Tag Archives: Literature review

Literature review, reading research

Google’s Beauty is Only Skin Deep: Go for the Database!

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maxresdefaultGoogle–not to mention yahoo, bing & other web search engines–are mere popularity contests of literature.   Google Scholar is a step up, but it is still a search engine.  It can miss important articles entirely.

If you want to be sure that you are getting the BEST, you gotta look in the right place if you want to find the right articles on the right topic at the right time!Beauty contest winner

You need a Database!

Don’t believe me?  Watch “What are databases and why you need them?”(youtube 2:34)

Reputable publishers give away very few articles for free, so when you want the best literature out there you need a Database that will systematically help you to find quality articles that fit your topic.

PubMed.gov is a tax funded database that is highly comprehensive.  CINAHL is strong on nursing literature.  If you are enrolled in a university, you have access to lots of full-text articles at no added cost.  Check with your librarian if your database search is not turning up what you need–with a few hints, you could get the best.

Needle in haystackFor more info:  Look for that needle in the haystack.

experiment, RCT, reading research, Research design

True or False: Experiment or Not

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Experiments are the way that we confirm that one thing causes another.   If the study is not an experiment (or combined experiments in a meta-analysis), then the research does not show cause and effect. imagesCALQ0QK9

Experiments are one of the strongest types of research.

So…how can you tell a true experiment from other studies?   Hazel B can tell you in 4:04 and simple language at https://www.youtube.com/watch?v=x2i-MrwdTqI&index=1&list=PL7A7F67C6B94EB97E

Go for it!

[After watching video:  Note that the variable that is controlled by the researcher is call the Independent variable or Cause variable because it creates a change in something else. That something else that changes is the Dependent variable or Outcome variable.]Learning

CRITICAL THINKING:  

  1. Based on the video, can you explain why true experiments are often called randomized controlled trial (RCT)?
  2. Take a look at The Effect of the Physical and Mental Exercises During Hemodialysis on Fatigue: A Controlled Clinical Trial, that is free in full-text via PubMed. How does it meet the criteria of a true experiment as described by Hazel B in the video?

FOR MORE INFORMATION:   Go to “What’s an RCT Anyway?” (https://discoveringyourinnerscientist.wordpress.com/2015/01/23/whats-a-randomized-controlled-trial/ )

Evidence based nursing, Professional Nursing, reading research

Introduction to Introductions!

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I have a lot of new readers, so let’s revisit the standard sections of a research article.  They are:

  • Introduction (or Background)
  • Review of literature
  • Methods
  • Results (or findings)
  • Discussion & Implications
  • Conclusion

If we begin at the beginning, then we should ask: “What’s in an Introduction?”  Here’s the answer:

“[a] …Background of the problem or issue being examined,

[b] …Existing literature on the subject, and

[c] …Research questions, objectives, and possibly hypothesis” (p. 6, Davies & Logan, 2012)

This is the very 1st section of the body of the research article.  In it you will find a description of the problem that the researcher is studying, why the problem is a priority, and sometimes what is already known about the problem.  The description of what is already known may or may not be labelled separately as a Review of Literature.

KEYKey point #1: Articles & research that are reviewed in the Intro/Background should be mostly within the past 5-7 years.  Sometimes included are classic works that may be much older OR sometimes no recent research exists.   If recent articles aren’t used, this should raise some questions in your mind.   You know well that healthcare changes all the time!!  If there are no recent studies the author should explain.

KEY
Key point #2:  The last sentence or two in the Intro/Background is the research question or hypothesis.  If you need to know the research question/hypothesis right away, you can skip straight to the end of the Intro/background—and there it should be!

Happy research reading!

Critical Thinking: Do the sections of the abstract AND the sections of the research article match above headings?  Does it match the description of Introduction? Take a look at the free article by Kennedy et al. (2014). Is there a relationship between personality and choice of nursing specialty: An integrative literature, BMC Nursing, 13(40). Retrieved from the link http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4267136/.  question

 

Evidence based nursing, Literature review, Professional Nursing, reading research

