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 Clinical Performance Evaluation of Pefakit® PiCT® UC In Vitro Diagnostic Medical Device (NCT02052544), a registered phase not stated study. The primary outcome is Overall Sensitivity and Specificity of Pefakit and Hemosil..
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02052544 |
| Phase | Phase not stated |
| Condition | Thromboembolic Events |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 123 |
| Arms in the primary outcome | n/a |
| Lead sponsor | dsm-firmenich Switzerland AG |
| Results posted | Yes |
2. Clinical Question
Population
The study population was patients receiving unfractionated heparin therapy. The primary outcome description defines the analysis population as all valid subjects with no major deviation affecting the outcome. The registry reports enrollment of 123 and says 413 samples total were analyzed. Those are different types of counts; the record does not explain their relationship or report how many samples came from each subject.
Intervention
The test device was Pefakit® PiCT® UC. The stated purpose was to assess its clinical performance in determining heparin levels in subjects undergoing heparin therapy, in support of a United States Food and Drug Administration 510(k) submission. The registry describes sensitivity and specificity for the device, but does not report their numerical estimates.
Comparator
The predicate device was aPTT-SP (Hemosil). The study description says the sensitivity and specificity of both Pefakit and Hemosil were assessed relative to Biophen, identified as the reference method. This is not described as a randomized treatment comparison. The registry record does not report how device testing was assigned, ordered, or blinded.
Primary question
How did Pefakit® PiCT® UC and aPTT-SP (Hemosil) identify positive and negative cases relative to Biophen in the overall study population and separately at each of three medical centers? Sensitivity is defined as the proportion of positive cases identified as positive; specificity is the proportion of negative cases identified as negative. The stated timeframe was within 2 - 4 days. Numerical sensitivity and specificity estimates and their confidence intervals are not reported in the registry record.
3. Trial Design
This completed clinical performance evaluation was registered as NCT02052544 and sponsored by dsm-firmenich Switzerland AG. The registry lists a study start of 2012-04 and primary completion of 2013-05. The enrollment figure is 123. The listed study-patient group comprised patients receiving unfractionated heparin (UFH).
The stated objective was to demonstrate substantial equivalence of Pefakit® PiCT® UC, the test device, to aPTT-SP (Hemosil), the predicate device, for determining heparin levels in people undergoing heparin therapy. The stated context was support for a United States Food and Drug Administration 510(k) submission. The primary outcome description identifies Biophen as the reference method for assessing sensitivity and specificity of both devices.
The registry describes an overall study population analysis and separate analyses for each of three medical centers. The outcome population is described as all valid subjects with no major deviation affecting the outcome, and the record states that 413 samples total were analyzed. It does not explain how those samples relate to the enrollment figure, or give sample counts by device, participant, or center.
This is not described as a randomized comparison. Allocation is not stated, and the listed group is not a like-for-like control comparison. The registry record does not report the testing sequence, blinding, eligibility criteria, recruitment approach, or specific procedures for handling discordant results. It also does not provide a detailed statistical analysis plan. The status is COMPLETED, but the numerical primary outcome results are not reported in the registry record.
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: Plasma from subjects treated with any other anticoagulants other than UFH. Plasma from subjects who have been undergoing fibrinolytic therapy within the previous 4 weeks.
Overall Study
| Stage | Study Patients |
|---|---|
| STARTED | 123 |
| COMPLETED | 123 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: AVS (all valid subjects) population: All valid subjects with no major deviation affecting outcome.413 samples total analyzed
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: 144 subjects signed ICF. 4 out of 144 failed in/exclusion criteria 123 subjets are part of the AVS (all valid subjects) population. All 123 UFH treated study subjects had previous and concomitant medications and treatments.
| Characteristic | Unit | Plasma Samples From Subjects Receiving Unfractionated Heparin |
|---|---|---|
| Participants analysed | 123 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 56 |
| Age, Categorical: >=65 years | Participants | 67 |
| Age, Continuous | years | 65.5 (18 to 100) |
| Sex: Female, Male: Female | Participants | 55 |
| Sex: Female, Male: Male | Participants | 68 |
| Race/Ethnicity, Customized: Oriental | partecipants | 1 |
| Race/Ethnicity, Customized: African American | partecipants | 6 |
| Race/Ethnicity, Customized: Caucasian | partecipants | 114 |
| Race/Ethnicity, Customized: Hispanic | partecipants | 2 |
| Region of Enrollment: United States | participants | 51 |
| Region of Enrollment: Germany | participants | 38 |
| Region of Enrollment: Switzerland | participants | 34 |
6. Primary Endpoint
The registry lists the primary outcome as Overall Sensitivity and Specificity of Pefakit and Hemosil., measured over within 2 - 4 days.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | 95% Confidence Interval |
| Unit | percentage of cases |
| Endpoint classification | not reduced to a single comparison |
The primary outcome is titled overall sensitivity and specificity of Pefakit and Hemosil. It measures how often each device classifies cases in agreement with the reference method, Biophen. Sensitivity is the proportion of positive cases identified as positive; specificity is the proportion of negative cases identified as negative. These are separate properties: a device can identify positive cases well without necessarily identifying negative cases equally well, or vice versa.
