Investigational Extended Wear Insulin Infusion Set in People With Type 1 Diabetes: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Investigational Extended Wear Insulin Infusion Set in People With Type 1 Diabetes (NCT06273124), a na na study. The primary outcome is 7 Day Survival of Infusion Set for Primary Outcome Measure - Humalog.

2. Clinical Question

The registered primary outcome concerns survival of an infusion set through its intended extended wear period. A wear is counted as having a primary-outcome reason if it meets a protocol-defined criterion: hyperglycemia with failure to respond to boluses, hyperglycemia with ketones >1.0 mmol/L, or an investigator recommendation. The outcome is expressed as a percentage of infusion set wears and summarized as a mean.

This is a descriptive question about performance during use, not a randomized comparison of the device against another infusion set. The study also asked participants to measure blood glucose and ketones if the continuous glucose meter reading was at least 250 mg/dL for one hour. The registry record does not report the primary outcome estimate, so it does not establish what mean percentage was observed or how precisely it was estimated.

3. Trial Design

The registry describes an open, prospective, multicenter, single-group study of an investigational extended-wear infusion set during home use. Its status is completed. The recorded study dates are 2024-03-07 for study start and 2024-12-11 for primary completion. The registered enrollment is 260.

Participants were asked to wear the infusion set for up to 7 consecutive days during 12 consecutive wear periods. The intervention description identifies use with the Tandem t:slim X2 insulin pump with Control-IQ technology and a Dexcom G6 or G7 sensor. Participants were also asked to perform blood glucose and ketone measurements if the continuous glucose meter was at least 250 mg/dL for one hour. The registry identifies the intervention as a device.

The study has no randomized allocation, no masking, and no separate control group. The Humalog and Novolog safety groups therefore should not be interpreted as randomized treatment arms or as a controlled comparison. The primary endpoint is specifically described for participants using Humalog, while safety information is listed separately for Humalog and Novolog.

The registry lists phase as not applicable. It reports two outcome measures and two analyses, but the available record does not provide enough information to reconstruct the full analysis plan or the results for the primary outcome. Details such as a sample-size justification, interim analyses, and methods for handling missing outcome data are not reported in the registry record. The study's completed status indicates its administrative status, not by itself the direction or precision of its findings.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Analysis population for the primary outcome, as defined in the registry: To be considered for analysis in the primary outcome, participants had to have successfully inserted at least 6 sets per the study protocol.

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 7 Day Survival of Infusion Set for Primary Outcome Measure - Humalog, measured over 12 weeks.

The primary endpoint is 7-day survival of the infusion set, measured as a percentage of infusion set wears and summarized as a mean. The registered timeframe is 12 weeks. A wear is considered to meet the primary-outcome criteria for specified reasons: hyperglycemia with failure to respond to boluses, hyperglycemia with ketones >1.0 mmol/L, or an investigator recommendation. The primary endpoint description applies to participants using Humalog.

Survival is used to describe whether a set remains in use through the intended wear period without a protocol-defined reason for ending the wear. Defining the reasons in advance makes the endpoint more specific than a general report of device use or discontinuation. It also means that interpretation depends on the protocol definitions and how consistently they were applied. The registry record does not report the operational details beyond the listed reasons.

Because the measure is a percentage of wears, its interpretation concerns infusion set wear periods rather than simply whether a participant completed the study. The record says participants needed to have successfully inserted at least 6 sets to be considered for the primary analysis. It does not report the resulting mean, its standard error, or a confidence interval. Consequently, the endpoint definition is available, but the numerical primary result and its precision are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies the primary outcome as a continuous measure summarized by a mean, with standard error as its dispersion measure. In general, a mean condenses a set of measurements into a central value. Here, the individual measurements concern percentages of infusion set wears meeting the survival definition. The registry record does not state the observed mean, so the numerical level of the outcome cannot be assessed.

What does the standard error describe?

In general, standard error describes how much an estimate such as a mean would vary across repeated samples if the same study and analysis were repeated under the same assumptions. It reflects uncertainty about the estimated mean, rather than the variability among individual observations. A small standard error relative to the scale of the outcome indicates a more precisely estimated mean; a larger one indicates less precision. Since the registry record does not state the standard error for the primary outcome, that precision cannot be evaluated.

A confidence interval is a range calculated from an estimate and its uncertainty using a specified method. In general, it conveys which values are reasonably compatible with the observed data and method. It is not a guarantee that the true value lies in the interval, and it does not describe the range of individual observations. No confidence interval for the primary endpoint is reported in the registry record.

