# Data Monitoring Committee Charter: [Trial short title]

> Charter for the independent data monitoring committee (DMC, also
> called a data and safety monitoring board, DSMB, or independent data
> monitoring committee, IDMC) of a clinical trial: its role, membership,
> independence, meetings, reports, stopping guidelines and how its
> recommendations are communicated. The structure follows the charter
> proposed by the DAMOCLES Study Group (Lancet 2005;365:711-722) and
> supports SPIRIT 2025 items 28a and 28b on data monitoring. Replace every
> `[bracketed]` value and every row marked *Example*. This is a
> documentation format, not clinical, legal, statistical or regulatory
> advice; check the current official texts and consult your sponsor,
> statistician and ethics committee.

<!--
Guidance: How to use this template
- Agree and sign the charter before the first participant is
  randomised, and before anyone has seen comparative data. A charter
  written after the first interim look loses much of its credibility.
- Keep the charter consistent with the protocol (data monitoring
  section) and the statistical analysis plan (interim analysis section).
  When they differ, the protocol wins and the charter is amended.
- Fill sections 3 and 4 (role and membership) first, then section 8
  (stopping guidelines) with the trial statistician.
- The DMC recommends; the sponsor and trial steering committee decide.
  Write every section with that split in mind.
-->

## Document control

<!-- Guidance: The charter is a controlled trial document filed in the trial master file. Every member signs the current version. -->

| Field | Value |
|---|---|
| Document ID | [DMC-CHARTER-0001] |
| Trial | [Full title, acronym, registry ID] |
| Protocol version | [Version and date] |
| Charter version | [1.0] |
| Status | [Draft / Approved / Superseded] |
| Owner | [@trial-manager] on behalf of the sponsor |
| Reviewers | [DMC chair, DMC statistician, trial steering committee chair, sponsor representative] |
| Last updated | YYYY-MM-DD |
| Classification | [Confidential] |

### Approvals

| Role | Name | Signature | Date |
|---|---|---|---|
| DMC chair | [Name] | [Signature] | YYYY-MM-DD |
| Sponsor representative | [Name] | [Signature] | YYYY-MM-DD |
| Trial steering committee chair | [Name] | [Signature] | YYYY-MM-DD |
| Chief investigator | [Name] | [Signature] | YYYY-MM-DD |

### Revision history

| Version | Date | Author | Change summary |
|---|---|---|---|
| 0.1 | YYYY-MM-DD | [@name] | Draft for DMC review |
| 1.0 | YYYY-MM-DD | [@name] | Approved at DMC organisational meeting |
| 1.1 | YYYY-MM-DD | [@name] | *Example:* Safety review frequency changed from every 6 months to every 4 months after protocol amendment 2 |

## Contents

1. [Introduction and scope](#1-introduction-and-scope)
2. [Trial summary](#2-trial-summary)
3. [Role and responsibilities](#3-role-and-responsibilities)
4. [Membership and independence](#4-membership-and-independence)
5. [Relationships and data flow](#5-relationships-and-data-flow)
6. [Meetings](#6-meetings)
7. [Reports and confidentiality](#7-reports-and-confidentiality)
8. [Interim analyses and stopping guidelines](#8-interim-analyses-and-stopping-guidelines)
9. [Decision making and recommendations](#9-decision-making-and-recommendations)
10. [After the trial](#10-after-the-trial)
11. [Agreement by members](#11-agreement-by-members)
12. [Glossary and references](#12-glossary-and-references)
13. [Standard and licence note](#13-standard-and-licence-note)

## 1. Introduction and scope

<!-- Guidance: Say why this trial needs a DMC. Typical reasons are a mortality or serious morbidity outcome, a vulnerable population, a new intervention with uncertain harms, or a long trial with planned interim analyses. If a regulator or funder required the DMC, say so. -->

This charter describes how the data monitoring committee for [trial
title] ([registry ID]) works. It covers the committee's purpose,
membership, meetings, the data it receives, the guidelines it uses and
how it communicates with the trial steering committee (TSC) and the
sponsor.

The trial has a DMC because [reason, for example: the primary outcome
includes death and hospitalisation, the intervention is new to this
population, and the protocol plans two interim analyses of efficacy].

