Study end points. The primary efficacy endpoint was Pain Intensity
Difference (PID) on day 1, day 2, and day 3. PID is the difference
between the 24-h NRS scores before and after therapy.
The secondary efficacy endpoints were the number of
patients who experienced breakthrough pain and the number
who used IR morphine. Breakthrough pain is common among
patients with bone cancer and refers to a sudden, short-term
exacerbation of pain superimposed on a background of continuous
pain. Breakthrough pain includes spontaneous pain during
a resting state and pain caused by changes in bone stress during
activity.15
Additional statistical analyses included the Short Form-6
Dimensions (SF-6D) quality-of-life scale,16 which has a total of
six items: physical functioning, role limitation, social functioning,
bodily pain, mental health and vitality. The highest possible
score is 31, and the lowest possible score is 6. A higher score
indicates poorer quality of life. The scale is easy to use and
comprehensively reflects patients’ quality of life. These parameters
were measured on days 0 and 3, to represent baseline and
end of efficacy-phase scores. The general impression (GI)18 of
patient satisfaction with treatment, as measured on a 5-point
categorical verbal rating scale (0 = poor; 1 = fair; 2 = good;
3 = very good; and 4 = excellent), was also evaluated at the end
of the phase.
Statistical analysis
Quantitative data (continuous variables) were shown as
mean ± standard deviation. Within- and between-group variables
were analysed using one-way analysis of variance. Qualitative
data (categorical variables) were analysed using the chisquared
test and the Fisher’s exact test. The significance level a
was set at 0Æ05. All the analyses were carried out using spss version
13.0. (SPSS Inc., Chicago, IL, USA)