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 Evaluation of Capsule Endoscopy With PillCam® Colon 2 in Visualization of the Colon (NCT01269372), a na na study. The primary outcome is Accuracy of the PillCam® Colon 2 Capsule Endoscopy (CE) for Polyps Per Subject - Sensitivity.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01269372 |
| Phase | NA |
| Condition | Colorectal Lesions |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | Double |
| Enrollment | 30 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Medtronic - MITG |
| Results posted | Yes |
2. Clinical Question
Population
Subjects in a pilot study concerning colorectal lesions. Enrollment was 30.
Intervention
Capsule endoscopy using PillCam Colon 2.
Comparator
Standard colonoscopy, which the registry record identifies as the gold standard.
Primary question
How accurately did capsule endoscopy identify subjects with polyps equal to or larger than 6 mm and 10 mm, as measured by sensitivity against standard colonoscopy?
The study used a within-subject sequence rather than separate intervention and control groups: all subjects received capsule endoscopy followed by standard colonoscopy. The primary outcome was defined per subject, using the larger polyp identified in that subject. A positive event was defined using polyp-size measurement by optical colonoscopy. The registry record describes the study as a pilot and also states that it was intended to assess administrative feasibility and data management. It does not report the primary sensitivity results, so the degree of agreement between the two procedures cannot be assessed from the registry record alone.
3. Trial Design
The registry record describes a completed, multi-center pilot with a single-group model and enrollment of 30. Each subject received PillCam Colon 2 capsule endoscopy followed by standard colonoscopy. Thus, the comparison is between procedures performed in the same subjects, not a randomized comparison between separate groups. The allocation field is listed as NA. The record categorizes masking as double, but does not report which people were masked or how masking was implemented.
The study concerned colorectal lesions. Its stated primary outcome was sensitivity for detecting subjects with polyps equal to or larger than 6 mm and 10 mm, using standard colonoscopy as the gold standard. The primary outcome timeframe was up to 6 weeks. Secondary outcomes concerned sensitivity and specificity for detecting polyps per location. The record lists four outcome measures but no posted analyses.
The registry lists the study start as 2010-12, primary completion as 2011-07, and status as completed. Phase is recorded as NA. The sponsor is Medtronic - MITG. The brief summary also describes an aim to evaluate administrative feasibility and data management. Details such as the number of participating centers, the order or timing of procedures beyond the stated sequence, and the operational protocol are not reported in the registry record.
Because every subject received both procedures, the design provides a paired setting for comparing findings. That feature does not, by itself, establish how disagreements were resolved or how the analysis handled incomplete examinations or missing measurements. Those details 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
| Stage | Reporting Group |
|---|---|
| STARTED | 30 |
| COMPLETED | 30 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: The accuracy parameters were calculated per subject analysis, i.e. the accuracy events were generated by the larger polyp identified in a given subject.
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.
| Characteristic | Unit | Reporting Group |
|---|---|---|
| Participants analysed | 30 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 30 |
| Age, Categorical: >=65 years | Participants | 0 |
| Age, Continuous | years | 52.57 (50 to 58) |
| Sex: Female, Male: Female | Participants | 19 |
| Sex: Female, Male: Male | Participants | 11 |
| Region of Enrollment: United States | participants | 30 |
| Thirty patients were enrolled in the study. | Participants | 30 |
6. Primary Endpoint
The registry lists the primary outcome as Accuracy of the PillCam® Colon 2 Capsule Endoscopy (CE) for Polyps Per Subject - Sensitivity, measured over Up to 6 weeks.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | 95% Confidence Interval |
| Unit | percentage of sensitivity |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the sensitivity of PillCam Colon 2 capsule endoscopy for identifying subjects with polyps at the stated size thresholds, compared with standard colonoscopy. Sensitivity describes the proportion of reference-positive cases that are also identified by the test being evaluated. In this study, the record defines standard colonoscopy as the gold standard and says that a positive event was based on optical colonoscopy polyp-size measurement.
The endpoint is calculated per subject rather than per polyp or per location. The registry description says the accuracy events were generated by the larger polyp identified in a given subject. This distinction matters: a subject-level endpoint answers whether a person with a qualifying polyp was detected, while a location-level endpoint concerns detection at particular locations. The registry lists location-based sensitivity and specificity as secondary outcomes.
