New and unproved medical devices

There is a well established nomenclature for describing the uptake of new technologies.1 “Innovators” adopt a novel approach the fastest; they are often mavericks and have personalities that feature a high tolerance for risk. “Early adopters” are the next to take up the new technology. Their behavior, which is only slightly more circumspect, has been described as self conscious experimentation.2 Together, these professionals are one standard deviation greater than average in terms of speed of adoption than their peers and make up about 16% of the relevant population.2

In a linked paper (doi:10.1136/bmj.f6956), Kynaston-Pearson and colleagues show that innovation research would have accurately predicted the proportion of orthopedic surgeons in England and Wales at the vanguard of using new technology.3 The authors examined the National Joint Registry of England and Wales to identify the range of prostheses used in total hip arthroplasty in 2011, and they found that about half of the 261 brands in the database had been on the market for fewer than three years. After conducting a systematic review of the literature, they found that about half of these recently introduced brands had no published evidence of clinical effectiveness. These 57 brands accounted for nearly 8% of all hip implants put in place during that time in England and Wales.

Not all studies of new medical products are published, but the real problem is that there is little chance in this case that the evaluations have been done. The characteristics of medical device regulation encourage orthopedic surgeons to use unproved and inherently risky new technology in total hip arthroplasty. The United Kingdom and other European nations do not require promising new medical devices to show benefits in controlled testing before routine use. Instead, new devices are studied in small numbers of patients to see whether they appear to be safe and perform as expected. The difference is crucial. A left atrial appendage exclusion device, for example, can be approved in the European Union after showing that it can be deployed in the heart as intended. By contrast, in the United States, the Food and Drug Administration has the authority to ensure that new high risk devices are first tested for effectiveness and safety.4 As a result, the left atrial appendage device might be approved only if it reduces risk of stroke—the main reason for its use in the first place.