Comparison of information obtained by operative note abstraction with that recorded on a standardized data collection form

Background. The Ischemic Optic Neuropathy Decompression Trial compared optic nerve decompression surgery with careful follow-up for treatment of patients with nonarteritic ischemic optic neuropathy. Surgeons submitted a standardized data collection form and operative notes for 123 patients randomized to and undergoing surgery. The purpose of this study was to see whether operative notes have sufficient and reliable data to avoid development of a surgery data collection form in future trials. Methods. We abstracted data from Ischemic Optic Neuropathy Decompression Trial patient operative notes, calculated the proportion of completed responses, and compared abstracted responses with those originally recorded on corresponding case report forms. Results. Variables used to identify persons, dates, or eye (left/right) were reported 100% of the time on operative notes and with excellent agreement with those recorded on the case report form (median agreement, 100%; range, 95% to 100%). Categoric variables, used to establish the characteristics of surgical steps, were also reported reliably on operative notes (median agreement, 84%; range, 0 to 100%). Open-ended variables tended to be reported more frequently on operative notes (exact agreement, 57% and 34 %, respectively, for complications and postoperative medications). Quantitative variables were infrequently reported but correlated well with values reported on the data collection forms (Pearson correlation coefficients, 0.78, 0.79, 0.94, 0.96). For many variables, disagreements were minor and often were related to interpretation of the operative notes by the abstractor. Conclusion. In our trial, operative note abstraction adequately documented surgery date and surgeon and provided more complete.information than the standardized report form with respect to complications but did not provide complete information for other variables.