The outcome is expressed as a percentage of cases, with a 95% confidence interval specified as the measure of uncertainty. The registry says these measures were calculated for the overall study population and separately for each of the three medical centers. The stated timeframe was within 2 - 4 days. The population is defined as all valid subjects without a major deviation affecting outcome, and 413 samples total are reported as analyzed.
Sensitivity and specificity are useful for describing classification performance against a reference method. They do not, by themselves, provide all information about agreement, clinical consequences, or performance in populations beyond those studied. Interpretation also depends on how positive and negative cases were defined, how the reference method was applied, and how uncertain or invalid results were handled. Those details and the numerical estimates are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry states a clinical performance objective: assess Pefakit® PiCT® UC in comparison with aPTT-SP (Hemosil) for determining heparin levels, with both devices evaluated relative to Biophen. The primary measures are sensitivity and specificity, each with a stated 95% confidence interval. However, the registry record does not report the estimates, the confidence limits, or numerical results by medical center. Consequently, the posted record does not allow a reader to judge the observed classification performance or its precision.
The objective uses the language of substantial equivalence, but the objective is not itself evidence that equivalence was demonstrated. An equivalence conclusion requires results interpreted against a prespecified acceptable range or other decision criteria. Such criteria and a detailed equivalence analysis are not reported in the registry record. Nor does the record provide numerical findings that could be compared with any such criteria. The study title and objective should therefore be read as descriptions of what the evaluation set out to assess, rather than as reported proof of a particular conclusion.
The reference method matters. The stated sensitivity and specificity describe classification relative to Biophen, not an absolute truth independent of measurement. Interpretation depends on the reference method and on the rules used to define positive and negative cases. Those rules are not reported in the registry record. The record also does not provide the number of positive and negative cases, which is important because each measure is based on a different subset of cases.
The record reports 123 enrolled and 413 samples analyzed. These figures should not be treated as interchangeable: one is reported as enrollment and the other as a sample count. The registry does not report the number of subjects contributing samples, the distribution of samples across subjects, or the analysis counts for each center. Repeated samples from a subject can carry related information, so the unit of analysis and handling of within-subject dependence would be relevant to interpreting precision. Those analytic details are not reported.
The registry’s description of a valid-subject population excludes subjects with a major deviation affecting outcome by definition, but it does not explain how validity was determined or how many observations were unavailable or excluded. The outcome timeframe is within 2 - 4 days; the record does not explain the timing relative to treatment or measurement procedures. In the absence of estimates, confidence intervals, analysis details, and prespecified decision criteria, the registry supports a description of the study question and outcome framework, but not a quantitative assessment of performance or equivalence.
9. Statistical Methods Explained
What do sensitivity and specificity describe?
In general, sensitivity describes the proportion of reference-positive cases that a test identifies as positive. Specificity describes the proportion of reference-negative cases that it identifies as negative. They answer different questions and should be interpreted separately. A single summary cannot show whether a device has similar performance for positive and negative cases.
For this evaluation, the registry identifies Biophen as the reference method and names Pefakit® PiCT® UC and aPTT-SP (Hemosil) as the devices being assessed. The definition of positive and negative cases, the classification thresholds, and any rules for borderline results are not reported in the registry record. Without those details, the endpoint definitions can be described at a high level, but the precise classification process cannot be reconstructed.
Why does the reference method matter?
In general, sensitivity and specificity are estimates of agreement with a chosen reference classification. If the reference method has measurement error or if its classification rules differ from those of the device being evaluated, the resulting estimates reflect that comparison. They are not a complete account of every aspect of measurement quality. The record names Biophen as the reference method but does not describe its procedures or how disagreements between methods were adjudicated.
How should the confidence intervals be read?
