URSA-PHF-028b: SNF LOS in Days per 1000 Member-Years

  • Published on Apr 23, 2026
  • 12 minute(s) read
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Measure Description

Among active membership periods, the rate of SNF stay length of stay in elapsed calendar days per 1000 member-years.

Metadata

  • Measure Identifier: URSA-PHF-028b
  • Measure Type: Rate Measure
  • Temporal Structure: Interval
  • Component Class: Long-Form
  • Denominator Case Field: Patient ID
  • Target Direction: Down

Denominator Description

The elapsed patient-months among active membership periods during which the patient was alive and had medical claims data coverage, expressed in units of 1000s of patient-years.

Numerator Description

The number of elapsed calendar days between admission and discharge of a SNF stay falling within the denominator period; NB: a single admission straddling multiple reporting periods will contribute (partial, prorated) LOS to each of those reporting periods.

Published Fields

  • Data Model Keys

    • Patient ID -- The internal database identifier (used, e.g., for joins and primary keys) for the patient. This value is typically mastered, i.e., all records for the same patient, regardless of the source data system from which that record originated, should have the same Patient ID value. (Note that while the mastered Patient ID value might resemble a local identifier used in one of the upstream data sources, this does not indicate any special priority of that source system in determining the characteristics of the patient.) (See also [URSA-CORE] Patient)
    • Primary Payor ID -- The internal database identifier (used, e.g., for joins and primary keys) for the Primary Payor. (See also [URSA-CORE] Primary Payor)
    • Primary Plan ID -- The identifier for the health insurance plan product that is the first party responsible for payment.

  • Patient Fields

    • Patient Last Name
    • Patient Date of Birth -- The patient's date of birth. On the Patients Natural Object, this field reflects the "best" known value for the patient available from all data sources; on other Natural Objects, e.g., MMR Member-Months, the value faithfully reflects the date of birth found on that particular type of record in the source data.
    • Patient Age Integer -- Patient age, expressed as an integer, as of a reference date or interval.
    • Patient Age Category Tier 1 -- Non-overlapping ranges of the patient age in years into three categories; [01] Pediatrics < 19, [02] Adults 19 - 64, and [03] Older Adults >= 65. Coarser grain to the Patient Age Category Tier 2. (See also [URSA-CORE] Patient Age Category Tier 2)
    • Patient Age Category Tier 2 -- Non-overlapping ranges of the patient age in years representing finer grain categories than the Patient Age Category Tier 1. This field incorporates findings from publications on defining meaningful age groups in the context of disease. These ranges closely, but not exactly, align with standard age ranges such as those defined by the Medical Subject Headings (MeSH). See results of K-Means simple clustering method at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3825015/ (See also [URSA-CORE] Patient Age Category Tier 1)
    • Patient Sex Category
    • Is Patient Sex Female -- Indicates the patient's sex is female. On the Patients Natural Object, this field reflects the "best" known value for the patient available from all data sources; on other Natural Objects, e.g., MMR Member-Months, the value faithfully reflects the patient sex documented on that particular type of record in the source data.
    • Is Patient Sex Male -- Indicates the patient's sex is male. On the Patients Natural Object, this field reflects the "best" known value for the patient available from all data sources; on other Natural Objects, e.g., MMR Member-Months, the value faithfully reflects the patient sex documented on that particular type of record in the source data.
    • Count Hospital Inpatient Admissions in Last 12 Months
    • Count ED Visits Without Inpatient Admissions in Last 12 Months
    • PCP Attribution Category
    • Primary Care Engagement Category
    • Count Primary Care Visits in Last 36 Months
    • Specialty Care Engagement Category
    • Count Specialty Care Office Visits in Last 36 Months
    • Primary or Specialty Care Engagement Category
    • Count Clinician Office Visits in Last 3 Years

