Safety and Efficacy of the SMART Device for Overweight and Obese Adults: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Safety and Efficacy of the SMART Device for Overweight and Obese Adults (NCT02119299), a na na study. The primary outcome is Proportion of Subjects Achieving ≥5% Weight Loss at 16 Weeks Compared to Week 0.

2. Clinical Question

The question is about the frequency of participants crossing a prespecified weight-loss threshold by the stated assessment time. That is a binary outcome: each participant is classified according to whether the threshold was achieved. The primary endpoint is a count of participants, not a direct comparison between treatment groups.

The record describes a prospective, multicenter study of the SMART device for overweight and obese adults. Because there is no comparator group, the endpoint can describe outcomes in the study population but cannot by itself distinguish effects associated with the device from other influences. The record does not report details of the Per Protocol Population or the observed endpoint count, so the size and precision of the primary result cannot be assessed from the stated endpoint information.

3. Trial Design

The registry describes NCT02119299 as a prospective, single-arm, multicenter study evaluating the safety and weight-loss efficacy of the SMART device, with DVD weight-loss education named in the official title. The intervention entry identifies the SMART device, and the arm description says participants used the Sensor Monitored Alimentary Restriction Therapy device. Further details about the education component are not reported in the registry record.

The registry enrollment is 76. This is the recorded enrollment figure and should not be treated as the size of the Per Protocol Population or as the denominator for every outcome. The primary endpoint is specified for the Per Protocol Population, whose size is not reported in the registry record. The study is marked completed. Its recorded start is 2014-03 and its primary completion is 2014-12.

Allocation is recorded as NA, consistent with the single-arm description, and masking is recorded as NONE. The phase is recorded as NA. No randomized control group is described, so the study does not support a like-for-like comparison between intervention and control arms. The registry names Scientific Intake Limited Co. as sponsor.

The primary endpoint is the count of participants achieving at least 5% weight loss at 16 weeks compared with week 0. Listed secondary outcomes include mean percentage excess weight loss, mean absolute weight loss in kg, proportions achieving at least 4% weight loss and at least 12% excess weight loss, the correlation between percentage total body loss and treatment compliance, and device compliance. The registry does not report the details of the statistical analysis plan or the results for these outcomes.

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: Per protocol, there were two screening visits prior to the run-in visit to assess subject eligibility and oral health. A total of 4 visits (2 screening visits, 1 run-in visit and 1 wash-out visit) were included prior to the baseline visit.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Per Protocol Population

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 Proportion of Subjects Achieving ≥5% Weight Loss at 16 Weeks Compared to Week 0, measured over 16 weeks.

The primary endpoint counts participants in the Per Protocol Population who achieved at least 5% weight loss at 16 weeks compared with week 0. It is a binary endpoint at the participant level: a participant either meets the threshold at the specified assessment or does not. The recorded unit is participants, and the endpoint parameter is a count rather than a mean change.

A threshold endpoint can make a result easy to interpret as the frequency of participants reaching a defined weight-loss target. It also discards information about how far an individual’s weight change lies above or below that threshold. Two participants with different amounts of weight loss can be classified the same way if both meet the threshold, while a small difference around the cutoff can lead to different classifications. The listed mean percentage total body weight loss is a separate measure that captures average change rather than threshold attainment.

The registry’s description of the study purpose states that it sought to observe at least 40% of the Per Protocol Population with at least 5% weight loss at 16 weeks, and a mean percentage total body weight loss of at least 4% in that population. These are stated study objectives, not reported findings. The primary endpoint result—the observed count and the corresponding analysis denominator—is not reported in the registry record. The Per Protocol Population’s definition and size are also not reported, so the endpoint cannot be independently interpreted as a proportion from the information recorded.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a binary endpoint summarized as a count of participants. For each person in the specified analysis population, the endpoint asks whether weight loss reached the stated threshold at the stated follow-up compared with week 0. A count is the number meeting the endpoint; interpretation as a rate or proportion also requires the denominator, meaning the number of participants included in that analysis. The registry identifies the Per Protocol Population but does not report its size or the primary endpoint count.

What does a threshold endpoint capture?

A threshold converts a continuous measurement, such as percentage weight change, into a yes-or-no classification. This can be useful when the clinical question concerns reaching a target. It also simplifies the underlying information: values on the same side of the cutoff receive the same classification, even if they differ in magnitude. Values close to the cutoff may be classified differently despite being similar. For that reason, threshold outcomes are often interpreted alongside continuous measures when those measures are reported. The registry lists mean percentage total body weight loss as a secondary outcome, but its result is not reported in the record.

Why does the analysis population matter?

