Gera US Hospital Quality Index — Methodology
The full, reproducible formula behind the GUHQI score published on every hospital page in this cluster. Every input is a real CMS figure; no numbers are fabricated or estimated.
Data source
The GUHQI is computed from the CMS Hospital Care Compare — Hospital General Information dataset (dataset identifier xubh-q36u), published by the U.S. Centers for Medicare & Medicaid Services (CMS). This is a U.S. federal government work in the public domain — no copyright restriction applies (USA.gov — Government Works).
Current snapshot: April 2026 (CMS dataset modified 28 April 2026, fetched via the CMS open-data API on 19 June 2026). The dataset covers 3,182 hospitals with a real CMS Overall Star Rating (1–5 stars). Hospitals whose rating is “Not Available” are excluded.
GUHQI formula — step by step
Step 1 — four components (each 0–1):
star_norm = (star − 1) / 4// rescales CMS 1-5 stars to 0-1
mort_score = 1 − (mort_worse / mort_total)// default 0.5 if no measures
readm_score = 1 − (readm_worse / readm_total)// default 0.5 if no measures
hcahps_score = pt_exp_facility / pt_exp_total// default 0.5 if no measures
Step 2 — weighted composite:
raw = 0.4 × star_norm + 0.3 × mort_score + 0.2 × readm_score + 0.1 × hcahps_score
Step 3 — normalise to 0–100:
GUHQI = round((raw − global_min) / (global_max − global_min) × 100, 1dp)
global_min and global_max are computed across all 3,182 CMS-rated hospitals in the April 2026 snapshot, not just the 800 hospitals in this cluster.
| Component | Weight | CMS field(s) | Interpretation |
|---|---|---|---|
| Star rating (normalised) | 40% | hospital_overall_rating | Rescaled from 1–5 to 0–1: (star−1)/4 |
| Mortality outcomes | 30% | count_of_mort_measures_worse / count_of_facility_mort_measures | 1 − (worse/total): higher = fewer mortality measures worse than national rate |
| Readmission outcomes | 20% | count_of_readm_measures_worse / count_of_facility_readm_measures | 1 − (worse/total): higher = fewer readmission measures worse than national rate |
| HCAHPS coverage | 10% | count_of_facility_pt_exp_measures / pt_exp_group_measure_count | Fraction of patient-experience measures reported (coverage proxy) |
Design decisions and limitations
- Star rating carries the most weight (40%) because it is CMS’s own peer-reviewed, multi-dimensional composite.
- Mortality and readmission outcomes (50% combined) are the most clinically meaningful CMS quality signals beyond the overall star.
- HCAHPS coverage (10%) is a proxy for how comprehensively the hospital is evaluated, not a direct quality score.
- Missing measures default to 0.5 (the midpoint of the 0–1 component scale), so hospitals with no reported measures are not penalised or rewarded — they are treated as average on that component.
- This cluster shows only 4- and 5-star hospitals (800 of 3,182 rated). The normalisation uses the full 3,182-hospital population, so scores are comparable with the full dataset.
- The GUHQI is a summary, not a clinical verdict. It does not capture safety incidents, staffing, or specialist volumes. Always verify on CMS Hospital Care Compare before any healthcare decision.
Frequently asked questions
- What is the Gera US Hospital Quality Index (GUHQI)?
- The GUHQI is a 0–100 score summarising each US hospital's CMS Overall Star Rating combined with its CMS mortality, readmission, and patient-experience (HCAHPS) outcomes. It is computed from real CMS Hospital Care Compare open data and normalised so that 100 = highest-scoring hospital in the dataset, 0 = lowest.
- Where does the source data come from?
- The CMS Hospital Care Compare "Hospital General Information" dataset (identifier xubh-q36u), published by the U.S. Centers for Medicare & Medicaid Services. This is a U.S. federal government work in the public domain — no copyright restriction applies.
- What is the exact GUHQI formula?
- raw = 0.4 × (star−1)/4 + 0.3 × (1 − mort_worse/mort_total) + 0.2 × (1 − readm_worse/readm_total) + 0.1 × (pt_exp_facility/pt_exp_total). GUHQI = (raw − global_min) / (global_max − global_min) × 100, rounded to one decimal place. Where measure counts are "Not Available", the component defaults to 0.5 (midpoint).
- Why is the GUHQI normalised 0–100 rather than absolute?
- The CMS star rating is already an ordinal 1–5 scale. Normalising the composite score maps it onto a 0–100 range that is easier to compare across hospitals. The formula weights are documented transparently here so any user can reproduce the score from the same CMS data.
- Which hospitals are included?
- This cluster covers the top 800 hospitals by GUHQI from the 3,182 CMS-rated hospitals in the April 2026 dataset. All are 4- or 5-star CMS-rated acute care hospitals. Hospitals without a published CMS Overall Star Rating ("Not Available") are excluded — never substituted with fabricated values.
- How often is the GUHQI updated?
- CMS publishes Hospital Care Compare updates on its own schedule (typically quarterly). Gera re-computes and re-dates the GUHQI whenever a new CMS release is available. The current dataset reflects CMS data as of April 2026.
- Does the GUHQI constitute a Gera endorsement of any hospital?
- No. The GUHQI is a transparent summary of publicly available CMS government data. It is not a Gera endorsement, clinical recommendation, or safety certification. Always verify information on CMS Hospital Care Compare before making any healthcare decision.
View hospital profiles: Browse all 800 top-rated US hospitals →
Contains public sector information published by Centers for Medicare & Medicaid Services and licensed under the U.S. Public Domain (federal government work). Source: Centers for Medicare & Medicaid Services — Hospital Care Compare (Hospital General Information) (April 2026, published 28 April 2026).
Informational/educational only — not a substitute for professional medical advice; a clinician interprets results.