In Reply

We thank Dr. Kehlet for his comments on our article.¹  His letter raises important issues which we broadly agree with. The implementation of fast-track or “enhanced recovery” programs and the increasing use of minimally invasive surgical approaches are two examples of how surgical practice has changed in recent years, at least in some parts of the world. These may have impact on the risk of patient morbidity and mortality, particularly in the short term. Furthermore, improvements in the medical management of some chronic illnesses (e.g., ischemic heart disease) mean that the implications of such illnesses for patient health and perioperative prognostication are quite different today, compared with 20 yr ago when some of the risk-stratification tools featured in our systematic review were first developed and validated.

Thus, we agree that an approach to risk stratification is warranted which is responsive to such changes in practice and will also enable specialty-specific risks to be taken into consideration. The use of technology (such as mobile apps) and large datasets (“big data”) present opportunities to refine existing risk-stratification methodology for the modern era, leading to the development, validation, and regular reevaluation and recalibration of risk-prediction tools. However, the challenge of implementing the collection of such large datasets in a systematic manner remains significant in many healthcare systems outside the U.S. National Surgical Quality Improvement Program. The analysis of administrative data to achieve these goals may present a solution, but the accuracy and completeness of such data need evaluation in each healthcare setting where this is an option.