When planning a clinical performance study, the most conspicuous limiting factor is the availability of samples. Hundreds of blood samples, respiratory swabs, tissue biopsies etc. may be needed to statistically support the performance claim you wish to make for your product. We notice that a considerable portion of manufacturers focus on asking commercial biobanks for samples that are positive or negative for the condition their product is supposed to identify. For some products, this may be sufficient. However, whether this is the case, should not be decided by the level of simplicity of the sample procurement process, but by your product’s intended purpose. If your product is a PCR test for the identification of influenza subtypes in samples that are known to be influenza-positive, then just buying, and analysing influenza-positive frozen samples might yield sufficiently valid data.
The intended purpose of the vast majority of IVD devices, however, requires a more complex sample procurement strategy. For instance, a clinical performance study for a pregnancy test would require urine samples from women at specific time points before amenorrhea. This background data is usually not available for archived urine samples in biobanks. For a D‑dimer rapid test, one would need samples from patients with suspected deep venous thrombosis collected within a narrow time frame. A point-of-care white blood cell counting device must use non-frozen freshly drawn blood for analysis. For other products, it may be vital to know whether the donor was smoker or non-smoker, what their ethnicity was, or whether they were taking certain food supplements. They might need a specific novel sample type, certain pre-analytical conditions or simply a limited number of freeze-thaw cycles. The list goes on and on.
To put it in a nutshell: The sample requirements of most IVD devices are simply too specific to be coincidentally found in a biobank’s freezer. Anything that deviates from the current state-of-the-art medical routine is usually not collected in hospitals or elsewhere and therefore do not end up at a biobank.
Therefore, what manufacturers need, are service providers that are capable of establishing de novo procurement ways according to the intended purpose of the individual product that is to be validated.
At in.vent Diagnostica, we call this Targeted Sample Procurement.
Obviously, such services are more costly and time consuming than picking samples from a freezer. The alternative, however, might be that the notified body rejects your validation data due to unrealistic testing circumstances. A lot of IVD manufacturers will have to change their habits to avoid this dramatic outcome.
Do you need samples that correspond specifically to your product’s intended purpose? Contact us via email or give us a call, we would love to help you out!