  • Date Fields

    • Current Continuous Primary Payor Membership Episode Start Date -- The start date of the Continuous Primary Payor Membership Episode in effect as of the (potentially historical) period covered by the record. (See also [URSA-CORE] Continuous Primary Payor Membership Episode)
    • Current Continuous Primary Payor Membership Episode End Date -- The end date of the Continuous Primary Payor Membership Episode in effect as of the (potentially historical) period covered by the record. Values follow the standard exclusive convention for Period End Dates. (See also [URSA-CORE] Continuous Primary Payor Membership Episode, [URSA-CORE] Period End Date)
    • Segment Start Date -- The start date of the reporting segment. (See also [URSA-CORE] Reporting Segment)
    • Segment End Date -- The end date of the reporting segment. (See also [URSA-CORE] Reporting Segment)
    • Segmented Period Start Date
    • Segmented Period End Date

  • Provider Fields

    • Primary Plan Attributee Provider Description
    • Empirical Attributee Primary Care Individual Provider Description

  • Location Fields

    • Patient State Abbreviation
    • Patient ZIP Code 5-Digit
    • UW HIP ADI Quintile Category -- The UW HIP Area Deprivation Index National Percentile grouped into 5 levels, each spanning 20 percentile points (ADI 1 is percentile scores from 1 to 20 while ADI 5 is scores from 81 to 100). Higher scores indicate more deprivation, so ADI 1 is the least deprived while ADI 5 is the most deprived. Quintiles are frequently used in health research. They give larger sample sizes per group and are easier to plot and interpret. Quintiles also carry less information and group more dissimilar patients. Quintiles are good for descriptive analyses while the original percentile measure is preferable for predictive modeling. (See also [URSA-CORE] UW HIP Area Deprivation Index National Percentile)
    • CDC SVI Overall Quintile Category -- The CDC SVI Overall National Percentile grouped into 5 levels, each spanning 20 percentile points (the first quintile is percentile scores from 1 to 20 while the fifth is scores from 81 to 100). Higher scores indicate more vulnerability, so the first quintile is the least vulnerable while the fifth is the most vulnerable. Quintiles are frequently used in health research. They give larger sample sizes per group and are easier to plot and interpret. Quintiles also carry less information and group more dissimilar patients. Quintiles are good for descriptive analyses while the original percentile measure is preferable for predictive modeling.
    • CDC SVI Socioeconomic Quintile Category -- The CDC SVI Socioeconomic Theme National Percentile grouped into 5 levels, each spanning 20 percentile points (the first quintile is percentile scores from 1 to 20 while the fifth is scores from 81 to 100). Higher scores indicate more vulnerability, so the first quintile is the least vulnerable while the fifth is the most vulnerable. (See also [URSA-CORE] CDC SVI Socioeconomic Theme National Percentile )
    • CDC SVI Household / Disability Quintile Category -- The CDC SVI Household/Disability Theme National Percentile grouped into 5 levels, each spanning 20 percentile points (the first quintile is percentile scores from 1 to 20 while the fifth is scores from 81 to 100). Higher scores indicate more vulnerability, so the first quintile is the least vulnerable while the fifth is the most vulnerable. (See also [URSA-CORE] CDC SVI Household / Disability Theme National Percentile )
    • CDC SVI Minority / Language Quintile Category -- The CDC SVI Minority/Language Theme National Percentile grouped into 5 levels, each spanning 20 percentile points (the first quintile is percentile scores from 1 to 20 while the fifth is scores from 81 to 100). Higher scores indicate more vulnerability, so the first quintile is the least vulnerable while the fifth is the most vulnerable. (See also [URSA-CORE] CDC SVI Minority / Language Theme National Percentile)
    • CDC SVI Housing / Transportation Quintile Category -- The CDC SVI Housing/Transportation Theme National Percentile grouped into 5 levels, each spanning 20 percentile points (the first quintile is percentile scores from 1 to 20 while the fifth is scores from 81 to 100). Higher scores indicate more vulnerability, so the first quintile is the least vulnerable while the fifth is the most vulnerable. (See also [URSA-CORE] CDC SVI Housing / Transportation Theme National Percentile)

  • Insurance Fields

    • Primary Payor Description
    • Primary Plan Description
    • Primary Plan Financial Class Description