The primary endpoint names the Per Protocol Population. An analysis population determines whose outcome data contribute to an estimate. The meaning of a per-protocol population depends on the protocol’s eligibility and adherence rules, which are not reported in the registry record. The enrollment figure does not establish the number included in this population. Without its definition and size, readers cannot determine precisely which participants the endpoint represents or assess whether exclusions could affect the result.

How should uncertainty be understood?

A confidence interval is a general statistical way to express uncertainty around an estimate. It gives a range of values compatible with the data and the method used, under the method’s assumptions. A narrow interval indicates greater precision than a wide interval, while neither establishes that an estimate is free from bias. For a binary outcome, the interval method should be suitable for a proportion and the analysis denominator. The registry record does not report a primary endpoint estimate, denominator, or confidence interval, nor does it identify the method used to calculate an interval.

Over-dispersion is a general concern when observed variability exceeds what a statistical model assumes. It can make standard errors too small if the model does not account for that extra variability. It is most relevant when the outcome structure and analysis model make such variability a concern. The registry does not report a model or analysis details that would allow readers to determine whether over-dispersion is relevant to the primary endpoint.

What does the single-arm design allow?

A single-arm study can describe outcomes observed among participants receiving the intervention. It does not offer a concurrent control group for estimating how outcomes would have differed under another condition. A change from baseline may be affected by factors beyond the intervention, and the design alone cannot separate those influences. This limits causal interpretation even if an outcome estimate is available. In this record, the endpoint result itself is not reported, so even a descriptive estimate cannot be assessed.

What is the role of the planning illustration?

The stated planning illustration is described as a calculation based on the observed effect, rather than the trial’s own design. Its assumptions include a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect to detect expressed as a fraction of the observed effect. It specifies that non-time-to-event planning quantities are participants per arm for 80% power or another stated power level, while time-to-event quantities would be total event counts. These are planning assumptions, not evidence that the single-arm study used a two-arm design. Planning sample sizes are illustrations and are not observed power. The record does not report a trial-specific sample-size justification or statistical plan.

In general, a significance level describes a decision threshold for a specified statistical test, while power describes the chance of detecting a specified effect under assumptions if that effect is present. Neither supplies an outcome result. A planning calculation also depends on the effect size and analysis assumptions; it cannot replace an estimate with its uncertainty. The registry reports zero analyses, and the primary endpoint result and its analysis details are not reported in the record.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("SMART Device")
n      <- c(40)
events <- c(12)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  SMART Device  40  12  30.0  16.6  46.5  18.1  45.4  18.1  45.5

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 8 outcome measures and names secondary outcomes covering excess weight loss, absolute weight loss, weight-loss thresholds, the relationship between total body loss and treatment compliance, and device compliance. Considering multiple outcomes can raise a multiplicity issue: when several hypotheses are tested, the chance of at least one apparently notable result can increase. A prespecified analysis plan may address this through a primary outcome hierarchy or an adjustment procedure. The registry record does not report a multiplicity strategy, a hierarchy among the secondary outcomes, or a statistical analysis plan. It reports zero analyses, so no multiplicity adjustment can be assessed from the record.

Missing data can affect both the denominator and the interpretation of an outcome. For example, the analysis depends on how participants without an assessment are handled. That is a general concern for follow-up outcomes; the record does not report missing-data counts, reasons, imputation methods, or sensitivity analyses. It also does not report the size or rules for the Per Protocol Population, which is the named population for the primary endpoint.

The enrollment figure is 76, but it should not be assumed to be the denominator for the primary endpoint or every secondary outcome. The registry does not report how many participants contributed data to each analysis. Without the analysis population and missing-data handling, readers cannot determine how representative the analyzed participants are of those enrolled. The absence of these details limits assessment of both potential bias and precision.

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

Serious events with the highest arm-level rate: pregnancy (1.3%).

The registry reports 1 participant affected by a serious adverse event among 76 at risk in the SMART Device group. It reports 0 participants affected by other adverse events among 76 at risk. The listed top serious adverse event term is Pregnancy, reported as 1.3%. The registry does not clarify the denominator or further context for that percentage in the information recorded.

These figures describe recorded events in the study group; they do not establish whether an event was caused by the device. The registry record does not report an attribution assessment or enough detail to characterize the event’s timing, course, or clinical context. The deaths field is not reported in the registry record.

Safety counts should be read with their population and observation context in mind. The at-risk figures do not establish the size of the population used for the primary efficacy endpoint. Nor do the reported counts alone show whether all events were captured or how safety was monitored. The record’s safety figures are descriptive and should not be treated as a comparative estimate, since the study has no control group.

