[Federal Register: November 18, 2004 (Volume 69, Number 222)]
[Notices]
[Page 67584-67592]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr18no04-91]
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DEPARTMENT OF HEALTH AND HUMAN SERVICES
Centers for Disease Control and Prevention
Procedures and Costs for Use of the Research Data Center
AGENCY: National Center for Health Statistics, Centers for Disease
Control and Prevention (CDC), Department of Health and Human Services
(HHS).
ACTION: Notice and request for comments.
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SUMMARY: This notice provides information about the Research Data
Center (RDC) operated by the National Center for Health Statistics
(NCHS) within the Centers for Disease Control and Prevention (CDC). The
Research Data Center was established in 1998 to provide a mechanism
whereby researchers can access detailed data files in a secure
environment, without jeopardizing the confidentiality of respondents.
Historically, the data files accessed in the RDC have consisted of NCHS
survey data. RDC has recently begun accepting data files that were not
produced from NCHS survey data. In order to assure that all data files
are processed in a consistent manner, the original guidelines for
accessing files in the RDC are being reviewed and revised as necessary.
As part of the revision process, potential users are being given the
opportunity to provide input on how the procedures of the RDC can best
serve their research needs. This notice describes how to submit
proposals requesting use of the data, mechanisms to access the RDC,
requirements, use of outside data sets, costs for using the RDC, and
other pertinent topics. We are seeking comments on these procedures and
will post the final procedures on the NCHS Web site.
DATES: Submit comments on or before December 9, 2004.
ADDRESSES: Send comments concerning this notice to Ken Harris, National
Center for Health Statistics, 3311 Toledo Road, Room 3210, Hyattsville,
MD 20782, or e-mail to kwharris@cdc.gov.
FOR FURTHER INFORMATION CONTACT: Ken Harris at (301) 458-4262.
SUPPLEMENTARY INFORMATION:
Operational Procedures for Use of the Research Data Center; National
Center for Health Statistics; Centers for Disease Control and
Prevention
Table of Contents
Purpose
Background
Research Data Center--Operations
Submission of Research Proposals Using NCHS Data
Researcher--Supplied Data
General Requirements for Guest Researchers
General Requirements for Remote Access
Use of RDC/NCHS
Costs for Using the RDC
Disclosure Review Process
Appendix I--Examples of Data Available through the NCHS RDC
Appendix II--Requirements for the Release of NCHS Micro Data
Appendix III--Disallowed SAS Functions, Statements, and Procedures
Appendix IV--Project-Specific Requirements
Vaccine Safety Datalink Files
Appendix V--Agreement Regarding Conditions of Access to Confidential
Data in the Research Data Center of the National Center for Health
Statistics
Appendix VI--Researcher Affidavit of Confidentiality
Operational Procedures for the Use of the Research Data Center,
National Center for Health Statistics (NCHS); Centers for Disease
Control and Prevention (CDC)
Purpose
This document provides information about the National Center for
Health Statistics' (NCHS) Research Data Center (RDC), including how to
submit proposals requesting use of data, mechanisms to access the RDC,
requirements, use of outside data sets, costs for using the RDC, and
other pertinent topics. The Guidelines pertain to use of data produced
by NCHS and non-NCHS entities. If, after reading these guidelines, you
have further questions, you may seek clarification through e-mail
RDCA@cdc.gov) or by contacting Ken Harris at (301) 458-4262 or by e-
mail at kwharris@cdc.gov. The procedures described for use of the RDC
are under constant review to improve RDC operations and to be
responsive to changes in the environment that affect confidentiality
protections. Please check the NCHS Web site or contact the RDC to
determine if modifications have been made.
Background
In order to advance knowledge on the health and well-being of the
nation and its health care system, NCHS and other organizational
entities in the Department of Health and Human Services release
statistical micro data containing health and related variables. These
files allow outside researchers and analysts to develop statistics and
conduct independent research. However, any release of data, whether
micro data files or the results of statistical analyses, must be
consistent with the confidentiality provisions under which the data
were collected. For the case of data collected or
[[Page 67585]]
obtained by NCHS, Section 308(d) of the Public Health Service Act (42
U.S.C. 242m(d)) and the NCHS Staff Manual on Confidentiality do not
permit the release of data that are either identified or identifiable
to persons outside of NCHS. In order to preserve privacy and
confidentiality, details that might identify or facilitate the
identification of persons and organizations participating in surveys
and data systems are suppressed in published data products. Examples of
data elements that might be abridged are geographic identifiers,
details of sample design, and variables such as age or income that
might exist in other databases.
Despite the wide dissemination of data through publications, CD-
ROMs, etc., the inability to release files with, for instance, lower
levels of geography, severely limits the utility of some data for
research, policy, and programmatic purposes and sets a boundary on one
of the goals of the U.S. Department of Health and Human Services, i.e.,
to increase our capacity to provide state and local area estimates. In
pursuit of this goal and in response to the research community's
interest in restricted data, NCHS established the Research Data Center
(RDC), a mechanism whereby researchers can access detailed data files
in a secure environment, without jeopardizing the confidentiality of
respondents. The RDC provides restricted access to NCHS data. The RDC
also accepts outside data sets. Appendix I contains information about
some of the data sets currently available in the RDC.
Special requirements for use of non-NCHS data can be found in
Appendix IV, Project-Specific Requirements.
Authority: Sections 306 and 308 of the Public Health Service Act
(42 U.S.C. 242k and 242m).
Research Data Center (RDC)--Operations
The NCHS RDC is a research facility located at the NCHS
headquarters in Hyattsville, MD, where researchers meeting certain
qualifications are allowed access, under strict supervision, to
restricted statistical micro data files. To gain access to the RDC
researchers must submit a proposal for review and approval. Researchers
can use one of three access methods (see below): (1) Direct access
through local computing resources in the RDC that accommodate visiting
researchers; (2) a remote program submission system through which
researchers can submit work to be done in the RDC with the output
returned to them by e-mail; or (3) programming services for outside
researchers provided by RDC staff (see below). In all three methods,
confidential data files remain in the RDC where access to unit records
is restricted, and output is inspected before it leaves the RDC.
