This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Method Comparison Study of the Spartan FRX CYP2C19 Genotyping System Against Bi-directional Sequencing (NCT01718535), a registered phase not stated study. The primary outcome is Percent Agreement.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01718535 |
| Phase | Phase not stated |
| Condition | Genotyping Techniques |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 327 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Spartan Bioscience Inc. |
| Results posted | Yes |
2. Clinical Question
Population
The study concerns genomic DNA from buccal swab samples and CYP2C19 genotypes. The registry record lists genotype categories in its adverse-event results, but does not report detailed eligibility criteria or participant demographic characteristics.
Intervention
The Spartan FRX CYP2C19 Test System is a qualitative in vitro diagnostic test intended to identify CYP2C19 *2, *3, and *17 genotypes from genomic DNA obtained from buccal swabs.
Comparator
The comparison method is bi-directional DNA sequencing. The study description also says it evaluates agreement across three sample-transport embodiments used to transport reagent tubes with collected buccal swabs to a laboratory.
Primary question
The primary question is whether the FRX system’s percent agreement meets the study’s stated criterion after a second-pass result is complete. The registry record describes positive and negative percent agreement as measures of concordance, but does not report their observed values.
This is a diagnostic method-comparison question, not a question about the effect of a treatment on a clinical outcome. The study description focuses on whether genotype calls made by the FRX system agree with calls made by the sequencing comparator. Such agreement is relevant to characterizing how two methods classify the same type of genetic information, but it does not by itself establish how a test result changes clinical decisions or patient outcomes.
The record gives an enrollment of 327. It does not report participant characteristics, recruitment criteria, the number of samples with usable results, or how specimens were distributed across genotype categories for the primary analysis. It also does not provide the observed positive or negative percent agreement. Therefore, the primary question can be stated from the registry’s objective and endpoint definition, but its answer cannot be determined from the posted registry results.
3. Trial Design
The registry describes a completed method-comparison study of the Spartan FRX CYP2C19 *2, *3, and *17 Genotyping System. The study’s stated purpose was to compare the FRX system with bi-directional DNA sequencing and assess concordance. It also aimed to assess concordance across three sample-transport embodiments used to move reagent tubes containing collected buccal swab samples to a laboratory.
The record lists an enrollment of 327, the study start as 2012-09, primary completion as 2012-11, and status as completed. It identifies Spartan Bioscience Inc. as the sponsor. The intervention is listed as the Spartan FRX CYP2C19 Test System, classified as a device. The listed arm label is CYP2C19 Genotyping, but the arm description is blank.
This is not a randomized treatment comparison. The registry record does not state an allocation method, and its own caution indicates that the arms are not a like-for-like control comparison. A method-comparison design instead asks how results from a test method correspond to results from a comparator method. The record does not explain whether specimens were assigned to transport embodiments randomly, whether testing was blinded, or the order in which methods were applied.
The primary endpoint is named Percent Agreement, with a 95% confidence interval as its stated dispersion measure. The endpoint description says the study would pass if percent agreement was at least 99.0% and the lower bound of a one-sided 95% confidence interval was at least 95.0%, using the score method. The timeframe is after the second-pass result is complete (~3hours). The observed agreement estimate and confidence interval are not reported in the registry record, so the stated pass criterion cannot be evaluated from the posted results.
The record lists one outcome measure and no analyses. It does not report a detailed protocol, recruitment setting, study sites, specimen flow, or analysis population. Those omissions limit how fully the design and its execution can be reconstructed.
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.
Only the first 6 of 10 groups are shown.
Overall Study
| Stage | *1/*1 CYP2C19 Genotype | *1/*2 CYP2C19 Genotype | *2/*2 CYP2C19 Genotype | *1/*3 CYP2C19 Genotype | *3/*3 CYP2C19 Genotype | *1/*17 CYP2C19 Genotype |
|---|---|---|---|---|---|---|
| STARTED | 131 | 95 | 19 | 8 | 1 | 40 |
| First Pass | 128 | 94 | 19 | 7 | 1 | 39 |
| COMPLETED | 130 | 95 | 19 | 7 | 1 | 40 |
| NOT COMPLETED | 1 | 0 | 0 | 1 | 0 | 0 |
Reasons for not completing this period:
| Reason | *1/*1 CYP2C19 Genotype | *1/*2 CYP2C19 Genotype | *2/*2 CYP2C19 Genotype | *1/*3 CYP2C19 Genotype | *3/*3 CYP2C19 Genotype | *1/*17 CYP2C19 Genotype |
|---|---|---|---|---|---|---|
| Bidirectional Sequencing not possible | 1 | 0 | 0 | 1 | 0 | 0 |
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.
