Evidence-Based Medicine (EBM) is a clinical practice approach for medical practitioners to make quality clinical decision making. Today, the approach of Evidence Based Practice (EBP) is not limited to medical and surgical practice but also applies to broader clinical fields in healthcare such as nursing, midwifery and allied health.
To achieve the best patient outcomes, evidence alone is not enough. Evidence-based practice (EBP) consists of the following 3 elements:
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Reference: Sackett, D. L., Rosenberg, W. M., Gray, J. M., Haynes, R. B., & Richardson, W. S. (1996). Evidence based medicine: what it is and what it isn't. BMJ, 312(7023), 71-72. |
What are the benefits in general from Evidence-Based Practice in healthcare?
Achieve the highest quality care and the best patient outcome Reduce healthcare costs Increase clinician empowerment and role satisfaction Reduce turnover rate
References: Department of Health, Victorian Government. (2021). Implementing evidence-based practice fact sheet for clinicians. Access: https://www.health.vic.gov.au/patient-care/implementing-evidence-based-practice Regional Office for Europe, World Health Organisation. (2017). Facilitating evidence-based practice in nursing and midwifery in the WHO European Region. Access WHO-EURO-2017-5314-45078-64291-eng.pdf |
The EBP Process includes the following 5 steps:
Read the article below for an overview of the EBP process. Click on the orange tabs above to learn more about each step. From the tab of the last step, you will also be provided with an example of the whole EBP process in the context of palliative care in aged care setting.
Use PICOTT, a mnemonic for the key components of a clinical question, which can help to structure well-built answerable clinical question(s).
Learn more about Learn more about
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Specific type(s) of research provide better evidence for answering specific type(s) of clinical question. The research pyramid below shows the different level of evidence in terms of the type of research:
What are Systematic Reviews and Meta-analyses? Cochrane. (2016, January 28). What are systematic reviews [video]. YouTube. https://youtu.be/egJlW4vkb1Y Learn about the process of a Systematic Review and Meta-analysis from the Users Guides to the Medical Literature published by JAMAevidence Learn about Meta-analysis in details from the literature: Haidich A. B. (2010). Meta-analysis in medical research. Hippokratia , 4(Suppl 1), pp.29-37. Example of an systematic review and meta-analysis:
What are Randomised Controlled Trials?
Cochrane Austria. (2020, July 21). Randomised Controlled Trials [video]. YouTube. https://youtu.be/XvWmfLwC9XA Learn about Randomised Controlled Trial from the literature: Akobeng, A.K. (2005). Understanding randomised controlled trials. Archives of Disease in Childhood, 90(8), pp. 840-844. What are single randomised controlled trials compared to a gold standard? a single blind study means the participants/patients do not know which group they have been assigned to. A "gold standard" basically means the RCTs that are truly randomised and double blind. Example of a single-blind,randomised controlled trial article for answering Diagnosis type of clinical research question by a diagnostic study: Hollis, C., Hall, C.L. & Guo, B. et. al..(2018). The impact of a computerised test of attention andactivity (QbTest) on diagnostic decision-making in children and young people with suspected attention deficit hyperactivity disorder: single-blind randomised controlled trial. Journal of Child Psychology and Psychiatry, 59(12), pp. 1298-1308. doi:10.1111/jcpp.12921.
What are Observational Studies? Cochrane Austria. (2021, April 20). Observational Studies [video]. YouTube. https://www.youtube.be/BYc3zCqdlVs Learn about the 3 main types of observational studies: Cohort Studies, Case-Control studies and Cross-Sectional Studies. |
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Identify Key Concepts Sources of the key concepts can be identified from your PICO and the answerable clinical question as well as your knowledge on your research topic. |
Your answerable clinical question and PICO contains the key concepts of your research. Use those key concepts to start identifying related terms, synonyms (including variant spellings of medical terms) and related highly relevant concepts you would like to include in your search.
