Solution Manual for Statistics for Nursing Research A
Workbook for Evidence-Based Practice 3rd Edition
,Answer Guidelines for Questions to Be Graded
V V V V V V
Measurement: Nominal,
V
V
V V
V
1
The questions are in bold followed by answers.
1. In Table 1, identify the level of measurement for the current therapy variable. Pr
ovide a rationale for your answer.
*ANSWER** The current therapy variable was measured at the nominal level. These
drug c ategories were probably developed to be exhaustive for this study and included
the cate gories 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 h ealth 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 ratio
nale for your answer.
*ANSWER** The mode for current therapy was β blocker. A total of 100 (94%) of the cardiac
patie nts
were receiving this category of drug, which was the most common prescribed drug for t
his 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 inappropri
ate.
*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 (Gro
ve & 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 follo
w 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 op
en-ended
,AG 1-1
, AG 1-2 Answer Guidelines for Questions to Be Graded
categories ensure that all salary levels are covered. The categories are not exclusive, sinc
e catego-
ries (d) and (e) include an $80,000 salary, so study participants making $80,000 migh
t mark either (d) or (e) or both categories, resulting in erroneous data. Category (e) c
ould be changed to greater than $80,000, making the categories exclusive. The categor
ies can be rank ordered from the lowest salary to the highest salary, which is consiste
nt 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
participant s 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).
5. Were nonparametric or parametric analysis techniques used to analyze the CDS sc
ores 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 le
vel of data (Gray et al., 2017; Kim & Mallory, 2017).
7. Is the prevalence of depression linked to the NYHA class? Discuss the clinical im
portance 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,
where as 11% of the subjects were depressed in NYHA class I. Thus, as the NYHA
class incr eased, 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 trea
ted 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
inc luded 15 patients who were receiving an antidepressant (see Table 1). The
numb er of cardiac patients not treated for depression was 91 (106 –
15 = 91). The group percent is calculated by the following formula: (group frequ
ency ÷ total sample size) × 100%. For this study, (91 patients ÷ 106 sample siz
e) × 100% = 0.858 × 100% = 85.8% = 86%. The final answer is rounded to t
he nearest whole percent as directed in the question. You could have also subtracte
d the 14% of patients treated with antidepressants from 100% and obtained the 86%
who were not treated with an antidepressant.
t. What was the purpose of the 5-
minute walk test (5MWT)? Would the 5MWT 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
Workbook for Evidence-Based Practice 3rd Edition
,Answer Guidelines for Questions to Be Graded
V V V V V V
Measurement: Nominal,
V
V
V V
V
1
The questions are in bold followed by answers.
1. In Table 1, identify the level of measurement for the current therapy variable. Pr
ovide a rationale for your answer.
*ANSWER** The current therapy variable was measured at the nominal level. These
drug c ategories were probably developed to be exhaustive for this study and included
the cate gories 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 h ealth 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 ratio
nale for your answer.
*ANSWER** The mode for current therapy was β blocker. A total of 100 (94%) of the cardiac
patie nts
were receiving this category of drug, which was the most common prescribed drug for t
his 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 inappropri
ate.
*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 (Gro
ve & 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 follo
w 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 op
en-ended
,AG 1-1
, AG 1-2 Answer Guidelines for Questions to Be Graded
categories ensure that all salary levels are covered. The categories are not exclusive, sinc
e catego-
ries (d) and (e) include an $80,000 salary, so study participants making $80,000 migh
t mark either (d) or (e) or both categories, resulting in erroneous data. Category (e) c
ould be changed to greater than $80,000, making the categories exclusive. The categor
ies can be rank ordered from the lowest salary to the highest salary, which is consiste
nt 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
participant s 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).
5. Were nonparametric or parametric analysis techniques used to analyze the CDS sc
ores 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 le
vel of data (Gray et al., 2017; Kim & Mallory, 2017).
7. Is the prevalence of depression linked to the NYHA class? Discuss the clinical im
portance 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,
where as 11% of the subjects were depressed in NYHA class I. Thus, as the NYHA
class incr eased, 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 trea
ted 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
inc luded 15 patients who were receiving an antidepressant (see Table 1). The
numb er of cardiac patients not treated for depression was 91 (106 –
15 = 91). The group percent is calculated by the following formula: (group frequ
ency ÷ total sample size) × 100%. For this study, (91 patients ÷ 106 sample siz
e) × 100% = 0.858 × 100% = 85.8% = 86%. The final answer is rounded to t
he nearest whole percent as directed in the question. You could have also subtracte
d the 14% of patients treated with antidepressants from 100% and obtained the 86%
who were not treated with an antidepressant.
t. What was the purpose of the 5-
minute walk test (5MWT)? Would the 5MWT 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
