A Study of Clinical Outcomes of the REALIZE Adjustable Gastric Band-C: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of Clinical Outcomes of the REALIZE Adjustable Gastric Band-C (NCT00999661), a registered phase not stated study. The primary outcome is Percent Excess Weight Change From Baseline to 24 Months.

2. Clinical Question

3. Trial Design

This completed study evaluated outcomes associated with the REALIZE Adjustable Gastric Band-C during the first 24 months after surgery. The registry lists morbid obesity as the condition and identifies Ethicon Endo-Surgery as the sponsor. The study began in 2009-11, reached primary completion in 2012-05, and has a completed status.

The recorded enrollment was 231. The registry identifies the primary analysis population as all subjects implanted with a gastric band and signing informed consent, described as the Intent to Treat Population. The name of this population should be read alongside its explicit definition: it includes subjects who were implanted and signed consent. The record does not describe the status of any enrolled subjects who did not meet that definition.

The primary outcome was percent excess weight change from baseline to 24 months. Two secondary outcomes are listed: percent excess weight change from baseline to 12 months, and change in body mass index from baseline to 24 months. The registry lists three outcome measures and three analyses. It does not report further details connecting each analysis with a particular outcome.

Allocation is not stated, and no comparator is identified. The record therefore does not establish a randomized comparison or a like-for-like control group. The registry does not report the protocol, sample-size justification, interim analyses, or a detailed statistical analysis plan. Those omissions limit what can be inferred about how the study was designed and how its results were intended to be interpreted.

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: This was a longitudinal, single arm, observational, non-comparative study of clinical outcomes. Subjects were asked to consent to data collection to the study parameters from their study records.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intent to Treat Population - All subjects implanted with gastric band and signing informed consent.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

Population: Intent-to-Treat population defined as all subjects implanted with the Realize Gastric Band-C who signed informed consent.

6. Primary Endpoint

The registry lists the primary outcome as Percent Excess Weight Change From Baseline to 24 Months, measured over Baseline to 24 months.

The primary endpoint is percent excess weight change from baseline to 24 months, expressed as a percent of excess weight at baseline. It is a continuous measure, and the registry identifies the reported summary as the mean with standard deviation. The endpoint compares weight at baseline with weight at 24 months, using baseline weight relative to ideal body weight to define excess weight. The ideal body weight reference is the upper limit of the midpoint range in the Metropolitan Tables for Life Insurance, 1983.

In general, an endpoint should represent an outcome that is relevant to the study question and can be measured consistently. A continuous endpoint preserves information about the magnitude of change rather than reducing results to categories. A mean can describe the average change in the analyzed population, while a standard deviation describes the spread of individual measurements around that average. These are distinct summaries: the standard deviation is not the uncertainty around the mean.

The registry states that last observation carried forward was used for subjects who terminated early. This means an earlier recorded observation was used in place of a later one for those subjects under that stated approach. The registry does not report the endpoint's observed mean, standard deviation, or other numerical result. The endpoint definition is available, but its actual result and precision are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes the primary measure as a mean of a continuous outcome and gives a standard deviation as its dispersion summary. It also specifies last observation carried forward for subjects who terminated early. These details identify some features of the analysis, but they do not amount to a complete statistical analysis plan. The methods used for inferential testing, uncertainty intervals, covariate adjustment, or sensitivity analyses are not reported in the registry record.

What does the mean describe?

In general, the mean is the arithmetic average of the measurements in an analysis population. For this study, the outcome was defined as percent excess weight change from baseline to 24 months. A mean would summarize the average value of that measure among the population included in the analysis. It would not show the distribution of individual outcomes or establish that the average applies equally to every participant. The registry record does not provide the mean value, so the average change cannot be interpreted numerically.

What does the standard deviation describe?

In general, the standard deviation describes how dispersed individual observations are around their mean. A larger standard deviation indicates more variation in the measurements, while a smaller one indicates less variation. It is not a measure of uncertainty in the estimated mean. The standard deviation for the primary outcome is not reported in the registry record, so the amount of participant-to-participant variability cannot be assessed.

How should uncertainty be understood?

In general, a confidence interval expresses uncertainty around an estimate under a specified statistical method and its assumptions. Its width depends on factors such as variability and the amount of information available. A narrow interval indicates greater precision than a wide interval, although precision does not establish that an estimate is unbiased or clinically important. The registry does not report a confidence interval for the primary outcome or describe an inferential procedure for that endpoint. No p-value is reported for the primary outcome.