A 33,000 foot view: The Abstract

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 Abstracts are great; abstracts are not enough!
An abstract will not give you enough information to accurately apply the study findings to practice.   An abstract typically summarizes all the other sections of the article, such as  the question the researcher wanted to answer, how the researcher collected data to answer it, and what that data showed.  This is great when you are trying to get the general picture, but you should Never assume that the abstract tells you what you need to know.
airplaneWingIsland
Abstracts can mislead you IF you do not read the rest of the article.  They are only a short 100-200 words and so the authors have to leave out key information.   You may misunderstand study results if you read only the abstract.   An abstract’s 33,000 foot level FootprintsInSand
description of a study, cannot reveal the same things that you can learn from an up-close look at details.  You want to know exactly who was in the study, exactly what the researcher did, & exactly how outcomes were measured!  You want to follow the researcher’s footprints up close, not just do a fly-over.
So…what is the takeaway?  Definitely read the abstract to get the general idea.  Then read the article beginning to end.  Don’t give up reading the full article just because some parts of the study may be hard to understand.  Just read and get what you can. Then try a re-read or get some help understanding any difficult sections.   This is an important step toward EBP.   [revised from my former blogsite]
Critical thinking:  What info is missing from this abstract at this link that you would want to know before using the findings of this pain study to practice?
http://www.ncbi.nlm.nih.gov/pubmed/25659796QUESTION
Evidence based nursing, Literature review, Professional Nursing

Finding the Needles in the Haystacks: Evidence Hunting Efficiently & Effectively

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Searching for the right evidence is an art & a science.   In an effective search, the RN: twoOnComputer

  1. Identifies excellent key words based on a clear problem statement
  2. Systematically searches the best databases for those words
  3. Keeps a record of the search strategy.

This is actually a pretty simple time-saver because it keeps you from having to repeat searches because you can’t remember where you looked!!

Let’s take an example that we used previously.  Here’s how it was laid out in PICO (which stands for Population/problem, Intervention, Comparison intervention, & Outcome)

  • Population/problem= Postoperative patients with ileus (Patient population &Problem)
  • Intervention= Gum chewing postop (Intervention to try out)
  • Comparison intervention= NPO with gradual diet progression when bowel sounds start returning
  • Outcome= Reduce time of postop ileus with sooner return to nutritious eating

We would:magnifyingGlass

  1. Using PICO, identify key concepts (words), such as “postoperative ileus” “gum chewing” and “NPO.” Note that you can pick single words or combinations of words.
  2. Search for this set of words in the very comprehensive databases of PubMed and also in CINAHL. CINAHL is more nursing specific, and PubMed is one of the most comprehensive out there. Search from MOST RECENT to earlier.  Go for only most recent 5 years unless 5 years doesn’t give you enough articles.
  3. Keep notes of exactly which words and phrases you used to search each database

This 5 minute video shows you a GREAT way to make sure that your search is complete with minimal effort. It’s an easy-peasy tracking strategy for where you’ve already looked. https://www.youtube.com/watch?v=233DzkmimV4&list=PLE3A977BE32CF3956

CRITICAL THINKING: What are the key words of your clinical problem of interest.  (You can choose to use PICO or not.)  Plug them into PubMed.  Did you get enough articles?QUESTION

Evidence based nursing, Literature review, Research design, Sampling

“That is so random!” But is it Representative?

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What makes a good sample in research?  One thing.  And it isn’t random selection.  (Surprised?)

Portrait of a diversity Mixed Age and Multi-generation Family embracing and standing together. Isolated on white background. [url=http://www.istockphoto.com/search/lightbox/9786738][img]http://dl.dropbox.com/u/40117171/group.jpg[/img][/url]It is representativeness.  No matter how the sample was picked, it must be representative of all those in the larger population, if the researcher wants to say anything about anyone who wasn’t in the study.  Now, of course, it is true that random selection is more likely to give you a representative sample, but it is no guarantee.  Only likely.

What is random sampling?  It is when every member of the larger population has an equal chance of being selected for the study sample.  Example? Drawing names out of a hat.  It is well-accepted practice to generalize research results from a random sample to others like those being studied (assuming that all other aspects of the study are strong).

In contrast a convenience (or nonprobability) sample is when some people are more likely to be chosen to be in the study than others.  You shouldn’t generalize the results of these studies because the samples may Not represent others.

Example of when random sampling doesn’t work: Let’s say you have a mixture of red, green, & yellow apples, and you select a sample that has only yellow apples.  (The red & green ones are going to be offended!–They’re left out.)  You now have a sample that is biased in favor of yellow apples!   Your sample does Not represent the larger population of apples…even if you used random methods to get it.  If you want to apply the study to red & green & yellow apples…well….you must get some of them in your sample, too. The yellow apples might not be at all like the other types and studying just yellow might mislead you into thinking something about the red & green ones that isn’t true!   Of course you could study all the millions of apples in the world and exclude none, but that would be pretty cumbersome and expensive.   So, it’s better to go for a representative sample!

When else doesn’t random sampling create a representative sample?   If I am doing historical research, say on the Nursing Department at California State University/Northridge, then I want to hand pick the specific RNs by name who were in charge of the Department from the beginning.  Randomly selecting nurses from those who worked at the University won’t represent those leaders.