Sensitivity is used to characterize detection among cases classified as positive by the reference procedure. It does not, on its own, describe how often a test correctly identifies subjects without qualifying polyps; that is the distinct concept of specificity. Nor does sensitivity summarize every aspect of agreement or examination quality. The registry record names the endpoint and its 95% confidence interval as the dispersion measure, but does not report the estimated sensitivity or interval limits. Therefore, the primary endpoint's observed value and precision cannot be interpreted from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central statistical question is whether capsule endoscopy identified subjects classified as having qualifying polyps by standard colonoscopy, and how precisely that sensitivity was estimated. The record defines the target as polyps equal to or larger than 6 mm and 10 mm, with the largest polyp in each subject determining the per-subject accuracy event. It identifies optical colonoscopy measurement as the basis for a positive event and standard colonoscopy as the reference standard.
However, the registry record does not report an observed sensitivity estimate or the limits of its 95% confidence interval. Without those values, the posted record does not show the proportion of reference-positive subjects detected, or how uncertain that estimate is. No conclusion about the observed diagnostic performance should be inferred from the study title, stated objective, or enrollment alone.
The design is single-group: all subjects received capsule endoscopy followed by colonoscopy. These are paired procedures in the same participants, rather than independent groups assigned to different approaches. This structure is relevant to statistical interpretation because observations from the same subject are linked. The registry record does not report the analysis details used to account for that pairing, how discordant findings were handled, or how missing measurements were treated.
The record lists secondary outcomes for sensitivity and specificity per location, but does not provide their results. It also lists four outcome measures and zero analyses. The number of outcome measures should not be mistaken for evidence that each result is available or statistically supported. The record does not report p-values, confidence interval limits, denominators for the accuracy outcomes, or analysis populations.
The study is described as a pilot and includes administrative feasibility and data management among its aims. Its enrollment of 30 describes the number enrolled, not necessarily the number with evaluable results for each endpoint. The number analyzed for each outcome is not reported in the registry record. Overall, the posted information describes the question and design but does not contain the primary results needed to judge the estimate or its precision.
9. Statistical Methods Explained
What does sensitivity measure?
In general, sensitivity measures how often a test identifies a positive case among cases classified as positive by a reference standard. Here, the registry identifies standard colonoscopy as the gold standard and describes a positive event using optical colonoscopy polyp-size measurement. The evaluated procedure is PillCam Colon 2 capsule endoscopy. A sensitivity estimate therefore depends on which subjects the reference procedure classifies as positive and which of those subjects the capsule procedure also identifies.
The endpoint is defined per subject. The record says that the larger polyp found in a subject generated the accuracy event. This makes the analysis different from counting every polyp independently or evaluating detection separately at every location. The registry separately names location-based sensitivity and specificity as secondary outcomes, which are distinct questions from the primary per-subject outcome.
Why use a reference standard?
Diagnostic accuracy requires a basis for classifying cases when evaluating whether a test detects a condition or finding. In this record, standard colonoscopy serves that role. The comparison is not a comparison of outcomes in separate treatment groups; all subjects received capsule endoscopy followed by standard colonoscopy. The registry describes the colonoscopy findings as the reference for the primary accuracy question. It does not report additional adjudication procedures or rules for resolving disagreements.
What does a confidence interval add?
In general, a confidence interval expresses the statistical uncertainty around an estimated quantity. A narrower interval indicates greater precision under the assumptions of the method, while a wider interval indicates less precision. An interval is not a guarantee that the true value lies within its limits, and it does not replace the point estimate. The registry names a 95% confidence interval as the dispersion measure for the primary outcome, but does not report the estimate or its interval limits. The precision of the primary sensitivity estimate therefore cannot be judged from this record.
Why does the paired design matter?
In general, when two procedures are performed on the same subject, their findings are linked. A statistical comparison should reflect that pairing rather than treat the two sets of results as if they came from unrelated groups. The study description states that every subject received capsule endoscopy followed by standard colonoscopy. The registry record does not report the specific statistical method used to analyze paired results, or how incomplete or discordant observations were handled.
How should planning illustrations be understood?
In general, a sample-size calculation illustrates the number of participants that might be needed under stated assumptions to detect a specified effect at a chosen significance level and power. It is a planning exercise, not a result from the observed participants and not proof that a study had adequate power. The registry's planning assumptions describe two-sided significance level 0.05, equal allocation between two arms, a normal approximation, and effects defined as fractions of the observed effect. They also distinguish participants per arm for non-time-to-event outcomes from total events for time-to-event outcomes. Those assumptions are not a description of this single-group, within-subject study's own design. The trial's own sample-size justification is not reported in the registry record.
