Exercise:
The following data show the operation time of 3 hospitals for the same surgical procedure.
1) Analyze whether there are statistically significant differences among hospitals.
2) If there are significant differences among hospitals, find which hospitals have statistical differences in the operation time.
Hospital A: 57, 45, 77, 55, 54 Hospital B: 58, 42, 41, 50, 47 Hospital C: 67, 67, 77, 92, 95 minutes
Comparative Verification Test
MEDIAN test (Chi-square test): StaFinale, 0.01376; SPSS, 0.014; EZR, Not Done.
When dividing data into two groups by the median, the P value changes depending on which group the median is included in. In SPSS, the P value is displayed as the value when the same value as the median is included below the median. To display the P value “0.031” when the value is included above the median, users click the Custom button and enter a customized median value slightly smaller than the actual value to recalculate.
Pairwise comparisons: StatFinale, Tukey-type test; SPSS, Chi-square test with Bonferroni correction (adjusted P-values).
See the StatFinale homepage, Median test (MEDIAN) between two independent groups.
In the StatFinale, we use the program “CHI” to perform chi-square tests and Bonferroni corrections.
EZR does not have a corresponding program.
Reports of SPSS
In SPSS, a chi-square test was performed between the two groups, and then an adjusted P value (chi-square test P value x number of combinations) was calculated using the Bonferroni method. In this case, the number of combinations was 3. We show the results in StatFinale.
※Click pics to enlarge.
