CopiOs® Pericardium Membrane for Localized Alveolar Ridge Augmentation: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for CopiOs® Pericardium Membrane for Localized Alveolar Ridge Augmentation (NCT00889265), a na na study. The primary outcome is Change in Horizontal Ridge Widths From Baseline to 6 Months.

2. Clinical Question

3. Trial Design

This was a prospective, multi-center, single-group study of CopiOs Pericardium Membrane used with Puros Cancellous Particulate Allograft for localized alveolar ridge augmentation. The registry lists the study as completed and records enrollment of 51 participants. Its start is recorded as 2009-06, and primary completion as 2011-12. The condition listed is alveolar ridge defect.

A single-group design means that enrolled participants received the study intervention, rather than being assigned between intervention and control arms. Allocation is recorded as not applicable, and masking as none. The registry record therefore does not describe a randomized comparison, a masked assessment, or a concurrent control group. Its listed arm description gives the ridge eligibility characteristics: a partially edentulous ridge in the maxilla or mandible, at least one tooth-span long, and less than 5.5mm in the smallest buccolingual dimension as measured by ridge-mapping calipers.

The primary outcome was defined as the average change in horizontal ridge width between baseline and 6 months after surgery. Baseline was measured before surgery and grafting. The description says that the investigator selected the site of greatest ridge-width deficiency and that later measurements were made at the same location. A radiographic template with radiopaque foil was used to standardize clinical and radiographic measurements for each participant.

The registry record does not report the planned statistical analysis, sample-size justification, analysis population, handling of missing measurements, or any interim analyses. Although the study is marked completed, no primary outcome estimate or analysis is listed. The design and endpoint can therefore be described, but the registry record does not support a conclusion about the size or precision of the observed change.

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: All enrolled participants took part in the study.

Overall Study

Reasons for not completing this period:

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 Change in Horizontal Ridge Widths From Baseline to 6 Months, measured over 6 months.

The primary endpoint was the mean change in horizontal ridge width from baseline to 6 months, measured in mm. Baseline was defined as preoperative and before grafting; the follow-up measurement was taken 6 months after surgery. The registry describes taking measurements with ridge-mapping calipers at the location of greatest ridge-width deficiency identified by the investigator and repeating the measurements at the same location. A radiographic template with radiopaque foil was used to standardize clinical and radiographic measurements.

This endpoint is used to quantify change in ridge width over the study period. A mean gives the average change across the analyzed participants, while the individual measurements may vary around that average. The standard deviation, if reported, would describe that variability; it is not a measure of uncertainty in the mean. A confidence interval around the mean change would describe the precision of the estimate under the analysis assumptions.

The registry record does not report the observed mean change, standard deviation, confidence interval, number of participants with usable measurements, or a test result. It therefore identifies what was measured and when, but does not give the numerical result needed to assess the magnitude or precision of the change.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is a continuous measurement: horizontal ridge width in mm, expressed as an average change from baseline to 6 months. The registry identifies the parameter as a mean and the dispersion measure as a standard deviation, but gives no numerical estimate for either. The following concepts explain how such results are generally interpreted; they do not describe an analysis confirmed in the registry record.

What does a mean change describe?

For each participant with measurements at both time points, a change score can be formed by comparing the follow-up measurement with the baseline measurement. The mean change summarizes those individual changes as one average. It describes the analyzed group, not necessarily every participant. The registry record does not report the number of paired measurements or a mean change, so no numerical group estimate can be interpreted.

A change score is distinct from a follow-up value alone. It uses baseline as the within-participant reference, which can account for differences in starting measurements when describing change. It does not create a separate untreated comparison group. In a single-group study, a baseline comparison cannot by itself isolate the effect attributable to the intervention from all other influences over time.

What does the standard deviation describe?

In general, a standard deviation describes how spread out individual measurements or changes are around their mean. It is a measure of participant-level variability, not the precision of the estimated mean. A smaller standard deviation indicates that values are more closely clustered around the mean; a larger one indicates greater spread. The registry record names standard deviation as the dispersion measure but does not report its value.

Unusually variable data can affect statistical methods that assume a particular distribution or similar variability across observations. General statistical methods may use transformations, robust approaches, or models suited to the data structure when assumptions are not appropriate. The registry record does not state whether the investigators checked assumptions or used any such method. No approach should be attributed to the investigators without a reported analysis.

How does a confidence interval help?

In general, a confidence interval expresses the uncertainty around an estimate under the assumptions of the analysis. For a mean change, it would give a range of values compatible with the observed data and method. A narrow interval indicates greater precision than a wide interval, but precision is not the same as clinical importance. The registry record does not report a confidence interval for the primary endpoint, so neither the range of plausible values nor the precision can be assessed.

