Jos Wielders

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Questions related from Jos Wielders

What do you think is the best approach to method validation in clinical laborotories?

ISO15189 or American guidelines are only rough guidelines for method validation and incomplete. In general the focus is on (im)precision and trueness, where the latter is often complicated by the...

27 December 2021 6,662 5 View

How should a PPV or posLR be weighed against a NPV, resp negLR when comparing biomarker results in medical or forensic decision making?

When several biomarkers are used in medical or forensic decision making (or diagnosis) the diagnostic accurary can be compared with ROC curves and AOC (area under the curve). In addition Pos and...

15 September 2018 9,121 0 View

Which POCT tests (for private use) for vitamin D are on the market? Which are FDA approved?

I'm interested in private determination of vitamin D (as 25OH vitamin D). I know that there are blood spot tests to be send to labs for LC-MS/MS analyses. But I am looking for...

06 April 2018 4,587 4 View

Does vitamin D prevent influenza and / or upper respiratory tract infection?

Vitamin D status is associated with upper respiratory tract infection and / or influenza. Of course such association (or causal relation) is stronger when there is : - initially state of...

01 January 1970 4,200 13 View

Guidelines and ISO norms, are they a benefit or mainly a burden?

Medical guidelines, prescribing how to diagnose a disease and how to treat this can be very helpful. On the other side, if a physician is obliged to follow this to the letter, it can be a burden,...

01 January 1970 7,566 5 View

Metrologic weighing of biomarkers like gGT and CDT, next to using ROC and PPV and NPV

When several biomarkers are used in medical or forensic decision making (or diagnosis) the diagnostic accurary can be compared with ROC curves and AOC (area under the curve). In addition Pos and...

01 January 1970 6,467 0 View

Biomarkers for alcohol-abuse or questionnaires like CAGE, what is your choice ?

Especially in the field of psychiatry hesitation exist sometimes in the use of laboratory biomarkers like GGT, CDT or PEth for diagnosis of chronic abuse. The use of questionnaires like CAGE or...

01 January 1970 8,981 6 View