Randomized Trial Comparing EmbryoScope With EmbryoScope+.: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Randomized Trial Comparing EmbryoScope With EmbryoScope+. (NCT03522350), a randomized na study. The primary outcome is Number of Day 3 Embryos.

2. Clinical Question

3. Trial Design

The registry describes a randomized, parallel-group trial comparing EmbryoScope with EmbryoScope+. Allocation is listed as randomized, and masking is listed as none. The record lists the study phase as NA. The interventions are both classified as devices: EmbryoScope is described as the standard-of-care embryo incubator, and EmbryoScope+ as a new experimental embryo incubator. These descriptions define the comparison but do not provide operational details about device use or the randomization process.

The recorded enrollment is 18. The arm-level outcome records list 18 participants for each group. The registry lists infertility as the condition. It does not report further eligibility criteria, baseline characteristics, or details that would explain how participants or oocytes were allocated and analyzed. The primary endpoint is the number of Day 3 embryos, with a timeframe of Day 3 post retrieval. Implantation Rate and Pregnancy Rate are listed as secondary outcomes, with their respective timeframes recorded as 5-6 weeks post retrieval and 2 weeks post retrieval.

The study start date is 2017-09-06, and the primary completion date is 2018-06-04. The status is TERMINATED. The reason for termination is not reported in the registry record. Nor does the record explain whether termination affected enrollment, follow-up, or outcome reporting. No analysis results are listed as reported analyses. The registry record does not report the planned sample-size justification, a statistical analysis plan, interim analyses, or a protocol explanation for the termination. Those absences limit what can be inferred about the intended design and conduct beyond the information recorded above.

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: 18 subjects will undergo IVF. Participant's oocytes at retrieval will be randomly assigned to both groups for comparison: Standard EmbryoScope system versus EmbryoScope+. The best quality embryos are selected for embryo transfer and the pregnancy outcome is evaluated. "Best grade" embryos will be transferred regardless of EmbryoScope use.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Number of day 3 embryos compared in both groups

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.

6. Primary Endpoint

The registry lists the primary outcome as Number of Day 3 Embryos, measured over Day 3 post retrieval.

The primary endpoint is titled Number of Day 3 Embryos. It is described as a count of embryos that fertilized normally and had development at Day 3, compared between oocytes assigned to the standard EmbryoScope and those assigned to EmbryoScope+. The timeframe is Day 3 post retrieval, and the unit is embryos. The record also says the comparison is based on embryo grade, but does not provide a more detailed definition of grading or explain how counts were summarized across participants or oocytes.

A count endpoint can represent the quantity of an outcome within each study group. In general, such an endpoint may be useful when the research question concerns how many units meet a defined outcome, rather than only whether a participant experiences an event. Interpretation depends on the unit of analysis and the way observations are grouped. The registry record does not provide enough detail to determine those analysis choices for this endpoint.

The posted arm values are 42.0 for EmbryoScope+ and 42.0 for EmbryoScope. Each arm record lists 18.0. No spread or confidence interval is posted for this primary outcome, and the registry record does not provide an analysis comparing the groups. The matching reported counts therefore describe the posted summaries, but do not by themselves establish the precision of the comparison or whether the underlying distributions were similar.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies this as a randomized, parallel-group study with no masking. Those labels describe broad features of the design. Randomization is intended, in general, to make assignment independent of prognostic factors on average; it does not guarantee that groups will be balanced in a small study. A parallel-group design assigns groups to separate interventions for comparison. The record does not report the method used to generate or implement the allocation sequence, concealment procedures, or other practical details. The meaning of “NONE” for masking is recorded, but further details about who knew assignments are not reported in the registry record.

What does the primary count summarize?

The primary endpoint is a count of Day 3 embryos, with the unit recorded as embryos. The arm summaries are 42.0 for each device, and the arm records each list 18.0. A count is not necessarily analyzed in the same way as a continuous measurement or a binary event. General statistical practice considers how counts vary, how many zeros or unusually large values occur, and whether observations are independent. The registry record does not post the distribution of counts, a measure of spread, or the analysis method. It is therefore not possible to assess whether a particular count model or comparison was planned or appropriate.

In general, over-dispersion occurs when count variability is greater than a model assumes. If ignored, standard errors and interval estimates can be unreliable. This is a general consideration for count outcomes, not a claim that over-dispersion occurred in this trial. The record includes no dispersion estimate for the primary endpoint and no analysis results with which to examine that issue.

How should the secondary comparisons be read?

Implantation Rate and Pregnancy Rate are recorded as participant counts, with arm-level values for each. The posted recalculations express group contrasts as risk differences. A risk difference is the difference between the observed event proportions in two groups; a positive value in these comparisons corresponds to a higher observed proportion in the EmbryoScope arm than in EmbryoScope+. This describes the direction of the calculated contrast and does not establish a causal effect on its own.

