Frequently Asked Questions

NDWS data are available to all researchers at no cost. Please note that researchers who want to link NDWS data to CMS claims, encounter, or assessment data in LINKAGE – including the claims-based summary measures prepared by NDWS – must be U.S. citizens or permanent legal residents. 

All NDWS data, including data linkages listed on our website, such as CMS data, are free to researchers.

Yes, the sample is nationally representative. In Wave 1, the sample is truly national for the Community Clinician Survey and the Nursing Home Survey. For the Wave 1 Assisted Living and Home Care Surveys, the sample frame represents assisted living communities and home health agencies from about 20 states. That sample was expanded in Wave 2.

Surveys include built-in validation checks to ensure internal consistency and accuracy. These checks validate consistency between responses (e.g., total beds used ≤ total beds available), apply date and range checks (e.g., residency year vs. degree completion year), and enforce mutually exclusive multiple-choice options. Hard checks confirm demographic data, such as the year moved to the U.S., as well as soft checks, for example if respondents indicated they did not currently have a clinical job. We also evaluate paradata (e.g., section timings), pre-fill some questions (from respondents' pre-survey screening or sample data), and follow up on incomplete responses to improve data quality.

Many of the questions were adapted from other sources rather than being exact. Download Survey Source Crosswalks on the NDWS website. Each question's source (and link) is in the farthest right column. If there is no source, it means the question was developed by the NDWS survey team. The available links can be used to investigate if data from previous studies are publicly available.

Social workers and social services staff aren’t currently included, though they may be added in future waves. Job titles included in Waves 1 and 2 are below.

VA facilities are not part of our sampling plan at this time.

It depends on the subgroup. The Community Clinician survey has the largest Wave 1 sample size and thus will allow more possible subgroup analyses. However, the other surveys have smaller samples in Wave 1, so subgroup analyses will not likely be feasible.

No, CC respondents can’t be grouped within a specific clinic or practice setting. Given the national sample, which was not created at the organizational level (unlike the staff surveys), it is extremely unlikely that two clinicians from the same clinic would have been sampled.

Yes, the NDWS data was collected under IRB approval from the University of Michigan Medical School’s IRB (IRBMED) under project #HUM00284131. Contact info@ndws.org if you need additional documentation for your own IRB review.

We obtained informed consent from NDWS respondents, including secondary analysis/future research use: “Your deidentified survey data will be combined with data collected from other participants and stored in a NIH data repository. The deidentified survey data will be used for future research studies without additional informed consent.”

If you are accessing the Public Use File on NACDA, you do not need any prior IRB review or approval to download the data. Consult with your own IRB whether you need their review/approval before using the data for research purposes.

Restricted NDWS Data does not have any direct identifiers (PII) and does not contain any PHI. If you are accessing the Restricted NDWS Data on LINKAGE, we do require some form of IRB documentation. However, due to the de-identified nature of the restricted data, an IRB determination of either “Not Human Subject Research” or “Exempt” is acceptable, unless you are also requesting CMS data (see more below). 

CMS Claims Data contains health information but is de-identified. If you are accessing CMS claims data in addition to Restricted NDWS Data on LINKAGE, you will be required to obtain IRB approval for conduct of human subjects research. Exempt determinations are permitted, but a determination of “not Human Subjects Research” is not acceptable.

No, a current or prior record of NIH funding is not needed to access NDWS restricted data via the LINKAGE platform or to apply for pilot funding.

Per the NIA Data LINKAGE webpage in August 2025: "This platform offers a secure, easy-to-navigate, and remotely accessible statistical analysis environment that meets federal data security requirements for protecting personally identifiable and private health information. Users have access to SAS, STATA, R, Python, MS Office applications and more." Programs not listed on this webpage cannot be used.

There are no fees for access to NDWS Restricted Data on LINKAGE in any case. Students may apply for access to Restricted Data, though they must provide additional supporting documentation if they are to be the Primary Data User. Please see the Restricted Data Request Form on our How to Access Data page for details.

