What this methodology is
This page is the public, versioned methodology for the Dialysis Facility Quality by State (CMS Care Compare) dataset. It documents how the figures defined by the matched Fonteum Research study, /api/v1 endpoint, and Audit Pack were constructed — from registered public-source ingest through aggregation rules to the rendered output. It exists so buyers can satisfy auditor questions by linking to a single durable URL.
The sections below define Fonteum's transformation rules. Where the methodology differs from the underlying source's own description (for example: which taxonomies count, how Type-1 vs Type-2 NPIs are treated, how density per 100k is computed), the rule lives here, not in the source. Methodology versions (v2026.05.0 today) increment when those rules change; recorded snapshot observations are listed separately from publisher cadence and appear only where this manifest includes them.
Source provenance
- Source families
- CMS Care Compare datasets (public)
- Spatial resolution
- Facility (point) + state rollups.
- Temporal coverage
- CMS quarterly Care Compare release (current snapshot 2026-04-01).
- Publisher cadence
- Quarterly (matches CMS Care Compare release cadence).
- Snapshot scope
- 7,700 facilities across 51 states + DC; snapshot dated April 1, 2026.
The Fonteum sources registry holds the canonical entry for each source family — Tier classification, ToS posture, publisher cadence, and catalog status. Publisher cadence is not a loaded-date guarantee: /sources.
Reproducibility statement
An independent researcher with access only to the public sources listed above can recreate this dataset by following these steps. Discrepancies between an independent reproduction and the published figures belong in /corrections-log; we publish them when they arise.
Limitations
Limitations are surfaced explicitly, not buried. Each item below is a constraint a buyer’s compliance team should review before relying on the dataset for a specific use case.
- Each CMS measure carries its own published limitations; readers should review the CMS dataset documentation linked in the methodology for measure-specific caveats. We do not modify CMS's published measure values, only re-aggregate to state-level rollups.
- Sampling-based measures (e.g. patient-experience surveys) carry confidence bands CMS publishes alongside the values. State-level rollups average across facilities and do not preserve those bands; for facility-specific decisions, reference the original CMS Care Compare record.
- Date alignment: state rollups are computed from the CMS file's published reporting period, not the file release date. The reporting period typically lags the release date by 6-12 months per CMS convention.
Field schema
This manifest lists the documented fields for this dataset with source, publisher-cadence, and confidence definitions. Runtime responses can return a subset, and record-level provenance fields may be null or absent.
| Field | Description | Source | Publisher cadence | Confidence |
|---|---|---|---|---|
facility_ccn | CMS Certification Number for the dialysis facility. | CMS Care Compare — Dialysis Compare ↗ | Quarterly | 1.0 (verbatim) |
state | Facility state (USPS code). | CMS Care Compare — Dialysis Compare ↗ | Quarterly | 1.0 (verbatim) |
rating | CMS dialysis-facility rating where published. | CMS Care Compare — Dialysis Compare ↗ | Quarterly | 1.0 (verbatim) |
Version history
The methodology versions recorded in this manifest appear here with their change rationale. A listed data-only snapshot observation can appear as a same-version entry; the table is not a universal history or replay service.
| Version | Released | What changed |
|---|---|---|
v2026.05.0current | May 6, 2026 | Initial Audit Pack release. Methodology, provenance map, reproducibility statement, and limitations stack baselined. |
Cite this methodology
For procurement attachments, audit responses, footer attribution, or academic use. Pick a format and copy.
Downloads & cross-references
- Research study → the editorial findings + charts
- JSON methodology metadata — for programmatic ingestion
- Download per-state CSV
- Download per-state JSON
Methodology questions: methodology@fonteum.com. Data corrections: /corrections-log. B2B inquiries: api@fonteum.com.
This page is the durable URL a buyer’s compliance officer can link from their product. The version pinned at the URL (v2026.05.0) is the active methodology. The Version history table is a changelog, not a promise that each historical dataset snapshot remains queryable.