  • Diagnosis Fields

    • CCW Count Category
    • Count CCW Conditions -- The total of both Chronic Conditions and Potentially Disabling Events included in the CMS Chronic Condition Warehouse (CCW) library. (See also [URSA-CORE] CCW Comorbidity Category, [URSA-CORE] Count Potentially Disabling Events, [URSA-CORE] CMS Chronic Condition Warehouse (CCW), [URSA-CORE] Count Chronic Conditions)
    • CCW Systems Category
    • Count CCW Systems -- The count of distinct systems of the body with one or more active CCW Condition. CCW Systems are as a parent category to the individual CCW Conditions grouping them based primarily on the human body system they impact such as; Behavioral Health, Cancers, Cardiovascular, Cerebrovascular, Endocrine, Genitourinary, Musculoskeletal, and Pulmonary. (See also [URSA-CORE] CMS Chronic Condition Warehouse (CCW))
    • Is CCW System Behavioral Health -- Indicates the patient has one or more of the following CCW conditions; ADHD, Conduct Disorders, and Hyperkinetic Syndrome, Anxiety Disorders, Autism Spectrum Disorder, Bipolar Disorder, Depression, Depressive Disorders, Personality Disorders, PTSD, Schizophrenia, or Schizophrenia and Other Psychotic Disorders.
    • Is CCW System Cardiovascular -- Indicates the patient has one or more of the following CCW conditions; Acute Myocardial Infarction (AMI), Atrial Fibrillation, Heart Failure, Hypertension, Ischemic Heart Disease, or Peripheral Vascular Disease (PVD).
    • Is CCW System Congenital -- Indicates the patient has one or more of the following CCW conditions; Cerebral Palsy, Cystic Fibrosis and Other Metabolic Disorder, Intellectual Disability, Learning Disability, Muscular Dystrophy, or Other Developmental Delays.
    • Is CCW System Endocrine/Metabolic -- Indicates the patient has one or more of the following CCW conditions; Diabetes, Acquired Hypothyroidism, Hyperlipidemia, or Obesity.
    • Is CCW System Genitourinary -- Indicates the patient has one or more of the following CCW conditions; Benign Prostatic Hyperplasia or Chronic Kidney Disease (CKD).
    • Is CCW System Hematologic -- Indicates the patient has one or more of the following CCW conditions; Anemia.
    • Is CCW System Musculoskeletal -- Indicates the patient has one or more of the following CCW conditions; Hip or Pelvic Fracture, Rheumatoid Arthritis or Osteoarthritis, or Osteoporosis.
    • Is CCW System Neurological -- Indicates the patient has one or more of the following CCW conditions; Alzheimer's Disease, Alzheimer's Disease and Related Disorders or Senile Dementia, Stroke or Transient Ischemic Attack, Epilepsy, Migraine and Chronic Headache, Mobility Impairment, Multiple Sclerosis, or Deafness and Hearing Impairment.
    • Is CCW System Oncologic -- Indicates the patient has one or more of the following CCW conditions; Breast Cancer, Colorectal Cancer, Endometrial Cancer, Lung Cancer, Prostate Cancer, or Leukemia.
    • Is CCW System Ophthalmologic -- Indicates the patient has one or more of the following CCW conditions; Cataract, Glaucoma, or Blindness and Visual Impairment.
    • Is CCW System Pulmonary -- Indicates the patient has one or more of the following CCW conditions; Asthma, or Chronic Obstructive Pulmonary Disease (COPD) and Bronchiectasis.
    • Is CCW System Other -- Indicates the patient has one or more of the following CCW conditions; Fibromyalgia and Chronic Pain and Fatigue, Pressure or Chronic Ulcer.

