It is the consensus of the writing committee that these structural measures can provide important contribu- tions to the assessment of care equity and safety without imposing undue data collection burden on hospitals or practitioners. For both of the PCI case volume speci c structural measures, existing standards encourage reporting (24). However, although the experience of the operator and the hospital performing PCI has been associated with improved outcomes, it is not clear what speci c threshold volume of PCI cases represents a true clinically important indicator. Thus, the intent of these case-volume measures is to encourage data collection rather than speci c targets. Nallamothu et al. JACC Vol. 63, No. 7, 2014 ACC/AHA/SCAI/AMA-PCPI/NCQA February 25, 2014:722 45 In addition, the writing committee recognizes the unique challenges of accurately documenting operator volume because some data systems cannot capture data for opera- tors who work at multiple sites, and self-reporting can have limitations. Given the challenges in capturing the required data, the limitations of the evidence supporting a speci c threshold for operator volume, and the potential for un- intended consequences, the writing committee designated the operator volume metric for use only in internal quality improvement because it does not comply with all the desirable attributes required (see Table 4 and footnotes to Table 1). The writing committee believes it is important to encourage tracking of operator volume, but it would not be appropriate to evaluate operators on the basis of volume of procedures alone, so this measure should not be used in accountability or public reporting programs. 5. Measures Included in This Set 5.1. Comprehensive Documentation of Indications for PCI Comprehensive documentation of the indication for PCI is an absolute requirement for performing the procedure. 