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

The registry record describes a study intended to evaluate weight loss and safety with the SMART device among overweight and obese adults. Its primary endpoint is the count of Per Protocol Population participants achieving at least 5% weight loss at 16 weeks compared with week 0. The study purpose also states goals for the proportion reaching that threshold and for mean percentage total body weight loss.

Those goals are not outcome results. The record does not report the primary endpoint count, the Per Protocol Population denominator, or the mean percentage total body weight loss result. It therefore does not establish whether either stated benchmark was met. Without an endpoint estimate and information about its precision, the magnitude and uncertainty of the primary outcome cannot be assessed.

Even if a before-and-after weight change were reported, a single-arm study would describe change in its participants rather than provide a direct comparison with a control group. Other influences on change cannot be separated from intervention-associated change using a single-arm comparison alone. The absence of masking is also recorded, but the record does not describe how outcomes were measured or whether assessments could be influenced by knowledge of intervention use.

The safety information reports a serious adverse event count and a separate count for other adverse events, along with Pregnancy as a serious-event term. These are descriptive figures, not a comparative safety analysis. They do not determine causality or provide context about the event beyond what the registry records.

Accordingly, the record supports a description of the study design, intended endpoint, and reported safety counts. It does not support a conclusion about the observed primary weight-loss result or a causal estimate of the device’s effect. The missing outcome and analysis details leave both the efficacy result and its precision unresolved in the registry record.

14. Why This Trial Matters Statistically

This study illustrates why endpoint definitions and endpoint results must be distinguished. The registry gives a clear threshold-based primary endpoint and states the population and assessment time. Those details explain what the study intended to count. They do not reveal how many participants met the threshold, what proportion that count represents, or how uncertain an estimate would be.

It also highlights the importance of naming the analysis population. The endpoint applies to the Per Protocol Population, while the record separately reports an enrollment figure. Without a population definition and denominator, readers cannot assume that enrollment equals the analysis set. This distinction matters for interpreting both the size and generalizability of an outcome estimate.

The single-arm design is another important statistical feature. It can describe outcomes among participants using the intervention, but it does not provide a concurrent comparison group. Any change from baseline would therefore not, by itself, isolate an intervention effect. Clear recognition of this limitation helps keep descriptive results separate from comparative or causal claims.

Finally, the record offers stated efficacy objectives and limited safety counts but no primary endpoint analysis. This makes it a useful example of how registry records can contain design and outcome-definition information without enough results to judge the primary question. Statistical interpretation depends not only on the planned measure but also on the observed estimate, denominator, analysis methods, and uncertainty—details not reported for the primary endpoint in this record.

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 main limitation for interpreting the primary endpoint is that the registry record does not report its observed count or the size of the Per Protocol Population. The endpoint is defined, but readers cannot derive or assess an endpoint proportion from the recorded information. The record also does not report an uncertainty interval or the method used to estimate one.

The study is single arm, with allocation recorded as NA and masking recorded as NONE. Without a comparator group, the design cannot directly estimate how outcomes would differ under another condition. The record does not provide details about outcome assessment that would help evaluate possible measurement influences.

The primary endpoint applies to the Per Protocol Population, but its definition, size, and relationship to the enrollment figure are not reported. Missing-data counts and handling are also not reported. These omissions leave uncertainty about who contributed to the primary analysis and how absent assessments may have been treated.

The registry lists secondary outcomes but reports zero analyses. Results for those outcomes and any multiplicity approach are not reported. The record also does not report a trial-specific sample-size justification or full statistical analysis plan. Although it describes a planning illustration, that illustration is not the study’s design and does not resolve the missing outcome information.

The multicenter designation is recorded, but the number of sites is not reported in the registry record. The official title names DVD weight-loss education, while the intervention entry and arm description identify the SMART device; details about the education component are not reported. These limits are specific to interpreting this registry record and should not be filled in by assumption.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Safety and Efficacy of the SMART Device for Overweight and Obese Adults — NCT02119299.
• Registry record last updated 2017-07-17; status last verified 2017-07.
• Results first posted 2017-07-17.
• 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

NCT02119299 is a completed prospective, single-arm, multicenter study of the SMART device for overweight and obese adults, sponsored by Scientific Intake Limited Co. The registry reports enrollment of 76, a start of 2014-03, and primary completion of 2014-12. Allocation is recorded as NA, masking as NONE, and phase as NA.

The primary endpoint is the count of Per Protocol Population participants achieving at least 5% weight loss at 16 weeks compared with week 0. The record states study objectives of at least 40% meeting that threshold and mean percentage total body weight loss of at least 4%, but does not report the primary endpoint result or analysis population size. It reports 1 participant affected by a serious adverse event and 0 affected by other adverse events among 76 at risk; Pregnancy is listed as a serious event term at 1.3%. The record reports zero analyses.