A confidence interval describes the range of values reasonably compatible with the data under the calculation's assumptions. Wider intervals indicate less precision. For implantation, the interval is 0.045 to 0.621; for pregnancy, it is -0.023 to 0.578. The latter includes zero, which represents no risk difference. Neither interval should be read as a probability that a particular effect is true. The p-values are unadjusted recalculations from the posted summary statistics. They do not incorporate adjustment for multiple outcomes, and the registry record does not report an analysis plan or sponsor-reported inferential results. Because the discrepancy indicator is false, there is no posted discrepancy between a sponsor analysis and the recalculated results to resolve.

Risk ratios and odds ratios are also included in the posted secondary comparisons. These are alternative ways of expressing relative contrasts, while risk differences express absolute contrasts. In general, absolute and relative measures answer different questions, so interpretation should consider the measure and its interval together. The relative estimates are imprecise, as reflected in their broad intervals. The record does not identify a preferred effect measure in a statistical plan.

What do planning illustrations mean?

The sample-size planning illustrations are based on fractions of the observed secondary effects, not on the trial's own design justification. The recorded assumptions are a two-sided significance level of 0.05, equal allocation, and a normal approximation. The illustrations give participants per arm for 80% and 90% power at the stated effect fractions. These are planning scenarios, not observed power and not evidence that the trial was designed to detect those effects. A planning estimate based on an observed effect can be unstable, particularly when the estimate itself comes from limited data. The registry record does not report the original sample-size justification, target enrollment, or assumptions used when planning the trial.

In general, power is the probability that a specified analysis will detect an effect of a specified size under its assumptions. It is not a measure of the probability that a result is true. A calculation using an observed effect for planning does not describe the probability that the completed trial detected a real effect. These distinctions matter when reading the illustrative planning estimates alongside the recorded enrollment.

What information is missing for evaluation?

The registry record lists no reported analyses. It does not report the statistical model for the primary count, the analysis population, treatment of missing observations, multiplicity procedures, interim analyses, or prespecified covariates. It also does not say whether the reported arm counts represent all randomized participants or another analysis set. These are not details that can be reconstructed from the posted group summaries. Without them, the endpoint values and simple secondary recalculations are descriptive evidence rather than a full account of a prespecified confirmatory analysis.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome and two secondary outcomes, but does not report how hypothesis testing across outcomes was handled. The secondary risk differences and p-values are unadjusted recalculations from posted arm summaries. No multiplicity correction or hierarchy of tests is reported in the registry record. In general, testing multiple outcomes without adjustment can increase the chance of at least one result appearing statistically unusual by chance. This is why an unadjusted secondary result generally carries less confirmatory weight than a result supported by a prespecified analysis plan. The record does not state whether the secondary outcomes were intended as exploratory or confirmatory.

The registry record also does not report missing-data counts, reasons for missingness, or methods used to address missing outcomes. It does not identify an intention-to-treat, per-protocol, or other analysis population, and it does not explain how participants or observations were included in each endpoint analysis. The arm records list 18.0 for each group, but this alone does not establish the analysis population or completeness of follow-up for every outcome.

No interim analyses, stopping rules, or analysis-plan details are reported. The status is TERMINATED, but the reason for termination and its relationship to outcome collection are not reported in the registry record. These omissions prevent assessment of whether the posted analyses followed prespecified methods, whether missingness could have affected the estimates, or how the secondary findings should be interpreted within a larger testing strategy. They should be treated as unknowns, not as evidence that a particular procedure was or was not used.

11. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The adverse-event record lists All Participants Enrolled as the group, with 18 at risk for serious adverse events and 18 at risk for other adverse events. The posted affected counts are 0 for serious adverse events, 0 for other adverse events, and 0 deaths. No serious adverse-event terms are listed. These figures describe the registry entries; they should not be taken to mean that no events occurred beyond what was recorded or that the devices have been established as equally safe.

In general, safety counts need to be read in relation to the number observed, follow-up duration, event definitions, and completeness of reporting. The registry record does not give further details on those matters, nor does it report a comparative safety analysis. The study status is TERMINATED, but the reason is not reported in the registry record. The available figures are therefore a limited description of recorded events, not a precise estimate of comparative safety or a basis for broad safety conclusions.

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

The posted primary summaries show 42.0 Day 3 embryos in each arm. This is a description of the recorded endpoint values, not a demonstration that the devices produce identical outcomes. The registry does not report a measure of variability or an inferential comparison for the primary endpoint. Without those details, the precision of the observed equality cannot be assessed. A finding of no observed difference in these summaries is also not the same as a formal equivalence conclusion; equivalence requires a defined margin and a suitable analysis, neither of which is reported in the registry record.

