STUDY NOTES & REFERENCE GUIDE
Solution Manual for
Statistics for Nursing
Research A
Workbookfor
Evidence-Based
Practice 3rd Edition
Susan Grove Daisha
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, STUDY NOTES & REFERENCE GUIDE
Answer Guidelines for Questions to Be Graded
EXERCISE
Identifying Levels of
Measurement: Nominal,
Ordinal, Interval, and Ratio
1
The questions are in bold followed by answers.
1. In Table 1, identify the level of measurement for the current therapy variable. Provide
a rationale for your answer.
Answer: The current therapy variable was measured at the nominal level. These drug
categories were probably developed to be exhaustive for this study and included the
categories of drugs the subjects were receiving. However, the categories are not exclusive,
since patients are usually on more than one category of these drugs to manage their health
problems. The current therapies are not measured at the ordinal level because they cannot
be rank ordered, since no drug category can be considered more or less beneficial than
another drug category (see Figure 1-1; Grove & Gray, 2019).
2. What is the mode for the current therapy variable in this study? Provide a rationale
foryour answer.
Answer: The mode for current therapy was β blocker. A total of 100 (94%) of the cardiac patients
were receiving this category of drug, which was the most common prescribed drug for
thissample.
3. What statistics were conducted to describe the BMI of the cardiac patients in this
sample?Discuss whether these analysis techniques were appropriate or inappropriate.
Answer: BMI was described with a mean and standard deviation (SD). BMI measurement
resulted in ratio-level data with continuous values and an absolute zero (Stone & Frazier,
2017). Ratio- level data should be analyzed with parametric statistics such as the mean and
SD (Grove & Gray,2017; Knapp, 2017).
4. Researchers used the following item to measure registered nurses’ (RNs) income in a
study: What category identifies your current income as an RN?
a. Less than $50,000
b. $50,000 to 59,999
c. $60,000 to 69,999
d. $70,000 to 80,000
e. $80,000 or greater
What level of measurement is this income variable? Does the income variable follow the
rules outlined in Figure 1-1? Provide a rationale for your answer.
Answer: In this example, the income variable is measured at the ordinal level. The income
catego- ries are exhaustive, ranging from less than $50,000 to greater than $80,000. The two
open-ended
AG 1-1
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AG 1-2 Answer Guidelines for Questions to Be Graded
categories ensure that all salary levels are covered. The categories are not exclusive, since
catego- ries (d) and (e) include an $80,000 salary, so study participants making $80,000
might mark either (d) or (e) or both categories, resulting in erroneous data. Category (e)
could be changed to greater than $80,000, making the categories exclusive. The categories
can be rank ordered from the lowest salary to the highest salary, which is consistent with
ordinal data (Grove & Gray, 2019; Waltz et al., 2017).
5. What level of measurement is the CDS score? Provide a rationale for your answer.
Answer: The CDS score is at the interval level of measurement. The CDS is a 26-item Likert
scale developed to measure depression in cardiac patients. Study participants rated their
symp- toms on a scale of 1 to 7, with higher numbers indicating increased severity in the
depression symptoms. The total scores for each subject obtained from this multi-item scale
are considered to be at the interval level of measurement (Gray et al., 2017; Waltz et al.,
2017).
6. Were nonparametric or parametric analysis techniques used to analyze the CDS scores
forthe cardiac patients in this study? Provide a rationale for your answer.
Answer: Parametric statistics, such as mean and SD, were conducted to describe CDS
scores for study participants (see Table 1). CDS scores are interval-level data as indicated in
Questions 5, so parametric statistics are appropriate for this level of data (Gray et al., 2017; Kim
& Mallory, 2017).
7. Is the prevalence of depression linked to the NYHA class? Discuss the clinical
importance of this result.
Answer: The study narrative indicated that the prevalence of depression increased with the
greater NYHA class. In NYHA class III, 64% of the subjects were depressed, whereas 11% of
the subjects were depressed in NYHA class I. Thus, as the NYHA class increased, the number of
sub- jects with depression increased. This is an expected finding because as the NYHA class
increases, cardiac patients have more severe physical symptoms, which usually result in
emotional distress, such as depression. Nurses need to actively assess cardiac patients for
depression, especially those in higher NYHA classes, so they might be diagnosed and treated
as needed.