The following example shows you how to turn a PlCO and clinical question into a key concepts and related terms table:
| Scenario |
Ms. C, has been newly diagnosed with Type 2 diabetes and obesity. She is 45 years old and has a family history of diabetes. She dosn't want to spend the rest of her life on drugs. Her doctor Dr. K. thinks she may be able to control her diabetes with diet and exercise and refers Ms. C to a nutritional consultation to discuss a low-carbohydrate diet. Ms. C later on did a search on the internet and found that some government authorities recommend a low fat diet. Now she is confused and calls Dr. K. to ask him which diet is really better for keeping her off medication. Dr. K. told her that he needs to review the current evidence before getting back to her. |
| PICO |
P - middle age female Type 2 diabetic patient with obesity I - low carbohydrate diet C - low fat diet O - managing early-stage Type 2 diabetes without medication |
| Clinical Question / Research Question | Is a low carbohydrate diet more effective than a low fat diet for managing Type 2 diabetes without medication? |
| key concepts | type 2 diabetes | obesity | low fat diet | low carbohydrate diet |
| related terms / synonyms | overweight | mediterranean diet |
However, the key-concept and related-term table is not finalised at this stage. When you make use of the next tip to look up Subject Headings, you may find more related terms and concepts for your evidence-based research. Let's check out the next tip: Use Subject Headings to learn more.
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Use Subject Headings Subject headings are a controlled vocabulary or thesaurus used to index the key concepts of articles. Using Subject Headings in your search will enhance the effectiveness of your search and help to ensure retrieval of relevant articles. |
Each bibliographic database has their own specific Subject Headings controlled vocabulary used to index the key concepts in articles. How Subject Headings are searched and applied will vary depending on the databases being used. The following table shows you the main bibliographic databases with examples of different subject headings used for describing the same search term.
| Databases | Subject Headings / Indexing Systems | Example Term | Subject heading used |
| PubMed, Cochrane Library, Medline, Ovid Nursing Database | Medical Subject Headings (MeSH) | low carbohydrate diet | Diet, Carbohydrate-Restricted |
| APA PsycInfo | APA Thesaurus of Psychological Index Terms | low carbohydrate diet | No subject heading for this but you can still search "low carbohydrate diet" as a keyword |
| Embase, Emcare | EMTREE Subject Headings | low carbohydrate diet | low carbohydrate diet |
| CINAHL Complete | CINAHL Subject Headings | low carbohydrate diet | Diet, Low Carbohydrate |
The videos below provides guidance on how to apply Subject Headings in different platforms:
| Platform | Where to look up Subject Headings and/or how to apply Subject Headings in the specific platform |
| PubMed |
PubMed Subject Search: How it works (U.S. National Library of Medicine, 2020) |
| Cochrane Library |
Searching the Cochrane Library (including how to look up MeSH terms) (Cochrane Training, 2019) |
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Ovid Emcare, Medline, Embase, APA PsycInfo, Ovid Nursing Database |
Mapping terms with Subject Headings in Advanced Mode of Ovid platform - using Medline as an example (OvidWoltersKluwer, 2021) These databases on the Ovid platform each use their own individual thesaurus. The Map Term to Subject Heading feature in Ovid will map your keyword to the most appropriate subject headings in the relevant thesaurus for the database selected. |
| EbscoHost: CINAHL Complete | Using the CINAHL/MeSH Subject Headings Feature in EBSCOhost (EBSCO, 2021) |
To access the databases listed above, please visit our Databases page.
References:
Cochrane Training. (2019, May 14). Searching the Cochrane Library [Video]. Youtube. https://www.youtube.com/embed/HLD7w63rqB0?start=74
EBSCO. (2021, November 4). Using the CINAHL/MeSH Subject Headings Feature in EBSCOhost [Video]. EBSCO Connect. https://connect.ebsco.com/s/article/Using-the-CINAHL-MeSH-Headings-Feature-in-EBSCOhost-Tutorial?language=en_US
OvidWoltersKluwer. (2021, September 29). Mapping in Advanced Mode [Video]. YouTube. https://www.youtube.com/watch?v=3736KB9Udn
U.S. National Library of Medicine, (2020, November 30). PubMed Subject Search: How it works [Video]. PubMed.gov, U.S. National Library of Medicine. https://www.nlm.nih.gov/oet/ed/pubmed/quicktours/topic_how_it_works/index.html?_gl=1*10vieks*_ga*OTc5Nzk1NjMwLjE2NDgxNzg5NzU.*_ga_7147EPK006*MTY0ODE4MjI2MS4yLjEuMTY0ODE4Mzk2OC4w*_ga_P1FPTH9PL4*MTY0ODE4MjI2MS4yLjEuMTY0ODE4Mzk2OC4w=
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Apply Search Operators Make use of Boolean operators - AND and OR - to combine key concepts and Subject Headings to build your search strategies for a narrower or broader search result. |
The "OR" operatoris used when searching for related terms or synonyms. |
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. When applying the "OR" operator, it will broaden your search. When building your search strategy, it is recommended that to start with applying "OR" operator to connect between the key concepts with their related terms or synonyms first. |
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. Then applying the "AND" operator which used to connect different key concepts and narrowing down the number of search results. The "AND" operatoris used for connecting between different key concepts. |
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When using the AND operator it is recommended to initially combine only 2 key concepts so you can assess the number and contents of search results before adding additional search concepts.
