Targeted sample procurement – What is it and why is it needed?

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!