The registry record lists zero analyses. It does not report a statistical analysis plan, the method for computing the confidence interval, an analysis population, or handling of missing data. Those omissions limit what can be reconstructed about the analysis, even though the outcome definitions and broad design are stated.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary per-subject sensitivity outcome and secondary outcomes for sensitivity and specificity per location. It also lists four outcome measures, but zero analyses. The registry record does not report a multiplicity adjustment, a hierarchy among the outcomes, or a rule for interpreting results across multiple endpoints. Without those details, it is not possible to determine how the study intended to control the chance of misleading findings when considering several outcomes.
The record does not report whether any enrolled subjects lacked evaluable capsule or colonoscopy findings, whether outcome measurements were missing, or how missing observations were handled. Enrollment of 30 does not establish that every subject contributed to every endpoint. The number analyzed for the primary outcome and the denominators used in any accuracy calculations are not reported in the registry record.
The record also does not identify an analysis population, such as whether all enrolled subjects or only those with complete paired examinations were included. It does not describe exclusions, protocol deviations, or handling of indeterminate findings. These details matter because the set of subjects included can affect both an accuracy estimate and its precision.
No interim analysis plan or stopping rule is reported in the registry record. The registry record also does not provide a statistical analysis plan or explain whether the posted endpoint definitions were finalized before outcome data were examined. These are unreported details, not 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.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| PillCam Colon 2 and Standard Colonoscopy | 0 | 30 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| PillCam Colon 2 and Standard Colonoscopy | 0 of 30 |
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 |
|---|---|
| PillCam Colon 2 and Standard Colonoscopy | 6 of 30 |
Most frequent non-serious adverse event terms
| Event term | Organ system | PillCam Colon 2 and Standard Colonoscopy |
|---|---|---|
| alergic reaction to adhesive | Skin and subcutaneous tissue disorders | 2 of 30 |
| abdominal pain | General disorders | 2 of 30 |
| Globus Hystericus | Gastrointestinal disorders | 1 of 30 |
| diarrhea | Gastrointestinal disorders | 1 of 30 |
| nausea | Gastrointestinal disorders | 1 of 30 |
| headache | Gastrointestinal disorders | 1 of 30 |
| vomiting | Gastrointestinal disorders | 1 of 30 |
The registry reports one group, titled “PillCam Colon 2 and Standard Colonoscopy,” with 30 participants at risk for serious adverse events and 0 affected. It also reports 30 participants at risk for other adverse events and 6 affected. Deaths are recorded as 0. These are participant counts in the registry record; they do not provide event descriptions, timing, severity details beyond the serious-event category, or an account of attribution to either procedure.
A count of zero recorded serious adverse events should be read as no serious events recorded in this group in the registry entry, not as proof that the risk is absent. In general, safety counts are most informative when the observation period, definitions, event collection procedures, and completeness of follow-up are clear. Those details are not reported in the registry record. Since both procedures were received by the same participants, the group-level counts do not separate events by procedure.
The registry does not list serious adverse-event terms. The other-adverse-event count should not be treated as a complete description of the types of events, their duration, or their relationship to study procedures. No clinical recommendation follows from these counts alone.
12. What the Result Does, and Does Not, Mean
The record establishes that this was a completed pilot study in which 30 subjects received PillCam Colon 2 capsule endoscopy followed by standard colonoscopy. It states that the primary diagnostic question concerned sensitivity for detecting subjects with polyps equal to or larger than 6 mm and 10 mm, using standard colonoscopy as the gold standard. It also identifies a per-subject approach based on the largest polyp found in each subject and lists location-based sensitivity and specificity as secondary outcomes.
Those descriptions define the intended comparison, but they do not provide the results needed to answer it. The registry record does not report the observed primary sensitivity, the 95% confidence interval limits, or the number of subjects included in the accuracy analysis. It also does not report results for the secondary outcomes. Consequently, the record alone cannot show the magnitude or precision of the diagnostic accuracy estimates.
