The Euro­pean Com­mis­sion has pub­lished a deroga­to­ry report on the lev­el of evi­dence avail­able for COVID-19 tests – RNA, anti­gen and anti­body tests – arriv­ing on the mar­ket. It explains the val­ue of using dif­fer­ent tests at dif­fer­ent stages in the dis­ease and draws atten­tion to the defi­cien­cies in the val­i­da­tion of tests.

The report comes after the recent­ly pub­lished guide­lines on COVID-19 in vit­ro diag­nos­tic tests and their performance.

In the new work­ing doc­u­ment, the Com­mis­sion points out that there is a dis­par­i­ty between the cur­rent­ly exist­ing or report­ed qual­i­ty assur­ance about COVID-19 tests and per­for­mance cri­te­ria. It men­tions per­for­mance cri­te­ria based on the prin­ci­ples of good ana­lyt­i­cal (test­ing) prac­tice and cor­re­spond­ing inter­na­tion­al stan­dards, like ISO/IEC 17025 (test­ing and cal­i­bra­tion lab­o­ra­to­ries) and ISO 15189 (require­ments for qual­i­ty and com­pe­tence in med­ical lab­o­ra­to­ries). It also says that there is a cru­cial need to accu­rate­ly val­i­date the per­for­mance of exist­ing and devel­op­ing test meth­ods tar­get­ing the viral RNA, SARS-CoV-2 as anti­gen or its antibodies. 

The required qual­i­ty stan­dards, like well-char­ac­terised ref­er­ence (con­trol) mate­ri­als rep­re­sent­ing real patient sam­ples, and ref­er­ence test meth­ods have to be record­ed, ver­i­fied or ascer­tained as quick­ly as pos­si­ble. Fur­ther­more, the Com­mis­sion says that more pro­fi­cien­cy test­ing exer­cis­es should be estab­lished allow­ing lab­o­ra­to­ries to demon­strate their COVID-19 test­ing capability.

A test’s intend­ed pur­pose is espe­cial­ly impor­tant. Each appli­ca­tion will need a dif­fer­ent per­for­mance and present dif­fer­ent risks.

A test’s intend­ed pur­pose is espe­cial­ly impor­tant. Each appli­ca­tion will need a dif­fer­ent per­for­mance and present dif­fer­ent risks. For exam­ple, when test­ing for an active infec­tion, false neg­a­tives present a sig­nif­i­cant risk. Like­wise, false pos­i­tives present a sig­nif­i­cant risk when test­ing for immu­ni­ty. It is imper­a­tive that man­u­fac­tur­ers clear­ly spec­i­fy their intend­ed use.

The doc­u­ment also advis­es on the shar­ing of infor­ma­tion and organ­is­ing joint stud­ies to avoid lengthy clin­i­cal stud­ies. Essen­tial for any suc­cess­ful assess­ment of per­for­mance is the avail­abil­i­ty of the required con­trol sam­ples and ref­er­ence mate­ri­als. Some of these, e.g. pos­i­tive virus sam­ples need­ed for anti­gen tests, will be extreme­ly dif­fi­cult to develop.

The pub­lic sees test­ing as a step back towards nor­mal­i­ty, but test­ing must have a ben­e­fit and all asser­ta­tions have to be accu­rate, so that every­one is con­scious of the lim­i­ta­tions of the test. This doc­u­ment is seen as a good step in this regard. 

Source: Medtech Insight (an Infor­ma product)

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