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 Investigation of Two Newly Developed 1-piece Convex Baseplates in Subjects With Ileostomy and Colostomy (NCT01957462), a randomized na study. The primary outcome is Degree of Leakage.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01957462 |
| Phase | NA |
| Condition | Ileostomy - Stoma, Colostomy - Stoma |
| Allocation | Randomized |
| Design model | Crossover |
| Masking | None (open label) |
| Enrollment | 31 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Coloplast A/S |
| Results posted | Yes |
2. Clinical Question
Population
People with ileostomy or colostomy are the population named in the registry record. The record does not report further eligibility criteria or describe the participants in greater detail.
Intervention
One experimental device was Coloplast Test V, a newly developed 1-piece convex baseplate. Participants tested both experimental products in randomized order, switching products during the crossover trial.
Comparator
The comparison was with the other experimental device, Coloplast Test X. This was not a comparison against a stated usual-care or untreated group: both trial products were tested by participants.
Primary question
The primary outcome was degree of leakage, measured on a 32-point scale at each baseplate change during a 14-day timeframe. The registry reports mean scores of 3.5 for Test V and 3.1 for Test X, and a mean difference of -0.4 for Test X relative to Test V. The confidence interval and unadjusted p-value describe the uncertainty around this reported comparison.
The trial aim was to investigate newly developed, soft and more flexible 1-piece convex ostomy products. In statistical terms, the central question is whether the observed mean leakage scores differed between the two devices over the reported period, and how precisely the registry estimates that difference. The scale defines lower scores as better: 0 represents no leakage and 32 represents full plate leakage. The registry record does not report a threshold for a clinically important difference, so the size of the observed contrast cannot be classified against such a threshold from this record alone.
3. Trial Design
This was a randomized, open-label crossover study of two devices: Coloplast Test V and Coloplast Test X. The record describes participants testing both products in a randomized order. One sequence began with Test V and then switched to Test X; the other began with Test X and then switched to Test V. The allocation is listed as randomized, masking as none, and the model as crossover. The trial status is completed.
The registry reports enrollment of 31 and lists ileostomy and colostomy as the conditions. The outcome summaries include 31 for Test V and 29 for Test X. These are the reported group counts for the endpoint; the record does not explain the difference between them or provide a participant flow account. The trial began in 2013-04 and had primary completion in 2013-05. The record does not report further detail about the period between product use, the crossover procedures, adherence, or how the outcome data were collected beyond measurement at each baseplate change.
The primary endpoint was degree of leakage over 14 days. The registry reports the endpoint as a mean with standard deviation for each device. Although crossover order is described, the registry record does not report whether the primary comparison accounted for the paired measurements within participants, sequence, period, or possible carryover. It also does not give an analysis population definition or a detailed statistical analysis plan. Those omissions matter when interpreting an endpoint from a crossover study, because measurements from the same person are related and because the order of product use can be relevant to analysis.
The study was sponsored by Coloplast A/S. The phase is listed as NA, which is not a clinical drug phase designation for interpreting this device comparison. No further design rationale, masking procedures, or original sample-size assumptions are 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.
Test Period 1
| Stage | FirstColplast Test V, Then Coloplast Test X | First Coloplast Test X, Then Coloplast Test V |
|---|---|---|
| STARTED | 16 | 15 |
| COMPLETED | 14 | 15 |
| NOT COMPLETED | 2 | 0 |
Reasons for not completing this period:
| Reason | FirstColplast Test V, Then Coloplast Test X | First Coloplast Test X, Then Coloplast Test V |
|---|---|---|
| Withdrawal by Subject | 1 | 0 |
| Adverse Event | 1 | 0 |
Test Period 2
| Stage | FirstColplast Test V, Then Coloplast Test X | First Coloplast Test X, Then Coloplast Test V |
|---|---|---|
| STARTED | 14 | 15 |
| COMPLETED | 14 | 15 |
| NOT COMPLETED | 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.
| Characteristic | Unit | All Subjects |
|---|---|---|
| Participants analysed | 31 | |
| Age, Continuous | years | 61.4 (SD 12.7) |
| Sex: Female, Male: Female | Participants | 24 |
| Sex: Female, Male: Male | Participants | 7 |
6. Primary Endpoint
The registry lists the primary outcome as Degree of Leakage, measured over 14 days.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | units on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint, Degree of Leakage, is a continuous measure recorded on a 32-point scale developed by Coloplast A/S. Its endpoints are described directly: 0 represents no leakage, the best possible outcome, and 32 points represents full plate leakage, the worst possible outcome. The registry says leakage is measured at each baseplate change and gives a timeframe of 14 days. It reports the mean and standard deviation for each device.
