Health care efficiency is a comparison of delivery system outputs, such as physician visits, relative value units, or health outcomes, with inputs like cost, time, or material. Efficiency can be reported then as a ratio of outputs to inputs or a comparison to optimal productivity using stochastic frontier analysis or data envelopment analysis. An alternative approach is to look at latency times and delay times between a care order and completion of work, and stated accomplishment in relation to estimated effort.