For laboratories and networks
Changing an analyser without moving your patients.
You already run a method comparison. We turn it into the answer your clinicians will ask for: which of their patients now sit on the other side of a decision limit, and what to do during the transition.
01Input
What you send
OfferSomething we do for you. Described here, not a track record.
- The paired results from your method comparison or parallel run: the same samples measured on the old and the new analyser.
- Your decision limits, as your laboratory already publishes them.
- Your repeat-test imprecision, if you have it. If not, we assume it and the report says so.
- For a network, one file per site.
02Beyond the bias
What this adds to your method comparison
Your validation software tells you the bias. It does not tell you which patients now sit on the other side of a decision limit, how many of those moves repeat testing would have caused anyway, or what to re-test while both analysers are in use. Those three answers are what the report adds, and it can run on the same paired results you already collected.
03Output
What you get back
The comparison line, with its interval.
How the new analyser's results relate to the old one's across the whole range you measured.
Bias, with limits of agreement.
How far apart the two analysers read on the same sample, and how much that varies.
Bias at each of your own decision limits.
Not an average: the difference at the concentrations where your clinicians act.
Patients across each limit, in each direction.
How many results changed category, set against how many repeat testing alone would have moved.
A re-test band for the transition.
A narrow range around each limit inside which a new result is repeated, sized to a budget you choose.
A one-page note for requesting clinicians.
What changed and what it means for their patients, in their words rather than ours.
For networks, whether sites report interchangeably.
The same analysis across sites, at your limits, showing which site moves which patients.
Guide: Crossings by chance
04Where it runs
Runs inside your laboratory
If you run it on your own computer, no patient row leaves your laboratory; only aggregate files do, and you sign off what is released.
The program runs with the network off and prints checksums of itself, its configuration and your input, so you can show what ran on what. Counts below five are shown as <5 in anything that leaves. You sign a statement of what is released.
If you would rather not run it yourself, you can share coded paired results with us under a written data agreement instead. Separately, and only if you choose, you can contribute the comparison to the Analyser-Change Registry, a pooled record of analyser changes that gives each contributing laboratory a peer benchmark. It is never a condition of the report, and no laboratory has joined yet.
05Networks
One result, many instruments
For a network, the same analysis across sites shows whether sites report interchangeably at your limits, and which site moves which patients. It is the question ISO 15189 asks about comparability of results, answered in patients rather than in percent.
06Limits
What it does not replace
The report supports your verification work. It is not an ISO 15189 verification, not a device approval and not advice about an individual patient. Where it depends on an assumption, such as repeat-test imprecision you did not supply, it says so on the page where the number appears.
07Evidence
Open it before you ask
- Sample
Sample analyser-change report, CD4
A sample report built from one public platform change, as if a laboratory had exported its pairs. It shows three of the seven report parts in full and three in part; the other one needs more than one site. The sample page lists each part and what is not shown, with the reason. Reported without adjustment, 535 of 1,885 results change CD4 category, against about 238 expected from repeat testing alone. Nobody commissioned it; it is there so you can see what you would receive.
535results changed category
- Public data
Analyser change explorer
34 method comparisons at 14 stand-in sites, from 12 open-access studies. Of the 34 method comparisons, 21 get a full re-test band and 5 an indicative one, because they have fewer pairs than the minimum we set; the other 8 are shown as a comparison only or are too small for a band. In 6 of the 34 comparisons, the change moved fewer results across a limit than repeat testing alone would. All five checks we fixed before the run passed. The checks are ours, not an outside review.
10,579paired results
Changing an analyser soon?
Send us the change you are planning. We will tell you what the report would show and what it needs from you.