A confidence interval expresses uncertainty around an estimated quantity under the statistical model used. In general, a narrower interval indicates greater precision, while a wider interval indicates more uncertainty. The registry specifies a 95% confidence interval for sensitivity and specificity. It does not report the interval endpoints, the method used to calculate them, or the case counts that contribute to each estimate. Precision therefore cannot be assessed from the registry record.
Precision for sensitivity depends on the reference-positive cases, while precision for specificity depends on the reference-negative cases. The total sample count alone does not reveal how many cases contribute to either measure. The record reports 413 samples total analyzed, but does not report the numbers of positive and negative cases, or how samples were distributed between the overall and center-specific calculations.
What does the center-specific analysis add?
In general, reporting performance by center can help readers assess whether results are consistent across study settings. A difference between center estimates can reflect random uncertainty, differences in case mix, measurement practice, or other factors. Center-specific estimates are most informative when their denominators and uncertainty are also available. The registry says analyses were conducted separately for each of three medical centers, but numerical estimates, center-specific case counts, and confidence intervals are not reported in the registry record.
Differences between estimates across centers should not automatically be treated as proof of a true site effect. Formal assessment would require a defined analysis and consideration of uncertainty. The registry record does not describe a test of center differences or an adjustment for center.
What is the role of substantial equivalence?
In general, an equivalence assessment asks whether the observed difference between methods is sufficiently small under a prespecified criterion. It is not established merely by failing to find a statistically significant difference. The registry describes substantial equivalence as the study objective, but does not report an acceptable equivalence margin, hypotheses, decision rule, or numerical comparison. It is therefore not possible to determine from the record how equivalence was operationalized or whether its criteria were met.
What do the planning illustrations represent?
In general, a sample-size planning illustration explores how many participants might be needed under specified assumptions to detect an effect. Such an illustration is not an observed trial result and does not establish the probability that the completed study detected an effect. The planning assumptions associated with this evaluation describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a stated fraction of the observed effect. No specific sample-size illustration values are reported in the registry record. The registry also does not report that these assumptions were used to design the study.
Any recalculation from posted summary statistics would be an unadjusted calculation and would not replace the sponsor’s analysis. The registry record lists no analyses and provides no numerical primary outcome results, so there is no reported sponsor estimate to interpret alongside a recalculation. A planning scenario should not be described as observed power or as evidence of actual performance.
10. Multiplicity, Missing Data and Analysis Populations
The primary outcome description includes sensitivity and specificity for two devices, both assessed against Biophen, with analyses for the overall population and separately for each of three medical centers. This creates multiple estimates to interpret, but the registry record does not report a multiplicity strategy, a hierarchy among the measures, or a prespecified rule for drawing an overall conclusion. It also lists no analyses. Without the analysis details and numerical results, it is not possible to determine whether or how multiplicity was addressed.
The analysis population is described as all valid subjects with no major deviation affecting outcome. The record does not explain how validity was determined, what constituted a major deviation, or how many subjects or samples were omitted for that reason. Missing observations, invalid test results, indeterminate classifications, and imputation procedures are not reported in the registry record. The description therefore identifies a population definition but does not fully specify the handling of incomplete or unusable data.
The record states that 413 samples total were analyzed and reports enrollment of 123. It does not explain how samples were distributed across subjects, devices, or centers, or whether repeated samples were included. Such information would help clarify the analysis unit and the independence assumptions used for confidence intervals. The registry record does not report a statistical plan addressing these issues.
Because numerical results and analysis methods are absent, the record does not support a conclusion about the effects of missingness, multiplicity, or analysis-population choices on the reported performance. Those details are not reported in the registry record.
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 |
|---|---|---|---|
| Study Patients | 0 | 123 | 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 |
|---|---|
| Study Patients | 0 of 123 |
The registry lists Study Patients with 123 at risk for serious adverse events and 0 affected. It also lists 123 at risk for other events and 0 affected. These entries describe what was recorded for the listed group; they do not provide event narratives, definitions, follow-up details, or a breakdown by event type. No serious-event terms are listed.
The deaths entry is not reported in the registry record. It should not be interpreted as a reported zero. Likewise, the absence of listed event terms does not provide detail about how events were collected or classified. The safety figures should be read as registry reporting for the stated group, not as evidence about risks beyond the recorded categories and observation period. The registry does not report the safety follow-up period or additional safety analysis details.
12. What the Result Does, and Does Not, Mean
This evaluation is described as a comparison of Pefakit® PiCT® UC with aPTT-SP (Hemosil) for determining heparin levels in patients receiving unfractionated heparin. Its primary performance measures are sensitivity and specificity relative to Biophen, with a 95% confidence interval specified. Those measures are appropriate for describing classification performance against a reference method, when the classification rules and relevant case counts are known.