A leakage score provides a way to summarize how much leakage occurred during product use, rather than recording only whether any leakage occurred. Reporting a mean describes the average score, while the standard deviation describes the spread of scores around that mean. These summaries can make a device comparison more informative than a single yes-or-no outcome, but they do not show the distribution of individual scores or how many baseplate changes contributed to each participant’s result.
The endpoint is relevant to the stated aim of investigating new convex ostomy products. However, the registry does not report evidence about how the scale was validated, whether its scoring was standardized across users, or what score difference would be important to participants. It also does not specify how repeated measurements within the 14-day period were combined to produce each reported mean. The results therefore describe the posted score summaries, while the interpretation of their clinical importance and measurement properties remains limited by information not reported in the registry record.
7. Results Posted in the Registry
- Test X: mean 3.10 versus 3.50 on control; difference -0.40 (95% CI -2.96 to 2.16), standardized effect d = -0.08; z-test p = 0.759.
Mean difference: Test X
95% CI: -2.96 to 2.16
Recalculated from the posted summary statistics
8. Statistical Interpretation
The registry reports a mean leakage score of 3.5 for Test V, with a standard deviation of 5.0, and a mean score of 3.1 for Test X, with a standard deviation of 5.1. The reported mean difference for Test X relative to Test V is -0.4. Because lower scores are defined as better on this scale, the direction of the point estimate is toward a lower average score for Test X. That descriptive direction does not by itself establish a reliable or clinically important difference.
The confidence interval for the mean difference extends from -2.958 to 2.158. It includes values in both directions, so the posted results are compatible with a lower mean score for Test X as well as a lower mean score for Test V. The unadjusted p-value is 0.759. This does not provide evidence of a statistically clear difference under conventional testing, but a p-value is not a measure of the probability that the devices are equivalent, nor does it establish that any difference is unimportant.
The estimates should be read in the context of the crossover design. Participants tested both products in randomized order, but the record does not report whether the comparison used the paired nature of those observations or accounted for period and sequence. The reported summaries alone do not reveal the within-participant relationship between scores on the two products. As a result, the registry does not provide enough detail to assess the analysis method for the crossover structure or to independently judge whether it was appropriate.
The observed standard deviations are large relative to the mean scores, indicating variation in the reported scores across observations. That variation helps explain why a modest point estimate can be accompanied by a wide confidence interval, although the record does not provide participant-level data or details about repeated observations to clarify the source of variability. The score scale also has a defined upper limit, but the registry does not describe the shape or distribution of the measured outcomes.
Only one outcome measure is posted, and the registry lists no analyses. It does report a comparison estimate and an unadjusted p-value, but does not describe a full analysis plan, adjustment strategy, missing-data method, or analysis population. These gaps limit assessment of how the endpoint result was generated. The record also does not report a clinically important difference threshold, so the interval cannot be judged against such a benchmark. The appropriate reading is therefore descriptive: the posted means are close, the point estimate favors a lower score for Test X, and the uncertainty is broad enough to include differences in either direction.
9. Statistical Methods Explained
What does the mean difference represent? A mean difference compares the average outcome in one group or condition with the average in another. Here the registry reports Test X relative to Test V, with a mean difference of -0.4. Given the scale definition, the negative direction corresponds to a lower mean leakage score for Test X. The estimate is a summary of the observed data, not a statement that every participant had a lower score with that device.
The registry also reports a mean and standard deviation for each device. A mean locates the average of the recorded scores. A standard deviation describes how dispersed scores are around that average. It is not the uncertainty interval for the mean, and it does not tell whether each person’s score changed in the same direction. For a crossover study, the standard deviations for each device do not convey the correlation between the two measurements within a participant.
How should the confidence interval be understood? A confidence interval expresses the precision of an estimated effect under the assumptions of the statistical method used. The reported interval for the mean difference runs from -2.958 to 2.158. Its breadth indicates substantial uncertainty about the size and direction of the difference. Since it includes values on both sides of no difference, the data do not pin down a single direction with precision. The confidence interval does not state the range containing a specified proportion of individual participants’ scores.
