SUSAN B. FOWLER, PHD, RN, CNRN, FAHA

Getting Started: What’s Out inthe Literature and Is It Any

Good?

Literature

Research Critique

Is not synonymous with “criticize”Examines the strengths, weaknesses,

meaning, and significance of the study (substantive and theoretical dimensions)

Be objective and realistic in identifying the study’s strengths and weaknesses

Important Points

All studies have weaknesses or flawsResearch is critiqued to broaden

understanding, improve practice, and provide background for conducting a study

The critique process involves comprehension, comparison, analysis, and evaluation

Cochrane Systematic Reviews

Cochrane Library www3.interscience.wiley.com/cgi-bin/mrwhome/106568753/HOME

The Cochrane Collaboration. Oxford: Update Software; 1996-. Updated quarterly.

Cochrane Database of Systematic Reviews (Cochrane Reviews) 'Gold Standard' for high-quality systematic reviews Full-text included in Cochrane Library Cochrane Reviews includes complete reviews and

protocols (reviews that are still in progress) Cochrane Reviews abstracts are in PubMed

More Reviews

Database of Abstracts of Reviews of Effects (Other Reviews - DARE) prepared by the National Health Service Centre for

Reviews and Dissemination, University of York, England

Complements the Cochrane Reviews by offering a selection of quality assessed reviews in those subjects where there is currently no Cochrane review

Brief critical appraisals of previously published reviews of the effects of health care

Structured abstracts, not full-text DARE not indexed in PubMed, but original research

articles may be Also available at no charge on the web from

University of York | www.crd.york.ac.uk/crdweb/

Other Systematic Reviews and Meta-analyses

PubMed MEDLINE - Systematic Reviews | www.ncbi.nlm.nih.gov/entrez/query/static/clinical.shtml access: part of PubMed's Clinical Queries (linked on

PubMed Home and Advanced Search pages) Identifies systematic reviews and other similar types of

studies found in biomedical journals included in PubMed database

No evaluation of comparative quality of different reviews on a topic

Abstracts supplied by authors/journals. No separate evaluation of quality of research

Identify systematic reviews in the biomedical area - gathers together much larger collection than other evidence-based practice resources

Evidence Guidelines/Summaries

BMJ Clinical Evidence | www.clinicalevidence.com/ Compendium of evidence on the effects of clinical interventions Summarizes the current state of knowledge, including knowns and

unknowns, based on thorough search Categorizes interventions as beneficial, likely beneficial, no known

benefit, harmful ... DynaMed | www.ebscohost.com/dynamed

Best available evidence summaries for nearly 2000 topics Clinical reference tool developed for use at the 'point-of-care' Outline format to quickly identify key conclusions Updated daily

Other Resources USPSTF Guidelines | www.ahrq.gov/clinic/prevenix.htm AHRQ Evidence Reports | www.ahrq.gov/clinic/epcix.htm

FPIN Clinical Inquiries included in Journal of Family Practice | www.jfponline.com and American Family Physician | www.aafp.org/afp/

RCTs, Case Cohorts, Control Studies

PubMed | (pubmed.gov ) note: Filtered by publication type, but not quality Clinical Queries - Uses preconfigured search strategies to

retrieve research-based citations on clinical topics in the areas of therapy, diagnosis, etiology, or diagnosis

Use Limits to search by specific publication type (e.g. meta-analysis, randomized controlled trial, review)

Cochrane Library | www3.interscience.wiley.com/cgi-bin/mrwhome/106568753/HOMEThe Cochrane Collaboration. Oxford: Update Software; 1996-. Updated quarterly. Cochrane Central Register of Controlled Trials (Clinical

Trials) Bibliography of controlled trials as part of an international effort to

hand search the world's journals Includes reports published in conference proceedings and in many other

sources not in PubMed or other bibliographic databases

Content of Research Reports

The AbstractThe Introduction (review of the literature,

theoretical framework, significance of and need for the study)

The Methods SectionThe Results SectionThe Discussion SectionThe References

The Beginning

The title Could you tell what the article was about by reading

the title?

The abstract Includes a brief description of the problem How the study was done (methodology) The results Conclusions

Next Steps

The Problem Is it clear what the problem the authors are trying to solve?

