Secretin-Stimulated Magnetic Resonance Cholangiopancreatography (S-MRCP) in Pancreatic Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Secretin-Stimulated Magnetic Resonance Cholangiopancreatography (S-MRCP) in Pancreatic Patients (NCT01094561), a na na study. The primary outcome is S-MRCP and S-EUS Concordance.

2. Clinical Question

3. Trial Design

This was a completed, open-label, single-group pilot study. The registry lists allocation as NA and masking as none; it does not describe randomized assignment or a blinded assessment process. Enrollment was 23. The study began in 2006-07, and primary completion was recorded as 2015-02. These dates describe the registry record and do not establish how long any individual participant was followed.

The planned assessment involved S-MRCP with contrast-enhanced MRI/MRA, followed within thirty days by EUS with and without secretin enhancement. A radiologist was to analyze the images. If EUS showed abnormalities, EUS-guided fine-needle aspiration was to be performed. The image findings were to be categorized as benign or suspicious/malignant for the concordance assessment. These are descriptions of the intended procedures; the registry does not provide participant-level completion information.

The intervention listings include synthetic human secretin, secretin-enhanced MRCP, and secretin-enhanced EUS. The arm description identifies a single open-label arm for synthetic human secretin. The registry does not report a concurrent control group, allocation procedure, or a comparison of outcomes between treatment arms. Accordingly, the study is not a randomized treatment comparison.

The registry states that poor enrollment resulted in inadequate data for analysis and that data analysis was not conducted. Although the study status is completed, completion does not mean that the planned primary question was answered. Details such as eligibility criteria beyond the high-risk description, recruitment flow, protocol deviations, and the number of participants who completed each procedure 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.

Overall Study

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 S-MRCP and S-EUS Concordance, measured over Day 1 and up to 30 days after S-MRCP.

The primary endpoint was concordance between S-MRCP and S-EUS image findings. Concordance describes the extent to which two assessment methods assign the same category to the findings they evaluate. In this study, the planned categories were benign and suspicious/malignant. The timing was Day 1 and up to 30 days after S-MRCP.

Concordance is relevant when a study asks whether two diagnostic approaches produce similar classifications. It is not, by itself, a measure of diagnostic accuracy. Agreement does not establish that either method correctly identifies disease; that requires an appropriate reference standard and a comparison of each test’s classifications with that standard. The registry describes EUS-guided fine-needle aspiration when EUS showed abnormalities, but does not report a complete reference-standard strategy or any resulting accuracy analysis.

The primary endpoint is therefore a planned measure of agreement, not a reported estimate of sensitivity, specificity, or clinical benefit. The registry explicitly says the collected data were inadequate for analysis and that no data are available to report. No concordance estimate or uncertainty interval is reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The central statistical idea was concordance: whether S-MRCP and S-EUS assigned the same category to the imaging findings. The registry planned to classify findings as benign or suspicious/malignant. In general, concordance is useful when the question concerns consistency between assessment methods. It differs from diagnostic accuracy, which asks whether a test’s classification matches the true disease status according to an appropriate reference standard. Similar classifications can occur even when both tests are wrong, and different classifications do not by themselves reveal which test is correct.

What would an agreement estimate describe?

In general, an agreement estimate summarizes how often paired assessments yield matching categories among the observations included in the analysis. Its interpretation depends on the analysis population, how missing or indeterminate readings are handled, and the distribution of categories. A chance-adjusted agreement measure would answer a different, more specific question than a simple proportion of matching readings. The registry record does not identify a planned agreement statistic, a chance-adjustment method, or a detailed analysis procedure. It reports that no analysis was conducted, so no estimate can be interpreted.

The timing matters to the measurement question. The stated timeframe is Day 1 and up to 30 days after S-MRCP. A paired comparison requires usable findings from both procedures for the same participant. When assessments are not made at the same time, findings may not reflect precisely the same clinical state; this is a general consideration in diagnostic comparisons, not a reported problem in this study. The registry does not provide individual procedure dates or report how timing was handled in an analysis.

How should uncertainty be understood?

In general, a confidence interval expresses the range of effect or measure values reasonably compatible with the observed data under the statistical model. Its width conveys precision: wider intervals indicate greater uncertainty. A point estimate without an interval can conceal substantial uncertainty, while an interval does not remove bias from incomplete data or an unsuitable design. No concordance estimate or confidence interval is reported for this study, so statistical precision cannot be evaluated.

Sample-size calculations can be used during planning to illustrate how much information a future study might need under stated assumptions. They are not a substitute for observed results and are not observed power. The registry’s planning assumptions refer to two-sided significance level 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of an observed effect. These assumptions are not a report of the study’s original design; the registry identifies the planning illustration as separate from that design. The record does not provide the underlying effect values needed to assess the illustration, and its primary outcome description says no analysis was conducted because the data were inadequate. Any planning illustration should therefore be read as hypothetical rather than as a result of this pilot study.