Only the first 6 of 11 groups are shown.
| Characteristic | Unit | *1/*1 CYP2C19 Genotype | *1/*2 CYP2C19 Genotype | *2/*2 CYP2C19 Genotype | *1/*3 CYP2C19 Genotype | *3/*3 CYP2C19 Genotype | *1/*17 CYP2C19 Genotype |
|---|---|---|---|---|---|---|---|
| Participants analysed | 130 | 95 | 19 | 7 | 1 | 40 | |
| Age, Categorical: <=18 years | Participants | 3 | 0 | 0 | 0 | 0 | 1 |
| Age, Categorical: Between 18 and 65 years | Participants | 124 | 95 | 19 | 7 | 1 | 38 |
| Age, Categorical: >=65 years | Participants | 3 | 0 | 0 | 0 | 0 | 1 |
| Sex/Gender, Customized: Gender Not Collected | Participants | 130 | 95 | 19 | 7 | 1 | 40 |
| Region of Enrollment: Canada | participants | 130 | 95 | 19 | 7 | 1 | 40 |
6. Primary Endpoint
The registry lists the primary outcome as Percent Agreement, measured over After second pass result is complete (~3hours).
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | 95% Confidence Interval |
| Unit | Percent Agreement |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is Percent Agreement. In a diagnostic method-comparison study, agreement describes how often classifications from the method under evaluation match classifications from a comparator. The study description specifies positive and negative percent agreement as concordance measures, comparing the Spartan FRX system with bi-directional DNA sequencing. These measures address agreement separately for positive and negative classifications rather than describing a clinical treatment effect.
Agreement is used because the purpose is to compare genotype calls made by two testing methods. It is a direct description of correspondence between methods. Agreement should not automatically be interpreted as proof that either method is correct: that interpretation depends on the comparator’s role and performance, and the registry does not describe an independent adjudication method. The posted record does not report separate observed positive and negative percent agreement values.
The endpoint description sets a passing criterion of at least 99.0% percent agreement and a lower bound of at least 95.0% for a one-sided 95% confidence interval, calculated using the score method. The stated timeframe is after the second-pass result is complete (~3hours). These are protocol criteria, not reported outcome values. The registry record does not give the observed estimate, its interval, or a statement that the criterion was met.
In general, a confidence interval expresses uncertainty around an estimated quantity under the method used to calculate it. Its lower bound is especially relevant to the stated criterion because the criterion requires the lower bound to clear a specified threshold, not merely the point estimate. Without the actual estimate and interval, precision and criterion attainment cannot be assessed.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes the study’s purpose and its planned decision criterion, but does not report the numerical primary result. It states that the FRX system was compared with bi-directional DNA sequencing and that positive and negative percent agreement were of interest. It does not give either agreement estimate, a confidence interval, the number of evaluable specimens, or an outcome statement indicating whether the prespecified criterion was met.
The distinction between a target and an observed result is important. The endpoint description says that the study would pass if percent agreement was at least 99.0% and the lower bound of a one-sided 95% confidence interval was at least 95.0%, using the score method. Those values define a criterion; they do not show that the result reached it. The posted information therefore does not support a conclusion about whether the study passed or about how closely the observed agreement estimate approached either threshold.
Nor can the precision of the comparison be judged from enrollment alone. The record reports enrollment of 327, but does not report how many participants or specimens contributed to each agreement calculation, how many results were available for analysis, or the distribution of positive and negative classifications in the primary analysis. These details matter because the uncertainty around an agreement estimate depends on the data contributing to that estimate, including the number and pattern of classifications.
