Evaluation of the Spectra Optia PMN Cell Collection Procedure: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluation of the Spectra Optia PMN Cell Collection Procedure (NCT01805180), a randomized na study. The primary outcome is Granulocyte/PMN Cell Collection Efficiency.

2. Clinical Question

The registry describes a controlled evaluation in which both devices appear in the assigned procedure sequences. The central statistical question is comparative: whether the collection-efficiency measurements differ between procedures performed with Spectra Optia and COBE Spectra. The primary endpoint is a continuous measure expressed as percent cells processed, with the mean and standard deviation specified as the summary statistics.

The crossover structure is relevant to how such a comparison could be made. In general, crossover studies can compare each participant's measurements under the different procedures, which may account for stable differences between participants. However, the registry record does not describe the actual primary analysis or whether it used paired measurements. It also does not report the primary endpoint values or a statistical estimate comparing the devices. Consequently, the record establishes the question and its measurement framework, but does not establish the direction, magnitude, or precision of a comparative result.

The available information should not be read as a comparison of clinical outcomes. The specified endpoint is device collection efficiency, and the listed secondary measures concern performance, product characteristics, and system operation. The registry record does not report whether any observed differences were considered clinically important.

3. Trial Design

NCT01805180 is listed as a completed, randomized crossover study of the Spectra Optia and COBE Spectra Apheresis Systems. Its purpose was to compare procedures for granulocyte/PMN cell collection. Enrollment is recorded as 42. The registry lists the study phase as not applicable and identifies Terumo BCT as the sponsor.

The two sequences were Spectra Optia followed by COBE Spectra, and COBE Spectra followed by Spectra Optia. Allocation is recorded as randomized, while masking is recorded as none. This means the registry describes randomized assignment to procedure order, not a masked comparison. The record does not explain how the random sequence was generated, whether allocation was concealed, or what steps were used to limit operational or measurement bias.

In a crossover design, participants undergo the procedures in different orders. General statistical reasoning is that order and period can matter: results might differ depending on which procedure came first or when a measurement was made. The registry gives the two sequences but does not report a washout interval, period-specific results, or an analysis of sequence or period effects. Those details should not be inferred from the design label alone.

The primary endpoint was measured using donor and blood product blood counts collected immediately before and after each collection procedure. The stated timeframe is within 1 hour prior and within 5 minutes after each procedure. The registry also lists secondary outcomes covering performance, PMN yield, yield per liter of blood processed, cell viability, red blood cell contamination, product volume, time, and adjustments. It records 11 outcome measures in total. The primary endpoint results and the analyses of these outcomes are not reported in the registry record.

The study is marked completed, with a start date of 2013-02 and primary completion of 2013-07. Completion status indicates the registry's recorded status, but by itself does not provide evidence about the findings or whether all planned analyses were conducted.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: A screening period was used to evaluate and confirm eligibility criteria prior to enrollment \& randomization to treatment assignment (Arm 1 or Arm 2). Fifty subjects consented to the pivotal study. Eight pivotal subjects consented but screen failed prior to treatment assignment. Forty-two received treatment assignment below.

Lead-in Donor Phase

Reasons for not completing this period:

Pivotal Randomization Through Study Exit

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

Population: Subjects in the Full Set Analysis (n=32) were randomized to either Arm 1 or Arm 2 and completed both procedures as assigned. Subjects who did not complete the collection (withdrawn n=10) did not have data and could not be included in the full set analysis.

6. Primary Endpoint

The registry lists the primary outcome as Granulocyte/PMN Cell Collection Efficiency, measured over within 1 hour prior and within 5 minutes after each collection procedure.

The primary endpoint is granulocyte/PMN cell collection efficiency, expressed as percent cells processed. It is described as a measure of device performance calculated using donor and blood product blood counts collected immediately before and after the collection procedure. The measurement window is within 1 hour prior and within 5 minutes after each procedure.

