Evidence-Based Practice: Understanding the Process

Katherine J. Dontje MSN, APRN, BC


Topics in Advanced Practice Nursing eJournal. 2007;7(4) 

In This Article

Implementing Evidence-Based Practice: The Iowa Model

The Iowa Model of EBP was developed by Marita G. Titler, PhD, RN, FAAN, Director Nursing Research, Quality and Outcomes Management, Department of Nursing Services and Patient Care, University of Iowa Hospitals and Clinics, Iowa City, Iowa, and her colleagues to describe knowledge transformation and to guide implementation of research into clinical practice.[6]

The Iowa model highlights the importance of considering the entire healthcare system from the provider, to the patient, to the infrastructure, using research within these contexts to guide practice decisions. A number of steps have been identified in the Iowa model to facilitate NP engagement in problem identification and solution development as it relates to incorporating evidence findings into practice.

The first step in the Iowa Model of EBP is to identify either a problem-focused trigger or a knowledge-focused trigger that will initiate the need for change. A problem-focused trigger could be a clinical problem, or a risk management issue; knowledge triggers might be new research findings or a new practice guideline.

In the Iowa model, it is important for the NP to consider if the issue identified is a priority problem for the organization. Once the problem is identified and its priority determined, the second step is to review and critique relevant literature. If there is sufficient evidence to make a change in practice, the third step is to identify research evidence that supports the change in clinical practice. The final steps are to implement a change in practice and monitor the outcomes.

The concept of EBP goes beyond the NP and the patient -- it is important for it to be part of the organizational culture. Titler and associates[6] point out that the commitment to EBP needs to be at multiple system levels, from the clinician through to high-level management.[6] Thus, the NP needs to encourage and be a champion of the EBP process. One way to facilitate incorporation of EBP initiatives is to partner them with quality improvement initiatives. NPs need to understand the ways in which literature findings can be reviewed to determine if they are relevant to the population we serve and if the findings are clinically significant.[7]

As an illustration, a new guideline related to depression in primary care might be identified by an NP as a knowledge trigger. Even though depression is almost as common as hypertension, it is frequently undiagnosed and untreated, causing significant morbidity to individuals.[8] An organization might find this an important topic because of the increase in the use of healthcare services by depressed patients, who have a 50% to 100% higher utilization of healthcare services than patients without depression.[9]

The organization would have to agree that this knowledge trigger indicates a need for change in the healthcare delivery system. For this change to happen, the literature needs to have evaluated and reviewed, as well as the topic needs to be considered in the context of the population of patients served by the organization.

One of the most challenging issues in using EBP in the clinical setting is learning how to adequately frame a clinical question so that an appropriate literature review can be performed.[10] One method used is called the "PICO" model:

P = Who is the Patient Population?
I = What is the potential Intervention or area of Interest?
C = Is there a Comparison intervention or Control group?
O= What is the desired Outcome?

The NP needs to consider each of these components when developing a focused question.[4]

Exploring the evidence related to depression in the current example, the population of interest must first be determined to narrow the search. This involves considering both the patient and the setting of interest The NP needs to determine whether the population of interest is patients with depression in all age groups, or limited to adults, and if so, what is the age range considered for adults? The decision might be to limit the search question to the adult population above the age of 18 years. The setting also needs to be identified; in this case, for example, it will be primary care.

Refining and focusing the question includes articulating the definition of depression for this PICO question. The NP should consider whether the search will encompass all types of depression, including post partum depression and premenstrual dysphoric disorder (PMDD), or if the question should be limited to a specific type of depression. There are a variety of classifications of depression identified by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition - text revision (DSMIV-TR) including[11]:

  • Major depressive disorder (MDD);

  • Minor depression; and

  • Dysthymia.

As the NP further considers this question, exploration of the different clinical types of depression and which of these are important to the population of patients being served will need to be addressed.[7]

The next step in the PICO process is to determine the intervention or exposure that will be examined.[7] For the example discussed the NP will need to consider whether they are interested in depression screening, depression management, or both. The decision depends on the needs of the:

  • NP;

  • Patient population; and

  • Organization.

For this case example, we will assume that focus is depression screening. The 'C' part of the PICO question relates to whether there is a comparison intervention or control group. The groups being compared would be depression screening vs no depression screening.

The final component of the PICO process is what outcome the group wants to evaluate.[4] The NP will need to consider whether the outcomes, which will be the focus of the question, will be:

  • Patient vs provider outcomes; or

  • Short vs long term.

In the example of depression screening, provider outcomes could refer to evaluating whether there is a difference in management therapies related to depression care based on screening recommendations. A patient outcome might be to assess whether rates of depression decreased over time and, ultimately, whether the outcomes of depression care improved for this patient population.

Utilizing the components of the PICO process, the question formulated is: For adult patients older than the age of 18 years in primary care settings, does the evidence support whether screening vs not screening for MDD affects the provider management of individuals with depression? According to the Iowa Model of EBP,[6] once the question is clearly articulated, including all of the PICO components, then the NP needs to search the literature for appropriate evidence.


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