Quality of Life
All three questionnaires were analysed using multi-level mixed effects models, where repeated measurements from baseline through to 2 years post-surgery were analysed as random effects with stratification factors and radiotherapy schedule forced into the model as fixed effects. Trial stratification factors included centre, axillary surgery, chemotherapy regimen and inclusion of radiotherapy boost. In addition, treatment and questionnaire form number were included as interaction terms, i.e. additional variables upon which outcomes are dependent. The multi-level mixed effects model analysis takes into consideration the type and patterns of missing data. All raw data (mean with standard deviations) are shown graphically, with adjusted point estimates and confidence intervals presented within the text and tables.