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SoHP: Doctor of Nurse Anesthesia Practice Resources

Use for resources on DNAP topics.


PICO(T) is a mnemonic used to describe the five elements of a good clinical question. 

Pstands for Patient, Population, or Problem

Who is the patient(s) or population and what is their particular condition or healthcare problem?

  • Adult African-American patients with hypertension (age, ethnicity)
  • Elderly patients at risk for influenza (age)
  • Elementary school-age children with attention-deficit disorder (age)
  • Low-income Latino children exposed to second-hand smoke (age, ethnicity, economic status)
  • 45 y/o Asian woman with asymptomatic mitral valve prolapse (age, ethnicity, gender)

stands for Intervention  or Issue of Interest

What are the main interventions or exposures in my question?

  • Therapeutic: diet rich in fruits, vegetables, legumes, and low in salty snacks and sweets (for high blood pressure)
  • Preventive: influenza vaccination
  • Diagnostic: CT Scan (head injury)
  • Harm/Etiology: exposure to a Rx, disease, or other risk factor (second-hand smoke)
  • Prognostic factor: moderate to severe mitral regurgitation


 stands for Comparison Intervention or Group

Does your question include a "counter intervention" or exposure, e.g., a recognized standard, or the absence of treatment or exposure?

  • Therapeutic/Preventative: blood pressure medication, no influenza vaccination
  • Diagnostic: clinical observation only of patient with head injury
  • Harm Etiology: no exposure to cigarette smoke (absence of risk factor)
  • Prognostic factor: mild mitral regurgitation

Ostands for Outcome


Outcomes of interest from a clinical and patient perspective; what do you want to accomplish?

Will this intervention/exposure:

  • increase or decrease the risk of disease?
  • affect the accuracy of diagnosis?
  • improve quality of life?
  • lead to greater patient comfort
  • affect the rate of occurrence of adverse outcome, e.g., morbidity, mortality

Tstands for Time/Type

  • Time it takes to demonstrate a clinical outcome
  • What is the duration of your data collection?
    • Flu Season
    • Once weekly for 6 weeks
    • Within 3 months
  • Type of Question/Study
    • Therapy/Treatment
    • Diagnosis
    • Prognosis
    • Harm/Etiology

Your Librarian Recommends

Robb, M., & Shellenbarger, T. (2011). Strategies for searching and managing evidence-based practice resources. Journal Of Continuing Education In Nursing, 42(7), 461-466 6p. doi:10.3928/00220124-20140916-01

This article provides suggestions for strategies to aid in identifying search terms. Strategies also are recommended for refining searches by using controlled vocabulary, truncation, Boolean operators, PICOT (Population/Patient Problem, Intervention, Comparison, Outcome, Time) searching, and search limits.

Which articles are the "best"

stack of booksYou have your question, and you've got a great search strategy, but how do you know which articles are the "best"?

That depends on the type of information you are looking for:

  • Primary Sources: first hand evidence concerning a topic under investigation
  • Randomized controlled trials, cohort studies, case series, etc.

   Secondary Sources: summaries and analyses of the evidence derived from and based on primary sources

  •     Systematic Reviews/Meta-analyses, Qualitative Reviews, Practice Guidelines, etc. 

Evidence-Based Practice

Evidence-Based Practice (EBP) is the judicious use of the best research evidence (found in health sciences literature), clinical expertise (what the health provider knows), and patient values (what the patient wants and believes) to create a plan of action regarding patient care.

Recommended Links & Lists for EBP Research

Conducting Research

The EBP Process can be summarized in 6 steps:

  1. Ask focused questions
  2. Find the best evidence
  3. Evaluate the evidence
  4. Integrate evidence, expertise, patient preferences & values
  5. Evaluate and improve the above steps
  6. Disseminate the results & put into practice!

Adapted from: Melnyk, B. M., Fineout-Overholt, E., Stillwell, S. B., & Williamson, K. M. (2010). Evidence-based practice: step by step: the seven steps of evidence-based practice. Am J Nurs, 110(1), 51-53. doi: 10.1097/01.NAJ.0000366056.06605.d2

ASK: Good Clinical Questions

Two additional elements of the well-built clinical question are the type of question and the type of study. This information can help focus the question and determine the most appropriate type of evidence or study.

For a definition of study types see the Useful Definitions Tab on the EBP Page.

Common Question Types

THERAPY (treatment)

How to select treatments that do more good than harm and are worth the efforts and costs

Example of a Therapy Question           


  • Most frequently asked.
  • Questions about the effectiveness of interventions in improving outcomes in sick patients and patients suffering from some condition.
  • Clinician treatments are most likely medications, surgical procedures, exercise, counseling about lifestyle changes.    

Type of Study

Randomized controlled trial, cohort study


How to select and interpret diagnostic tests

Example of a Diagnosis Question


  • Questions about the ability of a test or procedure to differentiate between those with and without a condition or disease.

Type of Study

Prospective, blind comparison to a gold standard or cross-sectional

PROGNOSIS (forecast)

How to estimate the patient’s likely clinical course over time (based on factors other than the intervention) and anticipate likely complications of disease.

Example of a Prognosis Question


  • Questions about the probable cause of a patient’s disease or the likelihood that s/he will develop an illness.

Type of Study

Cohort study, case control, case series

HARM/ETIOLOGY (causation)

How to identify causes for disease (including iatrogenic forms)

Example of an Etiology Question


  • Questions about the harmful effect of an intervention or exposure on a patient.                                       

Type of Study

Cohort study, case control, case series

Adapted from: Fineout-Overholt, E. & Johnston, L. (2005), Teaching EBP: asking searchable, answerable clinical questions. Worldviews on Evidence-Based Nursing, 2, 157–160. doi:

Formulating Answerable Clinical Questions is the Foundation of EBP!