As currently designed, the NCHS RDC facility in Hyattsville has
four user workstations and a secure room for the RDC printer. In
addition, there is office space for the RDC staff and long-term outside
researchers.
The RDC computers have no electronic link either to the NCHS
network, the CDC-NCHS mainframe, or the Internet. The RDC workstations
consist of Pentium III 933 MHz computers running Windows 2000. There is
sufficient storage on the workstations and the server for any
confidential data. PC-SAS[supreg], SUDAAN[supreg], Watcom Fortran
77[supreg], and Stata[supreg] are installed on the workstations, and
additional programming/analytic languages can be added as needed.
The computers have been configured so that removable media such as
floppy disks are inaccessible to users. All print output is routed to a
central printer which is monitored by RDC staff while the RDC is open
to external researchers. Further, the system's workstations are
configured such that researchers are given read-only access to
requested data files and can write only onto the local workstation's
hard disk. These restrictions ensure that users cannot remove
information that has not been subjected to a review for
confidentiality.
The three methods of access to restricted data through the Data
Center include:
(1) Guest Researcher (on site)--The researcher submits a research
proposal to the RDC and, upon approval, conducts his/her research on
site at NCHS in the RDC. RDC staff constructs the necessary data files
before the guest researcher arrives and ensure that no restricted data
leave the facility. Data from virtually all of the NCHS data collection
systems may be made available through the RDC. Also available are data
from other data collection systems.
PC-SAS[supreg], SUDAAN[supreg], Watcom Fortran 77[supreg], and
Stata[supreg] are installed on the RDC workstations. Other programming
languages or data analysis packages can be made available with
sufficient lead time.
Researchers may take the results of their analyses off-site only
after disclosure review by NCHS RDC staff. Disclosure review consists
of looking for tabular cells less than 5, tables with geographic
variables in any dimension, models with geographic variables (or
variables tantamount to geographic variables) as outcome variables, or
case listings. In general, disclosure review is consistent with the
guidelines published in the NCHS Staff Manual on Confidentiality (see
Appendix II, Requirements for the Release of NCHS Micro Data Files).
(2) Remote Access--Users are able to electronically submit
analytical computer programs using SAS as the programming language.
After their proposals are approved, researchers are registered with the
RDC remote access system and introduced to the procedures and
programming limitations to be followed in accessing data. Researchers
send programs to the RDC and receive output by e-mail. RDC staff
prepares the requested data files which may consist of confidential
data merged with user data. Both submitted programs and output undergo
a programmed disclosure limitation review and are also subject to a
manual review. Certain procedures and SAS[supreg] functions are not
allowed (see Appendix II, Disallowed SAS[supreg] Functions, Statements,
and Procedures for a complete list). For example, users cannot use PROC
TABULATE or PROC IML, nor are functions allowed that are capable of
producing listings of individual cases such as LIST and PRINT.
Additionally, functions that may select individual cases are not
allowed (R--, FIRST., LAST., and others). The output is scanned for
cells containing less than five observations. If any are found, not
only is that cell suppressed, but several additional cells will also be
suppressed (complementary suppression). Alternatively, the researcher
may be asked to revise and resubmit his/her analyses. The job log is
also scanned with particular attention to certain types of error
conditions that may spawn case listings. Some projects are not suitable
for the remote access method. Stewards of the file/s in consultation
with RDC staff make this determination.
(3) RDC Staff-Assisted Research: This is mainly useful for those
planning to use statistical software programming languages other than
SAS[supreg] or who are not able to travel to the RDC facility. Under
this method, an approved researcher e-mails a statistical software
program to the assigned RDC staff person who runs the program and,
after disclosure review, provides the output to the researcher by e-
mail. More extensive programming services are also available.
Each of the access methods outlined above has an associated cost
which includes equipment and space rental, staff overhead, and setup.
The staff overhead and setup include the time and resources necessary
for monitoring progress, setting up equipment and data
[[Page 67586]]
files, disclosure limitation review, and file management. Since these
reflect varying demands on resources, accurate cost estimates cannot be
given without complete knowledge of the proposed research. In general,
though, the setup fee is $500 per day of effort (see Costs of Using the
RDC, below).
Submission of Research Proposals Using NCHS Data
Researchers must submit proposals that are detailed enough in their
data specifications to permit RDC staff to easily determine what data
elements are required. Prospective researchers are encouraged to check
with RDC staff prior to writing their proposals to ensure that the data
of interest can be made available to them. Researchers should develop
their proposals in a way that facilitates the ability of the RDC staff
to create the analytic files required by the project. Proposals should
be explicit regarding the variables needed as well as any case
selection required. Only those data items required to conduct the
proposed analyses will be included in the analytic data file and the
proposals should address why the requested data are needed for the
proposed study. Overly large and complex projects or poorly defined
projects will require extensive communication between RDC staff and the
researchers proposing the project, and this can cause the process to
move slowly. Work to prepare data files can be accomplished most
expeditiously if large, complex projects are subdivided into manageable
parts and requested data are clearly defined.
Researchers wishing to link data in the RDC with external data
should provide the external data to RDC staff in advance of their entry
to and use of the RDC (a minimum of 7 days prior to the approved date
for access to the RDC).
The RDC expects that all researchers will adhere to established
standards and principles for carrying out statistical research and
analyses. Researchers must conduct only those analyses which received
approval. Failure to comply will result in cancellation of the research
activity and potential disbarment from future research activities in
the RDC. In the case where Institutional Review Board (IRB) approval is
required to conduct research, RDC staff will notify relevant IRBs of
infringements of protocol approvals.
Appendix IV (Project-Specific Requirements) contains information on
submitting a research proposal requesting use of data other than those
produced by NCHS. The format detailed below pertains specifically to
use of NCHS data. If no project specific requirements are provided for
non-NCHS data, the format below is to be used.
