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: dThe dstudy dnarrative dindicated dthat dthe dprevalence dof ddepression dincreased dwith
dthe dgreater dNYHA dclass. dIn dNYHA dclass dIII, d64% dof dthe dsubjects dwere ddepressed,
dwhereas d11% dof dthe dsubjects dwere ddepressed din dNYHA dclass dI. dThus, das dthe dNYHA dclass
dincreased, dthe dnumber dof dsub- djects dwith ddepression dincreased. dThis dis dan dexpected dfinding
dbecause das dthe dNYHA dclass dincreases, dcardiac dpatients dhave dmore dsevere dphysical
dsymptoms, dwhich dusually dresult din demotional ddistress, dsuch d as d depression. d Nurses d need
d to d actively d assess d cardiac d patients d for d depression, d especially d those din dhigher dNYHA
dclasses, dso dthey dmight dbe ddiagnosed dand dtreated das dneeded.
8. What dfrequency dand dpercent dof dcardiac dpatients din dthis dstudy dwere dnot dbeing
dtreated dwith dan dantidepressant? dShow dyour dcalculations dand dround dyour danswer
dto dthe dnearest dwhole dpercent d(%).
Answer: dA dtotal d dof d d106 d dcardiac d dpatients d dparticipated d din d dthis d dstudy. d dThe d
dsample d dincluded d15 dpatients dwho dwere dreceiving dan dantidepressant d(see dTable d1).
dThe d dnumber d dof d dcardiac dpatients d not d treated d for d depression d was d 91 d (106 d – d 15
d = d 91). d The d group d percent d is d calculated dby d the d following d formula: d (group
d frequency d ÷ d total d sample d size) d × d 100%. d For d this d study, d(91 dpatients d÷ d106
dsample dsize) d× d100% d= d0.858 d× d100% d= d85.8% d= d86%. dThe d dfinal danswer d is
d rounded d to d the d nearest d whole d percent d as d directed d in d the d question. d You d could
d have dalso dsubtracted dthe d14% dof dpatients dtreated dwith dantidepressants dfrom d100% dand
dobtained dthe d86% d who d were d not d treated d with d an d antidepressant.
9. What dwas dthe dpurpose dof dthe d6-minute dwalk dtest d(6MWT)? dWould dthe d6MWT
dbe duseful din dclinical dpractice?
Answer: dHa det dal. d(2018) dstated, d“The d6-min dwalk dtest d(6MWT) dis da dmeasure dof dthe
dsubmaximal, dsteady-state dfunctional dcapacity” dof dcardiac dpatients. dThis dtest dwould dbe da
dquick, deasy dway dto ddetermine da dcardiac dpatient’s dfunctional dstatus din da dclinical d
dsetting. d dThis d dfunctional d dstatus dscore d could d be d used d to d determine d the d treatment
d plan d to d promote d or d maintain d functional d statusdof dcardiac dpatients.
, Answer d Guidelines d for d Questions d to d Be d Graded AG d1-3
10. How dwas dexercise dconfidence dmeasured din dthis dstudy? dWhat dwas dthe dlevel dof
dmeasurementdfor dthe dexercise dconfidence dvariable din dthis dstudy? dProvide da
drationale dfor dyour danswer. dAnswer: dExercise dconfidence dof dthe dpatients dwith dheart
dfailure d(HF) din dthis dstudy dwas dmeasureddwith dthe dExercise dConfidence dScale dthat
dincluded dfour dsubscales dfocused don dwalking, dclimbing,dlifting d objects d of d graded
d weight, d and d running d (see d the d study d narrative). d This d was d a d rating d scaledwith dvalues
dranging dfrom d0 dto d100. dThe dpatients’ dscores dfor dthe dTotal dExercise dConfidence dscale
dand d the d subscales d were d considered d interval-level d data d and d analyzed d with d parametric
d statistics,dsuch das dmeans dand dSDs d(see dthe dstudy dnarrative; dWaltz det dal., d2017).