## 2. Trial summary

<!-- Guidance: Give the DMC the facts it needs in one table. Point to the protocol for detail rather than copying it. -->

| Item | Value |
|---|---|
| Design | [Parallel-group, randomised, double-blind, placebo-controlled, two arms, 1:1] |
| Population | [Adults with condition X] |
| Intervention and comparator | [Drug A versus placebo] |
| Primary outcome | [Outcome, time point] |
| Key safety outcomes | [Serious adverse events, specified adverse events of interest] |
| Target sample size | 360 participants *(Example)* |
| Expected recruitment | 15 participants per month, 24 months *(Example)* |
| Sponsor | [Sponsor name] |
| Protocol and SAP | [Protocol version and date; SAP version and date] |

## 3. Role and responsibilities

<!-- Guidance: List what the DMC does and what it does not do. A common pitfall is a DMC drawn into trial management (recruitment targets, protocol design) that compromises its independence. -->

The DMC's primary responsibility is to protect the safety and interests
of trial participants, while also safeguarding the integrity and
credibility of the trial. In this trial the DMC will:

- review accumulating safety data at the intervals in section 6;
- review the planned interim analyses of efficacy in section 8;
- review trial conduct data that bear on the reliability of the
  results: recruitment, adherence, follow-up completeness, data quality
  and protocol deviations;
- consider relevant external evidence, for example results from other
  trials of the same intervention, that the TSC or sponsor passes on;
- recommend to the TSC whether the trial should continue unchanged,
  continue with changes, pause recruitment or stop.

The DMC will not: design or amend the protocol, manage recruitment, see
individual participant data beyond what it needs, or communicate interim
results to anyone outside the closed session.

## 4. Membership and independence

<!-- Guidance: Name at least one statistician and clinicians with expertise in the condition and the intervention. Members must not be trial investigators, sponsor employees or anyone with financial or intellectual interests in the result. Record competing interests at appointment and at each meeting. -->

| Member | Role on DMC | Expertise | Affiliation | Competing interests declared |
|---|---|---|---|---|
| Member A *(Example)* | Chair, clinician | [Specialty] | [Institution] | None, YYYY-MM-DD |
| Member B *(Example)* | Clinician | [Specialty] | [Institution] | None, YYYY-MM-DD |
| Member C *(Example)* | Statistician | Clinical trial statistics, group sequential methods | [Institution] | None, YYYY-MM-DD |

| Supporting role | Name | Access |
|---|---|---|
| Independent (unblinded) reporting statistician | [Name, organisation] | Unblinded data; prepares closed reports; not otherwise involved in the trial |
| DMC secretary | [Name] | Open session materials and minutes only |
| Trial statistician (blinded) | [Name] | Open reports only |

Quorum: [the chair or a nominated deputy, the statistician and at least
one other clinician]. If a member leaves, the TSC appoints a replacement
with the DMC chair's agreement. Payment: [members receive an honorarium
of a fixed amount per meeting, not linked to any trial outcome].

## 5. Relationships and data flow

<!-- Guidance: Draw the flow of data and recommendations. The firewall between unblinded and blinded people is the most important line on the diagram; keep it consistent with section 7. -->

```mermaid
flowchart LR
    DB[(Trial database)] --> RS[Independent reporting statistician]
    RS -->|Open report| DMC[DMC]
    RS -->|Closed report, unblinded| DMC
    DMC -->|Recommendation letter| TSC[Trial steering committee]
    TSC -->|Decision| SP[Sponsor]
    SP -->|Notification if required| REG[Regulators and ethics committees]
    TS[Trial statistician, blinded] -->|Open report content| RS
```

| Party | Relationship to the DMC |
|---|---|
| Trial steering committee | Receives DMC recommendations and makes trial decisions; does not see closed reports |
| Sponsor | Receives recommendations through the TSC; funds and administers the DMC; does not see unblinded comparative data |
| Independent reporting statistician | Prepares closed reports; reports only to the DMC |
| Investigators and site staff | No contact with the DMC on trial matters; remain blinded |
| Regulators and ethics committees | Informed by the sponsor of recommendations that change the trial, as required |

