Electromyography of the External Anal Sphincter during Micturition and Electrophysiological Bulbocavernosus Reflex in Healthy Spayed Female Canines
Table 2
Computations made with a series of 10 EBCR onset latency values (ms).
Method
Untransformed data
Box-Cox transformed data
Nonparametric
Standard
Robust
Standard
Robust
N
10
10
10
10
10
Mean
18.72
1.47
Median
18.40
18.57
1.47
1.47
SD
2.69
2.87
0.06
0.06
Minimum
15.2
15.2
1.39
1.39
Maximum
23.5
23.5
1.56
1.56
λ1 coefficient Box-Cox
−5.185
−5.185
λ2 coefficient Box-Cox
−0.484
−0.484
P value Anderson–Darling
0.685
0.923
Symmetry test for robust
0.746
0.998
Outliers Dixon
Outliers Tukey
0
0
0
0
Suspect data Tukey
0
0
0
0
Lower limit of reference interval
12.34a
12.07a
13.92a
13.85a
Upper limit of the reference interval
25.10a
25.07a
27.30a
27.44a
90% CI for lower limit
9.98
12.65
15.10
15.59
90% CI for upper limit
22.22
22.46
27.81
34.50
Comments
The sample size is too small (n < 40) to compute a nonparametric reference interval. Data should be analyzed with the nonparametric method. As an alternative, the robust method with a Box-Cox transformation may be used after checking the symmetry of the distribution. The robust method with a Box-Cox transformation of the data gives the following reference interval: [13.85; 27.44]. The sample size is too small (n < 20) to compute the CIs for the limits of the reference interval obtained with the robust method with Box-Cox transformation.