  • Numerator Fields

    • Segmented Admit Date
    • Segmented Discharge Date
    • Encounter ID -- The internal database identifier (used, e.g., for joins and primary keys) for the encounter. (See also [URSA-CORE] Encounter)
    • Facility Provider ID -- The internal database identifier (used, e.g., for joins and primary keys) for the facility provider. (See also [URSA-CORE] Facility Provider)
    • Attending Provider ID -- The internal database identifier (used, e.g., for joins and primary keys) for the attending provider. (See also [URSA-CORE] Attending Provider)
    • Encounter Start Date
    • Encounter End Date
    • Encounter LOS in Elapsed Midnights
    • Encounter LOS in Distinct Calendar Days
    • Is LOS in Days > 100
    • Is Discharge Status Home or Home with Home Health
    • Is Routine Discharge Home
    • Is Discharged Home with Home Health
    • Principal Discharge Diagnosis ICD-10-CM Code
    • Principal Discharge Diagnosis ICD-10-CM Description
    • Principal Discharge Diagnosis AHRQ CCS Multi-Level Diagnosis Category Tier 1 Code
    • Principal Discharge Diagnosis AHRQ CCS Multi-Level Diagnosis Category Tier 1 Description
    • MS-DRG Code -- The standard 3-digit Medicare Severity Diagnosis Related Group code; MS-DRG codes should include leading zeros.
    • MS-DRG Description -- The natural language description of a standard 3-digit Medicare Severity Diagnosis Related Group code.
    • Facility Provider Description -- The natural language description of the facility provider. (See also [URSA-CORE] Facility Provider)
    • Attending Provider Description -- The natural language description of the attending provider; typically, the name of the provider. (See also [URSA-CORE] Attending Provider)
    • CMS Admit Source Code -- The standard 1-character CMS Admit Source code; e.g., 1 = Physician Referral, 2 = Clinic Referral, etc.
    • CMS Admit Source Description -- The natural language description of a standard CMS Admit Source code. (See also [URSA-CORE] CMS Admit Source Code)
    • CMS Admit Type Code -- The standard single-digit CMS inpatient admission type code found on Inpatient and Skilled Nursing Facility claims; ; 1 = Emergency, 2 = Urgent, 3 = Elective, 4 = Newborn, 5 = Trauma Center, 9 = Information Not Available.
    • CMS Admission Type Description -- The natural language description of a CMS Admission Type code (See also [URSA-CORE] CMS Admission Type Code)
    • CMS Place of Service Code -- The standard CMS 2-digit Place of Service code; e.g., 01 = Pharmacy, 02 = Telehealth, etc.
    • CMS Place of Service Description -- The natural language description of a standard CMS Place of Service code (See also [URSA-CORE] CMS Place of Service Code)
    • CMS Patient Discharge Status Code -- The standard 2-digit CMS Patient Discharge Status code; 01 = Discharged to Home or Self Care, etc. Patient Discharge Status codes should include leading zeros.
    • CMS Patient Discharge Status Description -- The natural language description of a standard CMS Patient Discharge Status code. (See also [URSA-CORE] CMS Patient Discharge Status Code)
    • Total Plan Paid Amount from All Plans
    • Primary Plan Paid Amount -- The amount actually paid by the health plan to the provider for a service or product. Subtracting the plan paid amount from the total due amount typically yields the patient responsibility amount. On billing records, which may identify up to three plans responsible for payment, the Primary Plan Paid Amount, Secondary Plan Paid Amount, and Tertiary Plan Paid Amount fields identify the amounts paid by the primary, secondary, and tertiary plans listed on the bill, respectively; the total paid by any and all plans on a bill is identified by the Any Plan Paid Amount field.
    • Primary Plan Allowed Amount -- The maximum amount that the payor agrees to pay the provider for a service or product, typically governed by a contract. The Allowed Amount for a claim or billing record is calculated by adding the Contractual Adjustment Amount (which is typically negative) to the Charge Amount. Adding the total Non-Contractual Adjustment Amount to the Allowed Amount yields the Total Due Amount. On billing records, which may identify up to three plans responsible for payment, the Primary Plan Allowed Amount, Secondary Plan Allowed Amount, and Tertiary Plan Allowed Amount fields identify the amounts paid by the primary, secondary, and tertiary plans listed on the bill, respectively. (See also [URSA-CORE] Charge Amount, [URSA-CORE] Contractual Adjustment Amount, [URSA-CORE] Non-Contractual Adjustment Amount, [URSA-CORE] Total Due Amount)
    • Patient Paid Amount -- The amount paid by the patient to the provider for health care services or products.

  • [No Field Group]

    • Ursa Serial ID

  • Measure Fields

    • Denominator