The county and state of survey respondents is available in the LINKAGE (restricted data) version of the surveys and in the linkable data sources that are available at the county- and state-levels. However, this geographic information is encrypted so that the actual state or county of the respondents is protected. For example, for respondents from the state of Michigan, the state variable "MI" would be replaced with a unique encrypted variable (e.g., "S2YWX3" [to be clear, this is not the actual encrypted identifier on LINKAGE]). In linkable data sources available at the state level, information for Michigan would also be indicated by that same encrypted variable.

Yes – Researchers who want to use CMS data and/or the claims-based summary files must take extra steps to access these data, which include execution of a NIA DUA. Please see How to Access Data for more information. 

Yes, the NDWS data supports linking between the administrator and staff survey data sources. No, these aren’t linked in the PUF. If you want to use any information from the administrator surveys as part of your study of staff, you will need to request linked data and conduct your analyses in the LINKAGE platform. There is no charge for access through this route.

NDWS survey data don’t include direct linkages between clinician NPI and the nursing home CCNs where they practice, if they provide care in a residential setting. The researcher would need to request survey data linked with beneficiary-level CMS data via LINKAGE and follow established methods to link clinicians with facilities using the beneficiary-level data obtained through LINKAGE. At this time there are no identifiers in CMS data that uniquely identify assisted living communities.

As part of survey consent, all respondents (both Community Clinician and the organizational surveys) consent to data linkages including but not limited to CMS data. The NPI of the CC respondents is then used to identify care they provide in the CMS data. Individual beneficiaries do not provide consent. In other words, researchers are able to access – with appropriate justification – all relevant CMS data for respondent clinicians.

CMS data are available for all beneficiaries that a survey respondent saw, including their encounters and assessments with other clinicians (or in other nursing facilities). Some data are available from prior years.

Yes. For the Nursing Home Staff Survey, NDWS surveys in LINKAGE include the CCN, which can then be used by LINKAGE to identify patients who received care in those participating facilities (through the MDS assessments conducted in that facility). Then, with those patients, LINKAGE can connect to Medicare and Medicaid beneficiary-level claims and encounter information. The summary files referred to on the LINKAGE website are things like the MBSF Chronic Conditions file and Cost & Utilization file. (One additional thing to keep in mind is that there is a lag in the availability of CMS data to researchers, so CMS data available will not be from the same time as survey fielding.) Researchers will not have access to identifying employer information to do their own linkages. Please note that beneficiary-level claims can’t be linked to individual assisted living communities or home health agencies with survey data in Wave 1, but we aim to have this linkage available in subsequent years.

Researchers have access to--with appropriate justification--any CMS data available in NIA LINKAGE, which includes traditional Medicare, Medicare Advantage, and Medicaid (MAX and TMSIS) data. Because of the lag in CMS data availability for research projects, any and all CMS data requested will be from years prior to survey fielding.

Yes, the linked Medicare claims include all beneficiaries a clinician has seen, not just those with a dementia diagnosis.

CMS data is generally available through LINKAGE at the same time as it is available to individual researchers through the VRDC. Projects using LINKAGE (e.g., NDWS or NHATS) request new files through an updated DUA; these data are then available to individual research teams. After the initial Wave 1 data release, NDWS plans to update its DUA for CMS data on a regular, annual basis. Each update will include the new CMS data that have become available in the interim. At this time, we tentatively plan to update our DUA by November 2025; that DUA update will include whatever additional CMS data have become available to projects in LINKAGE by that time. In the experience of the NDWS team, we generally anticipate new CMS data to be available about 12 months after the last release of that specific file (dates can be found through ResDAC). This can help anticipate what additional files might be available by Fall 2025 (e.g., the most recent year of MA data that might be expected by then) when we update our DUA. However, with recent changes in the federal government, the anticipated timing of data release may change significantly.

