Solution Manual for
Statistics for Nursing
Research A Workbook
for Evidence-Based
Practice 3rd Edition
Susan Grove Daisha
,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 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.
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
,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: aThe astudy anarrative aindicated athat athe aprevalence aof adepression aincreased awith
athe agreater aNYHA aclass. aIn aNYHA aclass aIII, a64% aof athe asubjects awere adepressed,
awhereas a11% aof athe asubjects awere adepressed ain aNYHA aclass aI. aThus, aas athe aNYHA aclass
aincreased, athe anumber aof asub- ajects awith adepression aincreased. aThis ais aan aexpected afinding
abecause aas athe aNYHA aclass aincreases, acardiac apatients ahave amore asevere aphysical
asymptoms, awhich ausually aresult ain aemotional adistress, asuch a as a depression. a Nurses a need a to
a actively a assess a cardiac a patients a for a depression, a especially a those ain ahigher aNYHA aclasses,
aso athey amight abe adiagnosed aand atreated aas aneeded.
8. What afrequency aand apercent aof acardiac apatients ain athis astudy awere anot abeing
atreated awith aan aantidepressant? aShow ayour acalculations aand around ayour aanswer
ato athe anearest awhole apercent a(%).
Answer: aA atotal a aof a a106 a acardiac a apatients a aparticipated a ain a athis a astudy. a aThe a
asample a aincluded a15 apatients awho awere areceiving aan aantidepressant a(see aTable a1). aThe
a anumber a aof a acardiac apatients a not a treated a for a depression a was a 91 a (106 a – a 15 a =
a91). a The a group a percent a is a calculated aby a the a following a formula: a (group a frequency
a ÷ a total a sample a size) a × a 100%. a For a this a study, a(91 apatients a÷ a106 asample asize)
a× a100% a= a0.858 a× a100% a= a85.8% a= a86%. aThe a afinal aanswer a is a rounded a to a the
a nearest a whole a percent a as a directed a in a the a question. a You a could a have aalso asubtracted
athe a14% aof apatients atreated awith aantidepressants afrom a100% aand aobtained athe a86%
a who a were a not a treated a with a an a antidepressant.
9. What awas athe apurpose aof athe a6-minute awalk atest a(6MWT)? aWould athe a6MWT abe
auseful ain aclinical apractice?
Answer: aHa aet aal. a(2018) astated, a“The a6-min awalk atest a(6MWT) ais aa ameasure aof athe
asubmaximal, asteady-state afunctional acapacity” aof acardiac apatients. aThis atest awould abe aa
aquick, aeasy away ato adetermine aa acardiac apatient’s afunctional astatus ain aa aclinical a asetting.
a aThis a afunctional a astatus ascore a could a be a used a to a determine a the a treatment a plan a to
a promote a or a maintain a functional a statusaof acardiac apatients.
, Answer a Guidelines a for a Questions a to a Be a Graded AG a1-3
10. How awas aexercise aconfidence ameasured ain athis astudy? aWhat awas athe alevel aof
ameasurementafor athe aexercise aconfidence avariable ain athis astudy? aProvide aa
arationale afor ayour aanswer. aAnswer: aExercise aconfidence aof athe apatients awith aheart
afailure a(HF) ain athis astudy awas ameasuredawith athe aExercise aConfidence aScale athat
aincluded afour asubscales afocused aon awalking, aclimbing,alifting a objects a of a graded a weight,
a and a running a (see a the a study a narrative). a This a was a a a rating a scaleawith avalues aranging
afrom a0 ato a100. aThe apatients’ ascores afor athe aTotal aExercise aConfidence ascaleaand a the
a subscales a were a considered a interval-level a data a and a analyzed a with a parametric a statistics,
asuch aas ameans aand aSDs a(see athe astudy anarrative; aWaltz aet aal., a2017).
Statistics for Nursing
Research A Workbook
for Evidence-Based
Practice 3rd Edition
Susan Grove Daisha
,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 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.
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
,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: aThe astudy anarrative aindicated athat athe aprevalence aof adepression aincreased awith
athe agreater aNYHA aclass. aIn aNYHA aclass aIII, a64% aof athe asubjects awere adepressed,
awhereas a11% aof athe asubjects awere adepressed ain aNYHA aclass aI. aThus, aas athe aNYHA aclass
aincreased, athe anumber aof asub- ajects awith adepression aincreased. aThis ais aan aexpected afinding
abecause aas athe aNYHA aclass aincreases, acardiac apatients ahave amore asevere aphysical
asymptoms, awhich ausually aresult ain aemotional adistress, asuch a as a depression. a Nurses a need a to
a actively a assess a cardiac a patients a for a depression, a especially a those ain ahigher aNYHA aclasses,
aso athey amight abe adiagnosed aand atreated aas aneeded.
8. What afrequency aand apercent aof acardiac apatients ain athis astudy awere anot abeing
atreated awith aan aantidepressant? aShow ayour acalculations aand around ayour aanswer
ato athe anearest awhole apercent a(%).
Answer: aA atotal a aof a a106 a acardiac a apatients a aparticipated a ain a athis a astudy. a aThe a
asample a aincluded a15 apatients awho awere areceiving aan aantidepressant a(see aTable a1). aThe
a anumber a aof a acardiac apatients a not a treated a for a depression a was a 91 a (106 a – a 15 a =
a91). a The a group a percent a is a calculated aby a the a following a formula: a (group a frequency
a ÷ a total a sample a size) a × a 100%. a For a this a study, a(91 apatients a÷ a106 asample asize)
a× a100% a= a0.858 a× a100% a= a85.8% a= a86%. aThe a afinal aanswer a is a rounded a to a the
a nearest a whole a percent a as a directed a in a the a question. a You a could a have aalso asubtracted
athe a14% aof apatients atreated awith aantidepressants afrom a100% aand aobtained athe a86%
a who a were a not a treated a with a an a antidepressant.
9. What awas athe apurpose aof athe a6-minute awalk atest a(6MWT)? aWould athe a6MWT abe
auseful ain aclinical apractice?
Answer: aHa aet aal. a(2018) astated, a“The a6-min awalk atest a(6MWT) ais aa ameasure aof athe
asubmaximal, asteady-state afunctional acapacity” aof acardiac apatients. aThis atest awould abe aa
aquick, aeasy away ato adetermine aa acardiac apatient’s afunctional astatus ain aa aclinical a asetting.
a aThis a afunctional a astatus ascore a could a be a used a to a determine a the a treatment a plan a to
a promote a or a maintain a functional a statusaof acardiac apatients.
, Answer a Guidelines a for a Questions a to a Be a Graded AG a1-3
10. How awas aexercise aconfidence ameasured ain athis astudy? aWhat awas athe alevel aof
ameasurementafor athe aexercise aconfidence avariable ain athis astudy? aProvide aa
arationale afor ayour aanswer. aAnswer: aExercise aconfidence aof athe apatients awith aheart
afailure a(HF) ain athis astudy awas ameasuredawith athe aExercise aConfidence aScale athat
aincluded afour asubscales afocused aon awalking, aclimbing,alifting a objects a of a graded a weight,
a and a running a (see a the a study a narrative). a This a was a a a rating a scaleawith avalues aranging
afrom a0 ato a100. aThe apatients’ ascores afor athe aTotal aExercise aConfidence ascaleaand a the
a subscales a were a considered a interval-level a data a and a analyzed a with a parametric a statistics,
asuch aas ameans aand aSDs a(see athe astudy anarrative; aWaltz aet aal., a2017).
