Test Kit Research & Comparison Center
Compare test kit evidence
Two figures can only be compared when they measure the same thing in the same way. This page enforces that rule.
The comparison rule
Two results are shown side by side only when all four of these are identical:
- Analyte: the same drug or metabolite (for example amphetamine, not "amphetamines" in general).
- Cutoff: the same threshold in ng/mL. An amphetamine test at 300 ng/mL and one at 1,000 ng/mL answer different questions.
- Sample type (matrix): urine with urine, saliva with saliva.
- Study type: the same design, for example a lay-user study with spiked urine in a test cup, or a method comparison on clinical samples against mass spectrometry.
If any one differs, the comparison shows "Insufficient comparable evidence" instead of numbers. That is a deliberate answer, not a missing feature: a higher percentage from an easier study design is not evidence that one product is better.
Why most of today's records cannot be compared
K091588 tests amphetamine at 1,000 ng/mL in a lay-user study; K091612 tests it at 300 ng/mL in a point-of-care study; K221871 has no published figures in its FDA review; the two independent studies report pooled figures for professional devices. None of those pairs meets the rule. Within K091588, the card and cup used different lay users, so they are also kept as separate study types.
P in the Cup does not perform the testing or certify these products. You can select up to four records from the evidence table.
Comparison
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