In fourteen years of reviewing hospital quality data, nothing has struck me as more preventable — or more underappreciated by patients — than hospital-acquired infections. The CDC estimates that on any given day in the United States, about 1 in 31 hospital patients has a healthcare-associated infection. Over the course of a year, that translates to roughly 720,000 HAIs and 75,000 deaths.
These aren't freak accidents. The majority are preventable with rigorous protocols. And CMS data allows us to see, hospital by hospital, which facilities are beating national benchmarks and which are not.
The Six HAIs CMS Tracks
Through the CDC's National Healthcare Safety Network (NHSN), every Medicare-certified hospital reports data on six specific infection types:
🦠 Tracked Hospital-Acquired Infections
- CLABSI — Central line-associated bloodstream infection. These occur when bacteria enter the bloodstream via a central venous catheter. Mortality ranges from 12% to 25%. Highly preventable with proper insertion and maintenance protocols.
- CAUTI — Catheter-associated urinary tract infection. The most common HAI type. Often preventable by minimizing catheter use duration.
- SSI (colon surgery) — Surgical site infection following colon surgery. Reflects bowel prep, antibiotic timing, and wound care protocols.
- SSI (abdominal hysterectomy) — Surgical site infection following abdominal hysterectomy. Tracked as a separate indicator.
- C. difficile — Clostridioides difficile infections, often triggered by antibiotic disruption of normal gut flora. Responsible for 15,000+ deaths annually in the U.S.
- MRSA — Methicillin-resistant Staphylococcus aureus bloodstream infections. MRSA is resistant to most common antibiotics; infections are serious and difficult to treat.
How to Read HAI Performance Data
CMS reports HAI performance as a Standardized Infection Ratio (SIR) — the ratio of observed infections to predicted infections based on the hospital's patient population. An SIR below 1.0 means fewer infections than predicted (better than expected). Above 1.0 means more infections than expected.
In our scoring system, we translate these SIRs into a simple "better than / worse than national benchmark" metric. A hospital with 4 or more HAI measures performing better than the national benchmark has meaningfully strong infection control. Zero measures better is a warning sign worth understanding before elective admission.
Questions to Ask Before Your Admission
I've reviewed enough cases to know that asking these questions in advance changes outcomes:
- "What is your CLABSI rate compared to the national benchmark?" (Expect the charge nurse or quality department to be able to answer this.)
- "Does this hospital have an antimicrobial stewardship program?" (Hospitals with ASPs have systematically lower C. difficile rates.)
- "What is the hand hygiene compliance rate on this unit?" (Top hospitals publicly post this and have rates above 90%.)
- For surgery: "What antibiotic will be given before the procedure and when?" (Timing matters — antibiotic prophylaxis should be administered 30–60 minutes before incision.)
What You Can Do as a Patient
You have more power here than most patients realize:
- Ask every person who enters your room to wash their hands — or use the provided alcohol sanitizer. This is not rude. It is clinically important.
- If you have a urinary catheter, ask daily whether it's still necessary. Every extra day of catheterization increases infection risk.
- Keep your central line site clean and ask nurses to check it every shift if you're immunocompromised.
- Report to staff immediately if your IV site looks red, swollen, or warm.