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THE JOURNEY TO EVIDENCE-INFORMED NURSING PRACTICEChoosing the most appropriate evidence to answer questions by Maureen Dobbins
In my previous column, I addressed the importance of formulating a clear and concise practice- or policy-based question. I also described the necessary components of a question. In this column, I discuss how a practice- or policy-based question identifies the type of research evidence needed to answer it. To facilitate understanding, I will use very straightforward examples. In actual practice, however, multiple types of evidence will likely be needed for any given practice- or policy-based decision, meaning that more than one research design would be appropriate. Let’s return to the questions posed in the previous column:
Take a moment to consider how these questions differ from one another and how you might go about answering them. Note that a different research design is necessary to answer each question in the most rigorous and appropriate way possible. Can you identify the type of research each question will require? The underlying goal of the first question is to determine if support provided by APNs to newly diagnosed breast-cancer patients helps those patients navigate the health care system. We want to know if the intervention (APN support) is effective in achieving a certain outcome (improved navigation). When researchers are interested in effectiveness, the most appropriate approach is a scientific experiment—in this case, a study that compares two groups before and after each is exposed to the intervention. A randomized controlled trial (RCT) is the most rigorous research approach for answering this question, because an RCT ensures that the only difference between those in the intervention group and those in the control group is the intervention itself. While it is not always feasible or ethical to conduct an RCT, it is the only research design that allows us to say with confidence that differences between groups are the result of an intervention. In summary, if your practice- or policy-based question is concerned with identifying if an intervention works, you should seek out effectiveness studies. The purpose of the second question is to determine if exposure to a certain factor (a diet high in fiber) results in fewer events (myocardial infarctions). In this instance, we are not interested in the effectiveness of an intervention, but rather the relationship or association between a factor and an event—in this case, dietary fiber and myocardial infarctions. Studies that focus on association between two or more factors are known as studies of causation. Similar to studies of effectiveness, the design that gives us the most confidence when looking for associations is an RCT. In most instances, however, RCTs are not feasible, practical or appropriate for that purpose. Take, for example, smoking and lung cancer. While an RCT would give us the greatest confidence in stating that there is an association between smoking and lung cancer, it would not be feasible or ethical to randomly allocate people to either a smoking or nonsmoking group. The next most rigorous design for investigating the possibility of association is a cohort study. A cohort study allows us to examine—over time—the development of lung cancer in two groups, those who smoke and those who don’t. However, sometimes the development of an outcome such as lung cancer takes so long that a cohort study is also not feasible. In such instances, case-control studies are conducted to compare cases (people diagnosed with an outcome) with controls (people who don’t have that outcome) with regard to whether or not they smoke. In summary, if your practice- or policy-based question focuses on identifying relationship between factors, you must seek out studies of causation. The purpose of our final question is to explore and understand what happens to a certain population (women with substance-use issues and their children) when they utilize the health care system (phenomenon). The main focus of the question is to understand experiences. When the focus is on understanding experiences, we use qualitative research studies. From our question above, we will gain a much deeper understanding of a phenomenon by hearing about lived experiences of these women and their children. There are several qualitative research designs and, similar to quantitative studies, different designs answer different questions. For our question, the appropriate research design is phenomenology, as this approach seeks to gain greater understanding of the lived experiences of patients. Future columns will explore in greater detail the most commonly used qualitative research designs. In summary, if your practice- or policy-based question focuses on understanding lived experiences of patients, you should seek phenomenological studies. In this column, we have identified three types of research questions and the most appropriate research design to address each question. It is important to note that there are many more types of research questions than the ones described here. More thorough discussions of all types of research questions can be found in the many evidence-based nursing textbooks available. Determining which research design is most appropriate for answering a specific question is important, but it is just one step in the evidence-informed decision-making process. Identifying different research designs is necessary because different criteria exist to assess how well a study was conducted. Future columns will discuss in greater detail how one goes about assessing the quality of various types of research studies. Earlier in this column, I asked you to identify what types of research questions we were using. How did you do? Reinforce these concepts by developing other practice- or policy-based questions, keeping in mind the three components of a good question, discussed in my previous column. Then take the next step by identifying the type of research question you have asked and what research design is best for answering it. In my next column, I will provide useful hints for identifying high-quality research evidence. RNL Maureen Dobbins, RN, PhD, associate professor at McMaster University School of Nursing in Hamilton, Ontario, Canada, is a founder and primary investigator for www.health-evidence.ca, a free, searchable online registry of public health review evidence that saves researchers time and effort in locating, screening and assessing the quality of evidence for improved decision making. Dobbins holds cross appointments with the School of Rehabilitation Sciences and the City of Hamilton Public Health Services. |
How does support (intervention) from advanced practice nurses (APNs) impact the ability of newly diagnosed breast cancer patients (population) to navigate the health care system (outcome)?