The study assumed that heath benefits are comparable between groups, which seems reasonable given the nature of the strategies being compared (drug preparation strategies). The cost study was well designed and the drugs prepared appear to reflect those normally expected in a local hospital, although the authors noted that some non-routine preparations were also made. Costs relevant to both groups were calculated although the authors noted that the reuse of medications requires quality assurance support and cold chain validation, the costs of which were not calculated. These costs should be determined in order to assess the true level of resources which would be saved for alternative use. The study does not state the skill levels of the pharmacists, technicians and nurses involved and, whilst sensitivity analysis has been performed on the costs of labour, the time taken by different staff grades in the preparation of doses might also be subject to variation.