|Research Evidence||Non-Research Evidence|
Meta-analysis / meta-synthesis Primary Research:
The number of articles needed to make a practice change is based on a combination of factors.
1. Level and quality of evidence found.
2. The decision is also influenced by the depth of clinical knowledge of the team.
Which type of study is it?
Experimental - Must have 2 groups -1 group that has the intervention and 1 group that has NO intervention and the participants must be randomly chosen. Experimental studies must have all three -
Manipulation of a variable (they did an intervention)
Control group (a group with NO intervention)
Randomization (participants randomly chosen) (Newhouse, et al., 2007, p. 79)
Meta-analysis - quantitatively synthesizes & analyzes findings of multiple primary studies addressing a similar question (Newhouse, et al., 2007, p. 79)
Quasi-experimental - "performed when it is not practical, ethical, or possible to randomly assign subjects to experimental or control groups." (Newhouse, et al., 2007, p. 79)
Some manipulation of a variable
Some control (a group with NO intervention)
No randomization Examples -
Non-equivalent control group: posttest only or pretest-posttest
One group: posttest only or pretest-posttest
Untreated control, repeated measures
Repeated treatment where subjects serve as their own controls
Non-experimental - studies what has already happened. "it involves the study of naturally occurring phenomena (groups, treatments, and individuals) without the introduction of an intervention. (Newhouse, et al., 2007, p. 79)
Little control Examples -
Qualitative - "represent a category of descriptive research (historical, grounded theory, ethnographic) that challenges the traditional scientific worldview." (Newhouse, et al., 2007, p. 85)
Meta-Synthesis - synthesizes & analyzes qualitative scientific evidence
Was the sample size appropriate? Subjective, based on the body of evidence that you find. (If most studies have 100 participants then a study with only 10 is not appropriate.)
Were study participants randomized? The study should describe how they selected participants - if so, it should use the word randomized.
Was there an intervention? Did they do something to the patient?
Was there adequate description of the data collection methods? This is subjective - they should describe in detail how the collected the data so that it could be replicated
Were results clearly presented? This is subjective. Do you understand their findings?
Was an interpretation/analysis provided? Did they adequately describe an analysis?
Were conclusions based on clearly presented results? This is subjective. Does it make sense?
Were study limitations identified and discussed? Either they did or they didn't.
PERTINENT STUDY FINDINGS AND RECOMMENDATIONS: This is the cliff notes of the article. What are the most important things you learned from this study? The information here will be included in the summary of overall findings.
Quality of Evidence - See Evidence Level and Quality Guide
P Values and Confidence Intervals Simplified
P (probability value) indicates the probability of a "false positive." Think of it as the probability that the results of the study are NOT true. Ideally, the p-value is a very low number because you only want to accept what is true. A P value of <.OS or < .01 is deemed significant.
The confidence interval means that if the study was replicated using the same interventions and methods, it should result in the same findings within certain parameters. Ideally, the CT is a very high percentage. A CJ o/ 95% or > is deemed significant.
Non Research Evidence - Level V
Most questions in this tool are self-explanatory, below are tips on a few selected questions.
PERTINENT CONCLUSIONS AND RECOMMENDATIONS