Quality Measures, decoded
Most SNF underwriters look at the 1-5 star QM rating and stop there. The data underneath that rating is publicly available from CMS — and it answers the questions a star number can't. This is a short, no-jargon walkthrough of what we surface, what each number means, and what the gaps tell you.
What the QM Star Rating actually measures
The CMS overall 5-star rating for a nursing home is a blend of three sub-ratings: Health Inspections, Staffing, and Quality Measures (QM). The QM sub-rating is itself a roll-up of about 17 individual clinical measures — things like the percentage of long-stay residents who lost too much weight, who experienced a fall with major injury, or who were rehospitalized within 30 days of admission.
Each measure is published with its raw number (e.g. "6.5% of long-stay residents had a fall with major injury this year"). CMS turns those numbers into the 1-5 star QM rating using percentile thresholds within each measure. The star rating is the headline; the underlying measures are where the actual diagnostic signal lives.
The two datasets behind it
CMS publishes the QM detail in two separate files:
~17 clinical measures sourced from the MDS (Minimum Data Set) — the standardized resident assessments every nursing home submits to CMS. These measure clinical processes and resident-level outcomes: ADL decline, falls, pressure ulcers, depressive symptoms, restraint use, vaccinations. Reported as quarterly scores plus a 4-quarter average.
4 outcome measures sourced from Medicare claims — what actually happened to residents (rehospitalization, ER visits, etc.) regardless of what the SNF reported. These are risk-adjusted, meaning each facility's rate is compared against what would be expected given its specific patient mix.
Observed vs Expected vs Risk-Adjusted
The claims-based outcome measures are reported as three numbers per facility. Most platforms only show one. The other two are where the underwriting signal actually lives.
The raw rate at this facility. Just numerator / denominator. "X of Y short-stay residents went back to the hospital within 30 days." Doesn't account for who the patients are.
What CMS predicted for this facility's specific patient mix, using a risk-adjustment model that weights age, prior hospitalizations, comorbidities (diabetes, COPD, heart failure, dementia, etc.), and acuity on admission. A facility taking sicker post-stroke patients gets a higher Expected than one taking healthier post-knee-replacement patients — because that patient population is statistically more likely to bounce back to the hospital regardless of facility quality.
The standardized rate that lets you compare facilities apples-to-apples. Roughly: (Observed / Expected) × national-average-rate. It answers "what would this facility's rate look like if it took the national-average patient mix?" Use this number for cross-facility comparison.
Five patterns underwriters should recognize
The signal is in the gap, not any single number. SNF Shark auto-classifies each measure into one of these patterns and surfaces a one-line takeaway under the chart so you don't have to do the math.
Why some scores are blank (footnote codes)
When CMS suppresses a score (you'll see no number, just an explanatory note), it's almost always because the facility doesn't have enough residents in the measure's denominator for a reliable estimate. The most common codes:
| Code | Meaning |
|---|---|
| 9 | Insufficient claims data for a reliable score (typically: facility has too few short-stay admissions to compute the rehospitalization or ER-visit rate) |
| 10 | Too few resident assessments to report |
| 11 | Too few stays to report |
| 21 | Score not reported — insufficient data on file |
| 5 | Newly certified facility — not yet enough data |
Suppressed measures aren't errors or red flags — they just mean the facility's case volume on that specific measure is too low to publish a reliable estimate. SNF Shark hides suppressed rows from the main table and surfaces a count at the bottom ("+ 4 measures suppressed by CMS") so you know the data exists for some facilities but not this one.
Sources & cadence
- NH_QualityMsr_MDS & NH_QualityMsr_Claims — published quarterly by CMS at data.cms.gov. SNF Shark refreshes both within a week of each CMS publish.
- State and national averages — computed in our database across every facility in the most recent CMS snapshot, so the comparison you see is always against the same vintage as the facility's own score.
- For the technical methodology, see CMS's Five-Star Quality Rating System Technical Users' Guide — the official document covering risk-adjustment models, scoring thresholds, and footnote definitions.