Measuring the quantitative performance of surgical operating lists: theoretical modelling of 'productive potential' and 'efficiency'.

We previously defined surgical list 'efficiency' as: maximising theatre utilisation, minimising over-running, and minimising cancellations. 'Efficiency' maximises output for input; 'productivity' emphasises total output. We define six criteria that any measure of productivity (better termed 'quantitative performance') needs to satisfy. We then present a theoretical analysis that fulfils these by incorporating: 'speed' of surgery (with reference to average speeds), 'patient contact' (synonymous with minimising gaps between cases), and 'efficiency' (as previously defined). 'Speed' and 'patient contact' together constitute a 'productive potential'. Our formula satisfies the pre-set criteria and yields plausible results in both hypothetical and real data sets, To be productive in these quantitative terms, teams in any specialty need to achieve minimum quality standards defined by their sub-specialty; to plan their lists to utilise the time available with no cancellations or over-runs and to work at least as fast as average with minimal gaps between cases. 'Productive potential' combined with 'efficiency' yielding 'actual productivity' in our theoretical analysis more completely describes quantitative surgical list performance than any other single measure.