Three are identical to measures in the AHA/ASA ischemic stroke performance measure set. The Discussion provides additional comments on the measures, including the limitations of some of the current measures, opportunities for improvement, and rec- ommendations for implementation and field testing. Appendix Table A1 provides full specifications for each measure. Data Collection The process whereby data are collected for reporting of per- formance measures influences data quality, cost of assessment, and ultimately the ways that the data can be used. To maximize the reliability of data capture, a prospectively designed report form should be used. The move of hospitals and healthcare systems to electronic health records means that some data ele- ments can be automatically captured through these systems. Some data elements (eg, laboratory results or medications dis- pensed) have highly structured elements in electronic health records that facilitate automatic data abstraction, whereas other data elements (eg, baseline severity score or performance of a swallowing screen) are captured in less structured for- mats or require prospective addition of standardized elements to narrative admission and progress notes to increase compli- ance and to facilitate data abstraction. Capturing and verifying the accuracy of these elements and other crucial clinical data Hemphill et al Performance Measures for ICH e247 (eg, a contraindication to a process) may still require manual chart review and abstraction. Regardless of how the data are collected, the reliability of data abstraction methods used in performance measure assessment should be validated by inde- pendent review of a subset of cases consisting of manual chart review (in the case of electronically derived performance data) or independent abstracter review (in the case of chart review based performance data). 