(1) The research proposal must contain the following information:
A. Cover letter.
B. Project Title.
C. Abstract: approximately 100-300 words summarizing the project.
D. Full personal identification, institutional affiliation, mailing
addresses (including overnight express mail address), phone, and e-mail
address. Applicants who are students must append a letter from the
department chair or advisor stating that the applicant is a student
working under the direction of the department.
E. Dates of proposed tenure at the RDC (or use of the remote access
system). Proposals requesting remote access should include an appendix
describing the computer and e-mail account that will receive output as
well as the security provisions established for them.
F. Source of funding for the proposed project.
G. Background of study:
1. Key study questions or hypotheses.
2. Public health benefits.
H. A summary of the data requirements for the proposed research
along with an explanation of why the data are needed for the proposed
study.
1. Identification of cases to be included in the analytic file.
2. Identification of variables to be included in the analytic file.
3. Data to be supplied by the researcher and merged with NCHS or
other data.
4. A description of why publicly available data are insufficient.
I. Methods for the study:
1. Analytic strategy and statistical methods to be used.
2. Software requirements (currently, PC-SAS[supreg] for
Windows[supreg], Stata[supreg], SUDAAN[supreg], LIMDEP[supreg],
HLM[supreg], SPSS[supreg], and Watcom Fortran 77[supreg] are available
in the RDC; other languages can be made available with sufficient lead
time).
J. A description of the output that the researcher intends to have
reviewed for non-disclosure. This should include table shells, model
equations, or test statistics of any output that the researcher plans
to remove from the RDC. This will help the reviewers to determine the
risk of disclosure.
K. Appendices.
1. A current resume or Curriculum Vitae for each person who will
participate in the research activity. Resumes or CVs must specify
nationality.
2. A letter from student applicant's department chair or academic
advisor stating that student is working under the direction of the
department.
3. A data dictionary: a complete listing of the specific data
requested--data system, files, years, cases, variables, matching or
linking variables, etc.
4. A data dictionary for researcher-supplied data, if any, to be
merged with the confidential data. This includes identifying the source
of the data, variable names, variable codes or ranges, file layout,
number of records, and restrictions on NCHS use of the data (currently
the RDC policy prohibits release of merged data to anyone other than
the prospective researcher).
5. A description of the computer and e-mail system to be used to
receive output from the remote access system as well as the security
provisions established for them.
Portions of doctoral proposals or grant applications with
appropriate modifications may suffice for the research proposal.
Proposals to use the Research Data Center should be sent to:
Research Data Center, National Center for Health Statistics, 3311
Toledo Road, Suite 4113, Hyattsville, MD 20782, RDCA@cdc.gov.
Upon receipt, the Research Proposal will be evaluated by a review
committee convened for that purpose. The Proposal Review Committee
consists of (at minimum) the director of the NCHS RDC, the RDC staff
liaison, the NCHS Confidentiality Officer, and the director (or
designee) of the NCHS data division whose data are requested in the
proposal. Proposals for use of non-NCHS data undergo review as
determined by the steward/s of those data.
(2) The following criteria apply to proposal review for projects
requesting use of NCHS data:
A. Scientific and technical feasibility of the project;
B. Availability of resources at the RDC;
C. Risk of disclosure of restricted information; and
D. For projects using NCHS data, whether the proposed project is in
accordance with the mission of the NCHS to provide statistical
information that will guide actions and policies to improve the health
of the American people.
Researchers should note that approval of their application does not
constitute endorsement by NCHS of the substantive, methodological,
theoretical, or policy relevance or merit of the proposed research.
NCHS approval only
[[Page 67587]]
constitutes a judgment that this research, as described in the
application, is not an illegal use of the requested data file and that
there is high probability that the project can be successfully done in
the RDC.
Researcher-Supplied Data
The RDC allows researchers to supply their own data to be linked
with RDC data sets to create merged data sets that will be stored in
the RDC. The researcher-supplied data may consist of proprietary data
collected and ``owned'' by the researcher or other publicly available
data obtained by the researcher such as census data. Researchers MUST
provide RDC staff with complete documentation of any data proposed to
be merged with RDC data. Researchers expecting to use merged files are
responsible for interacting with RDC staff to ensure that their data
can be merged with the data resident at the RDC and the format of the
data is consistent with the RDC data. The RDC will accept user data
files in SAS[supreg], Stata[supreg], or ASCII[supreg] format (flat
files) with variables either column-delimited or column-specific. Other
formats may also be proposed. RDC staff prior to the arrival of the
researcher will do the merging of researcher-supplied data with RDC
data sets. Identifying information in linking fields will be removed
after the merge and will not be made available to the researchers.
Owners or stewards of RDC data sets make the determination of
whether and how the resultant merged files would be made available to
other researchers. For RDC files that are owned by NCHS, this
determination is made by the owners of the researcher-supplied data
that will be merged with the NCHS owned RDC files. For files that are
NOT owned by NCHS, the determination is made by the stewards or owners
of the RDC files. The owners of these files can require that any merged
files be made available to all interested researchers or allow this
determination to be made by the owners of the researcher supplied data.
The RDC periodically creates and maintains backup copies of all
computer files. Backup files are stored in a secure storage area
accessible by RDC staff only, although they may be made available to
researchers who need to return for additional analyses. These backup
files will contain user-supplied data as well as the merged files.
These backup files will be destroyed only upon the written request of
the user.
General Requirements for Guest Researchers
1. Researchers must work under the supervision of RDC staff and
only during normal working hours (Monday-Friday, 8:30 a.m.-5 p.m.).
Admittance to the RDC will be limited to the researchers whose names
are included in the Research Proposal (Section D). Researchers will be
required to show photo identification before admittance. A maximum of 3
collaborating researchers can sit at a computer station in the RDC.
2. Computers will be pre-loaded with the approved datasets by NCHS
staff approximately one day prior to the external researcher's use of
the RDC. Once the analysis is completed, NCHS staff will remove the
datasets from the RDC computer.
3. Guest researchers must be able to conduct their analyses with
the software specified in their research proposal.