What does last observation carried forward mean?

The registry says last observation carried forward was used for early-terminated subjects. In general, this approach substitutes an earlier observed value for a later outcome that was not observed after termination. It relies on an assumption that the earlier value is an acceptable stand-in for the missing later value. That assumption may not hold when an individual's outcome would have changed after the last measurement. The record does not report how many subjects terminated early, how much outcome data were missing, or whether other missing-data approaches were examined. It is therefore not possible to assess the practical impact of this method in this study.

What do the planning assumptions represent?

The registry's sample-size assumptions describe a planning illustration rather than the trial's own design justification. In general, a power calculation asks how much information a study would need to detect a specified effect under stated assumptions. The described illustration uses 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. The registry does not report a sample-size justification for the study itself. A planning illustration is not observed power and does not indicate the probability that a result is true. Because the observed primary effect is not reported in the registry record, the corresponding effect size cannot be assessed from the registry information.

What cannot be inferred from the listed analyses?

The record lists three outcome measures and three analyses, but does not report their detailed statistical methods or link each analysis to an outcome. It does not state whether any tests were adjusted for multiple outcomes, whether analyses were adjusted for participant characteristics, or whether interim analyses were conducted. These details are not reported in the registry record. General statistical methods can clarify what summaries such as a mean, standard deviation, and confidence interval signify, but cannot supply unreported study results or methods.

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("Realize Adjustable Gastric Band-C")
n   <- c(231)
m   <- c(39.8)
sp  <- c(25.12)
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  Realize Adjustable Gastric Band-C  231  39.800  25.120  36.543  43.057

11. Multiplicity, Missing Data and Analysis Populations

The registry lists three outcome measures, including the primary outcome and two secondary outcomes. It also lists three analyses. The record does not explain how the analyses map to the outcomes, whether additional comparisons were planned, or whether any adjustment for multiple testing was used. Multiplicity matters in general because conducting several statistical tests can increase the chance of finding an apparently notable result by chance. Whether that issue affected interpretation in this study cannot be determined from the registry record.

For the primary outcome, the record specifies that last observation carried forward was used for subjects who terminated early. In general, missing data can affect both the estimate and its uncertainty, especially if the availability of measurements is related to participants' outcomes. Carrying an earlier value forward makes an assumption about what the later unobserved value would have been. The registry does not report the number of early terminations, the extent of missing outcome data, reasons for missingness, or analyses using alternative assumptions. The effect of missing data on the result is therefore not reported in the registry record.

The named analysis population includes all subjects implanted with a gastric band and signing informed consent. The registry does not report participant counts for each outcome analysis or describe how missing measurements were handled beyond the stated early-termination approach. It also does not report whether any other analysis populations were used. The label Intent to Treat should therefore be interpreted with the population definition recorded, rather than as evidence of additional analysis details that are not stated.

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 serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: medical device complication (0.9%), dysphagia (0.4%), gastrointestinal obstruction (0.4%), cholelithiasis (0.4%), device migration (0.4%).

The adverse-event summary lists one group, Realize Adjustable Gastric Band-C. For serious adverse events, 231 participants were at risk and 9 were affected. For other adverse events, 231 were at risk and 200 were affected. These counts describe the registry's recorded safety summary; they do not provide details about event timing, duration, severity beyond the serious classification, or relationships to the device or procedure.

The most frequently listed serious-event terms and their recorded percentages are Medical device complication (0.9%), Dysphagia (0.4%), Gastrointestinal obstruction (0.4%), Cholelithiasis (0.4%), Device migration (0.4%), and Incisional hernia (0.4%). The registry does not give counts for each listed term in this summary. These percentages should not be treated as rates of all possible events or as comparisons with another group.

Deaths are not reported in the registry record. The record also does not provide a comparator group, so these safety figures cannot establish comparative risk. In general, adverse-event summaries describe recorded events in the observed study population; they do not alone establish causation or predict an individual's experience.

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

The record establishes that a completed study evaluated the REALIZE Adjustable Gastric Band-C in a population described as having morbid obesity, with outcomes assessed through 24 months. Its primary outcome was percent excess weight change from baseline to 24 months. The registry provides a definition for that outcome, specifies a mean and standard deviation as the summary, identifies the analysis population, and notes the use of last observation carried forward for subjects who terminated early.

However, the numerical result for the primary outcome is not reported in the registry record. The mean, standard deviation, confidence interval, and p-value are not reported. The named secondary outcomes also have no numerical results in the record. As a result, the direction and size of the recorded outcome change, and the precision with which it was estimated, cannot be evaluated from the registry information.

