How accurate is the AHRQ patient safety indicator for hospital-acquired pressure ulcer in a national sample of records?

In 2008, we conducted a retrospective cross-sectional study to determine the test characteristics of the Agency for Healthcare Research and Quality patient safety indicator (PSI) for hospital-acquired pressure ulcer (PU). We sampled 1,995 inpatient records that met PSI 3 criteria and 4,007 records assigned to 14 DRGs with the highest empirical rates of PSI 3, which did not meet PSI 3 criteria, from 32 U.S. academic hospitals. We estimated the positive predictive value (PPV), sensitivity, and specificity of PSI 3 using both the software version contemporary to the hospitalizations (v3.1) and an approximation of the current version (v4.4). Of records that met PSI 3 version 3.1 criteria, 572 (PPV 28.3%; 95% CI 23.6-32.9%) were true positive. PU that was present on admission (POA) accounted for 76% of the false-positive records. Estimated sensitivity was 48.2% (95% CI 41.0-55.3%) and specificity 71.4% (95% CI 68.3-74.5%). Reclassifying records based on reported POA information and PU stage to approximate version 4.4 of PSI 3 improved sensitivity (78.6%; 95% CI 62.7-94.5%) and specificity (98.0; 95% CI 97.1-98.9%). In conclusion, accounting for POA information and PU staging to approximate newer versions of the PSI software (v4.3) moderately improves validity.