Review of the Literature Do the articles relate to the problem? Is it organized, broad to specific? Does it tell a story? Comprehensive and current? What years are covered in the

ROL?Research Question/Aim/Purpose/Hypothesis

Do authors pose a research question or hypothesis? Is it explicitly stated what the aim or purpose of the study is?

Design Is the design stated? Does the design flow from the research question or aim? Did the authors explain why they choose this research design?

QuantitativeQuantitative QualitativeQualitative

Analysis of numerical data Experimental Quasi-experimental Comparative Longitudinal Correlational

Analysis of data such as words (e.g., from interviews), pictures (e.g., video), or objects (e.g., an artifact) Grounded theory - social

processes Phenomonology – lived

experience Ethnography – culture Historical

Design

The Journey Continues

Sample Is the population described? Is the sample method, or how the sample was chosen

described? Is the sample size right for the analysis? Was a power

analysis done to determine sample size? Were standards for protection of human subjects

discussed?Tool

Was the tool created by the authors or already established?

Is a copy of the tool included in the article? Is reliability discussed? Is validity discussed?

ValidityValidity ReliabilityReliability

Extent to which the tool measures what it was intended to Content Criterion related construct

Results are repeatable and consistent Internal consistency Test-retest Inter-rater

Tool, Instruments, Questionnaires, and More

Power

The probability that a statistical test will detect a significant difference that exists - the risk of a Type I error can be calculated using power analysis.

Level of significanceSample sizePower - acceptable level is .80Effect size - the degree to which the null

hypothesis is false

Effect Size

An estimate of how large the treatment effect is, that is how well the intervention worked in the experimental group compared to the control group (intervention studies)

The larger the effect size, the stronger are the experimental intervention’s effects.

Effect size for intervention studies: .2 = small effect .5 = medium effect .8 = large effect

Getting Closer to the End

Methodology Are methods of data collection sufficiently described? Is the time frame when the study occurred described?

Data Analysis Is information presented sufficient to answer the

research question(s)? Were statistical tests used to analyze the data? Were values obtained from the analysis? Was statistical significance reported? Are the results explained? Are tables and figures easy to understand and

informative?

Confidence Intervals

Probability that a value will fall within a range of variables

The larger the CI the less precise the measurement of that variable

A very wide interval may indicates that more data should be collected before anything very definite can be said about the parameter

95% CI most common

The End

Discussion Is a discussion section presented? If yes, are the results compared with the literature

review?

Conclusions Are conclusions clearly stated? Are conclusions directly related to the results? Do the findings add to the present nursing knowledge? Are study limitations identified? Did authors make recommendations for further

research? Carlson, J. (1999). J Emerg Nurs, 25, 330-332.

References

Relevance (extent to which the reference bears on the research question)

Primary sources (descriptions of studies written by the researchers)

Secondary sources (descriptions of studies written by someone other than the original researcher)

Opinion and anecdotal

Level of Significance

The researcher does not know when an error in statistical decision making has occurred. The researcher can control the risk of making a Type I Error by setting the level of significance.

Level of Significance (alpha level) is the probability of making a Type I Error or the probability of rejecting a true null hypothesis.

Level of Significance

Usual level set at .05 (willing to accept the fact that if the study were carried out 100 times, the decision to reject the null hypothesis would be wrong 5 times)

If researcher wants to have smaller risk of falsely rejecting null hypothesis, set at .01.

Decreasing risk of making Type I Error increases risk of Type II Error.

Findings are significant or not significant.

Clinical Significance

Related to practical importance of the findings

No common agreement in nursing about how to judge clinical significance Effect size? Difference sufficiently important to

warrant changing patient care?

Clinical Significance

Who should judge clinical significance? The patients and their families? The clinician or researcher? Society at large?

Clinical significance is ultimately a value judgment

Research Journals

Examples of peer reviewed / refereed journals: Nursing Research, Advances in Nursing Science, Applied Nursing Research, Clinical Nursing Research, Western Journal of Nursing Research

Example of Peer Reviewed online resource: Medscape

Peer Review – Look for statement in first few pages of journal that it is peer reviewed. Content is “reviewed” by experts in field before publication

Let’s Get to Work – Critique in Action!!