## 6. Meetings

<!-- Guidance: Fix the meeting schedule before the trial starts, tied to calendar time for safety and to information (participants with outcome data) for efficacy. Allow ad hoc meetings when a safety signal arises. -->

| Meeting | Timing | Purpose |
|---|---|---|
| Organisational meeting | Before the first participant is randomised | Agree the charter, report templates and stopping guidelines |
| Safety reviews | Every 6 months from first randomisation *(Example)* | Review safety and conduct data |
| Interim analysis 1 | When 120 participants have primary outcome data *(Example)* | Efficacy and safety review |
| Interim analysis 2 | When 240 participants have primary outcome data *(Example)* | Efficacy and safety review |
| Ad hoc meeting | At the chair's request or on a safety signal | Review the signal |

Each meeting has an **open session** (DMC with the trial statistician,
chief investigator and sponsor representatives, discussing blinded and
pooled data, conduct and external evidence) and a **closed session**
(DMC members and the independent reporting statistician only,
discussing data by arm). Meetings may be held by video call. The DMC
may ask for an extra closed session at any time.

## 7. Reports and confidentiality

<!-- Guidance: Agree the report shells at the organisational meeting. Closed reports present data by arm, labelled with codes (for example arm X and arm Y), with the key to the codes available to the DMC on request or by agreement. -->

| Report | Contents | Recipients |
|---|---|---|
| Open report | Recruitment by site and month, baseline characteristics pooled, follow-up completeness, adherence pooled, data quality, protocol deviations, pooled serious adverse events | DMC, TSC, sponsor, trial statistician |
| Closed report | Everything above by arm, primary and secondary outcomes by arm, adverse events by arm and by body system, deaths, interim analysis results against the stopping guidelines | DMC and independent reporting statistician only |

Reports are sent [7] days before each meeting through [secure transfer
method]. Closed reports and closed minutes are kept by the independent
reporting statistician until the trial is unblinded, then filed in the
trial master file. Members do not discuss interim data with anyone
outside the closed session and keep reports confidential until the main
results are public.

## 8. Interim analyses and stopping guidelines

<!-- Guidance: Stopping guidelines are guidelines, not rules. The DMC weighs the whole picture: consistency across outcomes, safety, external evidence and the likely effect on clinical practice. Copy the boundaries from the SAP so the two documents cannot drift. -->

The protocol plans two interim analyses of the primary outcome (section
6). The *Example* below uses a Haybittle-Peto approach.

| Look | Information | Guideline for efficacy | Guideline for harm |
|---|---|---|---|
| Interim 1 | 120 of 360 participants (one third) | Two-sided p < 0.001 (absolute z > 3.29) on the primary outcome | [Excess of serious adverse events judged clinically important, without a fixed boundary] |
| Interim 2 | 240 of 360 participants (two thirds) | Two-sided p < 0.001 (absolute z > 3.29) | As above |
| Final analysis | 360 participants | Two-sided p < 0.05 (absolute z > 1.96) | Not applicable |

With such a strict interim threshold the overall type I error stays
close to the nominal 0.05 (about 0.051 for this design by simulation,
*Example*); the trial statistician confirms the exact figure in the SAP.
Alternatives include alpha spending functions (Lan-DeMets with
O'Brien-Fleming-type boundaries) and formal futility boundaries; name
the method and software in the SAP. Safety guidelines are usually
descriptive, because a trial may need to stop for harm on less evidence
than for benefit.

## 9. Decision making and recommendations

<!-- Guidance: Say how the DMC reaches a recommendation (consensus where possible, vote if not), what it can recommend, and how and how fast it communicates. Keep the letter free of comparative data. -->

After each meeting the DMC recommends one of:

1. continue the trial unchanged;
2. continue with a change (for example to eligibility, monitoring or
   consent information), with reasons;
3. pause recruitment or treatment pending further data;
4. stop the trial, or one arm, for clear benefit, harm or futility.