8. What frequency and percent of cardiac patients in this study were not being treated
with an antidepressant? Show your calculations and round your answer to the nearest
whole percent (%).
Answer: A total of 106 cardiac patients participated in this study. The sample
included 15 patients who were receiving an antidepressant (see Table 1). The number of
cardiac patients not treated for depression was 91 (106 – 15 = 91). The group percent
is calculated by the following formula: (group frequency ÷ total sample size) × 100%.
For this study, (91 patients ÷ 106 sample size) × 100% = 0.858 × 100% = 85.8% =
86%. The final answer is rounded to the nearest whole percent as directed in the
question. You could have also subtracted the 14% of patients treated with antidepressants
from 100% and obtained the 86% who were not treated with an antidepressant.
9. What was the purpose of the 6-minute walk test (6MWT)? Would the 6MWT be
useful in clinical practice?
Answer: Ha et al. (2018) stated, “The 6-min walk test (6MWT) is a measure of the
submaximal, steady-state functional capacity” of cardiac patients. This test would be a
quick, easy way to determine a cardiac patient’s functional status in a clinical setting. This
functional status score could be used to determine the treatment plan to promote or
maintain functional statusof cardiac patients.
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Answer Guidelines for Questions to Be Graded AG 1-3
10. How was exercise confidence measured in this study? What was the level of
measurementfor the exercise confidence variable in this study? Provide a rationale
for your answer. Answer: Exercise confidence of the patients with heart failure (HF) in
this study was measured with the Exercise Confidence Scale that included four subscales
focused on walking, climbing, lifting objects of graded weight, and running (see the study
narrative). This was a rating scale with values ranging from 0 to 100. The patients’ scores
for the Total Exercise Confidence scaleand the subscales were considered interval-level
data and analyzed with parametric statistics, such as means and SDs (see the study
narrative; Waltz et al., 2017).
learndock ‐ Stuvia | Page 4 of 77
Solution Manual for
Statistics for Nursing
Research A
Workbookfor
Evidence-Based
Practice 3rd Edition
Susan Grove Daisha
learndock ‐ Stuvia | Page 1 of 77
, STUDY NOTES & REFERENCE GUIDE
Answer Guidelines for Questions to Be Graded
EXERCISE
Identifying Levels of
Measurement: Nominal,
Ordinal, Interval, and Ratio
1
The questions are in bold followed by answers.
1. In Table 1, identify the level of measurement for the current therapy variable. Provide
a rationale for your answer.
Answer: The current therapy variable was measured at the nominal level. These drug
categories were probably developed to be exhaustive for this study and included the
categories of drugs the subjects were receiving. However, the categories are not exclusive,
since patients are usually on more than one category of these drugs to manage their health
problems. The current therapies are not measured at the ordinal level because they cannot
be rank ordered, since no drug category can be considered more or less beneficial than
another drug category (see Figure 1-1; Grove & Gray, 2019).
2. What is the mode for the current therapy variable in this study? Provide a rationale
foryour answer.
Answer: The mode for current therapy was β blocker. A total of 100 (94%) of the cardiac patients
were receiving this category of drug, which was the most common prescribed drug for
thissample.
3. What statistics were conducted to describe the BMI of the cardiac patients in this
sample?Discuss whether these analysis techniques were appropriate or inappropriate.
Answer: BMI was described with a mean and standard deviation (SD). BMI measurement
resulted in ratio-level data with continuous values and an absolute zero (Stone & Frazier,
2017). Ratio- level data should be analyzed with parametric statistics such as the mean and
SD (Grove & Gray,2017; Knapp, 2017).
4. Researchers used the following item to measure registered nurses’ (RNs) income in a
study: What category identifies your current income as an RN?
a. Less than $50,000
b. $50,000 to 59,999
c. $60,000 to 69,999
d. $70,000 to 80,000
e. $80,000 or greater
What level of measurement is this income variable? Does the income variable follow the
rules outlined in Figure 1-1? Provide a rationale for your answer.