4. External researchers are not allowed to bring documents,
manuals, books, etc., that may enable them to identify and disclose
confidential information they access in the RDC. Neither are they
allowed to bring into the RDC cell phones, pagers, or other devices
which would enable them to communicate with persons outside of the RDC.
5. All logs will be printed or electronically archived and will be
kept by NCHS. NCHS will retain only the programs and procedures run by
external researchers. The logs will not include results from their
research.
6. All computer output generated by statistical programs and all
hand-written notes based on such computer output are subject to
disclosure review by NCHS staff before removal from the RDC. Output is
restricted to summary tables of geographic or patient-level data (e.g.,
line listings of diagnoses by study identifier will be prohibited).
7. Guest researchers may not save output, files, or programs to
transportable electronic media. RDC staff can copy output or programs
to transportable media, if requested.
8. Researchers proposing multiple analyses that employ multiple
data sets will have access to only one dataset at a time. Under no
circumstances will researchers be permitted any opportunity to merge
datasets on their own.
General Requirements for Remote Access
1. Researchers must register an e-mail address that is credibly
secure. Although programs can be sent to the RDC from any address,
results will always be returned to the registered e-mail address.
2. Data requests must be in the form of SAS[supreg] programs
(Version 8.2). However, certain SAS[supreg] commands/statements are not
allowed through remote access. A list of such commands/statements is
included in Appendix III. This list is periodically reviewed and may be
modified as necessary. The SAS[reg] program must be in plain
ASCII[supreg] format.
3. During the first week of registration, researchers' data
requests are executed in a manual mode, requiring RDC staff to review
the program and resulting output before its release. During this
period, remote access is available only during normal working hours.
After the first week, researchers may submit data requests any time
(day or night) and receive prompt response, except when the CDC e-mail
system is down or when the remote access system is taken off-line for
maintenance.
4. The remote access system does not allow users to write permanent
datasets in its disk space. Jobs that attempt to create permanent
datasets or files are flagged, terminated, and an error message is sent
to the researcher.
5. The remote access system limits researchers' time and storage.
No single program is allowed more than one hour to complete execution
or to generate output in access of 1.5 MB.
6. With one exception, macros are not allowed through the remote
access system. The exception, GLIMIX[supreg], requires special
permission.
Use of the RDC
In order to get access to restricted data files in the RDC,
researchers must include in their proposals a signed ``Agreement
Regarding Conditions of Access to Confidential Data in the Research
Data Center for the National Center for Health Statistics.'' (Appendix
V) All researchers participating on an approved project must sign the
agreement--which clearly states the penalties for violating the
conditions of agreement. In addition, each researcher must sign an
``Affidavit of Confidentiality.'' (Appendix VI) The RDC reserves the
right to terminate any project at any time that it deems that an
investigator's actions will compromise confidentiality or ethical
standards of behavior in a research environment.
Statistical micro data files are collections of data from
individual units such as persons or providers. Statistical agencies
world wide are bound by ethical and legal requirements to preserve the
privacy of individual respondents and the confidentiality of data
provided to the agency by them or otherwise pertaining to them. As
mentioned earlier, confidentiality protection at NCHS is governed by
Section 308(d) of the Public Health
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Service Act (42 U.S.C. 242m). This section states that:
No information, if an establishment or person supplying the
information or described in it is identifiable, obtained in the course
of activities undertaken or supported under section 304, 306, or 307
may be used for any purpose other than the purpose for which it was
supplied unless such establishment or person has consented (as
determined under regulations of the Secretary) to its use for such
other purpose and in the case of information obtained in the course of
health statistical or epidemiological activities under section 304 or
306, such information may not be published or released in other form if
the particular establishment or person supplying the information or
described in it is identifiable unless such establishment or person has
consented (as determined under regulations of the Secretary) to its
publication or release in other form.
Having read and familiarized themselves with the Researcher
Affidavit of Confidentiality, including Section 308(d) of the Public
Health Service Act (42 U.S.C. 242m) (see below), researchers agree:
1. To make no copies of any files or portions of files to which
they are granted access except those authorized by NCHS Research Data
Center staff.
2. To return to RDC staff all NCHS restricted materials with which
they may be provided during the conduct of their research at NCHS and
other materials as requested.
3. Not to use ANY technique in an attempt to learn the identity of
any person, establishment, or sampling unit not identified on public
use data files.
4. To hold in strictest confidence the identification of any
establishment or individual that may be inadvertently revealed in any
documents or discussion, or analysis. Such inadvertent identification
revealed in their analyses will be immediately brought to the attention
of RDC staff.
5. Not to remove any printouts, electronic files, documents, or
media until they have been scanned for disclosure risk by RDC staff.
6. Not to remove from NCHS any written notes pertaining to the
identification of any establishment, individual, or geographic area
that may be revealed in the conduct of their research at NCHS.
7. To the inspection of any material they may bring to or remove
from the NCHS Research Data Center.
8. To comport themselves in a manner consistent with principles and
standards appropriate to a scientific research establishment.
Appendix V Agreement Regarding Conditions of Access to Confidential
Data in the Research Data Center of the National Center for Health
Statistics, signed by all investigators on the project, must be
submitted with the initial proposal.
Deliberate violation of any of these conditions may result in
cancellation of the data access, and the researcher may be escorted
from the premises by the duly authorized Federal protection service on
duty at NCHS. The researcher may also be barred from any future use of
the RDC upon review and determination by the Director of NCHS that this
is necessary to protect the integrity and confidentiality of the RDC.
The RDC technical monitor will perform a disclosure review and must
provide approval to the researcher before removal of any data from the
RDC, whether it is in electronic or paper form. Any violation by the
researcher may be punishable by fine or imprisonment for up to 5 years
or both under Title 18 U.S.C. 1001.
As noted above, the RDC contains work stations with computers pre-
loaded by NCHS staff with the requested dataset(s) to be analyzed with
statistical software. External researchers must schedule time for use
of the RDC, pay the appropriate user fees, and abide by the standard
practices of the RDC. Among the requirements is a restriction on
equipment that can be brought into the RDC, signing agreements to
maintain confidentiality, and submitting to review of all results for
any potential breaches in confidentiality.
