Evaluation (Validation and Verification) - Medical Device Design: Innovation from Concept to Market - page 233

that the power of that message is stronger if the clinician has no link with your company. If
your device is CE marked then any clinician can use it to determine the significance of its
performance in real life. Hence, for example, if you think your device can be assembled in
half the time of your competitor's device then there is no point you stating this. If a clinician
demonstrates this and publishes it independently then your message is strong. Also it is not
your study hence you need not worry about ethical issues. Any clinician is allowed to perform
their own studies using currently CE marked devices under their own ethical procedures.
However you have to wait for someone to think of doing this, on their own.
If, however, you cannot wait for this clinician to turn up, you will have to pay for the service. It
is almost certain that you will be unable to do this without outside help. Now you have entered
the ethical circle and you are paying the clinician or study team to undertake this aspect for
you. Most university hospitals, indeed most universities, offer this service. However, it is not
a clinical trial…that is something completely different. This is an evaluation to identify any
statistically significant differences or benefits. This is a clinically led study; it is not a clinical
trial, nor is it a clinical evaluation. Do not get them confused as the confusion could bring the
metaphorically long legislative arm of the law down onto your metaphorically tender shoulder.
I'm afraid it's time to mention statistics. We shall look at hypothesis testing in more detail when
we examine clinical trials. However, it is worth noting that the whole of the clinical effectiveness
world works on hypothesis testing and values of p . The magic number, often quoted, is p <0.05 -
what does this mean? Later we shall see that the statistics will almost certainly be examining two
groups and the difference between them. We look for a small value of p as this demonstrates that
the two groups are different, and we hope that the only difference is your device!
Golden rule: do not state clinical benefits unless you have the evidence to do so.
9.6 Clinical Studies and Clinical Trials
The distinction between a clinical study and a clinical trial is very clear. If you are unable to
put your device onto the market without first performing a clinical study proving efficacy and
safety then this is called a clinical trial . If your device can be CE marked without a clinical
study, then it is not a clinical trial and does not require the same amount of legislative rigor.
In essence the actual tasks undertaken are the same, it is the paperwork and pretrial licenses
required that make them different. Whatever, or whichever, you are attempting you should
be working to ISO 14155:2011 (ISO, 2011). Before we delve into ISO 14155 let us examine
some critical terms.
9.6.1 The Hypothesis
Why are clinical studies and clinical trials (collectively known as clinical investigations )
effectively the same? Very simply, they both aim to test a hypothesis. “ What is a hypothesis ?”
I hear you ask. It is the important part of any clinical study, be it a trial or not.