The quote that opens the Institute ofMedicine’s 2007 report, TheLearningHealthcare System,1 succinctly captures the crux of the knowing-doing gap: the gap that exists between what weknowworksbasedon thebest available evidence andwhat weclinicallypractice. It is this gap that the evolving field of implementation science or knowledge translation seeks tomend. In this issueofJAMA InternalMedicine,Watersand colleagues2 evaluate the effectiveness of financial incentives directed toward clinical outcomes for closing theknowing-doinggap. Specifically, they examine the effect of the October 2008 Centers for Medicare and Medicaid Services (CMS) Nonpayment for HospitalAcquired Conditions Initiative on the prevention of 4 clinical “never events”: catheter-associated urinary tract infections (CAUTIs), central line–associated bloodstream infections (CLABSIs), falls, and pressure ulcers. Using multiple time points before and after implementationof theCMS initiative,Waters et al2 found that the slopedetermined by themonthly rate of CAUTIs andCLABSIs for the 9 monthsbefore theCMS initiativedroppedsignificantlyafter its implementation,whereas theslopedeterminedbythemonthly rate of falls and pressure ulcers was unaltered. These findings are different from those described in a seminal study published in 2012 by Lee and colleagues,3 which suggested no effect of the CMS financial penalties on hospital-acquired infection (HAI) rates. Two differences in the studies could have accounted for the inconsistent findings. First, the studybyLee et al3 examined fewer and different hospitals than the present study byWaters et al.2 Lee and colleagues evaluated 398 hospitals reportingHAI rates to theNationalHealthcareSafetyNetwork,whereasWatersandcolleaguesexaminedmore than600 hospitals reporting HAIs to the National Database of Nursing Quality Indicators. Second, because of differences in the reporting networks used in the studies (ie, National Healthcare Safety Network vs National Database of Nursing Quality Indicators), the study by Lee et al had 33months of HAI data availablebefore implementationof theCMS initiative,but thestudy byWaters et al had only 9months of preimplementation data. This limited amount of data may have been inadequate to define the true trend in HAI rates before the CMS initiative. The absence of an effect of the CMS initiative on the other 2 “never events” evaluated in theWaters et al study (falls and pressure ulcers) suggests thismayhave been the case. For both of these outcomes, the Waters et al study had 27 months of preimplementationdataavailable forexamination,similar to theamount available for the HAI outcomes in the Lee et al study. Despite the differences in preimplementation data available for the HAIs vs falls and pressure ulcers, Waters and colleagues2 suggest another reason for the differential effect of the CMS initiative on HAIs. They argue that because there was more robust evidence on how to prevent CLABSIs and CAUTIs at the time of the CMS initiative, hospitals weremore successful at reducing these never events when provided the Author Audio Interview at jamainternalmedicine.com