When I started in hospital quality research in 2011, the Leapfrog Group was already one of the most influential voices in patient safety advocacy. Their hospital safety grade — assigned twice annually — has become a shorthand used by healthcare journalists, insurance companies, and increasingly by patients themselves. Understanding what it measures, and where its limits are, makes you a more sophisticated consumer of this information.

What the Leapfrog Grade Measures

The Leapfrog Hospital Safety Grade uses approximately 28 measures across six safety domains to assign letter grades from A through F. Unlike the CMS star rating which is outcome-focused, Leapfrog emphasizes a mix of structural/process measures alongside outcomes:

🐸 Leapfrog Grade Components

  • Infections (HAI) — Standardized infection ratios for CLABSI, CAUTI, SSI, C. difficile, and MRSA — heavily weighted in the score
  • Problems During Surgery — CMS patient safety indicators for complications
  • Practices to Prevent Errors — Structural measures including CPOE (computerized physician order entry) adoption, ICU physician staffing, bar code medication administration, and hand hygiene protocol
  • Managing Serious Errors — Procedures for responding when serious errors occur, including error disclosure policies
  • Safety Problems — Serious reportable events data
  • Communication and Care Coordination — Discharge processes, care coordination metrics

Leapfrog vs. CMS Stars: Key Differences

The most important difference is that Leapfrog incorporates structural safety measures — the systems and technology a hospital has in place — not just outcomes. A hospital might have excellent outcomes in recent data while having structural gaps (no CPOE, inadequate ICU staffing) that create latent risk.

CMS stars are entirely outcomes-based from claims data. Leapfrog is roughly 30% structural/process and 70% outcomes. For patients, using both together gives a more complete picture than either alone.

The Self-Reporting Problem

Many Leapfrog measures rely on voluntary hospital surveys. Hospitals that don't respond to the Leapfrog survey have their grade calculated from publicly available CMS data only — which typically produces a lower grade. This creates a selection effect: hospitals that perform well on Leapfrog's structural measures tend to participate; hospitals with gaps may decline.

Leapfrog's response rate has improved significantly — most major hospitals now participate. But for rural and small hospitals, you may see grades based primarily on CMS data rather than full Leapfrog survey data.

When Leapfrog and CMS Stars Disagree

They frequently do, and this is informative rather than confusing. When a hospital has a 5-star CMS rating but a Leapfrog B or C, it often means outcomes are strong but structural safety systems have gaps. When a hospital has a 3-star CMS rating but a Leapfrog A, it often means strong safety systems but patient mix complexity affecting the outcomes-based CMS calculation.

My recommendation: weight clinical outcomes (CMS mortality, HAI) heavily for predicting your personal risk, and use Leapfrog structural measures as a secondary lens for evaluating safety culture and systems.