StatisticsforNursing t t
t ResearchAWorkbook t t
forEvidence-Based
t t
t Practice3rdEdition
t t
t SusanGroveDaisha
t t
, AnswerGuidelinesforQuestionstoBeGraded t t t t t t
EXERCISE
Identifying Levels of t
1
t t
Measurement: Nominal, t t
t Ordinal, Interval, and Ratio t t t
Thequestionsareinboldfollowedbyanswers.
t t t t t t t
1. In Table 1, identify the level of measurement for the current therapy variable. Provide a
t t t t t t t t t t t t t t
rationale for your answer.
t t t t
Answer: The current therapy variable was measured at the nominal level. These drug categorieswere
t t t t t t t t t t t t t t
probably developed to be exhaustive for this study and included the categories of drugs the subjects
t t t t t t t t t t t t t t t t
were receiving. However, the categories are not exclusive, since patients are usually on more than one
t t t t t t t t t t t t t t t t
category of these drugs to manage their health problems. The current therapies are not measured atthe
t t t t t t t t t t t t t t t t t
ordinallevel becausetheycannot berankordered,sincenodrugcategory can be considered more or less
t t t t t t t t t t t t t t t t t t
beneficial than another drug category (see Figure 1-1; Grove & Gray, 2019).
t t t t t t t t t t t t
2. What is the mode for the current therapy variable in this study? Provide a rationale for
t t t t t t t t t t t t t t t
your answer.
t t
Answer: The mode for current therapy was βblocker. A total of 100 (94%) of the cardiac patients
t t t t t t t t t t t t t t t t t
were receiving this category of drug, which was the most common prescribed drug for this
t t t t t t t t t t t t t t
sample.
t
3. What statistics were conducted to describe the BMI of the cardiac patients in this sample?
t t t t t t t t t t t t t t
Discuss whether these analysis techniques were appropriate or inappropriate.
t t t t t t t t t
Answer: BMI was described with a mean and standard deviation (SD). BMI measurement resulted in
t t t t t t t t t t t t t t
ratio-level data with continuous values and an absolute zero (Stone & Frazier, 2017). Ratio- level
t t t t t t t t t t t t t t t
data should be analyzed with parametric statistics such as the mean and SD (Grove & Gray, 2017;
t t t t t t t t t t t t t t t t t
Knapp, 2017).
t t
4. Researchers usedthefollowingitemto measure registered nurses’(RNs)incomein astudy:What t t t t t t t t t t t t t t
category identifies your current income as an RN?
t t t t t t t t
a. Lessthan$50,000
t t t
b. $50,000to 59,999
t t t
c. $60,000to69,999
t t t
d. $70,000 to 80,000
t t t
e. $80,000orgreater
t t t
What level of measurement is this income variable? Does the income variable follow the
t t t t t t t t t t t t t
rules outlined in Figure 1-1? Provide a rationale for your answer.
t t t t t t t t t t t
Answer: In this example, the income variable is measured at the ordinal level. The income catego- ries
t t t t t t t t t t t t t t t t
are exhaustive, ranging from less than $50,000 to greater than $80,000. The two open-ended
t t t t t t t t t t t t t t
AG 1-1 t
,AG 1-2 t Answer Guidelines for Questions to Be Graded t t t t t t
categoriesensurethatallsalarylevelsarecovered.Thecategoriesarenotexclusive,sincecatego-ries (d) t t t t t t t t t t t t t t t t
and (e) include an $80,000 salary, so study participants making $80,000 might mark either (d) or (e)
t t t t t t t t t t t t t t t t t
or both categories, resulting in erroneous data. Category (e) could be changed to greater than
t t t t t t t t t t t t t t t
$80,000, making the categories exclusive. The categories can be rank ordered from the lowest salary
t t t t t t t t t t t t t t t
to the highest salary, which is consistent with ordinal data (Grove & Gray, 2019; Waltz et al., 2017).
t t t t t t t t t t t t t t t t t t
5. What level of measurement isthe CDSscore? Provide arationale for your answer.
t t t t t t t t t t t t t
Answer: The CDS score is at the interval level of measurement. The CDS is a 26-item Likert scalet t t t t t t t t t t t t t t t t
developed to measure depression in cardiac patients. Study participants rated their symp- toms on a
t t t t t t t t t t t t t t t
scale of 1 to 7, with higher numbers indicating increased severity in the depression symptoms. The
t t t t t t t t t t t t t t t t
total scores for each subject obtained from this multi-item scale are considered to be at the interval
t t t t t t t t t t t t t t t t t
level of measurement (Gray et al., 2017; Waltz et al., 2017).