The study also aimed to assess agreement across three transport embodiments. No results for those comparisons are reported in the registry record. Consequently, the posted information does not establish whether the transport approaches produced similar results, nor whether any differences were evaluated using a prespecified statistical procedure.
General interpretation: agreement statistics describe concordance between methods, not necessarily accuracy against an error-free truth. When one method serves as the comparator, agreement can be informative about consistency, but disagreement does not by itself identify which method made an incorrect classification. The registry record does not describe an independent reference standard or a process for resolving discrepant calls.
The study is marked completed, but completion status does not supply missing outcome estimates. The available record supports describing the objective, comparison method, enrollment, and criterion. It does not support claims about the observed performance of the FRX system or whether the study met its stated success criterion.
9. Statistical Methods Explained
The endpoint is a method-agreement measure. The registry describes comparing the Spartan FRX system with bi-directional DNA sequencing and identifies positive and negative percent agreement as concordance measures. In general, positive percent agreement describes matching positive classifications, while negative percent agreement describes matching negative classifications. These are agreement measures between methods. They should not be treated as interchangeable with sensitivity and specificity against an independently established truth unless the study design supports that interpretation.
What does the confidence interval contribute?
The endpoint lists a 95% confidence interval as its dispersion measure and specifies a one-sided 95% interval for the pass criterion. In general, a confidence interval represents uncertainty about an estimate under the assumptions of the calculation method. A point estimate alone does not communicate that uncertainty. The stated criterion uses both the percent-agreement threshold and the lower confidence bound: the estimate must be at least 99.0%, and the lower bound must be at least 95.0%. The registry specifies the score method for this interval. The actual estimate and interval are not reported in the registry record, so neither the magnitude nor precision of observed agreement can be assessed.
Why use a lower confidence bound?
General explanation: requiring a lower bound to exceed a threshold is a way to account for sampling uncertainty when judging whether an estimate is sufficiently high. A high point estimate can still have a lower bound that falls short if uncertainty is substantial. Conversely, the bound depends on both the observed data and the interval method. Here, the registry’s stated thresholds define the intended rule, but the absence of posted estimates means the rule cannot be applied to the available record.
How should the comparator be understood?
Bi-directional DNA sequencing is the comparator named in the study description. In general, a comparator provides a basis for assessing agreement, but agreement does not automatically establish correctness. If methods disagree, an independent adjudication approach may be needed to determine which call is accurate. Whether this study used such an approach, how discordant results were handled, and whether laboratory personnel were blinded are not reported in the registry record.
What can be learned from the transport objective?
The study description says concordance across three transport embodiments would also be evaluated. This makes transport handling part of the study’s stated scope, alongside comparison of the genotyping system with sequencing. In general, a transport comparison can examine whether sample handling is associated with consistent classifications. The registry does not report the specific transport procedures, allocation or testing order, analysis method, or observed results for these comparisons. No inference about equivalence or differences among the transport embodiments can therefore be made.
What does the timeframe mean?
The endpoint timeframe is after the second-pass result is complete (~3hours). This identifies when the endpoint is to be assessed, as described in the record. The registry does not explain what triggers a second pass, how first-pass and second-pass results are combined, or whether the timeframe refers to every specimen or a particular testing workflow. Those details should not be inferred from the timeframe wording alone.
General explanation: repeated testing or additional passes can affect an analysis if the study selects a final result from multiple attempts. The handling rule matters because it determines which observation counts as the endpoint and may affect the proportion of specimens included. The record’s endpoint description names the second-pass result but does not provide a fuller rule for failed, indeterminate, or discordant results.
The registry lists the outcome parameter as a number and gives a confidence interval as its dispersion. It does not provide a full statistical analysis plan, assumptions for the interval calculation, or methods for subgroup or transport analyses. The record also reports no analyses and no numerical primary results. Accordingly, the statistical method that can be described is limited to the score method specified for the one-sided confidence-bound criterion; additional methods are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry record does not report how multiplicity was addressed. It names Percent Agreement as the primary outcome and describes positive and negative percent agreement as concordance measures, while also stating an objective to compare three sample-transport embodiments. It does not explain whether these were treated as separate hypotheses, whether one measure was designated as the sole confirmatory analysis, or whether any adjustment to account for multiple comparisons was planned.
