The Patient Safety Indicator Perioperative Pulmonary Embolism or Deep Vein Thrombosis: Is there associated surveillance bias in the Veterans Health Administration?

BACKGROUND: Studies disagree whether surveillance bias is associated with perioperative venous thromboembolism (VTE) performance measures. A prior VA study used a chart-based outcome; no studies have used the fully specified administrative data-based AHRQ Patient Safety Indicator, PSI-12, as their primary outcome. If surveillance bias were present, we hypothesized that inpatient surveillance rates would be associated with higher PSI-12 rates, but with lower post-discharge VTE rates.

METHODS: Using VA data, we examined Pearson correlations between hospital-level VTE imaging rates and risk-adjusted PSI-12 rates and post-discharge VTE rates. To determine the robustness of findings, we conducted several sensitivity analyses.

RESULTS: Hospital imaging rates were positively correlated with both PSI-12 (r = 0.24, p = 0.01) and post-discharge VTE rates (r = 0.16, p = 0.09). Sensitivity analyses yielded similar findings.

CONCLUSIONS: Like the prior VA study, we found no evidence of PSI-12-related surveillance bias. Given the use of PSI-12 in nationwide measurement, these findings warrant replication using similar methods in the non-VA setting.