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Guidelines for Data Monitoring and Oversight of Complex Epidemiological Studies


The National Eye Institute (NEI) is establishing the following system for the appropriate monitoring and oversight of the conduct of observational studies supported by the cooperative agreement mechanism in order to ensure the safety of participants and the integrity of the data. 


The NEI supports complex, large multi-centered and single-centered observational studies as cooperative agreements. When observational studies are conducted under a (U10) cooperative agreement, the NEI 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 NEI and the 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 NEI and study investigators. The overall role of DMOC is to assist the NEI and the study investigators in protecting the interests of study participants and in preserving the integrity and credibility of the study.

Study investigators are encouraged to use the DMOC Charter [Word].

Responsibility of the Data Monitoring and Oversight Committee

The specific role of the DMOC includes providing recommendations to the NEI Director or his designee and the study investigators regarding the following:

  • Determine the adequacy and appropriateness of the proposed study protocol and procedures. The first meeting of the DMOC will focus on the current study protocol to assess its readiness for implementation. DMOC will place major focus on review of the current protocol to ensure that issues raised in the initial review of the application or by the National Advisory Eye Council have been adequately addressed. Study protocols and procedures are assessed to determine their appropriateness to address the specific aims of the project. 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 protocol and participant consent form(s).
  • Recommend and review proposed protocol changes. Major protocol changes (i.e. sampling scheme, participant entry criteria, frequency or types of measurement) must be reviewed and must 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 Chairperson and the NEI Program Official to determine their study impact. The DMOC can recommend protocol changes when appropriate, based on review of the protocol or accumulating data or other relevant information. Procedural changes, those that typically would not require Institutional Review Board (IRB) approval, can be implemented without DMOC review.
  • Recommend/evaluate proposed ancillary or pilot/feasibility studies. Evaluate the impact of proposed studies on participant burden and ability to achieve overall study goals.
  • Evaluate patient safety. Determine appropriateness of procedures for notification and referral of participants for any abnormal findings.
  • Evaluate the informed consent document and procedures. The DMOC provides advice to the NEI Program Official and the investigators that the content of the consent form and the approach to informed consent are appropriate. The IRB approves the participant consent form.
  • Monitor performance, including recruitment, retention, overall study progress, and adherence to study protocol.
  • Assess data quality and quality control procedures.
  • Evaluate the data analytic plan.
  • Evaluate the publication plan, including topics and preparation schedule.
  • Review performance of individual centers, and if necessary, recommend actions to improve performance or terminate participation of specific centers.
  • Review and provide recommendations prior to submission of primary manuscripts and oral presentations that address the specific aims of the study. Study investigators will designate those manuscripts/presentations that are considered primary. Manuscripts will be sent to DMOC for review and comment at least two weeks prior to their planned submission. Abstracts for oral presentations, designated as primary, will be provided to 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.
  • Review overall scientific direction of the study.

Establishment of the DMOC

The NEI Director or his designee, in consultation with study investigators, is responsible for the establishment of the DMOC and appointment of its members. Study investigators will provide recommendations regarding potential members to the NEI Program Official, and will be consulted during the establishment process.

Selection of DMOC Voting Members

The aims of the study will dictate DMOC size and the types of expertise required of DMOC members. Membership will usually range from four-to-seven members. Expertise will be sought in the areas of epidemiology, survey methods, statistics, patient advocacy, and clinical expertise. The DMOC Chairperson will have experience in epidemiologic studies.

Conflicts of Interest

Any potential conflict of interest or the 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, which may be used in or 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 this relationship can be seen as affecting objectivity in regard to study recommendations.

Non-voting Members in Attendance

The non-voting members of the DMOC are the NEI Program Official, principal investigator, representatives of the statistical coordinating center; and, as appropriate, representatives of resource centers (i.e. the Photographic Reading Center) or those in a study leadership position. Additional investigators/consultants may be invited to the meetings as required.

Meeting Frequency

The DMOC will meet on an annual basis though often the DMOC may require two meetings in the first year. Conference calls and interim meetings may be scheduled as needed.

Meeting Format

The meeting will begin and end with a closed executive session attended by all voting members of the DMOC and the NEI Program Official. At the end of the closed executive session the DMOC Chairperson 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 those 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 Chairperson to the NEI Director 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 Chairperson and the NEI Program Official for review and comment. Meeting materials will be prepared and provided to the DMOC members at least one week prior to the meeting. Data submitted for review should be timely and of a high quality to allow the DMOC to adequately assess the integrity and progress in the study.

Meeting Minutes

The study investigators 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 Chairperson and the NEI Program Official.


Specific questions about this Notice may be directed to any member of the NEI Collaborative Clinical Research group at 301-451-2020:

Donald F. Everett, M.A.

Maryann Redford, D.D.S., M.P.H.

Sangeeta Bhargava, Ph.D.

Jimmy T. Le, Sc.D.

Last updated: September 9, 2022