Statistics for Nursing 7777 7777
7777 Research A Workbook 7777 7777
for Evidence-Based
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7777 Practice 3rd Edition
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7777 SusanGrove Daisha
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, Answer Guidelines for Questions to Be Graded 7777 7777 7777 7 777 7777 7777
EXERC ISE
Identifying Levels 7
1
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ofMeasurement: 7 7 7 7 7
77 7 7 Nominal, Ordinal, Interval, 7777 7 7 7 7
and Ratio 7 7 7 7 7 7 7 7
Thequestionsareinboldfollowedbyanswers.
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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 categories 7777 7777 7777 7 7 77 7 77 7 7 77 7 7777 7777 7 777 7 77 7 7 777 7 77 7 7 77 7
were probably developed to be exhaustive for this study and included the categories of drugs the
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subjects were receiving. However, the categories are not exclusive, since patients are usually on
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more than one category of these drugs to manage their health problems. The current therapies
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arenotmeasured attheordinal levelbecausetheycannotberankordered, sincenodrug category can be
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considered more or less beneficial than another drug category (see Figure 1-1; Grove & Gray,
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2019).
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2. What is the mode for the current therapy variable in this study? Provide a
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rationale foryour answer.
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Answer: The mode for current therapy was βblocker. A total of 100 (94%) of the cardiac patients
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were receiving this category of drug, which was the most common
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7 prescribed drug for 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 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7
resulted in ratio-level data with continuous values and an absolute zero (Stone & Frazier, 2017).
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Ratio- level data should be analyzed with parametric statistics such as the mean and SD (Grove &
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Gray,2017; Knapp, 2017).
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4. Researchers used thefollowing item tomeasure registered nurses’ (RNs) income in astudy:What 777 777 777 777 777 77 7777 777 777 77 777 777 77 7
category identifies your current income as an RN?
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a. Lessthan$50,000 7 7 7 7 7 7
b. $50,000to 59,999 7 7 7 7 77 777
c. $60,000to69,999 7 7 7 7 7 7
d. $70,000 to 80,0007 7 7 7 7777 777
e. $80,000orgreater 7 7 7 7 7 7
What level of measurement is this income variable? Does the income variable follow
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the 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 7777 77 77 7777 7777 7777 7777 7 777 7777 777 7 7777 7777 7777 777 7 7 777
catego- 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 7777 Answer Guidelines for Questions to Be Graded 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7
categories ensure that all salary levels are covered. The categories are not exclusive, since catego- ries 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7
(d) and (e) include an $80,000 salary, so study participants making $80,000 might mark either
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(d) or (e) or both categories, resulting in erroneous data. Category (e) could be
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changed to greater than $80,000, making the categories exclusive. The categories can be rank
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ordered from the lowest salary to the highest salary, which is consistent with ordinal data (Grove
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& Gray, 2019; Waltz et al., 2017).
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5. WhatlevelofmeasurementistheCDSscore?Providearationaleforyouranswer. 7 7 77 7 7 77 7 7 77 7 77 7 77
Answer: The CDS score is at the interval level of measurement. The CDS is a 26-item Likert 77 77 7777 7777 77 77 7 777 7777 7 77 7 7 77 7 7 77 7 7 77 7 7 77 7 7 77 7 7 77 7 7 77 7 7 777 7777
scale developed to measure depression in cardiac patients. Study participants rated their symp-
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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-item scale are considered
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to be at the interval level of measurement (Gray et al., 2017; Waltz et al., 2017).
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6. Were nonparametric or parametric analysis techniques used to analyze the CDS scores forthe
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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 7777 7777 7 77 7 7 77 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7
7 describe CDS scores for study participants (see Table 1). CDS scores are interval-level data
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as indicated in Questions 5, so parametric statistics are appropriate for this level of data (Gray et al.,
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2017; Kim & Mallory, 2017).
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7. Is the prevalence of depression linked to the NYHA class? Discuss the clinical importance
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of this result.
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Answer: The study narrative indicated that the prevalence of depression increased with the 7777 7777 7777 7777 7 77 7 7 77 7 7 77 7 7777 77 7 7 7 77 7 7 77 7 7 7 77
greater NYHA class. In NYHA class III, 64% of the subjects were depressed, whereas 11% of the
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subjects 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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cardiacpatients havemore severephysical symptoms, which usually result in emotional distress, such
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as depression. Nurses need to actively assess cardiac patients for depression, especially
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thosein 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 77 77 7777 7777 7 77 7 7 77 7 7 77 7 7 77 7 7 77 7 7 777 7 77 7 7 77 7 7 77 7 7 77 7 7777
an antidepressant? Show your calculations and round your answer to the nearest whole
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percent (%).
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Answer: A total of 106 cardiac patients participated in this study. The sample included 15 77 77 77 77 7777 7777 77 77 7777 7777 7777 7 77 7 7 77 7 7 77 7 7 77 7 7 77 7 7 77 7 77 77 7 77 7 7 7 77 7 77 7 7 77 7 77 7 7 7 77 7 77 7 7 7 77 7 77 7 7 7777
patients who were receiving an antidepressant (see Table 1). The number of cardiac patients
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7not treated for depression was 91 (106 – 15 = 91). The group percent is
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7calculated by the following formula: (group frequency ÷ total sample size)
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7 × 100%. For this study, (91 patients ÷ 106 sample size) × 100% = 0.858 × 100% =
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85.8% = 86%. The final answer is rounded to the nearest whole percent as
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7directed in the question. You could have also subtracted the 14% of patients treated
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with antidepressants from 100% and obtained the 86% who were not treated with an
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antidepressant.
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9. What was the purpose of the 6-minute walk test (6MWT)? Would the 6MWT be useful in 7777 7777 7777 7777 7 777 7 77 7 7777 7 777 7777 7 77 7 7 777 7 77 7 7777 7 77 7 7 77 7
clinical practice?
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Answer: Ha et al. (2018) stated, “The 6-min walk test (6MWT) is a measure of the submaximal, 7777 7777 7777 7777 7777 7777 7777 7 777 7777 7777 7777 7777 7777 7777 7777 7777
steady-state functional capacity” of cardiac patients. This test would be a quick, easy way to
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determine a cardiac patient’s functional status in a clinical setting. This functional statusscore
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7 could be used to determine the treatment plan to promote or maintain functional
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7 statusof cardiac patients.
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, Answer Guidelines for Questions to Be Graded 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 AG 1-3
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10. How was exercise confidence measured in this study? What was the level of measurementfor
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the exercise confidence variable in this study? Provide a rationale for your answer.
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Answer: Exercise confidence of the patients with heart failure (HF) in this study was measured
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with the Exercise Confidence Scale that included four subscales focused on walking, climbing,
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lifting objects of graded weight, and running (see the study narrative). This was a rating
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scalewith values ranging from 0 to 100. The patients’ scores for the Total Exercise Confidence scale
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and the subscales were considered interval-level data and analyzed with parametric
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statistics,such as means and SDs(see the study narrative; Waltz et al., 2017).
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