Table 1

Comparison of visual analogue scale pain scores of group A (unaffected by potential carry-over effect) and group B (affected by potential carry-over effect)

VAS pain baselineVAS pain placebo periodPlacebo response (difference in VAS)*
MeanSD (95% CI)MeanSD (95% CI)MeanSD(95% CI)
Group A (n=10)
Unaffected by potential carry-over effect
7.521.52 (6.43 to 8.60)6.551.54 (5.45 to 7.65)−0.971.85 (−2.29 to 0.35)
Group B (n=11)
Affected by potential carry-over effect
6.022.47 (4.36 to 7.68)4.551.82 (3.33 to 5.78)−1.471.81 (−2.69 to 0.25)
MeanSD (95% CI)
Carry-over effect (difference in placebo response between group A and group B)0.501.83 (−1.17 to 2.17)
  • *Difference in VAS pain between VAS pain baseline and VAS pain efficacy in placebo period.

  • VAS, visual analogue scale.