A p-value, when reported, addresses how compatible data are with a specified null hypothesis under a statistical model. It does not measure the size or importance of an effect, and it does not give the probability that a hypothesis is true. The registry record does not list a primary endpoint p-value or a statistical test. No significance claim can be drawn from the absence of one.

Why does the design affect interpretation?

This is a single-group study. General statistical interpretation of a before-and-after measurement can describe observed change in the participants who were measured. Without a concurrent comparator, it cannot establish how that change differs from what would have occurred without the intervention or under another treatment. This is a limitation of the design, not a statement about the direction or cause of any unreported result.

The registry records masking as none. Measurement procedures were described, including use of the same location and a radiographic template, but the record does not explain whether assessors were independent or how measurements were quality checked. Standardization can support consistency in measurement; it does not remove every possible source of measurement variability.

How should planning illustrations be understood?

General sample-size calculations estimate how many participants would be needed under specified assumptions to detect a target effect with a chosen significance level and power. The planning assumptions associated with this study describe a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. These are planning assumptions, not evidence that this single-group study used a two-arm randomized design. Any such planning figures are hypothetical illustrations and are not observed power.

The registry record does not report the study's own sample-size justification or its statistical plan. It also does not provide the observed effect needed to judge planning illustrations against the study's actual outcome. A planning calculation cannot replace a reported estimate, confidence interval, or analysis of the collected data.

What is needed for a full statistical reading?

A complete interpretation would require the outcome estimate, its variability and precision, the number analyzed, the analysis method, and information about missing measurements. For a multi-center study, site-related features of the analysis could also matter, but the registry record does not say whether or how site was considered. These omissions limit what can be said; they do not justify filling in an assumed method or result.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("CopiOs Pericardium")
n   <- c(44)
m   <- c(2.61)
sp  <- c(1.8)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  CopiOs Pericardium  44  2.610  1.800  2.063  3.157

11. Multiplicity, Missing Data and Analysis Populations

The registry names the mean Wound Healing Index at 6 Months as a secondary outcome and identifies change in horizontal ridge width through 6 months as the primary outcome. It records two outcome measures in total, but does not provide a complete account of all outcome definitions, results, or analyses. No approach to multiplicity—such as prioritizing tests or adjusting for multiple comparisons—is reported in the registry record.

Multiplicity is a general concern when several outcomes or statistical tests are examined: the chance of at least one apparently notable result can increase as more tests are considered. Whether and how that concern was addressed cannot be determined without a reported analysis plan and results. The registry record lists 0 analyses, so it gives no outcome-specific tests or estimates to assess.

The record does not report how missing baseline or 6-month measurements were handled, how many participants had complete measurements, or whether any participants were excluded from an analysis. It also does not specify an analysis population, such as all enrolled participants or participants with measurements at both time points. No imputation method or sensitivity analysis is reported in the registry record.

These are reporting gaps rather than evidence that data were missing or that a particular analysis population was used. Without this information, readers cannot assess whether the reported endpoint—whose numerical result is itself not reported—represents all enrolled participants or a subset, nor how robust any result would be to alternative assumptions about missing data.

12. 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 5% reporting threshold.

Most frequent non-serious adverse event terms

The registry records 0 serious adverse events among 51 participants at risk for the CopiOs Pericardium group. It lists 14 participants with other adverse events among 51 at risk. These are counts of participants affected, as recorded in the registry, and should not be read as event rates calculated in a different way.

No serious adverse-event terms are listed. The death count is not reported in the registry record; an unreported value should not be interpreted as zero. The record does not give descriptions or counts by type for the other adverse events, their timing, their severity, or whether investigators considered them related to the intervention. It also does not describe how adverse events were collected or how long participants were monitored for safety.

Accordingly, the figures provide a limited descriptive account of the recorded safety entries. They do not establish that no serious events could occur, and the count of other events alone does not characterize their clinical meaning. These data should not be used to make a treatment recommendation.

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

The record describes a prospective, multi-center study of CopiOs Pericardium Membrane with Puros Cancellous Particulate Allograft in people with localized alveolar ridge defects. It specifies a primary endpoint focused on mean horizontal ridge-width change between baseline and 6 months, as well as the measurement location and method. It also records enrollment of 51 and provides limited adverse-event counts.

