NR 503 Final Exam Study Info updated

NR 503 Final Exam Study Info updated Chamberlain College of Nursing NR503 Final Exam Study Notes • Be sure to review the terminology and concepts of the first four weeks: these concepts help to inform and support the last four weeks of the course. • All information listed on this review doc can be found in the course text, Gordis. Definitions of study designs: Chapter 10: Differentiate between the case-control and cohort studies. Ask yourself, which is used when, and why. the hallmark of the case-control study is that it begins with people with the disease (cases) and compares them to people without the disease (controls). cohort study, discussed in Chapter 9, which begins with a group of exposed people and compares them to a nonexposed group. What distinguishes the two study designs is whether the study begins with diseased and nondiseased people (case-control study) or with exposed and nonexposed people (cohort study). Primary, Secondary, Tertiary Prevention What are primary (remove disease risk factors eg immunizations, exercise), secondary (early detection and treatment eg. screening), tertiary prevention (reduce complications to reduce further deterioration eg. Beta blockers) measures? Case-Control: • Examine the possible relationship of an exposure to a certain disease • Identify group of individuals with the disease (cases) • For comparison, gather a group of people without that disease (controls) • Determine what proportion of the cases were exposed and were not • Also determine what proportion of the controls were exposed and not • Text: Thus, in a case-control study, if there is an association of an exposure with a disease, the prevalence of history of exposure should be higher in persons who have the disease (cases) than in those who do not have the disease (controls). • Ask yourself: Why is this important to the NP in primary care? How does this inform a provider’s decision-making? • Cohort Studies: In a cohort study, the investigator selects a group of exposed individuals and a group of nonexposed individuals and follows up both groups to compare the incidence of disease (or rate of death from disease) in the two groups If a positive association exists between the exposure and the disease, we would expect that the proportion of the exposed group in whom the disease develops (incidence in the exposed group) would be greater than the proportion of the nonexposed group in whom the disease develops (incidence in the nonexposed group). Chapter 13: Comparing Cohort and Case-Control Studies: See Figure 13-1 and 13-2 (busy pictures but hang in there) Chapter 13 comparison of studies - important to review Among the disadvantages of cohort studies is that they usually require large populations, and, in general, prospective cohort studies are especially expensive case-control studies have a number of advantages. They are relatively inexpensive and require a relatively small number of subjects for study. They are desirable when the disease occurrence is rare, because if a cohort study were performed in such a circumstance, a tremendous number of people would have to be followed to generate enough people with the disease for study. Because case-control studies often require data about past events or exposures, they are often encumbered by the difficulties encountered in using such data (including a potential for recall bias). Matching: Chapter 10: Text: A major concern in conducting a case-control study is that cases and controls may differ in characteristics or exposures other than the one that has been targeted for study. Matching is defined as the process of selecting the controls so that they are similar to the cases in certain characteristics, such as age, race, sex, socioeconomic status, and occupation. Matching may be of two types: (1) group matching and (2) individual matching. Group matching (or frequency matching) consists of selecting the controls in such a manner that the proportion of controls with a certain characteristic is identical to the proportion of cases with the same characteristic. Thus, if 25% of the cases are married, the controls will be selected so that 25% of that group is also married. This type of selection generally requires that all of the cases be selected first. After calculations are made of the proportions of certain characteristics in the group of cases, then a control group, in which the same characteristics occur in the same proportions, is selected. A second type of matching is individual matching (or matched pairs). In this approach, for each case selected for the study, a control is selected who is similar to the case in terms of the specific variable or variables of concern. For example, if the first case enrolled in our study is a 45-year-old white woman, we will seek a 45-year-old white female control. If the second case is a 24-year-old black man, we will select a control who is also a 24-year-old black man. This type of control selection yields matched case-control pairs; that is, each case is individually matched to a control. Randomization: The point of randomization is to prevent any potential biases on the part of the investigators/researchers. Text: Thus, the use of randomization is crucial to protect the study from any biases that might be introduced consciously or subconsciously by the investigator into the assignment process. Bias: any systematic error in the design, conduct or analysis of a study that results in a mistaken estimate of an exposure's effect on the risk of disease.” (selection bias) If the way in which cases and controls, or exposed and nonexposed individuals, were selected is such that an apparent association is observed—even if, in reality, exposure and disease are not associated—the apparent association is the result of selection bias. One form that selection bias can take results from nonresponse of potential study subjects. For example, if we are studying the possible relationship of an exposure and a disease and the response rate of potential subjects is higher in people with the disease who were exposed than in people with the disease who were not exposed, an apparent association could be observed even if in reality there is no association.