LAUSR

over time within the universe of non-ACSNSQIP hospitals. Two recent articles conducted this type of analysis (differencein-differences) on the basis of data within 2 distinct sources—Medicare and the University HealthSystem Consortium. In both of these analyses, there was no association between hospital-based participation in the ACS-NSQIP and improvements in postoperative outcomes over time. The authors do acknowledge this flaw in their study design, stating that a lack of control group exists with equivalent robust data. Despite this acknowledgment, the authors continue to state that their study (and previous studies) leads them to believe that ‘‘participation in ACS-NSQIP improves quality to a greater extent than secular trend (or is a critical component of observed trends).’’ They proceed to estimate that a large hospital participating in the ACSNSQIP will avoid as many as 14 deaths and 300 complications over 5 years of participation. The implication is that nonACS-NSQIP hospitals will not observe these same improvements. However, without a comparison group, it seems impossible to estimate the number of lives saved and complications avoided from participation alone. The ACS-NSQIP should be applauded for continuing to encourage the measurement of surgical outcomes. Participation in a quality measurement platform is, however, only 1 part of a comprehensive approach to quality improvement. For real quality improvement to take place, outcomes data need to be used to guide changes in practice. Across the country, hospitals are engaged in a broad range of quality improvement efforts, and as a result, rates of adverse surgical outcomes are improving steadily over time. We caution against a conclusion that participation in the ACS-NSQIP is directly responsible for a degree of improvement in outcomes that is greater than this national trend.