LDT rule deadlines and QC impact

The FDA’s 2024 final rule on LDTs is hitting another phase-in this quarter, so we’re tightening verification plans and data traceability on each method. For our respiratory PCR LDT, we added a 40-specimen split-comparison for lot bridging and are reviewing LIS audit trails weekly to confirm result integrity. How are you adjusting QC frequency and documentation to stay ahead of the deadlines?

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LIS audit trails weekly to confirm result integrity. How are you adjusting QC frequency and We bumped QC to two levels per shift for the first 10 days post-lot on our resp PCR and trended median Ct by target daily; if the LJ charts stay tight and your 40-split agrees, we drop back to daily. We still do the weekly LIS audit, but in that post-lot window we review exceptions daily and log it into an EP23 risk file so the documentation’s airtight.

My take: I’d lean toward the simplest next step and see if it changes anything this week — if not, you’ve got a clear case to escalate. What would block you from trying that?

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On our resp PCR LDT, we tighten to 1-2s/2-2s for the first week after a lot change and trend Ct medians by target; a >0.7 Ct nudge triggers a rerun using your “40-specimen split-comparison.” We also queue a once-per-shift low-positive third‑party control and require e‑sign on any template tweak in the LIS QA module — adds about 2 minutes but caught a primer lot drift. If that’s too heavy, @d_morrison92, at least watch IC Ct and invalid rate daily; it’s cheap and surprisingly sensitive to reagent hiccups.

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