The registry reports an unadjusted p-value of 0.759. A p-value measures how unusual data at least as incompatible with a null hypothesis would be under the assumptions of a specified test, if that null hypothesis were true. It is not the probability that the null hypothesis is true, and it does not quantify the chance that the observed difference arose by chance in an ordinary-language sense. The record does not describe the test used, so the assumptions underlying this p-value cannot be fully assessed from the registry entry.
Why does the crossover design matter? In a crossover trial, the same participant experiences more than one intervention, so the participant can serve as their own comparator. This may reduce the influence of stable differences between participants when an analysis uses the paired structure appropriately. However, observations from one person are generally related rather than independent. Analysis may also need to consider whether outcomes differ by period or sequence, and whether effects of the first product persist into the next period. These are general statistical considerations, not evidence that any particular issue occurred in this trial. The registry record does not describe the analysis of pairing, period, sequence, or carryover.
The posted comparison is accompanied by summaries for each device, but the information does not establish whether the reported contrast is a paired crossover estimate or a comparison treating the device summaries as independent. The record does not include participant-level results, within-participant differences, or a method description sufficient to reconstruct the intended analysis. Consequently, the confidence interval and p-value should be interpreted as reported rather than as independently verified estimates of a specified crossover model.
What does variability mean for this endpoint? The standard deviations are 5.0 for Test V and 5.1 for Test X, while the outcome is bounded by the 32-point scale described in the record. Over-dispersion is a general concern when outcome variation is greater than a model assumes: standard errors and significance tests can then be inaccurate if the model does not allow for that variation. The registry does not report a distributional assessment or a model, so it is not possible to determine whether over-dispersion was evaluated or whether it affected the analysis.
Repeated measurements at each baseplate change also raise a general statistical issue: observations collected repeatedly from the same participant may be correlated. A valid analysis needs to account for the structure actually used to create the endpoint. The record says the endpoint covers 14 days but does not report the number of changes per participant, how scores were combined, or how repeated observations entered the analysis. No inference should be made about those unreported details.
How do the planning illustrations work? The sample-size illustrations use the observed effect as a planning reference and show alternative effect fractions. They are not a report of the trial’s original design assumptions, which are not reported in the registry record. Their values depend on the listed assumptions, including two-sided significance level 0.05, equal allocation between two arms, and a normal approximation. Because the reference is the observed effect, the illustrations are especially sensitive to uncertainty in that estimate. They should be read as hypothetical planning calculations rather than as evidence that the trial had a particular power.
Overall, the registry provides outcome summaries, a contrast with an interval, and an unadjusted p-value, but it does not provide enough methodological detail to establish how the crossover structure, repeated endpoint measurements, or missing information were handled. General explanations of these methods clarify what would matter for interpretation; they do not fill in the missing analysis details for this trial.
10. Confidence Intervals and Precision
The reported mean difference is -0.4, with a confidence interval from -2.958 to 2.158. This interval is wide enough to include a range of plausible contrasts, with the direction changing across its limits. In practical terms, the data do not precisely determine whether the average leakage score was lower for Test X or for Test V. The interval also indicates that the point estimate should not be treated as an exact measure of the underlying difference.
A confidence interval reflects uncertainty about an estimated mean difference under the statistical method and assumptions used. It is not a range of individual leakage scores, and it does not say that the true difference has a particular probability of falling inside these endpoints. The registry does not report the method used to calculate the interval, so its assumptions cannot be fully reviewed. In particular, the record does not make clear whether the paired crossover observations were included in the uncertainty calculation.
The unadjusted p-value of 0.759 is consistent with substantial uncertainty, but it does not establish equivalence or exclude a meaningful difference. The registry does not give a clinical importance threshold for the scale, and therefore the interval cannot be evaluated against a stated threshold for a meaningful change. Nor does the record report participant-level data that could show whether average results conceal varied individual responses.
Precision is also affected by the amount of variation and the analysis structure. The reported standard deviations are 5.0 and 5.1. In a crossover study, precision may depend on the relationship between each participant’s outcomes on both products, information not reported in the registry. Thus the available interval is the result to interpret, while the precision of a correctly specified crossover analysis cannot be independently assessed from the posted details.