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: dThe dstudy dnarrative dindicated dthat dthe dprevalence dof ddepression dincreased dwith
dthe dgreater dNYHA dclass. dIn dNYHA dclass dIII, d64% dof dthe dsubjects dwere ddepressed,
dwhereas d11% dof dthe dsubjects dwere ddepressed din dNYHA dclass dI. dThus, das dthe dNYHA dclass
dincreased, dthe dnumber dof dsub- djects dwith ddepression dincreased. dThis dis dan dexpected dfinding
dbecause das dthe dNYHA dclass dincreases, dcardiac dpatients dhave dmore dsevere dphysical
dsymptoms, dwhich dusually dresult din demotional ddistress, dsuch d as d depression. d Nurses d need
d to d actively d assess d cardiac d patients d for d depression, d especially d those din dhigher dNYHA
dclasses, dso dthey dmight dbe ddiagnosed dand dtreated das dneeded.
8. What dfrequency dand dpercent dof dcardiac dpatients din dthis dstudy dwere dnot dbeing
dtreated dwith dan dantidepressant? dShow dyour dcalculations dand dround dyour danswer
dto dthe dnearest dwhole dpercent d(%).
Answer: dA dtotal d dof d d106 d dcardiac d dpatients d dparticipated d din d dthis d dstudy. d dThe d
dsample d dincluded d15 dpatients dwho dwere dreceiving dan dantidepressant d(see dTable d1).
dThe d dnumber d dof d dcardiac dpatients d not d treated d for d depression d was d 91 d (106 d – d 15
d = d 91). d The d group d percent d is d calculated dby d the d following d formula: d (group
d frequency d ÷ d total d sample d size) d × d 100%. d For d this d study, d(91 dpatients d÷ d106
dsample dsize) d× d100% d= d0.858 d× d100% d= d85.8% d= d86%. dThe d dfinal danswer d is
d rounded d to d the d nearest d whole d percent d as d directed d in d the d question. d You d could
d have dalso dsubtracted dthe d14% dof dpatients dtreated dwith dantidepressants dfrom d100% dand
dobtained dthe d86% d who d were d not d treated d with d an d antidepressant.
9. What dwas dthe dpurpose dof dthe d6-minute dwalk dtest d(6MWT)? dWould dthe d6MWT
dbe duseful din dclinical dpractice?
Answer: dHa det dal. d(2018) dstated, d“The d6-min dwalk dtest d(6MWT) dis da dmeasure dof dthe
dsubmaximal, dsteady-state dfunctional dcapacity” dof dcardiac dpatients. dThis dtest dwould dbe da
dquick, deasy dway dto ddetermine da dcardiac dpatient’s dfunctional dstatus din da dclinical d
dsetting. d dThis d dfunctional d dstatus dscore d could d be d used d to d determine d the d treatment
d plan d to d promote d or d maintain d functional d statusdof dcardiac dpatients.
, Answer d Guidelines d for d Questions d to d Be d Graded AG d1-3
10. How dwas dexercise dconfidence dmeasured din dthis dstudy? dWhat dwas dthe dlevel dof
dmeasurementdfor dthe dexercise dconfidence dvariable din dthis dstudy? dProvide da
drationale dfor dyour danswer. dAnswer: dExercise dconfidence dof dthe dpatients dwith dheart
dfailure d(HF) din dthis dstudy dwas dmeasureddwith dthe dExercise dConfidence dScale dthat
dincluded dfour dsubscales dfocused don dwalking, dclimbing,dlifting d objects d of d graded
d weight, d and d running d (see d the d study d narrative). d This d was d a d rating d scaledwith dvalues
dranging dfrom d0 dto d100. dThe dpatients’ dscores dfor dthe dTotal dExercise dConfidence dscale
dand d the d subscales d were d considered d interval-level d data d and d analyzed d with d parametric
d statistics,dsuch das dmeans dand dSDs d(see dthe dstudy dnarrative; dWaltz det dal., d2017).