Collection efficiency is used to characterize how effectively a collection procedure captures the target cell population relative to the cells available in the blood being processed. As a continuous endpoint, it can be summarized by a mean and standard deviation. A comparison of means can describe the average difference between the procedures, while an uncertainty interval around that difference can indicate how precisely the comparison is estimated. These are general statistical interpretations; the registry does not report an estimated difference or an uncertainty interval for this endpoint.

Before-and-after blood counts make the timing of measurement important. Counts taken close to the procedure are intended to characterize conditions around the collection, but the record does not report assay procedures, quality-control methods, or the exact calculation formula. The endpoint description therefore identifies the data used and the intended performance construct, without enough information to reproduce its calculation.

The endpoint is a technical measure, not a direct measure of patient benefit or harm. The registry's primary endpoint results are not reported in the registry record, so the record does not show which device had a higher mean collection efficiency or how precise any difference might be.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a continuous primary endpoint summarized by a mean and standard deviation. These statistics answer different questions. The mean represents the average collection-efficiency measurement, while the standard deviation describes how much measurements vary around that average. A mean alone does not convey the distribution of individual observations or the precision of a comparison.

What does a confidence interval convey?

In general, a confidence interval expresses uncertainty around an estimated quantity, such as the difference between two means. A narrower interval indicates greater precision under the assumptions of the analysis; a wider interval indicates more uncertainty. An interval can also show which effect sizes are compatible with the data. The registry record does not report a confidence interval for the primary comparison, so the precision of the estimated device difference cannot be assessed from the posted information.

What would a crossover analysis need to consider?

In general, a crossover study can use the fact that participants receive procedures in different orders. If measurements are available under both procedures for the same participant, a paired analysis accounts for the relationship between those measurements. Pairing can be useful because participants may differ in their underlying blood counts or other stable characteristics. It does not remove every source of uncertainty: procedure order, period effects, changes over time, and measurement error may still matter.

The registry gives the two randomized sequences but does not describe the statistical model, period adjustment, sequence assessment, or handling of incomplete paired observations. It therefore does not establish whether the analysis was paired, whether a model was used, or how any crossover-specific issues were addressed. General descriptions of appropriate crossover methods should not be mistaken for a report of the methods actually used in this trial.

Why does variation matter?

General statistical reasoning distinguishes the variation among observed measurements from uncertainty in an estimated mean or difference. Standard deviation describes variation in the observations. The standard error and confidence interval, when reported, describe uncertainty in an estimate and depend on the analysis and data structure. In a crossover study, the relationship between paired measurements can affect the precision of a paired comparison. Because the record does not provide the outcome summaries or analysis, these quantities cannot be evaluated for this trial.

Over-dispersion is a general concern when observed variability is greater than a statistical model expects. If a model assumes less variation than is present, uncertainty can be understated and inferential results can appear more precise than warranted. The endpoint is continuous and the registry specifies a mean and standard deviation; it does not report a distributional model or evidence of over-dispersion. No claim about whether this issue arose in the study is possible.

How should p-values be read?

In general, a p-value measures how incompatible the observed data are with a specified statistical null model, under the assumptions of the analysis. It is not the probability that the null hypothesis is true, and it does not quantify the size or practical importance of an effect. A p-value also does not replace an effect estimate and uncertainty interval. No primary p-value is reported in the registry record, so there is no posted test result to interpret.

The registry's planning assumptions mention a two-sided significance level of 0.05 and a normal approximation. These are stated assumptions for planning illustrations, not evidence that the primary analysis used that significance level or approximation. The record does not report the actual statistical analysis plan, any interim analyses, or a sample-size justification for the trial. Those details are not reported in the registry record.

What do the planning assumptions mean?

General sample-size planning asks how much information a future study might need to detect a specified effect under chosen assumptions. The registry describes planning illustrations computed from the observed effect, with equal allocation and a normal approximation; for time-to-event calculations, it describes total events, while other calculations are expressed as participants per arm. Such illustrations are not the trial's original design justification and are not observed power. Since the primary result and the numerical planning estimates are not reported in the registry record, readers cannot assess the effect value used in a particular calculation or its resulting sample-size implication.