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Using Search History via Ovid platform (applies to Medline, APA PsycInfo and Embase) |
Using Search History via EBSCO platform (applies to CINAHL Complete) |
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OvidWoltersKluwer. (2021, April 6). Ovid Help Mapping and Control Vocabulary [Video]. YouTube. www.youtube.com/watch?v=ihyY-gsGjDw OvidWoltersKluwer. (2018, April 24). Advanced Search on the Ovid Platform [Video]. YouTube. https://youtu.be/409Ik8aLF5M |
EBSCO Tutorials. (2019, February 28). Using the CINAHL/MeSH Headings Feature in EBSCOhost [Video]. YouTube. https://www.youtube.com/watch?v=eJJPp9yAIoA&t=3s EBSCO Tutorials. (2022, Oct 05). Using the EBSCOhost Search History - Tutorial [Video]. YouTube. https://www.youtube.com/watch?v=pM0A5Gw-Trs |
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Apply Limits A range of limits can be applied to your search strategy. You may restrict your search, for example, to specific types of articles, and/or to articles published within a specific date range. Applying such limits to your search helps to ensure results that are current and limited to the types of research which are best for answering the type of clinical question you asked. |
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Refining Search Strategy Limits via Ovid platform (applies to Medline, PsyINFO and Embase) databases |
Applied Search Limits via EBSCO platform (applies to CINAHL Complete) database |
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OvidWoltersKluwer. (2016, May 28). Refining Search Strategy Limits Tutorial [Video]. YouTube. https://www.youtube.com/watch?v=TfPoX5wzdXY&t=85s |
Please watch from 1 mins 25 sec EBSCO Tutorials. (2022, September 8). CINAHL Databases - Advanced Searching Tutorial [Video]. YouTube. https://www.youtube.com/embed/MMNzR03--90 |
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Check out the Research Design and Research Bias page The type of research-based folding tabs below brings |
Check out the Critical Appraisal session to see which questions |
Check out the next tab: Step 4 & 5: Apply and Assess |
Various questions addressing different research design aspects and statistical measurements, can be used to assess the risk of bias and how precise the results are. Unfold the tabs below to view the list of questions and the Cochrane videos relevant to the different types of research.
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Questions to determine the validity of a systematic review & meta analysis: 1. Did the review address a clinical question explicitly? 2. Were the selection criteria for articles stated clearly and are these criteria reproducible? 3. Were the relevant studies searched exhaustively? (a minimum of 3 academic databases is recommended and the cited references of each articles should also be checked) 4. Was the risk of bias of each collected study assessed? 5. Was the Confidence in Effect (95% CI) addressed?