The DMC aims for consensus; if it cannot reach consensus, the
recommendation follows a majority vote of members and records the
minority view. The chair sends a signed recommendation letter to the TSC
chair within [5] working days, or within [24 hours] for an urgent safety
recommendation. The letter states the recommendation and, where it is
not "continue unchanged", the reasons in terms that do not unblind the
reader beyond what is needed. If the TSC or sponsor does not follow a
recommendation to stop or change the trial, the TSC chair explains why
in writing and the DMC may [ask to meet the sponsor or, if participants
are at risk, raise its concern with the ethics committee].

| Record | Contents | Kept by |
|---|---|---|
| Open minutes | Attendance, open session discussion, recommendation | DMC secretary, shared with TSC |
| Closed minutes | Closed session discussion and reasons | Independent reporting statistician until unblinding |
| Recommendation letter | Recommendation, reasons without comparative data | TSC chair, trial master file |

## 10. After the trial

<!-- Guidance: Plan how the DMC is acknowledged and how its work is reported. SPIRIT 2025 asks protocols to describe data monitoring; trial reports should describe what the DMC did. -->

The DMC continues until [the final analysis is complete / the last
participant completes follow-up]. Members receive the main results before
publication. Publications name the DMC members (with their agreement)
and state the number of meetings and any recommendations that changed
the trial. DMC members are not authors of the main results paper unless
the TSC agrees it in advance.

Related templates: `science/trial-protocol` (data monitoring section,
items 28a and 28b), `academic/stats-analysis-plan` (interim analysis
methods), `science/case-report-form` (safety data collected),
`science/data-management-plan` and `science/clinical-trial-report`.

## 11. Agreement by members

<!-- Guidance: Each member signs to confirm they have read the charter, declared competing interests and will keep interim data confidential. Repeat after each charter amendment. -->

| Member | I agree to this charter and declare my interests | Signature | Date |
|---|---|---|---|
| [Name] | Yes / No; interests: [none or list] | [Signature] | YYYY-MM-DD |
| [Name] | Yes / No; interests: [none or list] | [Signature] | YYYY-MM-DD |
| [Name] | Yes / No; interests: [none or list] | [Signature] | YYYY-MM-DD |

## 12. Glossary and references

<!-- Guidance: Keep the names of committees consistent with the protocol. -->

| Term | Meaning |
|---|---|
| DMC, DSMB, IDMC | Data monitoring committee: an independent group that reviews accumulating trial data |
| TSC | Trial steering committee: oversees the trial and makes decisions on DMC recommendations |
| Open and closed session | Parts of a DMC meeting with and without non-members; comparative data appear only in closed sessions |
| Interim analysis | Analysis of accumulating data before the planned end of the trial |
| Stopping guideline | A pre-specified threshold that prompts the DMC to consider recommending a change or stop |

| Reference | Version or date | Link |
|---|---|---|
| DAMOCLES Study Group. A proposed charter for clinical trial data monitoring committees: helping them to do their job well. Lancet 2005;365(9460):711-722 | February 2005 | https://doi.org/10.1016/S0140-6736(05)17965-3 |
| SPIRIT 2025 statement (Chan A-W, et al. BMJ 2025;389:e081477), items 28a and 28b | 2025 | https://www.consort-spirit.org |
| US FDA draft guidance: Use of Data Monitoring Committees in Clinical Trials (docket FDA-2001-D-0219; once final, replaces the March 2006 guidance) | Draft, February 2024 | https://www.fda.gov/regulatory-information/search-fda-guidance-documents/use-data-monitoring-committees-clinical-trials |
| EMA Guideline on data monitoring committees (EMEA/CHMP/EWP/5872/03 Corr) | Effective 2006-01-01 | https://www.ema.europa.eu/en/data-monitoring-committees-scientific-guideline |
| ICH E6(R3) Guideline for Good Clinical Practice | Step 4, 6 January 2025 | https://database.ich.org/sites/default/files/ICH_E6%28R3%29_Step4_FinalGuideline_2025_0106.pdf |

## 13. Standard and licence note

Structure aligned with the DAMOCLES Study Group's proposed charter for
data monitoring committees (Lancet 2005;365:711-722) and with SPIRIT 2025
items 28a and 28b on data monitoring, cited by name and item number
only. The text is original and reproduces no wording from these sources.
The US FDA draft guidance (February 2024) and the EMA guideline
(effective 1 January 2006) are named as dated examples; check the
current official versions and your national requirements before use,
because the FDA guidance was still a draft when this template was
checked in October 2026. Stopping boundaries and error rates shown are
*Example* values to be replaced by your statistician's calculations.
This is a documentation format, not clinical, legal, statistical or
regulatory advice; consult your sponsor, statistician and research
ethics committee. Template licence: MIT.