These methods concepts explain what a complete statistical report could help readers assess. They do not supply missing estimates, establish the analysis used, or justify conclusions about comparative performance.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 11 outcome measures. The primary endpoint is collection efficiency, while listed secondary measures cover performance, PMN cell yield, yield per liter of blood processed, viability, red blood cell contamination, product volume, time, and adjustments. A set of outcomes can lead to multiple statistical comparisons, especially if outcomes are examined across categories or time points.

In general, multiplicity matters because conducting many tests can increase the chance of obtaining at least one apparently unusual result by chance. Possible approaches include identifying a primary comparison in advance, adjusting inference for multiple tests, or treating secondary analyses as exploratory. The registry record does not report a multiplicity plan, a hierarchy of secondary outcomes, or the number of statistical tests performed. It records no analyses. The record therefore does not establish whether any adjustment was used or whether secondary findings were confirmatory.

The primary outcome is not reduced to a single comparison in the registry information because it has several categories or time points. The exact categories or time points and the planned approach to combining or selecting among them are not reported in the registry record. This limits interpretation even apart from the absence of numerical endpoint results.

Missing-data procedures and analysis populations are also not reported in the registry record. The record does not describe whether all enrolled participants contributed to every endpoint, how missing measurements were handled, or whether the analysis followed an intention-to-treat, per-protocol, or other population definition. In a crossover design, the treatment of participants with only one procedure measurement can affect which observations contribute to a paired comparison. No specific handling method should be assumed.

These omissions do not prove that the study lacked a statistical plan or that data were missing. They mean only that the registry record does not provide enough information to evaluate those aspects of the analysis.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent non-serious adverse event terms

The registry reports zero serious adverse events affecting participants in the Spectra Optia group, with 48 at risk, and zero affecting participants in the COBE Spectra group, with 42 at risk. It also lists 23 other adverse events among 48 at risk for Spectra Optia and 11 among 42 at risk for COBE Spectra. These are counts in the registry's adverse event entries, not measures of the primary collection-efficiency endpoint.

The serious-event entries list no serious event terms. The death fields are null, so deaths are not reported in these entries; null should not be read as a recorded count of zero. The registry does not explain why the at-risk counts differ between the device entries or how they relate to the enrollment figure. It also does not provide further detail in the registry entries about event definitions, severity, timing, attribution, or whether the same participant could contribute events in both procedure groups.

Event counts alone do not provide a complete comparison of safety. Interpretation would require clear definitions, ascertainment methods, exposure information, and suitable analysis. In a crossover study, the sequence and timing of events may also be relevant. Those details are not reported in the registry record. The posted figures should therefore be read as the reported adverse event counts with their recorded at-risk denominators, not as proof of absence of risk or as a definitive comparative safety analysis.

12. What the Result Does, and Does Not, Mean

The registry record establishes that NCT01805180 was designed to compare granulocyte/PMN cell collection procedures performed with the Spectra Optia and COBE Spectra systems. It describes randomized allocation to procedure order in a crossover design, a primary measure of collection efficiency, and several secondary measures related to product characteristics and system operation.

It does not report the primary endpoint values or the comparative analysis. As a result, the posted information does not show whether average collection efficiency differed between the devices, the size or direction of any difference, or the precision of such an estimate. Missing results cannot be interpreted as evidence of no difference. Nor can the design description alone establish that one procedure performed better.

The endpoint concerns technical collection performance. Even if a comparative collection-efficiency result were available, that measure alone would not establish effects on patient outcomes or other clinical consequences. The secondary outcome list indicates additional areas of interest, but their results are not reported in the registry record. The adverse event counts are separate from the performance endpoint and do not answer the primary comparison.

The crossover structure may allow a comparison that accounts for participant-level differences, but the registry does not report the actual model, treatment of period or sequence effects, or analysis population. Thus, readers cannot determine how the design was reflected in the statistical analysis. The record also does not report confidence intervals or p-values for the primary endpoint.

