Patient Safety Indicators Patient Safety Indicators (PSIs). Introduction Patient Safety Indicators (PSIs) are standardized measures used to assess the quality of patient care, identify preventable medical errors, and improve hospital safety. Developed by the Agency for Healthcare Research and Quality (AHRQ), these indicators help hospitals, healthcare systems, and policymakers monitor and enhance patient safety. PSIs focus on hospital-acquired conditions (HACs), preventable complications, and medical errors that affect patient care outcomes.