Costs for Using the RDC
Time in the RDC can be scheduled in increments ranging from a
consecutive 2-day minimum to a consecutive 10-day maximum. Extensions
can be negotiated with RDC staff subject to scheduling requirements.
Scheduling time at the RDC is on a first-come, first-served basis.
Researchers using the NCHS RDC will be charged for space and
equipment rental and staff time necessary for supervision, disclosure
limitation review, maintenance of computer facilities (including both
hardware and software), and the creation and maintenance of data files
required by the researcher. The cost per project (or creation of an
analytic file) is given in the table below:
------------------------------------------------------------------------
------------------------------------------------------------------------
Guest Researcher (on site)............. $200 per day (2-day minimum).
Remote Access.......................... $500 per month for files with
less than 130,000 records.
$1,000 per month for files with
130,000 records or more.
$500 per year for selected
standard files.*
------------------------------------------------------------------------
* There are selected files that have been developed for repeat and
multiple users which require minimal set up procedures and involve
minimal content changes to the file when preparing for different
users. For that reason, charges for accessing these files are
considerably less expensive than the regular fees. Two files fall
under this category: the contextual data file for the National Survey
of Family Growth (NSFG-CDF) and the Polio file for the National Health
Interview Survey (NHIS-Polio). The cost for accessing standard files
of this type will be published as the files are developed.
There is a minimum setup charge of $500 per day for new file
creation. An additional $500 per day is charged as needed for file
creations and for special handling, such as the merging of additional
data or creating custom file formats.
More complex projects may require discussion between the researcher
and RDC staff to determine the cost of file creation. Researchers are
encouraged to develop their proposals in a way that facilitates the
ability of the RDC staff to create the analytic files required by the
project. Proposals should be explicit regarding the variables needed as
well as any case selection required. Overly large and complex projects
will require extensive communication between RDC staff and the
researchers proposing the project, and this can cause the process to
move slowly. Work to prepare data files can be accomplished most
expeditiously if large, complex projects are subdivided into manageable
parts.
Payment is expected in advance of the use of the RDC. A cashier's
check or money order made payable to NCHS RDC must be received seven
business days prior to the start date scheduled for use of the RDC.
Payments should be mailed to: NCHS RDC, Attn: RDC Director, 3311 Toledo
Road, Suite 4113, Hyattsville, MD 20782.
Disclosure Review Process
The disclosure review process in the RDC is centered on a
rigorously
[[Page 67589]]
conducted research base. Briefly, RDC staff, either independently or in
collaboration with staff from other areas of the NCHS, other government
agencies, and non-governmental researchers, conduct research into the
use of technological and statistical advances to develop and refine
additional methods to access restricted data such as the use of the
internet or encrypted data, assessment of disclosure risk through
statistical and automated procedures, and the use of disclosure
limitation methodologies (e.g., statistical noise) to enable the
release of otherwise restricted data files. The results of these
research activities are applied to disclosure review activities in the
RDC.
Researchers may take the results of their analyses off-site after
disclosure review by RDC staff. Disclosure review consists of looking
for tabular cells less than 5, tables with geographic variables in any
dimension, models with geographic variables (or variables tantamount to
geographic variables) as outcome variables, or line listings. In
general, disclosure review is consistent with the guidelines published
in the NCHS Staff Manual on Confidentiality (see Appendix II,
Requirements for the Release of Micro Data).
RDC staff review data summaries to assure maintenance of respondent
confidentiality. In no case may any table contain cells with fewer than
5 observations. If found, these small cells are suppressed, generally
by obliterating the cell. To assure that small cells cannot be
calculated from the other cells in the same row or column, staff makes
illegible the totals for the rows and columns corresponding to the
small cell. Once disclosure review is completed, researchers receive a
photocopy of the final tabulations.
RDC staff when reviewing cross-tabulations for small cell use the
following procedures:
1. Shred all tables having fewer than five total observations
(table total);
2. Shred all tables having fewer than five observations in each
cell ;
3.If the table passes the first two criteria, RDC staff will review
the table one row at a time;
4. Make illegible all counts and percents for cells with four or
fewer observations;
5. If one row cell is < 5, that cell and at least one other row cell
will be suppressed; if two or more row cells are each < 5, each will be
suppressed, but the row total need not be suppressed because the
suppressed row cells cannot be determined;
6. If one column cell is < 5, that cell and at least one other
column cell will be suppressed; if two or more column cells are each
< 5, each will be suppressed, but the column total need not be
suppressed because the suppressed column cells cannot be determined;
7. Row (or column) total is suppressed ONLY if it (i.e., total) is
< 5; since the cells that are < 5 (row or column as appropriate) are
suppressed, user cannot determine their values by knowing the row (or
column) total.
RDC staff will use best practices in determining whether data are
identifiable and will be conservative in their decisions. RDC decisions
are final and not subject to negotiation by researchers.
Publication
For NCHS files, any published material derived from the data should
acknowledge NCHS as the source and should include a disclaimer that
credits any analyses, interpretations, or conclusions reached by the
author (recipient of the file) to that author and not to NCHS, which is
responsible only for the initial data. Researchers who want to publish
a technical description of the data should make a reasonable effort to
ensure that the description is consistent with that published by NCHS.
Appendix I--Examples of NCHS Data Available Through the NCHS RDC
National Health Interview Survey--Data from the core and
supplements for survey years 1987-2002 are available for merging
user-supplied data at the state and county levels (note that RDC
users do not have access to county FIPS codes; these are replaced
with randomly assigned dummy codes). Additionally, state data files
may be made available for analysis and reporting.
National Survey of Family Growth--Contextual Data File--The 1995
NSFG has available sets of contextual variables at the state,
county, census tract, and block-group levels for the residence of
the respondents in 1990, 1993, and 1995.
Third National Health and Nutrition Examination Survey (1988-
1994)--Data from NHANES III are available with state and county
identifiers (there are restrictions on the use and reporting of
geographic units).
NCHS survey data, including vital statistics, Longitudinal Study
on Aging, and other data files with restricted information (sample
design information, lower levels of geography, etc.) can be made
available as requested and needed.
Appendix II--Requirements for the Release of NCHS Micro Data Files
The following rules apply to all files released by NCHS which
contain any information about individual persons or establishments,
except where the supplier of information was told, prior to his
giving the information, that the information would be made public:
A. Before any new or revised micro data files are published,
they, together with their full documentation, must be approved for
publication by the Confidentiality Officer who will rely upon
assistance from the NCHS Disclosure Review Board in reaching
decisions.
B. The file must not contain any detailed information about the
subject that could facilitate identification and that is not
essential for research purposes (e.g., exact date of the subject's
birth, excessive detail for occupation, extreme values of income and
age, detailed race or ethnicity for small and highly visible
groups--and other characteristics that would make an individual or
establishment easier to identify). It is recommended that the
following be consulted concerning possible techniques that would
permit the maximum amount of information to be released consistent
with sound principles of statistical disclosure limitation: The
Confidentiality and Data Access Committee's Checklist on Disclosure
Potential of Data (http://www.fcsm.gov/committees/cdac/checklist_799.doc
) and Statistical Policy Working Paper 22, Report on
Statistical Disclosure Limitation Methodology. Office of Information
and Regulatory Affairs, Office of Management and Budget (http://www.fcsm.gov/working-papers/wp22.html
).
C. Geographic places that have fewer than 100,000 people are not
to be identified on the file. Depending upon the statistical
structure of a file and other circumstances, a higher figure may be
employed. It is the responsibility of the program proposing the data
release to determine the disclosure risk associated with the
proposed minimum size of geographic areas to be identified.
D. Characteristics of an area are not to appear on the file if
they would uniquely identify an area of fewer than 100,000 people
(e.g., a variable describing the size of a Metropolitan Area in
which a respondent was interviewed providing for a category of fewer
than 100,000 in a file where Region is also provided).
E. Information on the drawing of the sample which might assist
in identifying a respondent must not be released outside the Center.
Thus, the identities of primary sampling units are not to be made
available outside the Research Data Center except in limited
circumstances and as approved by the Confidentiality Officer. When
such circumstances require the disclosure of the identity of areas
in which data collection activities take place, the survey manager
must insure that all information for this survey proposed for
release takes into account the greater risk of identification
because of this exception. The decision as to whether PSU identities
are to be made public should be made before data are collected and
plans for data release finalized.
Appendix III--Disallowed SAS[reg] Functions, Statements, and Procedures
The list below is used by the RDC remote access system to scan
user-submitted programs for functions, statements, and procedures
that may result in an unauthorized disclosure. Any user-submitted
program that contains one or more of these
[[Page 67590]]
keywords is automatically rejected, and the user is asked to correct
the problem and resubmit the program. Because the remote access
system is an automated system, the RDC does not and cannot make any
exceptions. This list may change pending development of additional
methodologies.
r--word
add
print
obs
firstobs
first.
last.
&
%
nocol
report
pctn
pctsum
tabulate
iml
nofreq
nocum
browse
editor
summary
list
put
file
r--
plot
PROC DATASET:
-Copy
-Delete
-Rename
-Repair
-Append
-List
Compress
Pointobs
multi part data set names
In addition to the above disallowed statements and functions,
users of the remote access system cannot use any statements or
functions that write permanent data files to the hard disk.
Appendix IV--Project-Specific Requirements
Vaccine Safety Datalink (VSD) Project
The VSD was established to allow the Centers for Disease Control
and Prevention (CDC) to carefully monitor vaccine safety in the
United States. The VSD, a large-linked database, contains medical
and immunization information on more than six million people
annually. Information available in the database includes basic
demographic information, managed care organization (MCO) enrollment,
dates of vaccination, and medical visits. The VSD is a collaborative
project involving CDC and several large MCOs. Information from the
VSD is used by CDC to conduct vaccine safety studies.
Recognition of the need for improved monitoring of vaccine
safety prompted the CDC to initiate the VSD project in 1990. This
project currently involves partnerships with MCOs to continually
monitor vaccine safety. All vaccines administered within a MCO are
recorded and include vaccine type, date of vaccination, concurrent
vaccinations (those given during the same visit), the manufacturer,
lot number and injection site. Medical visits are also recorded
which can be used to monitor for potential adverse events resulting
from immunization. The VSD project allows for planned vaccine safety
studies as well as timely investigations of emerging hypotheses. At
present, the VSD project is examining potential associations between
vaccines and a number of serious conditions. Data from the VSD also
are used to test new vaccine safety hypotheses that result from the
medical literature, signals from the Vaccine Adverse Events
Reporting System (VAERS), changes in the immunization schedule, the
introduction of new vaccines, or recommendations from the Institute
of Medicine (IOM) and Advisory Committee on Immunization Practices
(ACIP) recommendations. This project is a powerful and cost-
effective tool for the on-going evaluation of vaccine safety. It
should be noted that the MCOs, as owners of the data, have broad
decision-making authority over data release, as specified in CDC's
contract with America's Health Insurance Plans (AHIP). In addition,
MCOs have a recognized need and right to protect proprietary data.
In August 2002, CDC's National Immunization Program (NIP) and
its managed care partners created a data sharing program to allow
limited access to VSD data through the NCHS RDC with confidentiality
protection under Sec. 308(d) of the Public Health Service Act (42
U.S.C. 242m). Proposals requesting use of VSD data undergo a review
by the MCOs' Institutional Review Board(s) (MCO IRB) in addition to
a review by RDC staff. After approval of their research proposal and
payment of fees for the associated costs, researchers are able to
independently analyze data from the VSD.
Two types of VSD data may be accessed at the RDC by an external
researcher:
1. Analytic datasets created from the VSD data files that reside
at CDC to conduct new vaccine safety studies:
The VSD data files are comprised of several separate data sets
derived from computerized data sources from seven participating VSD
MCOs. The VSD data files contain data through December 31, 2000 and
include information such as vaccinations, hospital discharge and
other diagnoses, and demographic characteristics. With these data,
an external researcher may conduct a new vaccine safety study in
order to test his/her vaccine safety hypothesis. The external
researcher may request only the variables that are found in the VSD
data Files (as listed in the data dictionary).
To assist researchers, CDC makes available at its Web site: (1)
A list of recommended scientific references relevant to conducting
research using large linked databases such as the VSD data files and
(2) a data dictionary that lists all the variables contained in the
VSD data files available for new vaccine safety research (http://www.cdc.gov/nip/vacsafe/vsd/default.htm#data
).
Proposals for analyses of new vaccine safety studies using data
from the VSD data files should include only those specific variables
that are needed to conduct the proposed analyses, including a brief
explanation with justification for use of these variables.
Data contained in the VSD data files have been created from MCO
administrative data which are not solely collected for the purpose
of scientific research. It should be noted then that potential data
discrepancies and varying degrees of data quality that are specific
to such types of data do exist and typically are not resolvable with
data that are available in the RDC.
2. Final datasets from published VSD studies:
External researchers who would like to perform a reanalysis of a
published VSD study performed by VSD investigators may request the
final dataset for the specific study they wish to re-analyze. Data
collected for the final datasets of the published studies may
include additional variables not listed in the data dictionary that
is referenced above; therefore, the RDC will provide the external
researcher with the necessary data dictionary for the requested
dataset(s). No additional source or ``raw'' data are available for
reanalysis of published VSD studies.
In general, VSD studies published after August 2002 are
available for reanalysis. However, since many studies were published
prior to the establishment of the CDC data sharing policy, some of
the earlier published VSD study datasets may not be available for
re-analysis for the following reasons:
Some IRBs mandate that datasets be destroyed after
research is completed.
Principal investigator may no longer be affiliated with
VSD or the collaborating MCOs; therefore, the location of the
dataset is unknown.
Rapidly changing technology can mean that data are on
obsolete media.
Following receipt of a proposal for a reanalysis, the RDC will
verify that the data variables requested from the published study
are available. If these data are not available (for one or more of
the reasons stated above), the RDC will notify the external
researcher. Documentation for variables and datasets used in VSD
studies completed after August 2002 are maintained according to the
CDC data sharing policy regarding archival of data that are
available on the Web at http://www.cdc.gov/od/ads/pol-385.htm.
All proposals requesting use of VSD data should contain the
following information:
A. Project Title.
B. Name of proposed investigator and collaborators (RDC rules
limit number of persons at a work station to 3 at a time).
C. Name of point of contact, address, telephone number, and e-
mail address.
D. Summary of proposed study (i.e., background, reasons for
conducting the study, public health benefits).
E. Specific hypothesis for new vaccine safety studies to be
investigated or title of published VSD study to be reanalyzed.
F. Proposed methodology for new vaccine safety studies or the
specification of the methods used in published VSD studies:
1. Definition of the study population of interest and type of
study to be conducted:
a. Descriptive studies: specify the variables and values for
those variables to be used to select the study population.
b. Case-control studies: specify criteria for cases and
controls.
c. Cohort studies: specify criteria for the exposed and
unexposed population.
d. For all new vaccine safety studies, please include the
following information as
[[Page 67591]]
part of the definition of the study population of interest:
i. Adult or Pediatric data (0-17 or 18+).
ii. Study years of interest (i.e. 199X-2000). Please note the
study years available vary by HMO site.
iii. How the study population will be selected from the VSD data
files based on available fields in the VSD data dictionary.
2. Specification of the variables that will be required
including:
a. Exposures: Specific criteria defining exposures based on the
VSD data dictionary should be included. For instance, specific
vaccines given within 14 days of the outcome of interest.
b. Outcomes: Specific criteria defining those outcomes based on
the VSD data dictionary should be included. For instance, specific
ICD-9 codes for outcomes of interest and type of health care
encounter (hospitalization, outpatient encounter, emergency room
visit).
c. Person Time or Enrollment: Specify criteria to determine
calculation of person time, follow-up time, or MCO enrollment
restrictions.
d. Confounding or control variables, including:
1. Demographic information.
2. Pre-existing or co-morbid conditions.
3. Concurrent vaccinations.
4. MCO Site.
e. Other required variables to perform the proposed analysis.
G.Proposed analytic strategies.
The RDC staff will notify the external researcher whether his/
her proposal is complete and whether the requested variables are
available. If all the requested data variables can be located for
the proposed new vaccine safety studies or proposed reanalysis,
review of the proposal by the appropriate MCO IRBs takes place. In
compliance with federal law and regulations, access by external
researchers to a portion of the VSD data files or to datasets from
VSD published studies requires review and approval by the
appropriate IRBs of the relevant MCOs. The MCO IRBs have the
responsibility to protect the confidentiality and privacy of their
members' medical records and to adhere to the rules and regulations
applicable to their respective institution(s). Consequently, each of
the MCO IRBs must review any request for access to the VSD data
files that contain information on its MCO members. Any appeal by the
requestor of an IRB decision must follow the national, federal
procedures for IRBs. CDC is not involved in the MCO IRB process at
any time. General information pertaining to the rules and
regulations of IRB submission can be found at http://www.cdc.gov/od/ads/hsr2.htm/
.
Submission of Proposals to MCO IRBs
Review of a proposal submitted by an external researcher by a
MCO IRB does not imply that CDC approves or endorses the external
researcher's proposed research. IRB applications may require a more
detailed description of the proposed vaccine safety study and may
vary according to individual IRB requirements. Furthermore, various
IRBs may have different time lines for submission of proposals for
review. Each IRB may have specific policies or requirements for data
sharing that have not been adopted by the other MCO IRBs. These
policies may include required collaboration with an MCO
investigator, fees associated with the IRB review process, or
differing criteria for the IRB review process.
MCO IRBs will use their established procedures and time lines to
review the proposed research and to consider any appeals. As a rule,
IRBs attempt to inform researchers as to the status of their
proposals. Approval for access to MCO data contained within the VSD
data files does not indicate approval for obtaining additional data
contained within the MCO's member medical records or elsewhere, if
such data are not contained within the VSD data files that reside in
the RDC.
