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National Healthcare Disparities Report, 2004

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Minimum Data Set (MDS)


U.S. Department of Health and Human Services, Centers for Medicare & Medicaid Services (CMS)

Description/Primary Content

The MDS is the core source of assessment information for the Resident Assessment Instrument (RAI). The MDS is a standardized, primary screening and assessment tool of health status; it measures physical, medical, psychological and social functioning of nursing home residents. The general categories of data and health status items in the MDS include: demographics and patient history, cognitive, communication/hearing, vision, and mood/behavior patterns, psychosocial well-being, physical functioning, continence, disease diagnoses, health conditions, medications, nutritional and dental status, skin condition, activity patterns, special treatments and procedures and discharge potential.

Demographic Data

Gender, age, marital status, race or ethnicity, current payment sources, and health status.

Population Targeted

All residents in Medicare or Medicaid certified nursing and long-term care facilities.

Mode of Administration

Completed by facility personnel, with attestation of accuracy required.

Years Collected

Nursing homes have been collecting MDS since 1990; since June 1998, States have transmitted MDS to CMS central repository.

Data Collection Schedule

Administered on admission, quarterly, annually, whenever the resident experiences a significant change in status and whenever the facility identifies a significant error in a prior assessment. Also, residents receiving Medicare skilled nursing facility prospective payment system reimbursement require more frequent assessments (5, 14, 30, 60, 90 day).

Facilities are required to electronically transmit MDS data to the States. The State agencies have the overall responsibility for collecting MDS data in accordance with CMS specifications. The State is also responsible for preparing MDS data for retrieval by a national repository established by CMS.

Geographic Estimates

National, State, facility.

Contact Information

Agency homepage:

Oversight homepage:

Data system homepage:


The nursing home measures were changed in January 2004.

For the 2003 NHDR, an extract of MDS data, the Nursing Home Resident Profile Table, was used to make estimates of Long Term Care measures. This extract includes information about active residents of nursing homes. An active resident is a resident whose most recent MDS assessment transaction is not a discharge and whose most recent transaction has a target date less than 180 days old. If a resident has not had a transaction for 180 days, then that resident is assumed to have been discharged.

For the 2004 NHDR, the Nursing Home Resident Profile Table was again used to make most estimates of Long Term Care measures for long stay chronic care nursing home patients. However, this MDS extract can not assess measures that are longitudinal and require more that one MDS assessment or measures for short stay post-acute nursing home patients. To provide estimates of longitudinal measures and post-acute measures, full 2002 MDS data were used.


National Nursing Home Quality Measures, User's Manual, January, 2004 (V1), (consolidation of original User's Manual and Technical User's Manual), Sponsored by U.S. Dept. of Health & Human Services, Centers for Medicare & Medicaid Services, available at (PDF Help).



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