General statistical methods also depend on the data structure. For paired diagnostic findings, the analysis must preserve the pairing rather than treat each test result as if it came from a different participant. If some participants have only one evaluable examination, that can change which observations contribute to an agreement estimate. The registry does not report a paired-data analysis method, a rule for incomplete pairs, or an analysis population. With no reported endpoint data, it is not possible to determine whether such choices affected an estimate.

What does the design allow?

The open-label, single-group design is compatible with an assessment of paired test findings, but it is not a randomized comparison of screening strategies. In general, randomization can help make groups comparable when estimating treatment effects; it is not the mechanism that answers a paired agreement question. For a diagnostic study, blinding of image readers and clear reference standards can be important to limit interpretive bias and assess accuracy. The registry lists masking as none. It says a radiologist would analyze the images, but does not report reader blinding, independent reading procedures, or adjudication of disagreements.

The study description says EUS-guided fine-needle aspiration would be performed if EUS showed abnormalities. Because that procedure was linked to EUS findings, verification may not have been uniform across all participants. In general, when confirmation is obtained selectively, accuracy estimates can be affected by verification bias unless the design and analysis address it. The registry does not report a complete reference-standard plan or any accuracy analysis, so it is not possible to determine whether this issue was evaluated.

The registry lists positive predictive value as a secondary outcome. In general, positive predictive value is the proportion of positive test results that correspond to the target condition under the chosen definition and verification process. It depends on the population being assessed and on how disease status is established. The record provides no positive predictive value result, no confidence interval, and no detailed definition of a positive S-MRCP finding beyond the study’s imaging categories. Accordingly, that secondary outcome cannot be interpreted quantitatively.

The registry lists two outcome measures and zero analyses. The methods that would have governed endpoint definitions, reader procedures, missing observations, and statistical estimation are not reported in the registry record. Statistical interpretation must therefore distinguish the planned diagnostic question from evidence that was actually analyzed: the question is described, but estimates and their uncertainty are unavailable.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures: the primary concordance outcome and a secondary outcome concerning positive predictive value for S-MRCP. It reports zero analyses and states that data analysis was not conducted because the collected data were inadequate. No results are available for either listed outcome.

When a study examines multiple outcomes or multiple ways of analyzing an outcome, the chance of a false-positive finding can increase if results are selectively emphasized. In general, multiplicity procedures or a prespecified hierarchy can help address that concern. The registry does not report a multiplicity adjustment, outcome hierarchy beyond identifying the primary endpoint, or a detailed statistical analysis plan. Because no analysis was performed, there are no reported findings for which an adjustment can be evaluated.

The record attributes the lack of analysis to poor enrollment and inadequate data, but does not report the number of missing or unusable observations, the reasons for missingness at participant level, or which procedures were completed. It does not state how incomplete paired examinations, indeterminate readings, or absent verification results would have been handled. General approaches to missing data rely on assumptions about why observations are missing; those assumptions cannot be assessed from the registry record.

No analysis populations are described, such as a defined set of participants with paired, evaluable imaging. Enrollment of 23 does not establish the number included in any planned endpoint analysis. The record also does not report imputation, sensitivity analyses, or an approach for assessing the effect of missing data. These omissions, together with the absence of analyzed outcome data, prevent assessment of both statistical robustness and the representativeness of any potential estimate.

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 0% reporting threshold.

The adverse-event record lists 23 participants at risk for serious adverse events and records 0 serious adverse events in the synthetic human secretin arm. It also lists 23 at risk for other adverse events and records 0 other adverse events. These are the counts entered in the registry; they do not establish that every participant completed every procedure or that all events were captured.

A zero recorded count means that no events of that category were reported in the registry for the listed group. It does not prove that an event is impossible, establish the absence of risk, or provide a precise estimate of the event rate. Safety interpretation depends on the completeness of follow-up, definitions, and reporting procedures, details that are not available. The deaths field is not reported in the registry record. No serious adverse-event terms are listed.

The registry’s safety entries should be read separately from the diagnostic endpoint. They do not provide evidence about concordance, diagnostic accuracy, or the clinical value of either imaging approach. The available counts are descriptive registry entries, not a comparative safety analysis.

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

The record describes a planned pilot assessment of S-MRCP and S-EUS in patients at high risk for pancreatic adenocarcinoma. Its primary question concerned agreement between the two imaging assessments, using categories of benign and suspicious/malignant. The registry also lists positive predictive value for S-MRCP as a secondary outcome. These aims show what the study intended to examine, not what its results established.

