Outcomes after Abdominal Aortic Aneurysm Repair: Comparison of Mortality Defined by Centralized VA Patient Treatment File Data versus Hospital-Based Chart Review

Abstract

Background. Outcomes after abdominal aortic aneurysm (AAA) repair have been reported by individual Veterans Affairs medical centers (VAMCs) and for the entire VA patient population.Purpose. This study was done to determine whether outcomes defined using VA Patient Treatment File (PTF) data were comparable to those defined by direct chart review in those undergoing repair of intact AAA.Methods. Focused chart review was performed in all veterans undergoing such AAA repair in a sample of VAMCs (n = 5) for separate 1-year periods during fiscal years (FY) 1991–1993. A previous report of outcomes after AAA repair for all veterans in DRGs 110 and 111 during FY 1991–1993 was based on PTF data that were further analyzed by Patient Management Category (PMC) software. Outcomes after AAA repair were defined in a similar fashion using PTF data and PMC analysis in the same sample VAMCs for which direct chart review data were available. Outcomes defined by chart review were then compared to those based on PTF data.Results. Three of the 69 patients undergoing repair of intact AAA for which chart review data were available were assigned to DRGs other than 110 and 111 and, by definition, were not included in the PTF-derived database. Nine of 10 additional patients undergoing chart review were not identified as having undergone AAA repair by PMC software: 7 had procedure codes 39.25 instead of more standard AAA repair codes 38.34 or 38.44. Two additional patients with codes 38.64 or 38.66 were not identified as having undergone AAA repair by PMC software. The 10th patient not included in the PTF-derived database underwent additional operative procedures. Of the 13 patients missed by the combined PTF and PMC outcome analyses but identified by chart review, none died or had cardiac complications. One of these 13 patients had pulmonary complications based on chart review and PTF but was excluded by PMC analysis. There remained a total of 56 patients at the five sample VAMCs common to the PTF-derived and chart-derived databases identified as having undergone repair of intact AAA. There were two in-hospital deaths in these patients, and both were identified by each approach to outcome assessment. Four of these 56 patients had postoperative cardiac complications (ICD-9-CM code 997.10) which were identified by both PTF and chart review. Postoperative pulmonary complications (ICD-9-CM code 997.30) were present in 4 of the 56 cases and were also identified by both PTF-based and chart-based outcome analyses.Conclusions. All deaths as well as cardiac or respiratory complications identified by chart review at the study hospitals were also affirmed by the PTF. Due to study methodologies (which restricted analysis to those in DRGs 110 and 111 and which included secondary analyses of PTF data by PMC software), 19% of patients who underwent repair of intact AAA identified by hospital-based chart review were excluded from the PTF-based outcome analysis. Outcomes defined using large databases such as the VA PTF may be comparable to those defined by chart review if study methodologies permit. Discrepancies in outcome assessment between direct chart review and large database analysis in the present study were due to methodologies used, not to deficiencies, per se, in PTF data.