Every time we see a patient, we need new information about some element of the diagnosis, prognosis or management. Because our time to try to find this information is often limited, we need to be very efficient in our searching. To achieve this efficiency, we need to become skilled at formulating clinical questions.

  1. Start with the patient: clinical problems and questions arise out of patient care
  2. Translate the clinical questions into a searchable question using PICOT
  3. Decide on the best type of study to address the question
  4. Perform a literature search in the appropriate source(s)

Is your clinical question answerable?

  • "What is the best treatment for recurrent UTI in children?" is so broad that a meaningful answer is difficult to find due to the large number of articles you may retrieve addressing many possible treatments and clinical outcomes. 
  • "In children with recurrent UTI, is cranberry juice effective in reducing the number of recurrences?" is more focused and will lead to a doable search strategy. 

Express your clinical question in the PICO format

  • P - Patient or Population AND Problem
  • I - Intervention: a treatment, a diagnostic test, an exposure to a known or presumed risk factor, etc.
  • C - Comparison: treatment, placebo, gold standard diagnostic test, absence of risk factor, etc. 
  • O - Clinical outcome of interest
  • T - Time frame it should take you to determine whether your interventions had any affect or Type of Question Asked

The PICOT terms come from and should match your clinical question. 

ACQUIRE: The Best Evidence

Arrow pointing upSystematic reviews or meta-analyses are regarded as the strongest level of evidence on which to base treatment decisions, however, there are different levels of evidence for each kind of PICOT question.

Refer to the PICOT page on this guide for more information.

  • Level I: Evidence from a systematic review or meta-analysis of all relevant Randomized Controlled Trials (RCTs)
  • Level II: Evidence obtained from well-designed RCTs
  • Level III: Evidence obtained from well-designed controlled trials without randomization
  • Level IV: Evidence from well-designed case-control and cohort studies
  • Level V: Evidence from systematic reviews of descriptive and qualitative studies
  • Level VI: Evidence from single descriptive or qualitative studies
  • Level VII: Evidence from the opinion of authorities and/or reports of expert committees

As you move down this list, the study designs are less rigorous and allow for more bias or systematic error that may distract you from the truth. 


  1. Meta-Analysis is a statistical technique for combining the findings from independent studies to assess the clinical effectiveness of healthcare interventions.
  2. Systematic Review is a comprehensive, unbiased review of multiple research studies that tries to identify, appraise, select and synthesize all high quality research evidence relevant to that research question.
  3. Random Control Trial (RCT) is an experiment that delivers an intervention or treatment; subjects are randomly assigned to control and experimental groups, so it is the strongest design to support cause and effect relationships.
  4. Cohort Study looks at groups of patients who are already taking a particular treatment or have an exposure; subjects are followed over time, and then outcomes are compared with a similar group that has not been affected by the treatment or exposure being studied. 
  5. A Case Control Study looks at patients who already have a specific condition compared to people who do not have the condition. These studies rely on medical records and patient recall for data collection. 
  6. Case Series and Case Reports consist of collections of reports on the treatment of individual patients or a report on a single patient. 
  7. Literature Review is a scholarly analysis of a body of research about a specific issue or topic.

Adapted from Duke Library's EBP Tutorial: Introduction to Evidence-Based Practice

Your textbook covers the different clinical case studies used in evaluating and informing evidence-based practice. While not exhaustive, the most common case studies are: 

  • Systematic Review & Meta-Analysis
  • Randomized Controlled Studies or Trials
  • Case Series / Case Reports
  • Cohort Studies
  • Double Blind

Review the following PowerPoint for an overview of each case study in a nutshell:

 Where you look for information is determined by what kind of question you are asking.  One way of classifying your question is to ask whether you are seeking background information or foreground information.

 Background information is sought when a learner has general clinical questions regarding a topic such as what is the disorder; what causes it; how does it present; what are some treatment options.  These questions can be answered by using "background" resources such as textbooks (both in print and electronic) and narrative reviews in journals which give a general overview of the topic. 

Foreground information answers specific questions a clinician has regarding a specific patient.  Foreground resources can be divided into primary sources such as original research articles published in journals; and secondary sources such as systematic reviews of the topic, and synopses and reviews of individual studies.

APPRAISE: The Best Evidence

  Critical appraisal is a systematic process of analyzing research to assess methods, validity and usefulness. 


The key questions in critical appraisal are:

Why was the study done?

  • A clearly focused question should address population, intervention and outcomes.

What type of study was done?

  • The study design must match the question asked. Intervention questions are best answered with randomized controlled trials.

What are the study characteristics?

  • Use the PICO question format to help you answer the question. 

What was done to address bias?

  • Was the assignment of patients to treatments randomized?
  • Were patients, health workers and study personnel ‘blind’ to treatment allocation? 
  • Were all of the patients who entered the trial properly accounted for at its conclusion? Look for follow-up tables and whether patients were analyzed in the groups to which they were randomized. 
  • Were the groups similar at the start of the study?
  • Aside from the experimental intervention, were the groups treated equally?

What are the results and are the results valid?

  • Are the outcome measures relevant?
  • How large was the treatment effect? How precise was the estimate of the treatment effect?
  • Look for confidence limits and p values.

What conclusions can you make?

  • Are the results generalizable, that is, can the results be applied to my patients?  Were all clinically important outcomes considered? Are the benefits worth the harms and costs?
  • Are the results relevant to my situation? Patient population / similar definitions/protocols/health system similarities.

Adapted from: Voutier, C. (2013). Critical appraisal. Evidence Direct: A Service of the RMH Health Sciences Library. Retrieved 17 December 2015 from: