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NIDCD Guidelines for Data Monitoring and Oversight of Observational Studies

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The National Institute on Deafness and Other Communication Disorders (NIDCD) has established the following system to monitor and oversee the conduct of observational studies in order to ensure both participants’ safety and data integrity.


The NIDCD supports large, complex, multi-centered and single-center observational studies as cooperative agreements. When observational studies are conducted under a U01 or U10 cooperative agreement, the NIDCD assumes a partner role in project activities by providing assistance, advice, and coordination of study activities without assuming the primary directorship of the study. This partnership between the NIDCD and study investigators is enhanced through the expert guidance provided by a Data Monitoring and Oversight Committee (DMOC), which is constituted to provide advice to both the NIDCD and study investigators. The overall role of the DMOC is to assist the NIDCD and the study investigators in protecting the interests of study participants and preserving the study’s integrity and credibility.

Responsibility of the Data Monitoring and Oversight Committee

The specific role of the DMOC includes providing recommendations to the director of the relevant NIDCD scientific program; the director of the NIDCD Division of Scientific Programs; and study investigators regarding the following:

  • Determining the adequacy and appropriateness of the proposed study protocol and procedures. The first meeting of the DMOC will focus on the proposed study protocol to assess its readiness for implementation. The DMOC will place major focus on review of the proposed protocol to ensure that issues raised in the initial review of the application or by the National Deafness and Other Communication Disorders (NDCD) Advisory Council have been adequately addressed. Study protocols and procedures are assessed to determine their appropriateness to address the project’s specific aims. The Manual of Procedures (MOP) for the study will be reviewed and, as applicable, should include sections on study objectives; organizational structure; data collection processes; timetable; planned pilot/feasibility studies; disease definitions; statistical analyses (including power considerations, analytic methods, and risk factor analyses); protocol procedures (including eligibility/exclusion criteria, informed consent, questionnaires, survey or exam procedures, grading of photographs); data management, data transmission, and quality control procedures; and study policy issues (publication policy, conflict of interest policy, data sharing, protection of human subjects). The first meeting of the DMOC will end with a request for formal approval of the revised protocol and participant consent form(s), with amendments as appropriate.
  • Recommending and reviewing proposed protocol changes. Major protocol changes (i.e., sampling scheme, participant entry criteria, frequency or types of measurement) must be reviewed and receive a formal DMOC recommendation prior to implementation. Minor protocol changes during conduct of the study will be presented prior to implementation to the DMOC chair and the director of the relevant NIDCD scientific program to determine their study impact. Based on review of the protocol or accumulating data or other relevant information, the DMOC can recommend protocol changes when appropriate. Procedural changes—those that typically would not require Institutional Review Board (IRB) approval—can be implemented without DMOC review.
  • Recommending/evaluating proposed ancillary or pilot/feasibility studies. Evaluating the impact of proposed studies on participant burden and ability to achieve overall study goals.
  • Evaluating patient safety. Determining appropriateness of procedures for notification and referral of participants for any abnormal findings.
  • Evaluating the informed consent document and procedures. The DMOC provides advice to the director of the relevant NIDCD scientific program and the investigators on the appropriateness of the consent form’s content and the approach to informed consent. The IRB reviews and approves the participant consent form.
  • Monitoring performance, including recruitment, retention, overall study progress, and adherence to study protocol.
  • Assessing data quality and quality control procedures.
  • Evaluating the data analytic plan.
  • Evaluating the publication plan, including topics and preparation schedule.
  • Reviewing performance of individual centers and, if necessary, recommending actions to improve performance or to terminate participation of specific centers.
  • Reviewing and providing recommendations prior to submission of primary manuscripts and oral presentations that address the specific aims of the study. Study investigators will designate the manuscripts/presentations that are considered primary. Manuscripts will be sent to the DMOC for review and comment at least two weeks prior to their planned submission. Abstracts for primary oral presentations will be provided to the DMOC for comment and review one week prior to their planned submission. Manuscripts that address the secondary aims of the study or the results of any ancillary study do not require DMOC review.
  • Reviewing the overall scientific direction of the study.

Establishment of the DMOC

The director of the applicable NIDCD scientific program is responsible for establishing the DMOC and appointing its members in consultation with, and with the approval of, the director of the NIDCD Division of Scientific Programs. Study investigators can provide recommendations regarding potential members to the director of the relevant NIDCD scientific program and will be consulted during the establishment process.

Selection of DMOC Voting Members

The aims of the study will dictate the DMOC’s size (usually four to seven members) and the types of expertise required of members. Expertise will be sought in the areas of epidemiology, survey research methods, statistics, patient advocacy, and clinical expertise. The DMOC chair will have experience in epidemiologic studies.

Conflicts of Interest

Any potential conflict of interest or appearance of a conflict of interest must be documented prior to formal appointment of DMOC members and annually thereafter. Potential conflicts may arise from interests in commercial products or services that may be used in the study or that could be affected by the study results. The appearance of conflict of interest may occur when DMOC members have affiliations with institutions that could benefit from the research, and when this relationship might be seen as affecting the objectivity of study recommendations.

Non-Voting Members in Attendance

The non-voting members of the DMOC are the director of the relevant NIDCD scientific program; the principal investigator; representatives of the statistical coordinating center; and, as appropriate, representatives of resource centers (e.g., a reading center) or those in a study leadership position. Additional investigators and consultants may be invited to the meetings as required.

Meeting Frequency

The DMOC will meet annually, although the DMOC may require two meetings in the first year. Conference calls and interim meetings may be scheduled as needed.

Meeting Format

Meetings will begin and end with a closed executive session attended by all voting members of the DMOC and the director of the applicable NIDCD scientific program. At the end of the closed executive session, the DMOC chair will verbally communicate the recommendations of the committee to the study investigators. Adequate attendance, usually two-thirds of non-voting study members, is required.

DMOC Recommendations

Two-thirds of DMOC voting members constitute a quorum for voting recommendations. The DMOC should strive to achieve consensus in formulating specific study recommendations. Among the members present, a simple majority vote will define agreement for DMOC recommendations; dissenting and abstaining votes will be noted. DMOC recommendations regarding major protocol changes, regardless of whether these are initiated by DMOC or by the study investigators, will be sent simultaneously in a letter from the DMOC chair to the director of the relevant NIDCD scientific program and the principal investigator.

Meeting Materials

The study investigators will prepare a draft agenda at least three weeks prior to the meeting. The draft agenda will be sent to the DMOC chair and the director of the applicable NIDCD scientific program for review and comment. Meeting materials will be prepared and provided to the DMOC members at least one week prior to the meeting. To allow the DMOC to adequately assess the study’s integrity and progress, data submitted for review should be timely and of high quality.

Meeting Minutes

The director of the relevant NIDCD scientific program will consult with the DMOC chair in appointing a DMOC executive secretary, who will be responsible for preparing draft minutes from each meeting/conference call within 14 days. The minutes will be considered final only after review and approval by the DMOC chair and the director of the relevant NIDCD scientific program.


Specific questions about this notice may be directed to any member of the NIDCD Collaborative Clinical Research group at 301-496-5061:

Director, Division of Scientific Programs
Judith A. Cooper, Ph.D.

Director, Epidemiology, Statistics, and Population Sciences Section
Howard J. Hoffman, M.A.

Director, Clinical Trials Program
Trinh Ly, M.D. 

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