QUESTIONCritical Thinking:  Take a quick look at the linked abstracts. How were the samples selected?  How representative are the samples of a larger population of interest?  Could you generalize the results to other people, and if so to whom?

Want more information on sampline? Check this out.  It takes < 5 minutes:

https://www.youtube.com/watch?feature=endscreen&v=be9e-Q-jC-0&NR=1

Evidence based nursing, Literature review, Professional Nursing

“Is it?” “It is!” Expert opinion as valuable evidence for practice.

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Remember back when you asked your mom why you should make your bed, set the table, or do some other then-distasteful task? Maybe you said, “Do I have to?”

Because I Said SoRemember her answer? Sometimes it was just: “Because I said so!” Was that enough evidence to support your practice of setting the table or making your bed?  You bet! After all she was THE expert on such things.

Likewise…is expert opinion good evidence for your practice? Yes, it is. EXPERT OPINION of individuals or committees is the 7th level of evidence for nursing practice (Melnyk & Fineout-Overholt, 2005), and should be considered.

Of course the first question that you must ask is: “Is the person/committee (who is telling you how to prevent falls, promote safety, teach patients, and so on and on) an actual EXPERT on that topic?” The answer is a matter of judgment. If the person/committee has special education, credentials, or experience or is a recognized authority on the topic about which they are giving advice, then you could reasonably conclude yes, they are experts. In that case the advice should be considered evidence for practice.    (Caution: Your judgment of their expertise matters!–don’t just follow along.  Don’t forget that person who is expert in one area may not be an expert in another.)

The 2nd question that you must ask is; “Does any research or stronger level of evidence exist on the topic?”

  • If it does NOT exist, then you should use that expert opinion in combination with scientific principles, anecdotal case reports, and theory. Or you might create some new research yourself. (Source=Iowa EBP Model)
  • If it DOES EXIST, then you should pay most attention to the stronger evidence and interpret the weaker evidence of expert opinion in that light.

QUESTIONCritical thinking:  Try your new knowledge in this example. Many educators and professionals who run journal clubs consider journal clubs effective based on feedback from participants. At least in 2008, 80% of experimental studies suggested that journal clubs helped with learning and being able to critically review a research article. However, no research is available on whether the learning from journal clubs actually translates into practice (Deenadayalan et al., 2008). You are considering a journal club. What would you decide to do and why?

For more, see:

Evidence based nursing, Literature review, reading research

“Watch & Learn!” – Systematic Reviews of Non-experimental Studies

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Today’s top tip: Want to find the strongest research evidence for your project?   Go to http://www.ncbi.nlm.nih.gov/pubmed & add the strongest type of research designs as one of your search terms. For example, add the terms meta-analysis or systematic review to your other search terms. **********************************************

Now to the new!  What is a systematic review of descriptive studies? [Note: For information on stronger levels of research “I like my coffee (and my evidence) strong!)]Cat Fishbowl2

First, remember that in a descriptive study, the researcher merely watches or listens to see what is happening. Descriptive studies do not test interventions.

Second, a systematic review (not to be too silly) is a review that is done systematically in order to include all literature on a particular topic . The authors will tell us where they searched for studies, what search terms they used, and what years they searched. That way we can feel sure that all relevant articles are included.

Therefore, in a systematic review of descriptive studies the authors

  • Collect non-experimental studies related to the problem they are trying to solve,
  • Critically review them, &
  • Write up that analysis for you and me.

You won’t see a lot of numbers or statistics in these reviews of non-experimental studies.

Systematic review of descriptive studies are weaker than other levels of evidence in part because they are critical reviews of non-experimental studies in which the researchers only observed subjects. Those non-experimental studies that they are reviewing may be quantitative with results reported in numbers or qualitative with results reported in words.

Here’s an example with results reported in words (qualitative): Yin, Tse, & Wong (2015) systematically reviewed studies for what factors affect RNs giving PRN opioids in the postop period.   They searched publications 2000-2012 and ended up with 39 relevant studies. Within those 39 articles were descriptive studies that identified 4 basic influences on opioid PRN administration by RNs to postop patients: “(i) nurses’ knowledge and attitudes about pain management; (ii) the situation of nurses’ work practices in administrating range orders for opioid analgesics; (iii) factors that influenced nurses’ work practices; and (iv) perceived barriers to effective pain management from the nurse’s perspective.” [note: In this study a few of the 39 studies were experimental in which something was done to subjects and then outcomes measured, and Yin et al., commented separately on what those showed.]

Critical thinking: What are key differences between a meta-analysis of randomized controlled trials and a systematic review of QUESTIONdescriptive studies?

