How valid is the AHRQ Patient Safety Indicator "postoperative hemorrhage or hematoma"?

BACKGROUND

Postoperative hemorrhage or hematoma (PHH), an Agency for Healthcare Research and Quality Patient Safety Indicator, uses administrative data to detect cases of potentially preventable postsurgical bleeding requiring a reparative procedure. How accurately it identifies true events is unknown. We therefore determined PHH's positive predictive value.

STUDY DESIGN

Using Patient Safety Indicator software (v.3.1a) and fiscal year 2003-2007 discharge data from 28 Veterans Health Administration hospitals, we identified 112 possible cases of PHH. Based on medical record abstraction, we characterized cases as true (TPs) or false positives (FPs), calculated positive predictive value, and analyzed FPs to ascertain reasons for incorrect identification and TPs to determine PHH-associated clinical consequences and risk factors.

RESULTS

Eighty-four cases were TPs (positive predictive value, 75%; 95% CI, 66-83%); 63% had a hematoma diagnosis, 30% had a hemorrhage diagnosis, 7% had both. Reasons for FPs included events present on admission (29%); hemorrhage/hematoma identified and controlled during the original procedure rather than postoperatively (21%); or postoperative hemorrhage/hematoma that did not require a procedure (18%). Most TPs (82%) returned to the operating room for hemorrhage/hematoma management; 64% required blood products and 7% died in-hospital. The most common index procedures resulting in postoperative hemorrhage/hematoma were vascular (38%); 56% were performed by a physician-in-training (under supervision). We found no substantial association between physician training status or perioperative anticoagulant use and bleeding risk.

CONCLUSIONS

PHH's accuracy could be improved by coding enhancements, such as adopting present on admission codes or associating a timing factor with codes dealing with bleeding control. The ability of PHH to identify events representing quality of care problems requires additional evaluation.