11. Planning a Similar Trial: Sample Size
This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.
| Effect to detect | Participants per arm, 80% power | Participants per arm, 90% power |
|---|---|---|
| 100% of the observed effect | 2,501 | 3,348 |
| 75% of the observed effect | 4,446 | 5,952 |
| 50% of the observed effect | 10,003 | 13,391 |
The sample-size illustrations are planning scenarios based on fractions of the observed effect. Their entries are participants per arm for 80% power and participants per arm for 90% power; they are not total event counts. The planning assumptions listed are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The detectable effect in each scenario is the stated fraction of the observed effect. The registry record does not report the trial’s own original design assumptions or sample-size justification.
In plain language, the 80% power column gives the number of participants per arm estimated for a future study to have an 80% chance of detecting the specified effect under the calculation assumptions, if that effect is the true one. The 90% power column uses a higher target probability of detecting that effect and therefore gives a larger planning figure. For the rows labeled 100% of the observed effect, 75% of the observed effect, and 50% of the observed effect, the displayed figures apply to those respective effect sizes.
Smaller effects are harder to distinguish from random variation, so planning to detect a smaller effect requires more participants. The illustrations show that pattern across the effect fractions. They are hypothetical planning results based on the observed estimate, not observed power for this completed trial. Because the observed estimate itself is uncertain, the figures should not be read as a definitive recommendation for a future study; planning also requires a justified target effect and design assumptions appropriate to the intended study.
12. How the Sample Size Is Derived
Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z1−α/2 = 1.960) and the desired power (z1−β = 0.842 for 80% and 1.282 for 90%).
Formula
n is the number of participants in each arm, Δ is the difference in means to detect and σ is the common standard deviation.
Worked calculation for this trial
- Observed difference Δ = -0.400; pooled standard deviation σ = 5.049.
- n = 2 × (1.96 + 0.842)2 × 5.0492 / -0.4002 = 2,500.6, rounded up to 2,501 participants per arm for 80% power.
The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).
R code
alpha <- 0.05
z_a <- qnorm(1 - alpha / 2) # two-sided
delta <- -0.4 # observed difference in means
sigma <- 5.04852317087845 # pooled standard deviation
n_per_arm <- function(power, frac = 1) {
ceiling(round(2 * (z_a + qnorm(power))^2 * sigma^2 / (delta * frac)^2, 6))
}
for (f in c(1, 0.75, 0.5))
cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))
# Check against R's built-in function (t-based, so very slightly larger)
cat("power.t.test:", round(power.t.test(delta = delta, sd = sigma, power = 0.80)$n, 1), "\n")
# Simulation: exact two-sample t-test using simulated means and variances
set.seed(1957462)
n <- n_per_arm(0.80)
reps <- 20000
m_diff <- rnorm(reps, delta, sigma * sqrt(2 / n)) # difference in sample means
s2 <- sigma^2 * rchisq(reps, 2 * (n - 1)) / (2 * (n - 1)) # pooled sample variance
tstat <- m_diff / sqrt(s2 * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(tstat) > qt(0.975, 2 * (n - 1))), reps))
Output from running the code
100% of observed effect: n per arm = 2,501 (80% power), 3,348 (90% power)
75% of observed effect: n per arm = 4,446 (80% power), 5,952 (90% power)
50% of observed effect: n per arm = 10,003 (80% power), 13,391 (90% power)
power.t.test: 2501.6
Simulated power at n = 2,501 per arm: 0.800 (20000 replicates)The simulation draws many sets of group means and variances at the planned sample size and counts how often the two-sample t-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.
13. Multiplicity, Missing Data and Analysis Populations
The registry lists one outcome measure and no secondary outcomes. It also lists zero analyses, although a primary outcome comparison, confidence interval, and unadjusted p-value are posted. The record does not explain this difference in how outcome measures and analyses are recorded. It does not report a prespecified statistical analysis plan, an adjustment for multiple testing, or whether additional analyses were conducted but not entered in the registry.
Multiplicity is a general concern when many outcomes, time points, subgroups, or analyses are tested. Repeated testing can increase the chance of a statistically notable result arising by chance unless the analysis plan accounts for it. The posted record does not establish that multiple testing occurred, nor does it describe a correction. With only one outcome measure listed, the registry alone does not permit a full assessment of multiplicity across any unreported analyses.