Reference found with search terms: review of descriptive studies nursing pain – Yin, H.H.,Tse, M.M., & Wong, F.K. (2015). Systematic review of the predisposing, enabling, and reinforcing factors which influence nursing administration of opioids in the postoperative period. Japan Journal of Nursing Science, doi: 10.1111/jjns.12075.

 

Evidence based nursing, Literature review, reading research, Research design

Cohort & Case-controlled studies: Going forward & backward

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Got a clinical problem?  You probably want to solve it with evidence—STRONG evidence.   Click on this link to see one well-accepted hierarchy from strongest #1 to weakest #7 (Melnyk & Fineout-Overholt, 2005).   Today let’s look at the 4th strongest level of evidence = Case controlled or cohort studies

First a quick review

Click here for a quick review of the strongest 2 levels of evidence (#1 Systematic reviews, Meta-analyses, or Evidence-based clinical practice guidelines based on systematic review of RCTs. #2 Randomized controlled trials)

Click here for a review of the 3rd strongest type of evidence (#3Controlled trials without randomization)

Now on to the new “stuff”  strong

All 3 of the top, strongest levels of evidence are experimental studies (or include available experimental studies). That means the researcher actually does something or gives a treatment to some of the subjects and then records the outcomes. 

The weaker 4 levels of evidence are non-experimental designs. This means that the researcher merely observes & does Not do anything to subjects. So how does that work?!

First, a cohort study (non-experimental). A cohort study starts with a group of people who have something in common and then the researcher observes only & keeps collecting data from them over a long time into the future. Data collection into the future is called a prospective study.  “An example is the Nurses’ Health Study, in which over 20,000 nurses were identified and followed-up annually with tests and surveys for over 25 years (this study is still ongoing). These studies provide very valuable information, but are obviously very expensive and time-consuming.”(OMERAD EBM course, 2008)

Now a case-controlled study (non-experimental).  In a case controlled study the researcher observes only & collects data over time into the past (not the future). Data collection into the past is called a imagesCAH6C8NTretrospective study. Again, from the OMERAD EBM (2008) site this example: “Patients with a disease are identified who have suffered a bad outcome such as death or recurrence, and compared with patients who have the disease but haven’t suffered the bad outcome. For example, a researcher might  identify a group of breast cancer patients who have died…, and compare them with a similar group of patients with breast cancer who are still living.”

Critical thinking: Which of these would be better for casQUESTIONe-controlled study and which for cohort study.

  1. You are a runner in the Los Angeles marathon and you are interested in how that race can improve cardiovascular health among those who finish. Question: Cohort or Case controlled?
  2. Some finishers of the LA marathon die of heart attacks 20 years later; many survive another 40 years.   Question: Cohort or Case controlled?

For more info see:

 

Evidence based nursing, Literature review, nonrandom trials, Research design

Of Mice and Cheese: Research with Non-equivalent Groups

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Last week’s blog focused on the strongest types of evidence that you might find when trying to solve a clinical problem. These are: #1 Systematic reviews, Meta-analyses, or Evidence-based clinical practice guidelines based on systematic review of RCTs; & #2 Randomized controlled trials. (For levels of evidence from strongest to weakest, see blog “I like my coffee (and my evidence) strong!”)

So after the two strongest levels of evidence what is the next strongest? #3 level is controlled trials without randomization. (Sometimes called quasi-experimental studies.)

Here’s an example of a controlled trial without randomization: I take two groups of mice and test two types of cheese to find out which one mice like best. I do NOT randomly assign the mice to groups. The experimental group #1 loved Swiss cheese, & the control group #2 refused to eat the cheddar. I assume confidently that mice LOVE Swiss cheese & do NOT like cheddar. What’s the problem with my conclusion? If you want to know, then read on!swiss cheese

In my mouse Controlled Trial Without Randomization, the groups were formed by convenience and Not randomly assigned. Thus, any difference in outcomes between groups might be related to some pre-existing difference between groups. My outcome of mice loving Swiss & hating Cheddar might have nothing to do with the experimental treatment.   In fact, I did not know that all my mice in the Swiss cheese group #1 hadn’t eaten in 2 days, and my mice in the cheddar group #2 had just had a full lunch. Ooops.

On the other hand if I had randomly assigned all the mice to two groups, then I could be relatively confident that all little differences between group members were evenly distributed to both groups, so that the groups were equivalent. My two mouse-groups would have probably ended up with a pretty even distribution of both hungry and not-so-hungry mice.   Then if my Swiss cheese group devoured the Swiss and my cheddar group rejected the cheddar, I could be more certain that mice love Swiss and dislike cheddar.

Happy evidence hunting!