What the record does not provide is the primary outcome estimate. There is no reported mean change, standard deviation, confidence interval, or primary endpoint test. As a result, readers cannot determine the observed magnitude or direction of change, how variable the measurements were, or how precise an estimate would be. The secondary outcome is named, but its result is also not reported in the registry record.

Even if a numerical before-and-after change were available, the single-group design would describe change over time without a concurrent control comparison. General interpretation of such a design cannot separate the intervention's contribution from other influences. This limitation does not demonstrate that the intervention had no effect; it means the design alone does not support a controlled estimate of comparative effect.

The safety entries should also be read narrowly. They record 0 serious adverse events and 14 participants with other adverse events among 51 at risk. The record does not provide event descriptions or report the death count. These entries are not a complete safety profile and do not establish the absence of risk.

In short, the record is useful for identifying the research question, study structure, measurement approach, and some descriptive safety information. It is not sufficient for judging the size, precision, or clinical importance of the primary outcome, or for comparing the intervention with an alternative. Missing results are not equivalent to a null result, and an unreported analysis is not evidence of a particular statistical conclusion.

14. Why This Trial Matters Statistically

This study raises a useful statistical distinction between measuring change and estimating a comparative treatment effect. The primary endpoint uses repeated measurements at baseline and 6 months, with follow-up at the same site. That approach defines a within-participant change, but a single-group design does not include a concurrent control group. The design therefore determines the kind of conclusion that could be supported, even before considering the numerical result.

The measurement description is also important. The investigator selected the site of greatest ridge-width deficiency, and the site was revisited for subsequent measurements. The registry describes use of ridge-mapping calipers and a radiographic template with radiopaque foil to standardize measurements. These details identify how the endpoint was intended to be obtained, while leaving questions about assessor procedures and measurement quality unanswered.

For statistical interpretation, the missing endpoint estimate is consequential. A mean without its variability and precision would be incomplete; here, even the mean and standard deviation are not reported. Enrollment of 51 does not tell readers how many participants had complete outcome data or entered an analysis. The record also offers no reported statistical plan, missing-data method, or multiplicity approach.

The safety entries illustrate a related principle: simple counts have a defined but limited meaning. The reported counts can be described, but without event types, timing, and other context they cannot characterize the full safety experience. Overall, this record shows why transparent reporting of estimates, uncertainty, analysis populations, and methods is necessary for readers to evaluate a clinical study rather than infer conclusions from design details alone.

15. 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 for interpretation is that the registry record does not report the primary outcome result. The endpoint definition is detailed, but the mean change, standard deviation, confidence interval, and test result are absent. The secondary outcome is named without a result. Consequently, the record cannot establish the observed size, direction, or precision of change.

The single-group design has no concurrent control group, and allocation is recorded as not applicable. Baseline provides a within-participant reference, not a like-for-like control comparison. Masking is recorded as none. These design features limit the kinds of causal and comparative conclusions the study could support, independently of whether outcome data were collected.

The registry does not report the analysis population, how many participants contributed paired measurements, or how missing data were handled. It also does not report a statistical analysis plan, a sample-size justification, or whether interim analyses occurred. These details are not reported in the registry record, so no assumptions should be made about them.

The measurement description does not give further information about assessor training, measurement reliability, or whether measurements were independently checked. The study is described as multi-center, but the record does not explain how differences among sites were handled analytically. These omissions do not establish that measurement or site-related problems occurred; they limit assessment of those possibilities.

Safety reporting is also restricted: the record gives counts for serious and other adverse events but no serious-event terms, no detailed description of other events, and no reported death count. Together, these gaps mean the registry entry supports only a limited account of outcomes and safety.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: CopiOs® Pericardium Membrane for Localized Alveolar Ridge Augmentation — NCT00889265.
• Registry record last updated 2014-08-11; status last verified 2014-08.
• Results first posted 2014-08-07.
• 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.

19. Record Summary

NCT00889265 is a completed, prospective, multi-center, single-group study sponsored by Zimmer Biomet. It enrolled 51 participants with localized alveolar ridge defects and evaluated CopiOs Pericardium Membrane with Puros Cancellous Particulate Allograft. Allocation is recorded as not applicable and masking as none.

The primary outcome was mean change in horizontal ridge width from baseline to 6 months, measured in mm. The registry describes ridge-mapping calipers, repeated measurement at the same selected site, and use of a radiographic template with radiopaque foil. Mean Wound Healing Index at 6 Months is listed as a secondary outcome.

The record reports 0 serious adverse events and 14 participants with other adverse events among 51 at risk. It does not report the primary or secondary outcome results, statistical analyses, analysis population, missing-data handling, or sample-size justification. The death count is not reported in the registry record.