From my experience, the most post-market surveillance we would receive is from the end user, or the patient. People will often call the company’s main hotline if they have any major complaints. Additionally, doctors, responsible for administering the device, also were quick to provide feedback on any faulty designs. In some cases, patient surveys can be administered as well as holding focus groups to gain consumer feedback on the product can be especially useful but are the initiative of the company, and would ultimately cost money to gain information on.
Concerning the production of the device, in process controls and checks should be taken throughout the production to ensure the quality, safety, and efficacy of the product. Depending on the product, in some cases, failures are permitted as per the FDA guideline but the number of failures depends on the batch size and if the following sample pulled for testing from the batch does pass the next time. The monitoring of these failed samples is crucial for post-market surveillance as well because if the product is failing coming off of the production line, it is going to fail when it reaches the end user.