Solution Manual for Statistics for Nursing
Research A Workbook for Evidence-Based
Practice 4th Edition Author:Susan Grove Daisha
All Chapters Covered Latest Version
tion
1|Page
, 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 benefi cial 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 for your
answer.
Answer: The mode for current therapy was blocker. A total of 100 (94%) of the cardiac
patients were receiving this category of drug, which was the most common prescribed drug for
this sample.
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 (S tone & Frazier,
2017) . Ratiolevel data should be analyzed with parametric statistics such as the mean and
SD (G rove & Gray, 2017 ; Knapp, 2017 ).
4. Researchers used the following item to measure registered nurses’ (RNs) income in a study:
What category identifi es 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
categories are exhaustive, ranging from less than $50,000 to greater than $80,000. The two
2|Page
, open-ended
AG 1-1
3|Page
, AG 1-2 Answer Guidelines for Questions to Be Graded
categories ensure that all salary levels are covered. The categories are not exclusive, since categories
(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; W altz
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 symptoms 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 (G ray et al., 2017; W altz et al., 2017) .
6. Were nonparametric or parametric analysis techniques used to analyze the CDS scores for the
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 (G ray et al., 2017;
K im & 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 subjects with depression increased. This is an expected fi nding 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 T able 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?
Research A Workbook for Evidence-Based
Practice 4th Edition Author:Susan Grove Daisha
All Chapters Covered Latest Version
tion
1|Page
, 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 benefi cial 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 for your
answer.
Answer: The mode for current therapy was blocker. A total of 100 (94%) of the cardiac
patients were receiving this category of drug, which was the most common prescribed drug for
this sample.
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 (S tone & Frazier,
2017) . Ratiolevel data should be analyzed with parametric statistics such as the mean and
SD (G rove & Gray, 2017 ; Knapp, 2017 ).
4. Researchers used the following item to measure registered nurses’ (RNs) income in a study:
What category identifi es 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
categories are exhaustive, ranging from less than $50,000 to greater than $80,000. The two
2|Page
, open-ended
AG 1-1
3|Page
, AG 1-2 Answer Guidelines for Questions to Be Graded
categories ensure that all salary levels are covered. The categories are not exclusive, since categories
(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; W altz
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 symptoms 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 (G ray et al., 2017; W altz et al., 2017) .
6. Were nonparametric or parametric analysis techniques used to analyze the CDS scores for the
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 (G ray et al., 2017;
K im & 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 subjects with depression increased. This is an expected fi nding 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 T able 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?