Answer: In this example, the income variable is measured at the ordinal level. The income
catego- ries are exhaustive, ranging from less than $50,000 to greater than $80,000. The two
open-ended
AG 1-1
learndock ‐ Stuvia | Page 2 of 77
, STUDY NOTES & REFERENCE GUIDE
AG 1-2 Answer Guidelines for Questions to Be Graded
categories ensure that all salary levels are covered. The categories are not exclusive, since
catego- ries (d) and (e) include an $80,000 salary, so study participants making $80,000
might mark either (d) or (e) or both categories, resulting in erroneous data. Category (e)
could be changed to greater than $80,000, making the categories exclusive. The categories
can be rank ordered from the lowest salary to the highest salary, which is consistent with
ordinal data (Grove & Gray, 2019; Waltz et al., 2017).
5. What level of measurement is the CDS score? Provide a rationale for your answer.
Answer: The CDS score is at the interval level of measurement. The CDS is a 26-item Likert
scale developed to measure depression in cardiac patients. Study participants rated their
symp- toms on a scale of 1 to 7, with higher numbers indicating increased severity in the
depression symptoms. The total scores for each subject obtained from this multi-item scale
are considered to be at the interval level of measurement (Gray et al., 2017; Waltz et al.,
2017).
6. Were nonparametric or parametric analysis techniques used to analyze the CDS scores
forthe cardiac patients in this study? Provide a rationale for your answer.
Answer: Parametric statistics, such as mean and SD, were conducted to describe CDS
scores for study participants (see Table 1). CDS scores are interval-level data as indicated in
Questions 5, so parametric statistics are appropriate for this level of data (Gray et al., 2017; Kim
& Mallory, 2017).
7. Is the prevalence of depression linked to the NYHA class? Discuss the clinical
importance of this result.
Answer: The study narrative indicated that the prevalence of depression increased with the
greater NYHA class. In NYHA class III, 64% of the subjects were depressed, whereas 11% of
the subjects were depressed in NYHA class I. Thus, as the NYHA class increased, the number of
sub- jects with depression increased. This is an expected finding because as the NYHA class
increases, cardiac patients have more severe physical symptoms, which usually result in
emotional distress, such as depression. Nurses need to actively assess cardiac patients for
depression, especially those in higher NYHA classes, so they might be diagnosed and treated
as needed.
8. What frequency and percent of cardiac patients in this study were not being treated
with an antidepressant? Show your calculations and round your answer to the nearest
whole percent (%).
Answer: A total of 106 cardiac patients participated in this study. The sample
included 15 patients who were receiving an antidepressant (see Table 1). The number of
cardiac patients not treated for depression was 91 (106 – 15 = 91). The group percent
is calculated by the following formula: (group frequency ÷ total sample size) × 100%.
For this study, (91 patients ÷ 106 sample size) × 100% = 0.858 × 100% = 85.8% =
86%. The final answer is rounded to the nearest whole percent as directed in the
question. You could have also subtracted the 14% of patients treated with antidepressants
from 100% and obtained the 86% who were not treated with an antidepressant.
9. What was the purpose of the 6-minute walk test (6MWT)? Would the 6MWT be
useful in clinical practice?
Answer: Ha et al. (2018) stated, “The 6-min walk test (6MWT) is a measure of the
submaximal, steady-state functional capacity” of cardiac patients. This test would be a
quick, easy way to determine a cardiac patient’s functional status in a clinical setting. This
functional status score could be used to determine the treatment plan to promote or
maintain functional statusof cardiac patients.
learndock ‐ Stuvia | Page 3 of 77
, STUDY NOTES & REFERENCE GUIDE
Answer Guidelines for Questions to Be Graded AG 1-3
10. How was exercise confidence measured in this study? What was the level of
measurementfor the exercise confidence variable in this study? Provide a rationale
for your answer. Answer: Exercise confidence of the patients with heart failure (HF) in
this study was measured with the Exercise Confidence Scale that included four subscales
focused on walking, climbing, lifting objects of graded weight, and running (see the study
narrative). This was a rating scale with values ranging from 0 to 100. The patients’ scores
for the Total Exercise Confidence scaleand the subscales were considered interval-level
data and analyzed with parametric statistics, such as means and SDs (see the study
narrative; Waltz et al., 2017).
learndock ‐ Stuvia | Page 4 of 77
