Complaint Investigation Case Study (21 CFR 820.198): Part 2

This article is part 2 of a two-part series specific to complaint investigation requirements as specified in 21 CFR 820.198 ( of FDA QSR. This second part explains how to perform a complaint investigation and provides a complaint investigation case study.

complaint part 2 Complaint Investigation Case Study (21 CFR 820.198): Part 2


Last week’s blog  reviewed the requirements for a complaint investigation, while this blog includes the following information on how to conduct an investigation:h

  1. How thorough should your investigation be?
  2. Investigation Methods
  3. Verification of the Cause
  4. Documenting Your Investigation
  5. Complaint Investigation Case Study

How thorough should your investigation be?

The depth of investigation should be appropriate to the importance of the complaint. If a previous complaint of similar nature has already been investigated, the investigation may only gather enough information to verify that complaint has the same root cause. However, if a complaint involves an adverse event (i.e., is reportable under 21 CFR 803), then additional information needs to be recorded in the complaint record as per 21 CFR 820.198d:

  1. Does the device fail to meet specifications?
  2. Was the device used for treatment or diagnosis?
  3. What was the relationship, if any, between the device and the reported event?

If the person gathering information from the complainant cannot immediately identify a cause code, or the incident involves a severe injury or death, then it is essential to collect as much information as possible. Typically, the complainant will be asked to return the device to determine if the device malfunctioned.

Investigation Methods

A complaint investigation is not any different from any investigation you perform for a CAPA. The most critical first step is to determine the cause of the complaint. To determine the cause, you need to sample additional records and inspect the device if it is available. If the device is not available, you might also look at other product from the same lot that remains in inventory. The following article I wrote suggests seven ways to investigate a complaint when a device is not returned:

One of the methods described in the article above is an Ishikawa Diagram or “Fishbone Diagram.” This is one of the five root cause analysis tools that I teach in my CAPA webinar ( Ishikawa Diagrams are an ideal tool for root cause analysis if you have no idea what the cause of the complaint is because this tool provides a systematic process for narrowing down the potential causes, to the narrow few that are most likely. You are not required to use this tool, but you should describe in your complaint record what type of root cause analysis was performed.

Verification of Cause

Once you have identified the root cause, or at least narrowed your list to the most likely causes, you should then verify that the cause will result in the observed malfunction by recreating the scenario if possible. Ideally, you should be able to simulate the event that resulted in the complaint and demonstrate that you can reproduce the problem. This is important because if you cannot verify the cause of a device malfunction, then you will have difficulty verifying the effectiveness of corrective actions for an infrequent complaint.

Documenting Your Investigation

There is no specific format for the way a complaint investigation is documented. Still, most complaint records have a small section on the complaint form that allows them to write a short paragraph summarizing the investigation and the results. Unfortunately, most of the spaces provided on forms are completely inadequate for the amount of information that should be recorded. Therefore, the best approach is often to write, “See attached complaint investigation.” This is especially true if the complaint is reportable (i.e., requires MDR under 21 CFR 803). Good documentation is quantitative and specific. You need to identify which records were sampled as part of the investigation. You should demonstrate that you have expanded your initial search to determine if the problem exists in multiple production lots of the same product code, multiple product codes within the same product family and any other product families that may use similar raw materials, design features, equipment, testing methods or procedures.

Complaint Investigation Case Study

If your company manufactures cast orthopedic implants for the knee and you receive a complaint about an implant that has a small imperfection in the bearing surface of the femoral implant, you may need to perform an investigation–especially if this has not occurred previously. You should request a return of the implant for inspection to verify that the imperfection is nonconforming and not just a cosmetic defect.

Your investigation should include a review of the lot history record for an entire lot of implants–as well as any other parts that they may have been cast at the same time. All the process conditions identified throughout the manufacturing process should be compared to the validated process parameters. Special attention should be given to the inspection results that were recorded for the castings (i.e., radiographic inspection, fluorescent penetrant inspection, and metallurgical inspection). Ideally, these inspection methods should be repeated for 100% of the production lot to ensure that the inspection results meet the acceptance criteria. Documentation of the investigation should include copies of all records that were reviewed and photos if visual inspections were repeated.

If you are interested in learning more about complaint handling, you might be interested in downloading the webinar that Medical Device Academy recorded last year for complaint handling and vigilance reporting ( We can also help you one-on-one with a current complaint investigation you are conducting. Please don’t hesitate to contact me. Mobile: 802.281.4381 or

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  1. Pingback: Private Labeled Devices with FDA Approval - Medical Device Academy Medical Device Academy

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