The key outcome limitation is explicit: poor enrollment resulted in inadequate data for analysis, and data analysis was not conducted. There is no reported estimate of concordance, no positive predictive value result, and no precision measure for either outcome. The record therefore does not show whether the methods agreed, whether either method accurately detected abnormalities, or whether one performed better than another.

The study’s hypothesis that S-MRCP might be superior to traditional CT or MRI and approach EUS accuracy is not a finding. The registry reports no analyzed comparison with CT, MRI, or EUS accuracy, and no evidence that screening with any listed method changed patient outcomes. The primary endpoint of agreement would not, on its own, answer those broader questions even if an estimate had been available.

Nor does the completed status imply that the intended evidence was obtained. It indicates the study’s registry status; the outcome description states that analysis was not conducted. The enrollment count is not an estimate of the number with complete paired assessments. Overall, the registry record documents an unanswered diagnostic research question rather than a result that can establish the performance or clinical usefulness of S-MRCP.

13. Why This Trial Matters Statistically

This study is statistically informative as an example of the distinction between a planned endpoint and an analyzable result. A registry may describe a focused clinical question, a timeframe, and intended diagnostic categories, yet still provide no estimate if the data are inadequate. Here, the record names concordance as the primary outcome and specifies how the imaging findings were meant to be classified, but explicitly says that no analysis was conducted.

That distinction matters because a completed study is not necessarily a completed evidence base. Readers need outcome estimates and their uncertainty to judge what the data support. Enrollment alone cannot substitute for those quantities, and a stated hypothesis cannot be treated as a finding. The record’s explicit account of inadequate data helps prevent an unsupported interpretation of the study objective as a demonstrated diagnostic benefit.

The endpoint also illustrates why agreement and accuracy should not be conflated. Agreement asks whether tests classify findings alike; accuracy asks whether classifications correspond to the true condition under a suitable reference standard. These questions are related but not interchangeable. The planned use of EUS findings and possible fine-needle aspiration raises methodological questions about reference standards and verification, while the registry provides no accuracy analysis to resolve them.

Finally, missing analysis details are consequential rather than merely technical. Without a reported analysis population, handling of incomplete paired examinations, or statistical procedure, even a numerical estimate would require careful qualification. In this record, there is no estimate to qualify. The statistical contribution is therefore chiefly a clear account of the limits of what can be learned from the registry entry.

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 principal limitation is stated directly in the registry: poor enrollment left inadequate data for analysis, and analysis was not conducted. As a result, the primary endpoint and secondary outcome have no reported results. The record does not provide an analyzable denominator for paired imaging, an agreement estimate, or uncertainty around a result.

The enrollment entry is 23, but participant flow is not reported. It is not possible to determine from the record how many participants underwent S-MRCP, completed S-EUS, had both examinations evaluable, or had findings verified. The reasons for missing or unusable data beyond poor enrollment are not reported in the registry record.

The study is described as open-label, with masking listed as none. The registry does not report whether image readers were blinded to other findings or whether multiple readers independently assessed images. It does not describe adjudication procedures, handling of indeterminate classifications, or a detailed analysis plan. These details would be relevant to assessing the consistency and potential bias of diagnostic readings.

The intended endpoint is concordance, not a direct measure of diagnostic accuracy. Although EUS-guided fine-needle aspiration was planned when EUS showed abnormalities, a complete reference-standard strategy and accuracy analysis are not reported. The registry also does not report a CT comparison result, despite the rationale referring to CT and MRI. Finally, no analysis populations, missing-data methods, multiplicity approach, or precision estimates are reported. These limitations mean the study cannot support a statistical conclusion about comparative diagnostic performance from the registry entry.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Secretin-Stimulated Magnetic Resonance Cholangiopancreatography (S-MRCP) in Pancreatic Patients — NCT01094561.
• Registry record last updated 2016-09-09; status last verified 2016-07.
• Results first posted 2016-09-09.
• 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

The registry describes a completed, open-label, single-group pilot study of S-MRCP and S-EUS in patients at high risk for pancreatic adenocarcinoma because of a significant family history. Enrollment was 23. The planned primary outcome was concordance between imaging findings classified as benign or suspicious/malignant, assessed on Day 1 and up to 30 days after S-MRCP. Positive predictive value for S-MRCP was listed as a secondary outcome.

The study began in 2006-07, with primary completion recorded in 2015-02. The registry states that poor enrollment led to inadequate data for analysis and that no analysis was conducted. No primary or secondary outcome estimate is reported. The safety entries record 0 serious adverse events and 0 other adverse events in the listed arm; deaths are not reported in the registry record.