A systematic review of the literature, including both peer-reviewed and grey literature (e.g., conference abstracts), is recommended as part of a clinical/performance evaluation report and the post-market surveillance of medical devices.

The objective of the literature search is to obtain information about the safety and performance attributes of similar products for which clinical data is available.

Literature searches are limited by their ability to identify all published and unpublished studies that may exist on a particular topic.

That said, when performed correctly, they can provide important information regarding health outcomes, adverse events, and clinical effectiveness. As such, they are recommended as part of a clinical/performance evaluation, PMS, and PSUR.

The function of a literature review in Clinical Evidence

The literature review is a critical step of the Clinical/performance evaluation process. The literature review supports every aspect of the thes process by providing information on the etiology, pathobiology, and treatment of the disease or condition to be studied; potential harms and benefits associated with device use; and prior studies that have evaluated the device.

As the purpose of a literature review is to determine the current state of knowledge on a topic, e.g., to identify gaps or limitations in an area of study, it helps plan for the future as well.

Literature reviews are performed for two main purposes, considered from a Clinical/Performance report point of view: to provide contextual background for a clinical study and to locate relevant evidence for inclusion in the report.

The literature review is not intended to systematically identify all relevant literature, but rather to identify key studies that can serve as an evidence base for the study being conducted. In general, higher levels of evidence are more likely to include studies that have addressed specific questions of interest to the study being conducted and therefore may be more easily included in the report than lower levels of evidence. Hence, a good literature review helps a team to plan the clinical/performance evaluation, clinical trial, etc.

A literature review can help identify areas where future research is needed. It is important to be aware of what has already been published and the products that are already on the market so that the new products does not follow designs that failed scientifically.

Literature review and post-market surveillance plan

Literature searches are conducted to identify studies that have been done on the topic of interest. They are often used to evaluate the quality and existence of evidence on a topic before undertaking further research.

A literature search is an essential tool for post-market surveillance plans when done correctly. The main purpose of this approach is to estimate the risk associated with the medical devices and which adverse effects or risks one should keep an eye out for in the post-market surveillance. This is done by collecting information from different sources (e.g., published scientific literature or internal data). Literature searches are also used in post-marketing surveillance to help identify adverse events or adverse drug reactions associated with the devices that were not detected in clinical trials. Hence, it is an important tool for manufacturers who are looking to improve upon existing devices in the market or more importantly when making their post-market surveillance plan.

Literature searches can help with regulatory strategy. By determining whether other products on the market treat the same condition in similar ways, one can work out how to classify their product and what clinical information will be required to demonstrate safety and performance.

Literature reviews could also be used to explore variations in therapeutic approaches and interventions to provide evidence-based recommendations for parameters to include in the post-market surveillance of medical devices.

PSUR and literature review

A Periodic Safety Update Report (PSUR) is a pharmacovigilance document that enables regulators at specified time points following authorization to update the worldwide safety experiences of the medical devices.

The role of literature review in the Periodic Safety Update Report is in designing the report and mentioning any adverse reactions. As having a good literature review enables the manufacturing team to predict outcomes based on real-world evidence, it is easier to plan the reports accordingly.

Device safety vigilance and the use of literature review

Manufacturers are required to collect, record, and analyze all reported incidents in relation to their devices. This is known as vigilance. As part of vigilance, manufacturers must conduct a literature review for their medical devices at least annually and also during the lifetime of their device.

Hence, in a device vigilance system, the literature review is a vital tool to identify suspected adverse events that are already reported and possibly predict the ones that are not yet reported.
The information gathered from the literature review can help manufacturers update the risk management files and provide evidence that the design controls are appropriate and effective. It also provides a means to identify potential issues or topics for product improvement, which can be addressed in a post-market surveillance plan.