The ICIJ used the Food and Drug Administration’s (FDA’s) Manufacturer and User Facility Device Experience (MAUDE) database to conduct the research. This data is publicly available and contains eight million reports which have been filed by doctors, patients and manufacturers when a medical device is suspected of putting someone at risk, causing injury or resulting in death.

Steps had to be taken to identify the gender of those within the database as although the FDA gathers information on the sex of patients, this data is not made publicly available. Therefore, in order to overcome this obstacle, the ICIJ realised that the sex of patients was sometimes disclosed through pronouns and adjectives within the incident reports submitted to the FDA.

The ICIJ group followed four steps to identify the gender of those in the FDA MAUDE database:

1. Generate a set of labels

This stage involved classifying patient sex in 1,000 incident reports from the MAUDE database. Patient sex was classified as female, male or unknown.

2. Assign rules to the computer

The group used rules to train the computer to conduct automatic sex classification on the data.

3. Validate the results from the computer

Humans looked at the results from the computer and implemented additional rules to improve the quality of the results.

4. Run the code against all of the data in the FDA Maude database

Using 1997-2017 (the same time frame as the Implant Files investigation), the computer assigned a gender to 23% of patients with 96% accuracy.

The ICIJ claim that the algorithm created using the above steps was able to positively identify the sex of the patient in more than 340,000 injury and death cases. These findings reported 67% of these people were women and 33% were men.

Talking about the findings, the ICIJ stated: “The trend we noticed is consistent with studies that have shown that women experience higher rates of hip-implant failure than men and have stronger immunological reactions to metal-containing devices.”

Other experts within the industry were keen to voice their opinion over the importance of looking at the effects of medical devices on different genders. Diana Zuckerman, president of the National Center for Health Research commented: “Having information about sex is very important because some products differ in safety between men and women.”

Madris Tomes, founder and CEO of Device Events and a former FDA manager described the ICIJ’s work as critical. Tomes said: “It has long been unclear why the FDA’s device division redacts data elements that are so vital to scientific study…age, sex, and even the outcome of the adverse event are redacted by the device division but not the drug division.”

“But, if we are to look at allergy and autoimmune issues (presented in the FDA Immunology panel’s meeting on Metals in Implants) resulting from the metals and polymers in the hips, this could provide a second reason why the revision rates for women is higher than it is for men. It is an area where more research is necessary, and it shows the need for the FDA to un-redact fields which are so important for patients, physicians and hospitals to evaluate the safety of devices”, she added.

This report is part of the well-known Implant Files, which began from a report on medtech adverse events last year.