The appropriate reading is limited: the study question, procedures, design features, endpoint definition, and some adverse event counts are recorded, but the comparative efficacy-of-collection result is not. Any interpretation beyond those details would require results and methodological details not reported in the registry record.

13. Why This Trial Matters Statistically

This trial raises a useful statistical question about comparing devices in a crossover design. When procedures are performed in different orders, the analysis may need to account for the relationship between measurements from the same participant, as well as order and period effects. The registry records randomized sequence assignment, making those design features relevant to evaluating any comparative estimate.

The endpoint also illustrates the distinction between defining a measure and reporting its result. The registry describes collection efficiency, the blood-count timing, the unit, and the intended summary by mean and standard deviation. Those details help identify what the study sought to measure. They do not reveal the observed means, the difference between procedures, or its uncertainty. Statistical interpretation depends on both a clear endpoint definition and transparent numerical results.

The list of secondary outcomes demonstrates why a prespecified analysis strategy matters. Multiple performance and product measures can generate many comparisons. Without reported analysis methods and a multiplicity approach, readers cannot determine how the study treated those comparisons or how much weight to place on any potential secondary finding. The registry record does not report these methods or the analyses.

Finally, the adverse-event entries show why counts must be interpreted with their denominators and reporting context. Serious events and other adverse events are distinct entries, while null death fields are not equivalent to a reported zero. The at-risk counts also do not match the enrollment figure, and the registry does not explain that difference. A careful statistical reading separates what is explicitly recorded from what would require additional results or methodological detail.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The registry record leaves substantial gaps for interpretation of the primary comparison. It defines collection efficiency and its measurement window, but does not report primary endpoint summaries, a device contrast, an uncertainty interval, or a p-value. The direction, magnitude, and precision of any difference therefore cannot be assessed from the record.

Although the design is identified as randomized and crossover, the registry does not describe the randomization process, allocation concealment, period effects, or any washout procedure. Masking is recorded as none. The analysis model and the handling of sequence and period are not reported, so it is not possible to determine whether the analysis reflected the crossover structure appropriately.

The record does not report participant eligibility criteria, analysis populations, missing-data procedures, or the number of participants contributing endpoint data. Enrollment is recorded as 42, while the adverse event entries list 48 at risk for Spectra Optia and 42 at risk for COBE Spectra. The reason for the difference is not reported in the registry record. These figures should not be combined or treated as interchangeable denominators.

Other limitations include the lack of a reported statistical analysis plan, multiplicity strategy, sample-size justification, and outcome-specific results for the listed secondary measures. The registry specifies planning assumptions for illustrations, but those do not establish the trial's original design rationale or its analysis methods. The record also does not provide detailed adverse-event definitions or an explanation for null death fields. These are reporting limitations; they do not establish that corresponding procedures or analyses were absent from the conduct of the study.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Evaluation of the Spectra Optia PMN Cell Collection Procedure — NCT01805180.
• Registry record last updated 2015-03-18; status last verified 2015-02.
• Results first posted 2014-11-26.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

NCT01805180 is a completed randomized crossover evaluation of granulocyte/PMN cell collection using the Spectra Optia and COBE Spectra Apheresis Systems. Enrollment is recorded as 42, masking as none, and the sponsor as Terumo BCT. The study began in 2013-02 and primary completion is recorded as 2013-07.

The primary endpoint is granulocyte/PMN cell collection efficiency, expressed as percent cells processed and summarized by mean and standard deviation. Blood counts were to be collected within 1 hour prior and within 5 minutes after each procedure. The registry lists 11 outcome measures and records no analyses.

Primary and secondary comparative results are not reported in the registry record. Serious adverse event counts are recorded as zero affected in each device entry, with different at-risk counts; other adverse events are also listed. Death fields are null. The record does not explain the denominator difference or report the statistical methods needed to assess the primary comparison.