Missing-data handling is also not reported in the registry record. There is no description of how the analysis would handle absent, invalid, indeterminate, or failed test results; incomplete comparator results; or specimens without a second-pass result. The record does not state whether such observations would be excluded, counted as disagreements, or handled by another rule. These choices can affect an agreement estimate and its uncertainty.
The analysis populations are not described. Although the record reports enrollment of 327, it does not report how many participants or specimens were included in the primary analysis, whether all enrolled participants contributed usable samples, or whether different sets were used for positive and negative agreement or transport comparisons. The registry also does not state whether analysis was based on an intention-to-test, evaluable-specimen, or other defined population.
These omissions are consequential for interpretation, not evidence that a particular method was or was not used. Without a stated multiplicity plan, missing-data rules, and analysis population, the primary result cannot be fully reproduced or its susceptibility to exclusions assessed. The registry record reports no analyses and no numerical agreement results.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| *1/*1 CYP2C19 Genotype | 0 | 131 | 0.0% |
| *1/*2 CYP2C19 Genotype | 0 | 95 | 0.0% |
| *2/*2 CYP2C19 Genotype | 0 | 19 | 0.0% |
| *1/*3 CYP2C19 Genotype | 0 | 8 | 0.0% |
| *3/*3 CYP2C19 Genotype | 0 | 1 | 0.0% |
| *1/*17 CYP2C19 Genotype | 0 | 40 | 0.0% |
| *17/*17 CYP2C19 Genotype | 0 | 11 | 0.0% |
| *2/*3 CYP2C19 Genotype | 0 | 6 | 0.0% |
| *2/*17 CYP2C19 Genotype | 0 | 15 | 0.0% |
| *3/*17 CYP2C19 Genotype | 0 | 1 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| *1/*1 CYP2C19 Genotype | 0 of 131 |
| *1/*2 CYP2C19 Genotype | 0 of 95 |
| *2/*2 CYP2C19 Genotype | 0 of 19 |
| *1/*3 CYP2C19 Genotype | 0 of 8 |
| *3/*3 CYP2C19 Genotype | 0 of 1 |
| *1/*17 CYP2C19 Genotype | 0 of 40 |
The registry’s adverse-event results are organized by CYP2C19 genotype. For every genotype category listed, the record shows zero serious events and zero other affected participants. The listed at-risk counts are *1/*1: 131; *1/*2: 95; *2/*2: 19; *1/*3: 8; *3/*3: 1; *1/*17: 40; *17/*17: 11; *2/*3: 6; *2/*17: 15; and *3/*17: 1. These are the counts attached to the genotype categories in the adverse-event listing.
These entries should be read as posted counts, not as proof that no adverse events occurred in any broader sense. The record does not describe the event-collection period, event definitions, surveillance procedures, or whether participants were systematically asked about events. Death counts are not reported in the record; a missing value should not be interpreted as zero. No top serious-event terms are listed.
The study concerns a genotyping device and method agreement, rather than a randomized treatment comparison. The adverse-event listing does not establish comparative safety between methods or treatment groups. The registry does not report a safety analysis population or a narrative explaining how these event categories were collected.
12. What the Result Does, and Does Not, Mean
The record describes a completed study designed to compare the Spartan FRX CYP2C19 genotyping system with bi-directional DNA sequencing. Its primary measure is Percent Agreement, and its stated criterion combines a point-estimate threshold with a lower confidence-bound threshold. The study also aimed to assess concordance across three sample-transport embodiments.
What the posted record does not establish is the observed agreement. No numerical percent-agreement estimate, confidence interval, separate positive or negative agreement result, or statement of criterion attainment is reported. The enrollment of 327 is not a substitute for those results, because the number and classifications of specimens contributing to the analysis are not stated. The record therefore cannot show whether the test met the stated criterion or how precisely agreement was estimated.
General explanation: a method-comparison result is about correspondence between measurements or classifications. Strong agreement can support consistency between methods in the studied setting, but does not on its own prove that either method is correct or that results will be the same in every population, laboratory, or workflow. A comparator is not necessarily an error-free reference, and the registry does not describe an independent adjudication process.
