Nursing Research

Clinical and nursing practice questions can be broken down into the PICO(T) format, which breaks a question apart into searchable parts:

Population (P) – what individual or group are we interested in studying?
Intervention (I) – what is the action (intervention, treatment, etc.) we are considering taking?
Comparison (C) – to what other action (intervention, treatment, etc.) are we comparing the considered action?
Outcome (O) – what do we anticipate as the outcome?
Time (T) – how long will it take to reach the outcome?

• Note:  not all PICO(T) questions require the "TIME" component 

Potential PICO(T) Question Formats

In__[Population]__, how does __[Intervention]__ compared to __[Comparison]__ affect __[Outcome]__ within __[Time]__ ?

In__[Population]__, how does __[Intervention]__ compared to __[Comparison]__ influence/predict __[Outcome]__ over __[Time]__ ?

In__[Population]__, are/is __[Intervention]__ compared with __[Comparison]__ more accurate in diagnosing __[Outcome]__?

Are __[Population]__, who have  __[Intervention]__ compared with those without __[Comparison]__ at risk for/of  __[Outcome]__ over __[Time]__ ?
 

Sample PICO Question

Scenario:  A committee decides to conduct a case study to determine whether postoperative gum chewing for abdominal surgery patients can prevent postoperative ileus (lack of intestinal movement).

• P – Patients recovering from abdominal surgery
• I –  Gum chewing
• C – Not chewing gum
• O – Impacts post-operative ileus

PICO Question: “In patients recovering from abdominal surgery, is there evidence that suggests gum-chewing postoperatively, compared to not chewing gum, impacts postoperative ileus?”

Levels of evidence are assigned to studies based on the methodological quality of their design, validity, and applicability to patient care. The combination of these attributes gives the level of evidence for a study.  In nursing, the system for assigning levels of evidence is often from Melnyk & Fineout-Overholt's 2011 book, Evidence-based Practice in Nursing and Healthcare: A Guide to Best Practice. 

Depending on their purpose, design, and mode of reporting or dissemination, health-related research studies can be ranked according to the strength of evidence they provide, with the sources of strongest evidence at the top, and the weakest at the bottom:

Secondary Sources: studies of studies

A secondary source summarizes or quotes content from primary sources.

Systematic Review

• Identifies, appraises, and synthesizes all empirical evidence that meets pre-specified eligibility criteria
• Methods section outlines a detailed search strategy used to identify and appraise articles
• May include a meta-analysis, but not required (see Meta-Analysis below)

Meta-Analysis

• A subset of systematic reviews: uses quantitative methods to combine the results of independent studies and synthesize the summaries and conclusions
• Methods section outlines a detailed search strategy used to identify and appraise articles; often surveys clinical trials
• Can be conducted independently, or as a part of a systematic review
• All meta-analyses are systematic reviews, but not all systematic reviews are meta-analyses

Evidence-Based Guideline

• Provides a brief summary of evidence for a general clinical question or condition
• Produced by professional health care organizations, practices, and agencies that systematically gather, appraise, and combine the evidence

Meta-Synthesis or Qualitative Synthesis (Systematic Review of Qualitative or Descriptive Studies)

• a systematic review of qualitative or descriptive studies, low strength level

Primary Sources: original studies

Primary sources are written by the person who originated or is responsible tor generating the ideas published. 

Randomized Controlled Trial

• Experiment where individuals are randomly assigned to an experimental or control group to test the value or efficiency of a treatment or intervention

Non-Randomized Controlled Clinical Trial (Quasi-Experimental)

• Involves one or more test treatments, at least one control treatment, specified outcome measures for evaluating the studied intervention, and a bias-free method for assigning patients to the test treatment

Case-Control or Case-Comparison Study (Non-Experimental)

• Individuals with a particular condition or disease (the cases) are selected for comparison with individuals who do not have the condition or disease (the controls)

Cohort Study (Non-Experimental)

• Identifies subsets (cohorts) of a defined population
• Cohorts may or may not be exposed to factors that researchers hypothesize will influence the probability that participants will have a particular disease or other outcome
• Researchers follow cohorts in an attempt to determine distinguishing characteristics