Missing-data handling is not reported in the registry record. The outcome summaries list 31 for Test V and 29 for Test X. The record does not explain why the endpoint counts differ, whether any observations were missing, how incomplete follow-up was handled, or whether participants contributed data to both device summaries. No imputation method or sensitivity analysis is described. It is therefore not possible to assess whether missingness could affect the reported contrast.
The analysis populations are also not defined. The registry does not say whether results were based on all randomized participants, participants who completed both product periods, or another group. It does not report exclusions, adherence criteria, or a participant flow account. For a crossover trial, knowing which participants contributed paired observations is important to judging the analysis. These details are not reported in the registry record, so the estimates should be interpreted as posted summaries without assumptions about the underlying population or missing-data process.
14. 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 |
|---|---|---|---|
| Test V | 1 | 31 | 3.2% |
| Test X | 1 | 29 | 3.4% |
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 |
|---|---|
| Test V | 13 of 31 |
| Test X | 13 of 29 |
Most frequent serious adverse event terms
| Event term | Organ system | Test V | Test X |
|---|---|---|---|
| constipation | Gastrointestinal disorders | 0 of 31 | 1 of 29 |
| Absess in the bowl ( by a fistel channel 2 mm from stoma) | Gastrointestinal disorders | 1 of 31 | 0 of 29 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Test V | Test X |
|---|---|---|---|
| peristomal skin irritation | Skin and subcutaneous tissue disorders | 7 of 31 | 7 of 29 |
| Peristomal Itching | Skin and subcutaneous tissue disorders | 5 of 31 | 1 of 29 |
| Petekkie/pressure mark (peristomal) | Skin and subcutaneous tissue disorders | 1 of 31 | 2 of 29 |
| Peristomal skin Pain | Skin and subcutaneous tissue disorders | 0 of 31 | 1 of 29 |
| broken skin | Skin and subcutaneous tissue disorders | 1 of 31 | 0 of 29 |
| Pain and sorness by stoma and´in bowl | Gastrointestinal disorders | 1 of 31 | 0 of 29 |
| Obstipation | Gastrointestinal disorders | 0 of 31 | 1 of 29 |
| dehydration due to obstpation | Metabolism and nutrition disorders | 0 of 31 | 1 of 29 |
| fatigue | General disorders | 0 of 31 | 1 of 29 |
| Pain in bowl | Gastrointestinal disorders | 1 of 31 | 0 of 29 |
Serious events with the highest arm-level rate: constipation (3.4%), absess in the bowl ( by a fistel channel 2 mm from stoma) (3.2%).
The registry reports serious adverse events affecting 1 of 31 participants in the Test V group and 1 of 29 in the Test X group. These are the reported affected counts and the corresponding groups at risk; they should not be interpreted as evidence that the underlying risks are identical. The record does not describe the nature, timing, severity, or attribution of these serious events by device group.
The registry lists constipation at 3.4% and “Absess in the bowl ( by a fistel channel 2 mm from stoma)” at 3.2% among the top serious terms. The record does not clarify how these term-level percentages relate to the group-specific counts or provide further case descriptions. The number of deaths is not reported in the registry record; a blank value should not be interpreted as zero deaths.
Other adverse events affected 13 participants in each group according to the posted counts, but the registry entry does not provide the event types or severity details needed to interpret those figures fully. These safety summaries are descriptive. The record does not report a comparative safety analysis, and the study design and size do not support treating the counts as a precise estimate of uncommon risks.
15. What the Result Does, and Does Not, Mean
The posted results show similar average leakage scores for the two experimental devices, with a mean difference of -0.4 for Test X relative to Test V. The direction of that estimate corresponds to a lower average score for Test X on a scale where lower is better. The confidence interval extends from -2.958 to 2.158, and the unadjusted p-value is 0.759. Taken together, these results do not establish a clear difference between the devices in this endpoint, while also not demonstrating that the devices are equivalent.
The result does not answer every question a reader might have about product performance. The registry does not report a threshold for a clinically important difference, a detailed analysis plan, participant-level scores, or the handling of repeated baseplate-change measurements. It also does not describe how the crossover pairing was incorporated in the comparison. Those gaps prevent a fuller assessment of clinical relevance and analytic validity.
