Statistics for Nursing Research 4th Edition
Solution Manual | Grove & Cipherd – Evidence-
Based Practice
Answer Guidelines for Questions to Be Graded
EXERCISE
Identifying Levels of
Measurement: Nominal, 1
Ordinal, Interval, and Ratio
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
for your 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 this sample.
[Date]
,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
[Date]
,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 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
(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
[Date]
, 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 status of cardiac patients.
[Date]
Solution Manual | Grove & Cipherd – Evidence-
Based Practice
Answer Guidelines for Questions to Be Graded
EXERCISE
Identifying Levels of
Measurement: Nominal, 1
Ordinal, Interval, and Ratio
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
for your 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 this sample.
[Date]
,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
[Date]
,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 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
(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
[Date]
, 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 status of cardiac patients.
[Date]