The secondary comparisons show higher recorded implantation and pregnancy counts in the EmbryoScope arm, with uncertainty that differs between outcomes. Those unadjusted estimates are not a substitute for the missing primary analysis, and they do not establish that either device causes a better outcome. The registry does not report a multiplicity strategy or analysis plan, so the secondary p-values have limited confirmatory meaning.

The trial's randomized design is relevant to interpreting group comparisons in general, but it does not resolve limitations in the available outcome reporting. The record gives no reason for termination, no sample-size justification, and no detail on missing data or analysis populations. It also does not report how the primary count was modeled or summarized beyond the posted arm values. Therefore, the evidence supports a narrow account of what was recorded, not a complete assessment of the comparative performance, safety, or reliability of the devices.

The record's stated purpose was to compare the current EmbryoScope system with EmbryoScope+ and to demonstrate that the newer device was as safe and reliable as the existing system. The posted results do not establish that claim. They also do not establish the opposite. They leave important questions unresolved because the primary endpoint lacks an uncertainty estimate and analysis, the secondary comparisons are unadjusted, and the registry record does not provide key methodological details.

13. Why This Trial Matters Statistically

This study illustrates why an outcome value and a treatment comparison are not interchangeable. The primary endpoint reports the same count in both arms, but without variation estimates or an inferential analysis, that equality cannot show how precisely the groups were compared. For a count outcome, understanding its distribution and analysis unit is important; those details are not available in the registry record.

It also illustrates the distinction between a study's stated goal and the evidence needed to support it. The summary describes an aim of showing that EmbryoScope+ is as safe and reliable as EmbryoScope. A general difference test, even if reported, would not by itself establish equivalence. Equivalence assessment requires a defined acceptable difference and an analysis designed to evaluate it. The registry record does not report such a margin or analysis.

The secondary comparisons further demonstrate why estimates, confidence intervals, and multiplicity context should be read together. One unadjusted interval excludes zero and another includes it, but neither result can be interpreted in isolation from the study's analysis plan, which is not reported. The planning illustrations are also not evidence of observed power or of the original design rationale. They are scenarios based on observed effects.

For clinical researchers and biostatisticians, the central lesson is to separate descriptive outcomes, recalculated comparisons, and prespecified sponsor analyses. The record offers descriptive primary counts and limited secondary summaries, but no reported analyses. It therefore supports a careful account of recorded results and uncertainty, while leaving the intended analysis and the reason for termination unresolved.

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.

Several limitations are specific to the information recorded for this trial. The primary endpoint is a count of embryos, but the registry does not explain whether the analysis unit was the participant, oocyte, or another grouping, beyond describing oocytes assigned to each device in the endpoint definition. It does not provide the count distribution, spread, confidence interval, or inferential comparison. Equal reported arm values therefore cannot show whether the groups had similar variability or whether the observed counts were concentrated in different ways.

The record lists 18.0 for each arm, but gives no baseline characteristics or detailed eligibility criteria. It does not describe the allocation method or clarify how the primary and secondary analysis populations were defined. The status is TERMINATED, and the reason for termination is not reported in the registry record. The record also does not explain whether termination affected follow-up or completeness of outcome collection.

The secondary outcomes have unadjusted recalculated comparisons, but the registry lists no reported analyses or multiplicity procedure. Their interpretation is limited by the absence of a statistical analysis plan and by the uncertainty in the estimates. The safety record lists no affected participants and no deaths in its recorded categories, but it does not provide detailed definitions, follow-up information, or a comparative safety analysis.

Finally, the record does not report the original sample-size rationale, missing-data handling, interim analyses, or a formal approach to assessing safety and reliability. These gaps limit both statistical interpretation and assessment of whether the posted results address the study's stated aim. They should remain recognized as unreported information rather than being filled in by assumptions.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Randomized Trial Comparing EmbryoScope With EmbryoScope+. — NCT03522350.
• Registry record last updated 2019-05-31; status last verified 2019-05.
• Results first posted 2019-05-31.
• 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

NCT03522350 is a randomized, parallel-group device trial comparing EmbryoScope with EmbryoScope+. The record lists no masking and identifies infertility as the condition. Enrollment is recorded as 18, and the status is TERMINATED. The study start date is 2017-09-06, and the primary completion date is 2018-06-04.

The primary outcome is Number of Day 3 Embryos, measured at Day 3 post retrieval. Both arms report 42.0, but no measure of spread or inferential comparison is posted. The secondary outcomes are Implantation Rate and Pregnancy Rate. Their recalculated comparisons are unadjusted, and the registry lists no reported analyses. The reason for termination, analysis plan, missing-data procedures, and sample-size justification are not reported in the registry record.