t t t t t t t t t t t
6. Were nonparametric or parametric analysis techniques used to analyze the CDS scores for the
t t t t t t t t t t t t t
cardiac patients in this study? Provide a rationale for your answer.
t t t t t t t t t t t
Answer: Parametric statistics, such as mean and SD, were conducted to describe CDS scores
t t t t t t t t t t t t t
for study participants (see Table 1). CDS scores are interval-level data as indicated in Questions 5, so
t t t t t t t t t t t t t t t t t
parametric statistics are appropriate for this level of data (Gray et al., 2017; Kim & Mallory, 2017).
t t t t t t t t t t t t t t t t t
7. Is the prevalence of depression linked to the NYHA class? Discuss the clinical importance of
t t t t t t t t t t t t t t
this result.
t t
Answer: The study narrative indicated that the prevalence of depression increased with the greater
t t t t t t t t t t t t t
NYHA class. In NYHA class III, 64% of the subjects were depressed, whereas 11% of thesubjects were
t t t t t t t t t t t t t t t t t t
depressed in NYHA class I. Thus, as the NYHA class increased, the number of sub- jects with depression
t t t t t t t t t t t t t t t t t t
increased. This is an expected finding because as the NYHA class increases, cardiac patients have more
t t t t t t t t t t t t t t t t
severe physical symptoms, which usually result in emotional distress, such as depression. Nurses need
t t t t t t t t t t t t t t
to actively assess cardiac patients for depression, especially those in higher NYHA classes, so they
t t t t t t t t t t t t t t t
might be diagnosed and treated as needed.
t t t t t t t
8. What frequency and percent of cardiac patients in this study were not being treated with an
t t t t t t t t t t t t t t t
antidepressant? Show your calculations and round your answer to the nearest whole percent
t t t t t t t t t t t t t
(%).
t
Answer: A total of 106 cardiac patients participated in this study. The sample included 15 patients
t t tt tt tt tt tt tt tt tt tt tt tt t t
who were receiving an antidepressant (see Table 1). The number of cardiac patients not treated for
t t t t t t t t t tt tt tt t t t t
depression was 91 (106 – 15 = 91). The group percent is calculated by the following
t t t t t t t t t t t t t t t t
tformula: (group frequency ÷ total sample size) × 100%. For this study, (91 patients ÷ 106 t t t t t t t t t t t t t t t
sample size) × 100% = 0.858 × 100% = 85.8% = 86%. The final answer is rounded to the
t t t t t t t t t t t t t t t t t t t t
nearest whole percent as directed in the question. You could have also subtracted the 14% of
t t t t t t t t t t t t t t t t
patients treated with antidepressants from 100% and obtained the 86% who were not treated with an
t t t t t t t t t t t t t t t t
antidepressant.
t
9. What was the purpose of the 6-minute walk test (6MWT)? Would the 6MWT be useful in
t t t t t t t t t t t t t t t
clinical practice?
t t
Answer: Ha et al. (2018) stated, “The 6-min walk test (6MWT) is a measure of the submaximal, t t t t t t t t t t t t t t t t
steady-state functional capacity” of cardiac patients. This test would be a quick, easy way to
t t t t t t t t t t t t t t t
determine a cardiac patient’s functional status in a clinical setting. This functional status score
t t t t t t t t t t t t t t t t t t
could be used to determine the treatment plan to promote or maintain functional status of
t t t t t t t t t t t t t t t
cardiac patients.
t t
, Answer Guidelines for Questions to Be Graded
t t t t t t AG 1-3
t
10. How was exercise confidence measured in this study? What was the level of measurementfor
t t t t t t t t t t t t t t
the exercise confidence variable in this study? Provide a rationale for your answer. Answer:
t t t t t t t t t t t t t t
Exercise confidence of the patients with heart failure (HF) in this study was measuredwith the
t t t t t t t t t t t t t t t t
Exercise Confidence Scale that included four subscales focused on walking, climbing,lifting
t t t t t t t t t t t t
objects of graded weight, and running (see the study narrative). This was a rating scalewith values
t t t t t t t t t t t t t t t t t
ranging from 0 to 100. The patients’ scores for the Total Exercise Confidence scaleand the subscales
t t t t t t t t t t t t t t t t t
were considered interval-level data and analyzed with parametric statistics,such as means and
t t t t t t t t t t t t t
SDs(see the study narrative; Waltz et al., 2017).
t t t t t t t t t