US FDA CDRH Warning Letters: A Review of 2023

By Sarah Fitzgerald

Manufacturers can better understand quality and regulatory issues of concern by the U.S. Food and Drug Administration (FDA) by reviewing relevant warning letters. This can allow companies to focus on problem areas as they continually assess and improve their internal procedures and processes.

Importance of reviewing warning letters

The U.S. FDA Center for Devices and Radiological Health (CDRH) issued 567 warning letters in 2023, most related to drugs, tobacco products or food products. Of those, 4% of all warning letters (24) were issued for medical devices.

Overview of medical device warning letters

Most warning letters include multiple issues. However, one issue usually appears to be the main issue, based on the positioning within the warning letter (the first issue is usually considered the most significant), or is the more detailed discussion within the warning letter. For a few, the main reason was not apparent. There were an equal number of warning letters issued primarily for regulatory issues as for Quality Management System (QMS) issues in 2023. The table below provides a summary of what we at Emergo by UL believe are the main issues, based on a review of these warning letters.

Table 1. Main CDRH Warning Letter Issues

Details on medical device warning letters

To fully understand FDA concerns, we need to look beyond the primary issue, as the majority of warning letters included multiple areas of concern. Tables 2a and 2b show all deficiency categories by warning letter. Note that for brevity, overall topics are grouped, so a warning letter may contain more points than are provided, but the broad topics are addressed. Additionally, due to this short nature, titles are minimized — where something is noted as insufficient — that may range from no procedures covering a topic to procedures omitting certain required information. Minimized title may even refer to the company not completely following a procedure.

Table 2a. Warning Letters and Categories of FDA Concerns by Warning Letter

* Such as Device Master Records, Device History Records, etc.

Table 2b. Warning Letters and Categories of FDA Concerns by Warning Letter (Continued)

* Such as Device Master Records, Device History Records, etc.

Categorization of the warning letters

Table 3 provides a summary of all deficiencies and calculates a percentage of the total of the medical device warning letters.

Table 3. Warning Letters and Categories Overview

* Such as Device Master Records, Device History Records, etc.

50% or more of warning letters for 2023 include the following categories of concerns:

• CAPA Procedure Insufficient
• Complaint Procedure Insufficient
• Medical Device Reporting Procedure Insufficient
• Manufacturing / Infrastructure Validation Insufficient

Concluding remarks

Manufacturers should pay careful attention to the procedures and processes within the categories that the FDA has found frequently deficient, as they periodically assess these while working toward continual improvement.

It is interesting to note that in many cases, labeling and record inadequacies specifically indicated unique device identification (UDI). Indeed, one warning letter (664806) was solely for lack of having UDI and the associated lack of UDI being registered in the FDA Global Unique Device Identification Database (GUDID). Manufacturers should therefore also be careful to ensure that their UDI is appropriately addressed.

Emergo by UL is available to assist with the review and audit of any manufacturer’s QMS, as well as to provide regulatory consulting.