The registry also does not report the outcomes of the transport-embodiment evaluation. It is therefore not possible to infer from the posted record whether the transport approaches were concordant or whether any observed differences mattered statistically.
The appropriate conclusion is narrow: the study’s purpose, enrollment, methods under comparison, endpoint definition, and success criterion are recorded. The actual performance result and important details needed to evaluate its precision, completeness, and analysis are not reported in the registry record. Completion status and zero event counts in the listed categories do not fill that gap.
13. Why This Trial Matters Statistically
Method-comparison studies address a distinct statistical question from trials that compare clinical interventions. Their focus is whether methods yield concordant classifications, and interpretation depends on how the comparator is used, how discordant results are handled, and which specimens enter each calculation. This study’s stated focus is the agreement of a qualitative CYP2C19 genotyping system with bi-directional sequencing.
The endpoint description makes the distinction between an estimate and its uncertainty especially visible. The stated criterion requires both percent agreement of at least 99.0% and a lower bound of at least 95.0% for a one-sided 95% confidence interval using the score method. Reporting both quantities would allow readers to assess whether the target was reached and how precisely agreement was estimated. The registry record gives the criterion but not the observed quantities.
The additional transport objective also matters statistically. Specimen handling is part of a diagnostic workflow, and comparing transport embodiments can address whether handling is associated with consistent calls. Yet a statement of intent is not evidence of concordance: the registry does not report those results or the analysis method used to compare them.
This record is also a useful example of why enrollment alone does not answer a performance question. The enrollment is 327, but the number of evaluable specimens and the classification counts used for each agreement measure are not reported. Without that information and the observed estimate, precision cannot be judged. Missing descriptions of analysis populations and handling of invalid or absent results further limit reproducibility.
The statistical importance of the study is therefore in its design question and explicit threshold, while the registry’s missing outcome reporting prevents an assessment of the answer. Clear reporting of estimates, confidence bounds, denominators, and specimen flow is needed for readers to interpret a method-comparison claim.
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 gives limited detail about the study’s execution. It does not report the eligibility criteria, participant characteristics, recruitment setting, study sites, or sample-flow information. Although enrollment is listed as 327, the number of specimens that produced usable results and the denominators for the primary agreement measures are not reported.
The record does not provide the observed primary endpoint, its confidence interval, or a conclusion about whether the stated pass criterion was met. It also does not report separate positive and negative percent agreement results, results for the three transport embodiments, or a detailed account of discrepant or failed results. These omissions prevent assessment of performance, precision, and transport-related findings.
Key design and analysis details are absent. The allocation method is not stated, the listed arm description is blank, and the record does not report blinding, test order, handling of invalid results, missing-data rules, or analysis populations. It also does not report how multiplicity was handled or give a complete statistical analysis plan. Whether an independent method adjudicated disagreements is not reported in the registry record.
The safety listing shows zero serious and zero other affected participants within each listed genotype category, but does not describe event definitions, collection procedures, or the safety analysis population. Death counts are not reported. These entries should not be generalized beyond what the listing records.
These limitations concern what is documented in the registry, and do not establish that a particular procedure was absent from the study. They mean that the posted record is insufficient to independently evaluate the numerical method-comparison result or reconstruct its analysis.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Method Comparison Study of the Spartan FRX CYP2C19 Genotyping System Against Bi-directional Sequencing — NCT01718535.
- Registry record last updated 2013-08-28; status last verified 2013-05.
- Results first posted 2013-08-28.
- 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.
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18. Record Summary
The registry record describes a completed method-comparison study of the Spartan FRX CYP2C19 *2, *3, and *17 Genotyping System against bi-directional DNA sequencing. The study aimed to assess positive and negative percent agreement and concordance across three sample-transport embodiments. Enrollment was 327; the study started in 2012-09 and reached primary completion in 2012-11.
The primary endpoint was Percent Agreement after the second-pass result was complete (~3hours). The stated criterion was agreement of at least 99.0% and a lower bound of at least 95.0% for a one-sided 95% confidence interval using the score method. Observed agreement estimates, confidence intervals, transport results, and analyses are not reported in the registry record. The adverse-event listing records zero serious and zero other affected participants in each listed genotype category, while death counts are not reported.