Please note that Home Care Staff Survey data and this linkage are not available in Wave 1. In future waves, Care Compare Home Health Quality Reporting will be available for linkage with this survey. Researchers will not be able to upload any additional files to LINKAGE; however, all NDWS surveys may be linked to the specific geography-related sources that are outlined on the Data Linkages page. These linked data will be prepared for researchers by the LINKAGE and NDWS teams, but the specific geographic information collected in the surveys won’t be available to researchers (i.e., researchers will have a file prepared where a Home Care Staff survey respondent from an organization in Michigan would be linked to the appropriate Michigan data from the AARP LTSS Scorecard, but then the "Michigan" state value would be replaced by an encrypted value for state [or county, if using AHRF or SDI] in the file prepared for the researcher).

The claims-based summary files will not be updated until the Wave 2 data release that will occur in 2026. (Given the lag of CMS data availability, the claims-based files will always lag several years behind the period of survey fielding.)

Yes. As outlined on the Data Linkages webpage, through the LINKAGE platform researchers can use respondent encrypted NPI (for the Community Clinician Survey) or CCN (for employing organization of respondents to the Nursing Home Staff Survey) to link to the following beneficiary-level CMS data: traditional Medicare, Medicare Advantage, Medicare Part D, Medicaid (MAX and TMSIS), Minimum Data Set, and OASIS. More recent CMS data will be made available to researchers as it becomes available within LINKAGE. Note: CCN will be also available for employing agencies of respondents to the Home Care Staff Survey in future waves when Home Care Staff Survey data are available.

No, researchers will not be able to obtain the unique CCN for the participating facilities. Unique, encrypted identifiers will be used for the purposes of the available data linkages as outlined on the Data Linkages webpage, but researchers will not have access to the actual CCNs.

We welcome recommendations and suggestions for additional sources we could make available in LINKAGE in future years. Email us at info@ndws.org. 

Neither the public use files nor the datasets available via NIA LINKAGE contain identifiable employer information that will allow researchers to do their own linkages to external data sources. For the datasets available via LINKAGE, researchers may request to have the survey data linked at the organizational level by NIA LINKAGE personnel to data sources including Nursing Home Compare, Payroll Based Journal Data, LTCFocus, Area Health Resources Files, CMS Provider of Service File, and a series of NDWS-generated organizational measures. The NDWS-generated measures are available for nursing homes only in Wave 1. The data dictionary for these NH measures is available on the Data Linkages webpage. Researchers are not currently able to import other external data not housed on NIA LINKAGE for linkage to survey data.

These are available for the Assisted Living Frame in Wave 1 and will be for Home Care in future waves. We have the raw RUCA codes (1-10) and a recoded version where RUCA codes 7-10 are coded rural=1. We will include the geo-coded RUCA variable on the LINKAGE files for the Community Clinician and Nursing Home sample frames.

The RUCA codes in the NH and CC surveys were assigned by geocoding to the Census Tract. For the AL survey, we connected the RUCA code via the ZIP code. These RUCA codes (not just dichotomous urban/rural) will be available in LINKAGE. The full AHRF will be available and can be linked to surveys using an encrypted--not actual--FIPS county code. No version of the survey data (PUF or available in LINKAGE) will include unencrypted clinician, facility, or geographic identifiers.

The public-use surveys do not include geographic variables. At this time, the ability to link to geographic information can only be done on the LINKAGE platform and is limited to the specific data sources outlined on the website under the "Environment" section of the Data Linkages webpage. Researchers will not be able to bring their own data sources to LINKAGE, though we hope to expand the linked data available in the future.

Researchers have access to the data sources listed on the Data Linkages webpage, and any variables that they contain. In other words, any variable available in Nursing Home Care Compare and Provider Data Catalog Consolidated Data Dictionary is available in the version of the file available on LINKAGE (with the exception of the actual CCN or other facility-identifying information). In addition to linking the NDWS survey data with NH Care Compare, researchers can also request to link to the state-level AARP LTSS Scorecard. Finally, turnover could also be calculated using the Payroll Based Journal Data that will be available for each participating facility.

No. The only data available for linkage are listed on the Data Linkages webpage.