The following video demonstrate how to critically appraise a systematic review and meta-analysis: Cochrane Common Mental Disorders. (2019, March 30). 2. Systematic reviews and meta analysis [video]. YouTube. https://www.youtube.com/watch?v=NijldKW32H4 |
How to read a forest plot - a meta-analysis of the results of research studies
The included studies are listed on the left. Each study is represented by a horizontal line with a square on top of the line. The horizontal lines of individual studies represents the level of spread of data within a confidence interval (usually a 95% CI) for the individual studies. The wider the line is, the less precision the study has compared to those studies with a narrower 95% CI. The square on each study's horizontal line represents the weight of each individual study. Studies with a higher weight usually have a larger square representing the effect size. The middle line (also known as Line of Null Effect) represents there is no statistical and clinical difference between an intervention/exposure group and a control group. The horizontal line at the bottom represents the level of risk ratio. The studies presented closer to the left side from the middle line = a higher risk; the studies presented closer to the right side from the middle = a lower risk. The left side area from the middle line reflects the collective research results showing evidence of benefit from implementing the intervention whereas the right side area reflects the collective research results that do not support evidence of benefit from the intervention for the patient group researched. The diamond represents the overall estimate / the average of the results. By looking at meta-analysis therefore, you can understand the whole picture of the collective research results, whether there is evidence to show an intervention is relatively beneficial compared to alternative practice(s) or not, and how well the sample size of individual studies is representative. This is why a systematic review with meta-analysis is better evidence compared to a systematic review alone. |
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Questions for Critical Appraisal of Randomised Controlled Trials (RCTs): 1. Were patients randomised? 2. Was group allocation concealed? 3. Were patients in the treatment and control groups similar with respect to known prognostic factors? 4. Were people in 5 important groups (patients, care givers, data collectors, adjudicators, data analysts) aware of the group allocation? 5. Was follow-up completed? 6. Was an intention-to-treat analysis performed? 7. Was the trial stopped early? |
Cochrane Common Mental Disorders. (2019, March 30). 3. Randomised controlled trials [video]. YouTube. https://www.youtube.com/watch?v=FlQVQz5d02s |
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Question to assess the validity of a Cohort Study: 1. Was the sample of patients representative, defined clearly, and matched with the population group/patient problem in the PICO? 2. Were patients within groups similar with respect to known prognostic factors? 3. Was follow-up sufficiently completed? 4. Was an intention-to-treat analysis performed? 5. Did the study finish early or as planned? 6. Were the outcome criteria objective and unbiased? (Confidence in Effect (CI and P-value) and RR assessed?) |
Cochrane Common Mental Disorders. (2019, March 30). 4. Cohort studies [video]. YouTube. https://www.youtube.com/watch?v=uK7hnthu130 |
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Questions to assess the validity of a Case-control Study: 1. Was the sample of patients representative, defined clearly, and matched with the population group/patient problem in the PICO? 2. Were cases within groups similar with respect to known prognostic factors, how the cases were selected and the selection criteria? 3. Was follow-up sufficiently completed? 4. Was an intention-to-treat analysis performed? 5. Did the study finish early or as planned? 6. Were the outcome criteria objective and unbiased? (Confidence in Effect (CI and P-value) and RR assessed?) |
Cochrane Common Mental Disorders. (2019, March 30). 5. Case control studies [video]. YouTube. https://www.youtube.com/embed/tmpy62VXtCs" |
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Questions to assess the validity of a Cross-sectional Study: 1. Was the sample of patients representative, defined clearly, and matched with the population group/patient problem in the PICO? 2. Were patient within groups / period of time chosen similar with respect to known prognostic factors? 3. Was follow-up sufficiently completed? 4. Was an intention-to-treat analysis performed? 5. Did the study finish early or as planned? 6. To what extent would the outcome be affected by chance? |
Cochrane Common Mental Disorders. (2019, March 30). 6. Cross-sectional studies [video]. YouTube. https://www.youtube.com/watch?v=muGA7FKekaU |
Toolbox:
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Understanding clinical papers / Written by David Bowers, Allan House, David Owens & Bridgette Bewick (2013) |
Guiding questions for Step 4: Apply
After reviewing the best available evidence, now it is time to ensure that results are highly related to and practical for your patient instead of just answering your clinical question in general. The following questions should be asked before deciding the treatment / intervention pathway which should bring the best patient outcome:
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Were the study patients similar to your patient? Were all important patient outcomes / alternative treatments considered? Does the likely treatment / intervention benefits outweigh the potential harm, if any, in your patient's case? Does the likely treatment / intervention conflict with your patient’s values and expectations? Is the preferred treatment available in the health care system? |
Guiding questions for Step 5: Assess
The final step of the EBP process is to assess your performance so that next time you could improve your evidence-based practice. The following questions can be used for guiding your reflection:
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Was the clinical question well-built and answerable? Was good evidence located effectively? Was the evidence appraised effectively? Is there evidence of new practice found in the literature? Would the new clinical practice potentially favour other patient outcomes and should be included in daily practice? Was the diagnosis, treatment or intervention successfully applied? Why did the patient not respond as well as expected to the treatment / intervention (if any?) How could clinical decision making be improved? |
A palliative care & aged care example of EBP process:
Informing care decisions with the best available evidence / CareSearch
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