The record also does not identify a comparator or state allocation. Thus, it does not support a treatment-versus-control contrast. Even when a within-group outcome is reported, general statistical interpretation distinguishes observed change over time from a comparative effect, because change alone does not isolate the contribution of an intervention from other influences. Here, the absence of the numerical outcome further limits interpretation.

The adverse-event information documents affected participants and selected serious-event terms, but does not establish whether those events were caused by the intervention. With no comparator and limited detail on event timing and attribution, the safety summary cannot be interpreted as a comparative risk estimate. The record is informative about the study's question and some reporting definitions, but it does not provide the outcome results needed to judge the magnitude or precision of the primary measure.

14. Why This Trial Matters Statistically

This study is statistically informative in part because the registry defines a continuous primary outcome and states how it was calculated. Clear endpoint definitions matter: they determine what a reported estimate represents and make it possible to distinguish a change in the measured outcome from other possible summaries. The record also names the analysis population and discloses a specific approach for early termination, details that are relevant when interpreting any eventual estimate.

The record also illustrates why results and methods need to be read together. A mean would describe an average, while a standard deviation would show variation across individual measurements. Neither alone establishes the precision of the estimated mean. An uncertainty interval and a clear account of the statistical analysis would help readers understand how much the estimate could vary under the analysis assumptions. Those numerical results and details are not reported in the registry record.

Comparative interpretation depends on design information as well as outcome data. Since allocation is not stated and a comparator is not identified, the registry does not present a like-for-like control comparison. This distinction matters because an observed outcome in a single group cannot on its own establish what would have happened under an alternative. The record's limitation is not a statistical calculation problem; it is that the relevant comparison and numerical endpoint results are not reported.

Finally, the early-termination approach highlights the importance of missing-data assumptions. Carrying an earlier observation forward is a defined procedure, but its implications depend on the pattern and amount of missing data and on whether the assumption is plausible. Those details are not reported. Together, these features make the record useful for understanding the endpoint and analysis population, while leaving important questions about results, precision, comparisons, and robustness unanswered.

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.

A central limitation is that the registry record does not report the numerical result for the primary endpoint. Without the mean percent excess weight change, its standard deviation, or an uncertainty estimate, the magnitude and precision of the primary outcome cannot be assessed. The secondary outcomes are named but their results are not reported in the registry record either.

The record does not identify a comparator, and allocation is not stated. It therefore does not provide a randomized or like-for-like control comparison. The information available cannot distinguish changes associated with the study intervention from changes that could occur for other reasons. No comparative effect can be derived from the registry entries.

Although last observation carried forward is stated for subjects who terminated early, the record does not report how many subjects terminated, how much outcome data were missing, or what alternative missing-data analyses were conducted. The impact of that assumption is consequently unknown. The analysis population is defined, but the record does not give analysis-specific participant counts or explain whether other populations were examined.

The registry lists three outcome measures and three analyses without detailing their correspondence or whether multiplicity was addressed. It does not report an interim-analysis plan, a sample-size justification, or a complete statistical analysis plan. These are not reported in the registry record, so they should not be inferred.

The safety summary gives counts of affected participants and selected serious-event terms, but does not provide event timing, attribution, or a comparator. Deaths are not reported in the registry record. These limitations restrict both comparative safety interpretation and assessment of the overall context for the recorded events.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Study of Clinical Outcomes of the REALIZE Adjustable Gastric Band-C — NCT00999661.
• Registry record last updated 2014-02-07; status last verified 2014-01.
• Results first posted 2014-02-07.
• 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

NCT00999661 is a completed study sponsored by Ethicon Endo-Surgery, with enrollment of 231. It evaluated outcomes for the REALIZE Adjustable Gastric Band-C in a US patient population described as having morbid obesity. The study began in 2009-11 and reached primary completion in 2012-05.

The primary outcome was percent excess weight change from baseline to 24 months. Secondary outcomes were percent excess weight change from baseline to 12 months and change in body mass index from baseline to 24 months. The primary analysis population was defined as subjects implanted with a gastric band who signed informed consent, and last observation carried forward was used for subjects who terminated early.

The registry record does not report numerical results for the primary or secondary outcomes, or identify a comparator or allocation. It reports serious adverse events affecting 9 of 231 participants at risk and other adverse events affecting 200 of 231 participants at risk. The record does not report deaths.