> For the complete documentation index, see [llms.txt](https://docs.nested-knowledge.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nested-knowledge.com/guides/write-a-search-query/maude.md).
# MAUDE
Learn how to write a MAUDE search query.
MAUDE is the FDA's Manufacturer and User Facility Device Experience database. It holds adverse event reports for medical devices. Search it when your review needs device safety or post-market surveillance data for example, device-related systematic reviews, safety signal detection, or regulatory submissions that require a documented search of adverse event data alongside the published literature. Nested Knowledge searches MAUDE through openFDA.
MAUDE is a passive surveillance system: reports can be incomplete, inaccurate, submitted late, or unverified, and the number of reports for a device doesn't reflect the true incidence or prevalence of an event, since device usage and under-reporting both go unmeasured. Treat MAUDE as one input among several, not a standalone safety signal — see the [MAUDE API overview](https://open.fda.gov/apis/device/event/) for the FDA's full disclaimer, excerpted under Disclaimer below.
### Search Specific Fields
Structure a field search as `field_name:search_term`, using one of MAUDE's indexed fields:
* `device.mdr_report_key` — unique identifier for a device report
* `device.brand_name` — the device's trade or proprietary name
* `device.generic_name` — the device's generic or common name (for example, heart pacemaker)
* `device.udi_di` — the unique identifier for a specific device version or model
* `manufacturer_d_name` — the manufacturing company
* `report_number` — identifier for the adverse event report; can be empty
* `device.device_report_product_code` — the three-letter FDA product classification code
* `product_problems` — reported concerns with device quality, authenticity, performance, or safety
* `event_type` — Death, Injury, Malfunction, Other, or no answer provided
* `mdr_text.text` — narrative description of the event
* `date_received` — date the FDA received the report
See the [MAUDE documentation](https://www.fda.gov/medical-devices/mandatory-reporting-requirements-manufacturers-importers-and-device-user-facilities/about-manufacturer-and-user-facility-device-experience-maude-database), [data dictionary](https://open.fda.gov/fields/deviceevent.yaml), or full [searchable fields list](https://open.fda.gov/apis/device/event/searchable-fields/) for detail on each field.
Example searches:
```
device.brand_name:"embotrap III" AND device.generic_name:"thrombus retriever"
device.generic_name:"Thrombus retriever" OR device.udi_di:1088670408132
date_received:[20240115 TO 20240131]
device.device_report_product_code:(MUE OR MOM) AND date_received:[20200101 TO 20231231]
device.udi_di:00763000190439
device.generic_name:("glucose monitor" OR CGM) AND device.brand_name:Libre
```
#### Search Terms
`device.generic_name:glucose monitor`, with no quotation marks, returns results with either "glucose" or "monitor" in the generic name. Use double quotes for an exact phrase, for example `device.generic_name:"glucose monitor"`. Join and nest terms within a field using AND and OR: `device.generic_name:("glucose monitor" OR CGM)`.
#### Join Multiple Fields
A space between two fields joins them with OR by default: `device.brand_name:dexcom date_received:[20220101 TO 20240101]` returns results matching either field. Use AND to require both: `device.brand_name:dexcom AND date_received:[20240101 TO 20241231]`. Nested Boolean operators aren't supported across fields — see the FDA's [query syntax reference](https://open.fda.gov/apis/query-syntax/) for advanced cases.
### Search Without Field Syntax
A search entered without MAUDE's field syntax is passed to four fields at once — MDR Text, Device UDI-DI, Device Brand Name, and Product Problems — and returns a match on any of them.
### Search Size And Results
MAUDE searches return up to 10,000 records, drawn from reports filed from 2009 to the present. Each result is a Medical Device Report (MDR), uniquely identified by its MDR Report Key; one report can involve more than one patient and more than one device.
### Disclaimer
The FDA states: *"Do not rely on openFDA to make decisions regarding medical care. Always speak to your health provider about the risks and benefits of FDA-regulated products."* MAUDE's passive surveillance design means reports can be incomplete, inaccurate, untimely, unverified, or biased, and incidence or prevalence can't be determined from this system alone. See the [MAUDE API overview](https://open.fda.gov/apis/device/event/) for the full disclaimer.
### FAQs
Can I search MAUDE the same way I search PubMed?
No — MAUDE uses its own `field_name:search_term` syntax through openFDA, unrelated to PubMed's `[FIELD]` tags or Embase's Emtree.
How many results can one MAUDE search return?
Up to 10,000 records, from reports filed since 2009.
Can I use MAUDE data on its own to conclude a device is unsafe?
No — treat MAUDE as one input alongside other evidence. Its passive surveillance design means report counts don't establish true incidence or prevalence; see the Disclaimer above.
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.
Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:
```
GET https://docs.nested-knowledge.com/guides/write-a-search-query/maude.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.