The registry record does not report numerical sensitivity or specificity estimates, confidence interval limits, center-specific results, or a numerical comparison between the devices. It therefore does not establish from the posted results whether performance was similar, different, precise, or imprecise. The stated objective of substantial equivalence should not be mistaken for a reported conclusion that equivalence was achieved. The equivalence criteria and supporting analysis are not reported in the registry record.
The study description also does not support conclusions about clinical outcomes, treatment decisions, or performance outside the evaluated setting. Its stated focus is measurement of heparin levels, not a comparison of treatment effects. A performance estimate relative to a reference method would not by itself answer every question about how a device should be used or about patient outcomes.
The enrollment count and sample count are reported separately: 123 enrolled and 413 samples analyzed. The record does not explain their relationship, so the sample count should not be read as a count of participants. Details on sample distribution, missing or invalid results, case definitions, and statistical handling are not reported. These omissions limit assessment of the estimates even if numerical results were available. In this record, the objective and outcome definitions can be described, but quantitative conclusions about the device comparison cannot be drawn.
13. Why This Trial Matters Statistically
Clinical performance studies often report diagnostic measures rather than a treatment contrast. Sensitivity and specificity describe different aspects of classification and depend on how positive and negative cases are defined. This evaluation makes that structure explicit by identifying both measures and naming Biophen as the reference method for assessing Pefakit® PiCT® UC and aPTT-SP (Hemosil).
The record also illustrates why an objective and a result are not the same thing. It states that the evaluation was intended to demonstrate substantial equivalence, but does not report the numerical measures or the criteria used to define equivalence. Statistical interpretation requires both a clear question and the estimates, uncertainty, and decision rules needed to answer it.
Reporting an overall estimate and estimates for each medical center can be valuable because performance may not be uniform across settings. To interpret such estimates, readers need case counts, uncertainty intervals, and a clear account of the analysis. Those numerical details are not reported in the registry record. The stated 413 samples analyzed and enrollment of 123 also underscore the importance of distinguishing sample counts from participant counts.
Finally, the registry entry highlights the value of transparent reporting about analysis populations, missing or invalid observations, and multiplicity. These details affect how confidently performance estimates can be interpreted. Here, the record establishes the study’s purpose and outcome framework, while leaving the numerical evidence and key analytic details unreported.
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 primary limitation for interpreting the registry entry is that numerical sensitivity and specificity results are not reported. Neither the overall estimates nor the center-specific estimates are available, and confidence interval endpoints are absent. As a result, the precision and direction of the observed performance cannot be assessed.
The record identifies Biophen as the reference method but does not report the positive and negative classification rules, thresholds, handling of discordant findings, or method for calculating confidence intervals. It also does not provide the center-specific denominators or counts of positive and negative cases. These details are important for understanding what the endpoint measures and how stable its estimates may be.
The registry reports 123 enrolled and 413 samples analyzed but does not explain the relationship between those figures. It does not report how many samples came from each subject, or whether samples were repeated or distributed differently by device or center. The analysis population is defined as valid subjects without major deviations affecting outcome, but criteria for validity and the handling of unavailable or invalid observations are not reported.
Allocation is not stated, and the study is not described as a randomized comparison. Blinding, test sequence, eligibility criteria, and recruitment procedures are not reported. The equivalence margin, decision rule, and detailed statistical analysis plan are also not reported in the registry record. These omissions prevent a full assessment of design and analysis choices, independently of the missing numerical results.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Clinical Performance Evaluation of Pefakit® PiCT® UC In Vitro Diagnostic Medical Device — NCT02052544.
- Registry record last updated 2015-05-06; status last verified 2015-05.
- Results first posted 2015-05-06.
- 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
NCT02052544 is a completed clinical performance evaluation sponsored by dsm-firmenich Switzerland AG. The registry lists a study start of 2012-04, primary completion of 2013-05, and enrollment of 123. The listed patients were receiving unfractionated heparin.
The stated objective was to assess substantial equivalence of Pefakit® PiCT® UC to aPTT-SP (Hemosil) for determining heparin levels. Sensitivity and specificity were assessed relative to Biophen for the overall population and separately for each of three medical centers. The outcome population is described as all valid subjects without a major deviation affecting outcome, and the record states that 413 samples total were analyzed.
Numerical primary outcome estimates, confidence interval limits, and detailed analysis methods are not reported in the registry record. The listed safety entries report 0 affected for serious events and 0 affected for other events among the Study Patients group; deaths are not reported in the registry record.