WK 5 dis Data

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NURS_8211_WK5_RRT_ANOVA.docx

This student completed a Rapid Response Team (RRT) analysis with a sample of 75 completed RRTs. The student provided a survey on completed Rapid Response Team (RRT) calls asking activating nurses to respond to seven questions about the RRT, indicating their level of satisfaction with the RRT call. Each of the seven questions was measured on a 5-point scale where 1 indicated strong dissatisfaction with the RRT process and 5 equaled a very strong satisfaction with the way the RRT was conducted. Thus, the highest possible score on the RRT evaluation survey was 35 (5 x 7), and the lowest possible score was 7 (i.e., 7 x 1). Higher scores indicate higher satisfaction with the RRT response, and lower scores indicate lower satisfaction with the RRT response.

This sample had 75 observations. This time, there were no entries in the “other” category, only cardiac, respiratory, and neurology.

Description of the Call 1= cardiac 2= respiratory 3= neurology 4= other

Case Processing Summary

Description of the Call 1= cardiac 2= respiratory 3= neurology 4= other

Cases

Valid

Missing

Total

N

Percent

N

Percent

N

Percent

RRT Evaluation

cardiac

42

100.0%

0

0.0%

42

100.0%

respiratory

12

100.0%

0

0.0%

12

100.0%

neurology

21

100.0%

0

0.0%

21

100.0%

Descriptives

Description of the Call 1= cardiac 2= respiratory 3= neurology 4= other

Statistic

Std. Error

RRT Evaluation

cardiac

Mean

30.0238

.99095

95% Confidence Interval for Mean

Lower Bound

28.0225

Upper Bound

32.0251

5% Trimmed Mean

30.8466

Median

31.0000

Variance

41.243

Std. Deviation

6.42210

Minimum

5.00

Maximum

35.00

Range

30.00

Interquartile Range

7.00

Skewness

-2.152

.365

Kurtosis

5.323

.717

respiratory

Mean

31.0000

.95346

95% Confidence Interval for Mean

Lower Bound

28.9014

Upper Bound

33.0986

5% Trimmed Mean

31.0000

Median

31.0000

Variance

10.909

Std. Deviation

3.30289

Minimum

27.00

Maximum

35.00

Range

8.00

Interquartile Range

7.00

Skewness

.000

.637

Kurtosis

-1.872

1.232

neurology

Mean

13.9524

2.81955

95% Confidence Interval for Mean

Lower Bound

8.0709

Upper Bound

19.8339

5% Trimmed Mean

13.5582

Median

7.0000

Variance

166.948

Std. Deviation

12.92082

Minimum

.00

Maximum

35.00

Range

35.00

Interquartile Range

21.50

Skewness

.718

.501

Kurtosis

-.999

.972

Notice the difference in the means by type of RRT. It seems as if there is a difference. But remember, this is just descriptive statistics. To see if there is statistical significance, we need an inferential test. This time, I can assure you that the data meets the assumptions of the one-way ANOVA test, which is what we are going to do next.

One-Way

ANOVA

RRT Evaluation

Sum of Squares

df

Mean Square

F

Sig.

Between Groups

4020.391

2

2010.196

28.104

<.001

Within Groups

5149.929

72

71.527

Total

9170.320

74

Now, there is a lot of information in these results, most of which you do not see mentioned in a published study that used ANOVA. Sometimes, you see the F statistic (28.104). In Salkind and Frey (2019), you can learn how to actually do an ANOVA in Excel, which is for your information. In this course, we are most concerned about understanding the basic elements of the test and how to interpret it.

So, the F statistic is accompanied by the all-important p value in the table above, and as you can see, it indicates a statistically significant result. With a p value of <.001, we can be confident that the differences are not due to chance and more likely to some factor. But the ANOVA level of significance does NOT tell us WHERE those differences are. Is it between cardiac and respiratory, cardiac and neurology, or respiratory and neurology? Three groups, three possible comparisons.

A one-way ANOVA test is used when there is more than one comparison (that would be two groups and an independent sample t test). As we have three groups, we also have three comparisons. So, a post hoc test helps to fathom just where those comparisons are located.

Post Hoc Tests

There are a number of different types of post hoc comparisons. I chose the Scheffe test.

Multiple Comparisons

Dependent Variable: RRT Evaluation

Scheffe

(I) Description of the Call 1= cardiac 2= respiratory 3= neurology 4= other

(J) Description of the Call 1= cardiac 2= respiratory 3= neurology 4= other

Mean Difference (I-J)

Std. Error

Sig.

95% Confidence Interval

Lower Bound

Upper Bound

cardiac

respiratory

-.97619

2.76832

.940

-7.8958

5.9434

neurology

16.07143*

2.26032

<.001

10.4216

21.7212

respiratory

cardiac

.97619

2.76832

.940

-5.9434

7.8958

neurology

17.04762*

3.06049

<.001

9.3977

24.6975

neurology

cardiac

-16.07143*

2.26032

<.001

-21.7212

-10.4216

respiratory

-17.04762*

3.06049

<.001

-24.6975

-9.3977

*. The mean difference is significant at the 0.05 level.

As you can see, the Scheffe post hoc test computes the difference in the means and then calculates the significance level. (Behind the scenes in the statistical software, there are actually several independent sample t tests that make these two-group comparisons.)

Note the lack of statistical significance between cardiac and respiratory. That is likely because the difference was so small—less than a point. You would need a huge sample, far greater than 75 cases, to be able to see this statistically. But notice that the difference between cardiac and neurology is much bigger, and the p value is also statistically significant ( p <.001). Finally, notice that the difference between respiratory and neurology is also statistically significant (also with a p value of < .001).