Odato, Karen & Lei Wang. EBM Pyramid. Dartmouth University/Yale University. 2006.
Personal portable information technology is advancing at a breathtaking speed. Google has recently introduced Glass, a device that is worn like conventional glasses, but that combines a computerized central processing unit, touchpad, display screen, high-definition camera, microphone, bone-conduction transducer, and wireless connectivity. We have obtained a Glass device through Google's Explorer program and have tested its applicability in our daily pediatric surgical practice and in relevant experimental settings.
Glass was worn daily for 4 consecutive weeks in a University Children's Hospital. A daily log was kept, and activities with a potential applicability were identified. Performance of Glass was evaluated for such activities. In-vitro experiments were conducted where further testing was indicated.
Wearing Glass throughout the day for the study interval was well tolerated. Colleagues, staff, families and patients overwhelmingly had a positive response to Glass. Useful applications for Glass were hands-free photo/videodocumentation, making hands-free telephone calls, looking up billing codes, and internet searches for unfamiliar medical terms or syndromes. Drawbacks encountered with the current equipment were low battery endurance, data protection issues, poor overall audio quality, as well as long transmission latency combined with interruptions and cut-offs during internet videoconferencing.
Glass has the some clear utility in the clinical setting. However, before it can be recommended universally for physicians and surgeons, substantial improvements to the hardware are required, issues of data protection must be solved, and specialized medical applications (apps) need to be developed.