For new vaccine safety studies, it is possible that an external
researcher will receive approval for access to VSD data from some,
but not all, relevant IRBs. If this occurs, then the dataset(s)
needed to conduct the new vaccine safety study will still be
created, but only with data from the MCOs whose IRBs approved
access. VSD data sets for new vaccine safety studies must contain
data from two or more MCOs' data. Access will not be provided to
data from only one MCO. For reanalysis of a published VSD study, all
relevant IRBs from the MCOs that participated in the published study
must approve the proposal for reanalysis; therefore if one or more
IRBs do not approve access to VSD data used in the published study,
the final dataset cannot be provided.
Once the external researcher has received a response from all of
the appropriate IRBs, the RDC will begin the process of creating or
formatting the approved dataset(s). The RDC will not create or
prepare the dataset(s) until it receives copies of all final IRB
dispositions.
Publication of Research Using VSD Data
When an external researcher has completed his/her work at the
RDC and wishes to publish research results and findings using VSD
data, there are specific requirements that must be followed:
External researchers are required to submit a copy of
these data sharing guidelines with any manuscript submitted to a
journal.
External researchers are required to submit (to the
journal) a copy of the Confidentiality Agreement he/she signed prior
to conducting research at the RDC.
Disclaimers must be included in the manuscript which
state:
The research was conducted using data from the Vaccine Safety
Datalink Project, through the data sharing program at the Centers
for Disease Control and Prevention.
Any published material using VSD data must acknowledge
CDC as the original data source.
Additionally, disclaimers must be included that state:
The analysis, interpretations, and conclusions are the
responsibility of the authors and do not represent the views and
opinions of the CDC, the Federal Government, or the managed care
organization providing the data.
Appendix V--Agreement Regarding Conditions of Access to Confidential
Data in the Research Data Center of the National Center for Health
Statistics
I ---------------------- (please print name) am aware that the
information contained in the (name of data file) has been provided
to NCHS in accordance with the provisions of Section 308(d) of the
Public Health Service Act (42 U.S.C. 242m), with the assurance that
it will be used only for health statistical reporting and analysis
and will not be published or released in identifiable form. I am
also aware that I can be held legally liable for any harm incurred
by individuals or establishments who have provided or are described
in the information contained in the above work files to which I will
have access.
Having read and familiarized myself with the Researcher
Affidavit of Confidentiality, including Section 308(d) of the Public
Health Service Act (42 U.S.C. 242m) (attached), I agree:
1. To make no copies of any files or portions of files to which
I am granted access except those authorized by NCHS Research Data
Center staff.
2. To return to RDC staff all NCHS restricted materials with
which I may be provided during the conduct of my research at NCHS
and other materials as requested.
3. Not to use ANY technique in an attempt to learn the identity
of any person, establishment, or sampling unit not identified on
public use data files.
4. To hold in strictest confidence the identification of any
establishment or individual that may be inadvertently revealed in
any documents or discussion, or analysis. Such inadvertent
identification revealed in my analysis will be immediately brought
to the attention of RDC staff.
5. Not to remove any printouts, electronic files, documents, or
media until they have been scanned for disclosure risk by RDC staff.
6. Not to remove from NCHS any written notes pertaining to the
identification of any establishment, individual, or geographic area
that may be revealed in the conduct of my research at NCHS.
7. To the inspection of any material I may bring to or remove
from the NCHS Research Data Center.
8. To comport myself in a manner consistent with the principles
and standards appropriate to a scientific research establishment.
Deliberate violation of any of these conditions may result in
cancellation of the data access agreement, and the researcher may be
escorted from the premises by the duly authorized Federal protection
service on duty at NCHS. The researcher may also be barred from any
future use of the RDC upon review and determination by the Director
of NCHS that this is necessary to protect the integrity and
confidentiality of the RDC.
-----------------------------------------------------------------------
Researcher's Signature
-----------------------------------------------------------------------
Date
-----------------------------------------------------------------------
NCHS Witness
-----------------------------------------------------------------------
Date
[[Page 67592]]
Appendix VI--Researcher Affidavit of Confidentiality
I certify that no confidential data or information viewed or
otherwise obtained while I am a researcher in the National Center
for Health Statistics (NCHS) Research Data Center (RDC) will be
removed from NCHS. Further, I understand that NCHS will perform a
disclosure review and must provide approval to me before I remove
any data from the RDC, whether they are in electronic or paper form.
I acknowledge NCHS Confidentiality Statute, Sec. 308(d) of the
Public Health Service Act (42 U.S.C. 242m) stated below and fully
understand my legal obligations to NCHS to protect all confidential
data. Further, I understand that any violation may be punishable by
fine or imprisonment for up to 5 years or both under Title 18 U.S.C.
1001.
NCHS Confidentiality Statute--No information, if an
establishment or person supplying the information or described in it
is identifiable, obtained in the course of activities undertaken or
supported under section 304, 306, or 307 may be used for any purpose
other than the purpose for which it was supplied unless such
establishment or person has consented (as determined under
regulations of the Secretary) to its use for such other purpose and
in the case of information obtained in the course of health
statistical or epidemiological activities under section 304 or 306,
such information may not be published or released in other form if
the particular establishment or person supplying the information or
described in it is identifiable unless such establishment or person
has consented (as determined under regulations of the Secretary) to
its publication or release in other form.
Title 18 U.S.C. 1001--Deliberately making a false statement in
any matter within the jurisdiction of any Department or Agency of
the Federal Government violates Title 18 U.S.C. 1001 and is
punishable by a fine or up to 5 years in prison or both.
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Researcher's Signature
-----------------------------------------------------------------------
Date
-----------------------------------------------------------------------
NCHS Witness
-----------------------------------------------------------------------
Date
Dated: November 9, 2004.
James D. Seligman,
Associate Director for Program Services, Centers for Disease Control
and Prevention.
[FR Doc. 04-25537 Filed 11-17-04; 8:45 am]
BILLING CODE 4163-18-P