Analysis will be on an intention to treat basis. Primary analysis will be by analysis of covariance of the NRS at the final time-point with adjustment for baseline NRS in order to improve precision of the estimated BIS versus comparison effect. Secondary analysis will more sensitively incorporate all time-points in a repeated measures linear regression to be able to detect any differences between BIS & comparison emerging/changing over time within the initial period. All analysis will be documented prior to final data collection in an analysis plan, will be addressed with two-tailed tests & be assessed at the 5% level of significance. Effects within & between arms will be summarized using means & 95% confidence intervals. If randomised effects are similar in malignant & non-malignant groups, a combined effect will be estimated allowing a narrower overall confidence interval. Analysis will be conducted using SPSS software.