Measure explainer
Healthcare-Associated Infections
Rates of infections patients can acquire while receiving care, such as central-line and catheter-associated infections, MRSA, and C. difficile.
How CMS calculates it
CMS collects healthcare-associated infection (HAI) data through the CDC's National Healthcare Safety Network (NHSN). Standardized Infection Ratios (SIRs) compare the number of infections observed at a hospital to the number that would be predicted based on national baseline data.
Why it matters
These measures give patients, clinicians, and hospital boards a standardized way to compare care quality across facilities. For healthcare-associated infections, the general rule is lower is better. Always weigh a single measure alongside the full picture — case-mix, hospital size, and whether the measure is publicly reported for the hospital in question.
How to read the scores on this site
- Score: the hospital's reported value.
- Compared to national: better than, no different from, or worse than the US average, with a color dot and text label.
- Sample: the denominator or number of cases the score is based on. Larger samples are more statistically reliable.