The single-group design should not be interpreted as a randomized trial comparing separate groups. Each participant received both procedures, with capsule endoscopy followed by colonoscopy. This paired structure can support a within-subject accuracy assessment, but details of the analysis and handling of incomplete or discordant findings are not reported. The record's double-masking designation does not specify who was masked or how.
The stated pilot and administrative feasibility aims also do not establish that the study was designed or powered to provide a definitive accuracy estimate. A trial-specific sample-size justification is not reported in the registry record. Any planning illustrations based on an observed effect are hypothetical design calculations, not observed power and not a substitute for the missing endpoint results.
The safety entry reports zero serious adverse events, six participants with other adverse events, and zero deaths in the listed group. Those counts do not identify which procedure, if either, was associated with an event. Overall, the registry record describes the study question, sequence, and some safety counts, but does not support a conclusion about the observed diagnostic performance.
13. Why This Trial Matters Statistically
This trial raises a clear diagnostic-accuracy question: whether capsule endoscopy identifies subjects with qualifying polyps when standard colonoscopy is used as the reference. The statistical target is sensitivity, defined at the subject level and based on the larger polyp identified in each subject. Keeping the unit of analysis clear matters because per-subject detection and per-location detection answer different questions. The record distinguishes them by making location-based sensitivity and specificity secondary outcomes.
The within-subject sequence is also statistically important. Each subject received both procedures, so the observations are paired rather than independent. In general, paired data require analysis that respects the relationship between measurements from the same person. The registry record describes the sequence but does not report the analysis method. That distinction highlights why design descriptions and analysis details are both needed to interpret diagnostic studies.
Precision is central to evaluating an accuracy estimate. The record names a 95% confidence interval for the primary endpoint, but gives no interval limits or sensitivity estimate. Without them, readers cannot assess whether the estimate is precise or highly uncertain. The stated enrollment is useful context, but it does not reveal the number of reference-positive subjects or the number with evaluable paired results.
Finally, this is a pilot with an additional administrative feasibility and data-management aim. That context is relevant when distinguishing exploratory or feasibility work from evidence that provides a fully reported estimate of accuracy. The registry record makes the intended endpoint and reference standard visible, while its missing results and analysis details limit statistical interpretation.
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 most direct limitation for interpreting this record is that it does not report the primary sensitivity estimate or its 95% confidence interval. It likewise does not report the results for the secondary location-based outcomes. The registry lists four outcome measures but zero analyses, leaving the stated outcome definitions without posted analysis results.
The number of participants enrolled is reported as 30, but the number included in each accuracy analysis is not. The registry record does not give denominators for reference-positive or reference-negative subjects, nor does it describe missing findings, incomplete examinations, indeterminate results, or exclusions. These omissions prevent assessment of how much information contributed to the accuracy estimates.
The design is a single group in which all subjects received capsule endoscopy followed by standard colonoscopy. There is no randomized, separate control group. The registry categorizes masking as double, but does not state who was masked, what information was masked, or whether masking was maintained. It also does not report how paired or discordant results were analyzed.
The study is described as a pilot and includes administrative feasibility and data management as aims, but the trial-specific sample-size justification and statistical analysis plan are not reported in the registry record. Details about participating centers, protocol procedures, outcome adjudication, multiplicity, and interim analyses are also not reported. The reported safety counts are not separated by procedure and are not accompanied by event descriptions or follow-up details.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Evaluation of Capsule Endoscopy With PillCam® Colon 2 in Visualization of the Colon — NCT01269372.
- Registry record last updated 2020-10-01; status last verified 2020-07.
- Results first posted 2020-10-01.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT01269372 is a completed, multi-center pilot study of PillCam Colon 2 capsule endoscopy for visualizing the colon. Enrollment was 30. All subjects received capsule endoscopy followed by standard colonoscopy. The registry records a single-group model, allocation as NA, and masking as double; the people masked are not identified. The study start is listed as 2010-12 and primary completion as 2011-07.
The primary endpoint was per-subject sensitivity for detecting polyps equal to or larger than 6 mm and 10 mm, with standard colonoscopy identified as the gold standard and a 95% confidence interval specified. Location-based sensitivity and specificity were listed as secondary outcomes. The registry record does not report the primary estimate, its interval limits, or secondary outcome results. It lists zero analyses.
The safety entry reports 0 serious adverse events among 30 participants at risk, 6 participants with other adverse events among 30 at risk, and 0 deaths. The study's stated aims also included administrative feasibility and data management.