1. Background
The sponsor commissioned a serial-draw progesterone specimen collection program to support immunoassay verification work on a progesterone analyte across the analytical range.2 Single-analyte progesterone specimen banks are operationally simpler than the multi-analyte mass-spec or multi-marker host-response programs reported elsewhere in this engagement series — one analyte, one matrix, one assay-platform context — but the protocol-defined serial-draw cadence (multiple specimens per subject across a defined collection window) places the operational burden on per-site coordinator throughput rather than on subject-pool size or recruitment-funnel conversion.
The defining operational question for programs in this category is the network-architecture decision: execute through a single fully-resourced site at the per-site coordinator capacity ceiling, or distribute across a multi-site network at lower per-site cadence? Both architectures can deliver the program; the single-site architecture eliminates network-coordination overhead but concentrates execution risk on the chosen partner. The choice depends on program target size, available window, and the specific partner’s coordinator capacity disclosure.
2. Constraints encountered
Three constraints shaped the execution plan:
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Single-site execution risk concentration
A single-site program has no contingency network. If the partner site under-performs, falls out of operational compliance, or loses key coordinator capacity mid-program, there is no second site to redirect enrollment to within the available window. Site selection had to weight historical coordinator-throughput disclosure heavily, including peak-month performance disclosure on prior programs at the same partner. The chosen partner had previously delivered serial-draw programs at the per-month volume the protocol required.
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Per-site coordinator throughput as the binding constraint
The +376 single-month volume the program required is well above general-clinical-research per-site monthly cadence. Sustaining this throughput required: multi-coordinator coverage at the site, established healthy-adult-female patient panel of sufficient size to accommodate the protocol’s serial-draw cadence within the available window, and visit-flow templates pre-tuned for high-throughput operations. The site’s existing infrastructure was the operational lever; the program could not have run at this cadence at a partner without that infrastructure.
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Specimen-handling pipeline at the central reference lab
+376 specimens received in a single calendar month placed real throughput pressure on the central reference-lab specimen-handling pipeline: receipt logging, processing, aliquoting, freezer-bank inventory. Receiving-bench staffing was reviewed against the forecast specimen volume in the program-front planning phase; specimen-handling SOPs were tightened against the expected peak-month load. The reference lab’s ability to absorb the May 2023 peak was validated through the peak month itself.
3. Methods
RDI executed the program through a single fully-resourced clinical research site. Three operational moves are reported here in order of implementation.
3.1. Single-site architecture decision
The network-architecture decision was made in the program-planning phase against the program target, available window, and partner-coordinator-capacity disclosure. A multi-site network would have distributed the program across 3–4 partner sites at moderate per-site cadence; a single-site network concentrates the program at a single fully-resourced partner running near the per-site capacity ceiling. The single-site frame was chosen because (a) the program target was within reach of a single site within the available window, (b) the chosen partner had peak-month performance disclosure that supported the required cadence, and (c) the operational simplifications of single-site execution — no network-coordination overhead, no multi-site monitoring, no inter-site variability — were valuable on the program timeline.
3.2. Partner with multi-coordinator high-throughput infrastructure
The chosen partner site is a previously-qualified clinical research organization with multi-coordinator coverage on healthy-female adult enrollment, established healthy-adult-female patient panel of sufficient size to accommodate the protocol’s serial-draw cadence within the available window, and visit-flow templates pre-tuned for high-throughput operations. Site activation, master contracting, and IRB submission overhead were eliminated through partnership reuse; the program timeline at the program front was approximately 4 weeks faster than a new-site activation would have been.
3.3. Reference-lab pipeline scaled in advance of peak month
Receiving-bench staffing at the RDI central reference lab was reviewed and increased in advance of the May 2023 peak month; specimen-handling SOPs were tightened against the forecast peak-month load. Freezer-bank capacity was confirmed in advance against the program’s storage-volume forecast. The reference-lab pipeline absorbed the +376 May peak without specimen-handling drift or receiving-bench backlog.
Multi-site network architecture (alternative)
3–4 partner sites at moderate per-site cadence (~100–150 specimens/site/month). Network-coordination overhead, monitoring at multiple sites, inter-site variability. Lower single-partner execution risk but higher per-site management cost and program-front overhead.
Single-site architecture (this program)
One fully-resourced partner running near per-site capacity ceiling (+376 specimens in a single month). Concentrated execution risk on the chosen partner; offset by partner’s historical peak-month performance disclosure. Operationally lean — no network coordination, no inter-site variability, faster program-front timeline.
4. Results
Cumulative specimen count crossed 99 by end-April 2023 (program open and partial first month at the site), 475 by end-May 2023 (the program’s peak month at +376 specimens), 500 by end-July 2023 (after a quiet June reflecting a planned monthly pause for site staffing), and reached 575 at program close in August 2023 (Fig. 1).
Approximately 82% of program volume delivered in the first two months (April + May 2023): the partner site ran at full coordinator-throughput cadence through the protocol’s primary serial-draw window. The remaining 18% delivered across the closeout months (July + August 2023) as the protocol’s remaining serial-draw windows on already-enrolled subjects ran out (Table 1). The program target was attained in August 2023 and the program closed without any contingency-site activation.
| Month | Specimens | Cumulative | Operating note |
|---|---|---|---|
| April 2023 | +99 | 99 | Program open; partial first month at the site |
| May 2023 | +376 | 475 | Peak month; full coordinator-throughput cadence |
| June 2023 | +0 | 475 | Planned monthly pause for site staffing |
| July 2023 | +25 | 500 | Closeout cadence; remaining serial-draw windows |
| August 2023 | +75 | 575 | Program close at protocol-defined target |
| 4-month delivery window (effective) | 575 | — | Single-site execution at fully-resourced partner |
5. Discussion
Three observations bear noting. First, single-analyte specimen banks at the few-hundred-subject scale are well-suited to single-site execution architectures. The program target of 575 specimens is within reach of a single fully-resourced site within a 4-month window, and the operational simplifications of single-site execution — no network coordination, no multi-site monitoring, no inter-site variability — are valuable both on the program timeline and on per-specimen delivered cost. Programs in the multi-thousand-specimen range will outgrow this architecture; programs in the few-hundred-specimen range typically do not.
Second, the single-site architecture concentrates execution risk on the chosen partner, and that risk has to be managed up-front through partner selection and partner-disclosure review. The partner’s historical peak-month performance is the most important disclosure, more important than its general-throughput claims; the program’s viability depends on the partner being able to sustain peak-month cadence, not average cadence. The partner chosen here had previously delivered serial-draw programs at the per-month volume the protocol required.
Third, the +376 May 2023 peak is a useful benchmark for what a fully-resourced single-coordinator team can deliver on a single-analyte serial-draw protocol within a single calendar month. Multi-site network architectures should be benchmarked against this single-site capacity: a 4-site network at 100–150 specimens/site/month is operationally similar to one site at +400/month, and the choice between architectures should turn on the relative cost of network coordination versus single-site execution risk.
6. Conclusion
Single-site execution is a viable and operationally lean architecture for single-analyte specimen banks at the few-hundred-subject scale. A single fully-resourced partner, selected against historical peak-month performance disclosure, delivered 575 specimens in 4 months with 82% of program volume in the first two months and a +376 single-month peak demonstrating sustained per-site coordinator throughput. The same architecture transfers to other single-analyte specimen banks where the program target is within single-site capacity within the available window.