The results apply to the reported study context: people with ileostomy or colostomy testing two experimental products in randomized order over the stated 14-day timeframe. The record does not give additional eligibility details or evidence about use beyond that context. It should not be taken as a conclusion about other products, other populations, or longer-term outcomes.
The safety counts are also limited descriptions rather than definitive comparisons. The registry reports serious adverse events in each device group and lists selected serious terms, but does not provide enough detail to establish attribution or comparative risk. Overall, the record supports a cautious reading of the posted endpoint summaries and their uncertainty; it does not establish a treatment recommendation or a broad claim about whether either device works.
16. Why This Trial Matters Statistically
This trial is statistically instructive because its crossover structure changes what information is needed to interpret a comparison. When participants test both products, the relationship between each person’s outcomes on the two products can affect the precision of the estimated contrast. Group means and standard deviations alone do not show that relationship. The registry reports the randomized product order but does not explain whether the analysis used paired data or accounted for period and sequence.
The example also illustrates the distinction between a point estimate and its uncertainty. The mean difference is -0.4, while the confidence interval covers both directions. Reading only the sign of the estimate could suggest a favored direction; reading the interval shows that the estimate is imprecise. The unadjusted p-value is another part of the evidence, but it cannot replace the interval or establish equivalence.
Scale interpretation is also central. The 32-point measure has explicit endpoints, with lower scores indicating less leakage, but the record does not state what difference would matter clinically. Statistical detectability and practical importance are different questions. Without a stated meaningful-difference threshold and fuller information on measurement properties, the score contrast cannot answer the latter question.
Finally, registry completeness affects what can be assessed. The entry posts outcome summaries and safety counts but omits details about missing data, analysis populations, and the statistical method. Recognizing those gaps is part of sound interpretation: it separates what the posted results quantify from what remains unknown about the analysis and design.
17. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
Several limitations specific to this trial constrain interpretation. The registry identifies a crossover design and randomized order, but does not describe the primary analysis method. In particular, it does not state whether the comparison accounted for within-participant pairing, period effects, sequence, or carryover. These are relevant design features, and the posted group summaries do not resolve them.
The outcome is measured at each baseplate change over 14 days, but the registry does not explain how those repeated measurements were reduced to the reported mean, how many changes contributed, or whether the analysis accounted for correlation among observations from the same participant. It also does not report individual-level data or the distribution of scores. The standard deviations alone cannot show whether the score distribution was strongly skewed or whether a few observations influenced the means.
The endpoint counts differ between devices, with 31 listed for Test V and 29 for Test X. The record does not explain the difference, identify missing observations, or report how incomplete data were handled. It also does not define the analysis population or indicate whether each participant contributed to both summaries. These omissions make it difficult to assess selection or missing-data effects.
Further limitations include the absence of reported eligibility criteria beyond the named ostomy conditions, no stated threshold for a clinically important score difference, and no detailed account of the measurement scale’s validation. Masking is listed as none. The registry also does not provide a detailed statistical analysis plan or explain the discrepancy between one listed outcome measure and zero listed analyses. These limitations do not invalidate the posted results, but they restrict what can be concluded from them.
18. Related Tutorials
19. Related Statistical Calculators
20. Sources
- ClinicalTrials.gov: Investigation of Two Newly Developed 1-piece Convex Baseplates in Subjects With Ileostomy and Colostomy — NCT01957462.
- Registry record last updated 2016-09-26; status last verified 2016-08.
- Results first posted 2014-08-11.
- 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.
21. Record Summary
The completed study investigated Coloplast Test V and Coloplast Test X, two experimental 1-piece convex ostomy baseplates, in a randomized, unmasked crossover design. Participants tested both products in randomized order. The named population included people with ileostomy or colostomy, and enrollment was 31.
The primary endpoint was degree of leakage on a 32-point scale over 14 days, measured at each baseplate change. The registry reports mean scores of 3.5 for Test V and 3.1 for Test X, with a mean difference of -0.4 for Test X relative to Test V. The confidence interval is -2.958 to 2.158, and the unadjusted p-value is 0.759.
The registry also reports serious adverse events affecting 1 participant in each device group. Important details about analysis methods, missing data, analysis populations, and crossover-specific handling are not reported in the registry record. The endpoint contrast is therefore best read as a descriptive result with substantial uncertainty and methodological details that cannot be assessed from the record.