Searching for Clinical Guidelines, Algorithms, and Mixed Methods Studies: What's Wrong with PICO?

Background Information: The Population-Intervention-Comparison-Outcome (PICO) format has often been promoted in nursing as the best method to formulate a clinical question in seeking evidence-based practices for specific patient problems and populations. Although helpful in determining best interventions based on quantitative research, the PICO format less readily lends itself in projects or papers involving quality improvement, the search for clinical guidelines or algorithms, mixed methods studies or qualitative research. The PICO framework also assumes the comparison of two interventions rather than three or four.

Description:  PICO questions should be well defined with specific populations described, focused interventions with their comparative groups, and the outcomes of interest. Interventions are compared with either an active or inactive control intervention (Cochrane, 2011). No treatment is an example of an inactive control intervention. Comparison of meditation compared to no meditation as a method of lowering blood pressure would be an example of inactive control. An active control measure would be the comparison of interventions, for example, the use of meditation compared to yoga as blood pressure reduction interventions. The PICO framework also assumes the comparison of two interventions rather than three or four. Continuing with this example, how effective is meditation compared to yoga compared to prayer. A three or more comparison group is rarely found in most evidence-based practice textbooks or the nursing literature when it may very well be an appropriate format in initial attempts to locate evidence.

Huang and colleagues (2006) identified several challenges in using the PICO structure format. They discuss the difficulty in representing some clinical questions using a PICO framework. The practice that a well focused clinical question using well-articulated PICO elements is the sole key to efficiently locating high-quality evidence and also central to making evidence-based clinical decisions is debated. Clinical questions that are focused with known interventions and a clear outcome lend themselves best to the PICO format. They argue that the PICO question framework appears to be best suited for therapy or intervention clinical questions that are focused or specific in nature. In support of PICO, specific components of this framework do provide the key word search strategy that can yield more precise results when used correctly and appropriately. However, a different search strategy must be used in order to locate various forms of research and evidence-based clinical practices.

To date, evidence-based guidelines are becoming more prolific in the literature. Guidelines are generally comprised of a variety of evidence-based resources. These may include meta-analyses, randomized controlled trials, and experimental and quasi experimental studies. These guidelines are published by notable medical and nursing organizations such as the American Heart Association, Society for Gastroenterologists and the American Association of Critical Care Nursing and provide a high level of evidence as they form the basis of total patient care for a specific practice or disease entity. The PICO format may lend itself to one or two aspects of these guidelines but may not address the guidelines in total. Therefore, valuable evidence may be lost in the search process unless one is already aware that such guidelines exist. Evidence-based bundles and algorithms are increasingly used in clinical settings where appropriate. These comprise evidence-based practices that are bundled together to assist in the decision making process. Bundles such as that for ventilator-associated pneumonia are the gold standard in caring for patients on mechanical ventilation. Medication algorithms for the initiation and maintenance of glucose control are now considered evidence-based standard practice. The initiation, diagnosis, and management of acute coronary syndrome and stroke are other examples of lengthy evidence-based guidelines found in the literature and online. A search strategy for the location of such guidelines and algorithms will be proposed in the presentation.

Although the PICO format may be modified to include qualitative research, other formats such as Sample-Phenomenon of Interest-Design-Evaluation-Research Type (SPIDER) as proposed by Cooke, Smith & Booth (Qualitative Health Research, 2012) are being published. The authors devised the SPIDER method to better ascertain metasynthesis studies and mixed methods studies which are difficult to find under the PICO format. Specific search strategies for qualitative studies will be discussed in the presentation as well as how mixed methods studies may be located.

Students or practicing nurses initially learning the evidence-based retrieval process may find that the PICO framework is best suited to understanding this process and its basic premise. Once the student or nurse has enough background information or has an understanding of guidelines and algorithms, then the search strategy may need to change in order to locate evidence-based bundles, guidelines, and algorithms. These summarized evidence-based practices are often included in the electronic medical record for purposes of implementation and documentation and also in the computerized provide order entry. Implementation of the bundle or algorithm may then also be monitored and assessed as aggregate data for various reporting organizations and quality improvement or quality control.

Summary Recommendations: Leveling of the evidence-based process within the undergraduate curriculum should occur as the student advances from specific patient care to a population of care for patients with common clinical problems. It is debatable whether clinically-focused Undergraduate and Masters’ level projects or papers and clinicians new to the evidence-based retrieval process should first focus on the search process for evidence-based guidelines and algorithms which are considered filtered sources of evidence. Or should the PICO approach initially serve this purpose? A non-PICO approach may be best suited for advanced practice nurses responsible for diagnosing and treating patients in the in-patient or out-patient setting. If a guideline or algorithm cannot be located via the traditional search process, then the use of the PICO format would be more appropriate in locating evidence-based practices and answering clinical questions.

The pros and cons for using the PICO format for clinically-focused papers and projects will be presented along with exemplars. Alternatives to PICO will be used as a focus for discussion. It is important for both educators and clinicians to recognize when the PICO format is the appropriate tool to use when searching for research studies and evidence-based practices and to recognize that other search strategies may need to be utilized and/or developed to account for other sources of evidence. Nurse educators and clinicians, along with professional librarians who have expertise in the literature retrieval process, may well develop different retrieval formats for evidence-base practices in the future.