The computer program SPSS 16.0 for Windows (SPSS Inc.,
Chicago, IL, USA) was used for all statistical analyses. A
power analysis was performed with respect to VAS pain. A
mean of 3Æ5 and SD 2Æ4 were expected. A clinically significant
difference of 30% and statistically significant level of
a < 0Æ05 were expected. With a power of 80%, the sample
size of 83 patients for each group was calculated as being
appropriate.