Statistics for Nursing R b5 b5 b5
esearch A Workbookfo
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r Evidence-
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Based Practice 3rd Edit
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ion Susan Grove Daish
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, Answer Guidelines for Questions to Be Graded b5 b5 b5 b5 b5 b5
EXERCISE
Identifying Levels o b
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1
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fMeasurement: Nominal, O
b
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rdinal, Interval, and Ratio b 5 b 5 b 5
The questions are in bold followed by answers.
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1. In Table 1, identify the level of measurement for the current therapy variable. Provide a
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rationale for your answer.
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Answer: The current therapy variable was measured at the nominal level. These drug categorie
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swere probably developed to be exhaustive for this study and included the categories of drugs th
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esubjects were receiving. However, the categories are not exclusive, since patients are usually o
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n more than one category of these drugs to manage their health problems. The current therapie
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s are not measured at the ordinal level because they cannot be rank ordered, since no drug category
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can be considered more or less beneficial than another drug category (see Figure 1-
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1; Grove & Gray, 2019).
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2. What is the mode for the current therapy variable in this study? Provide a rationale
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5foryour answer. 5b b5
Answer: The mode for current therapy was β blocker. A total of 100 (94%) of the cardiac patients
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were receiving this category of drug, which was the most common prescribed drug fo
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r thissample.
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3. What statistics were conducted to describe the BMI of the cardiac patients in this sample
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?Discuss whether these analysis techniques were appropriate or inappropriate.
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Answer: BMI was described with a mean and standard deviation (SD). BMI measurement result
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ed in ratio- b5 b5
level data with continuous values and an absolute zero (Stone & Frazier, 2017). Ratio-
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level data should be analyzed with parametric statistics such as the mean and SD (Grove & Gray
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,2017; Knapp, 2017).
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4. Researchers used the following item to measure registered nurses’ (RNs) income in a study:
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What category identifies your current income as an RN?
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a. Less than $50,000
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b. $50,000 to 59,999
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c. $60,000 to 69,999
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d. $70,000 to 80,000
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e. $80,000 or greater
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What level of measurement is this income variable? Does the income variable follow t
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he rules outlined in Figure 1-1? Provide a rationale for your answer.
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Answer: In this example, the income variable is measured at the ordinal level. The income catego
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- ries are exhaustive, ranging from less than $50,000 to greater than $80,000. The two open-
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ended
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,AG 1-2
b5 Answer Guidelines for Questions to Be Graded
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categories ensure that all salary levels are covered. The categories are not exclusive, since catego-
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ries (d) and (e) include an $80,000 salary, so study participants making $80,000 might mark ei
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ther (d) or (e) or both categories, resulting in erroneous data. Category (e) could be change
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dto greater than $80,000, making the categories exclusive. The categories can be rank ordered
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from the lowest salary to the highest salary, which is consistent with ordinal data (Grove & Gr
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ay, 2019; Waltz et al., 2017).
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5. What level of measurement is the CDS score? Provide a rationale for your answer.
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Answer: The CDS score is at the interval level of measurement. The CDS is a 26-
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item Likert scale developed to measure depression in cardiac patients. Study participants rated
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their symp- b5
toms on a scale of 1 to 7, with higher numbers indicating increased severity in the depression
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symptoms. The total scores for each subject obtained from this multi-b5 b5 b5 b5 b5 b5 b5 b5 b5 b5
item scale are considered to be at the interval level of measurement (Gray et al., 2017; Waltz et
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al., 2017). b5
6. Were nonparametric or parametric analysis techniques used to analyze the CDS scores fo
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rthe cardiac patients in this study? Provide a rationale for your answer.
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Answer: Parametric statistics, such as mean and SD, were conducted to describe CDS sc
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oresfor study participants (see Table 1). CDS scores are interval-
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level data as indicated in Questions 5, so parametric statistics are appropriate for this level of data (
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Gray et al., 2017; Kim & Mallory, 2017).
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7. Is the prevalence of depression linked to the NYHA class? Discuss the clinical importanc
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e of this result.
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Answer: The study narrative indicated that the prevalence of depression increased with the gre
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ater NYHA class. In NYHA class III, 64% of the subjects were depressed, whereas 11% of thesubj
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ects were depressed in NYHA class I. Thus, as the NYHA class increased, the number of sub-
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jects with depression increased. This is an expected finding because as the NYHA class increases,
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cardiac patients have more severe physical symptoms, which usually result in emotional distress, s
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uch as depression. Nurses need to actively assess cardiac patients for depression, especially tho
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sein higher NYHA classes, so they might be diagnosed and treated as needed.
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8. What frequency and percent of cardiac patients in this study were not being treated with
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an antidepressant? Show your calculations and round your answer to the nearest whole
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percent (%). b5
Answer: A total of 106 cardiac patients participated in this study. The sample included
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15 patients who were receiving an antidepressant (see Table 1). The number of cardiac patie
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nts not treated for depression was 91 (106 –
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15 = 91). The group percent is calculatedby the following formula: (group frequency
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÷ total sample size) × 100%. For this study,(91 patients ÷ 106 sample size) × 100%
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= 0.858 × 100% = 85.8% = 86%. The finalanswer is rounded to the nearest whole per
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cent as directed in the question. You could havealso subtracted the 14% of patients treate
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d with antidepressants from 100% and obtained the 86% who were not treated with an antide
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pressant.
9. What was the purpose of the 6- b5 b5 b5 b5 b5 b5
minute walk test (6MWT)? Would the 6MWT be useful in clinical practice?
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Answer: Ha et al. (2018) stated, ―The 6- b5 b5 b5 b5 b5 b5 b5
min walk test (6MWT) is a measure of the submaximal,steady-
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state functional capacity‖ of cardiac patients. This test would be a quick, easy way to determin
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e a cardiac patient’s functional status in a clinical setting. This functional statusscore could
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5be used to determine the treatment plan to promote or maintain functional statusof cardia
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c patients.
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, Answer Guidelines for Questions to Be Graded
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10. How was exercise confidence measured in this study? What was the level of measuremen
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tfor the exercise confidence variable in this study? Provide a rationale for your answer.
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5Answer: Exercise confidence of the patients with heart failure (HF) in this study was measure
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dwith the Exercise Confidence Scale that included four subscales focused on walking, climbin
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g,lifting objects of graded weight, and running (see the study narrative). This was a rating s
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calewith values ranging from 0 to 100. The patients’ scores for the Total Exercise Confidence s
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caleand the subscales were considered interval-
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level data and analyzed with parametric statistics,such as means and SDs (see the study narrat
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ive; Waltz et al., 2017).
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