How should the endpoint definition be read?

The endpoint treats a wear as meeting the primary-outcome criteria when one of the protocol-defined reasons applies: hyperglycemia with failure to respond to boluses, hyperglycemia with ketones >1.0 mmol/L, or investigator recommendation. In general, a prespecified composite endpoint combines more than one event or reason into a single outcome. This can make an endpoint relevant to several ways a wear may end, but the combined result does not by itself show how much each component contributed. The registry record does not provide component-specific primary outcome results.

The primary measure is a percentage of infusion set wears, summarized as a mean. It is therefore important not to conflate the wear-level endpoint with a participant-level outcome. The record says that participants had to successfully insert at least 6 sets to be considered for the primary analysis. It does not report how many participants met this condition, how many wears contributed to the estimate, or the distribution of observations across participants. Those details affect how the mean and its standard error should be understood.

Why does the study design matter?

The design is open and single-group, with no random allocation and no separate control group. In general, a randomized control comparison helps distinguish an intervention's effects from changes or influences that might also affect an untreated or alternative-treatment group. A single-group study instead describes outcomes in the studied group. Its findings may be useful for characterizing use, but without a control comparison they do not establish that observed outcomes are caused by the device or show how outcomes compare with another set.

The Humalog and Novolog safety listings are not a substitute for randomization. The registry record does not state that these groups were assigned randomly, and it does not identify a like-for-like control arm. Differences in their listed counts should therefore be treated as descriptive, not as evidence of a comparative treatment effect.

What does the planning illustration mean?

The registry's sample-size assumptions describe a planning illustration based on an observed effect, not the design used to establish the trial's enrollment. The stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. For time-to-event calculations, the illustration gives the total number of events using the Schoenfeld method; other calculations give participants per arm.

In general, a planning calculation estimates how much information a future study might need under chosen assumptions. It does not demonstrate that the completed study had a particular probability of detecting an effect, and it is not observed power. These assumptions also do not turn the present single-group study into a randomized two-arm trial. No numerical planning results are reported in the registry record used for this analysis, and the assumptions should not be mistaken for a reported protocol sample-size justification.

Why can over-dispersion matter?

In general, over-dispersion occurs when observations vary more than a model assumes. If multiple wear periods from the same participant are treated as independent when they are correlated, the analysis may overstate the amount of independent information and understate uncertainty. Appropriate methods may need to account for within-participant clustering or other features of the data. The registry record does not report whether or how such dependence was handled. This is a methodological consideration, not evidence that the analysis was incorrect.

Likewise, the record does not report the distribution of the endpoint or the full model and estimation procedure. A standard error alone would not reveal whether the method accounted for repeated wears, missing observations, or any departures from its assumptions. Without the estimate and analysis details, the statistical precision of the primary endpoint cannot be independently assessed.

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("SteadiSet Extended Wear Infusion Set - Humalog")
n   <- c(124)
m   <- c(95)
sp  <- c(0.7)
sd  <- sp * sqrt(n)      # standard errors converted to SDs
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  SteadiSet Extended Wear Infusion Set - Humalog  124  95.000  7.795  93.614  96.386

11. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures and two analyses, but the available record does not describe how those analyses relate to one another or which results were treated as confirmatory. It does not report a multiplicity adjustment or a strategy for controlling the chance of false-positive findings across multiple outcomes or analyses. In general, testing multiple hypotheses can increase the chance that at least one appears noteworthy by chance; prespecified priorities and adjustment methods can help readers interpret that risk. The absence of reported details does not establish whether an adjustment was or was not used.

Missing-data methods are also not reported in the registry record. The primary analysis population is described in terms of successfully inserting at least 6 sets, but the record does not state how missing wear outcomes, incomplete wear periods, or withdrawals were handled. In general, missingness can affect an estimate when the availability of an observation is related to its outcome or to other relevant characteristics. The potential effect depends on why observations are missing and on the analysis method; neither is described.

The record does not report a full statistical analysis plan, interim analyses, or a sample-size justification for the completed study. It is therefore not possible to verify from this information whether outcome definitions, analysis populations, missing-data handling, or multiplicity procedures were prespecified. These are reporting limits, not evidence that particular methods were absent from the study conduct.

The enrollment and the primary analysis population are not interchangeable: the registered enrollment is 260, while the primary-outcome description applies only to participants meeting the insertion criterion. The number meeting that criterion is not reported in the registry record. The reported enrollment should not be assumed to be the denominator for the primary endpoint.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: severe hypoglycemia (0.8%), diabetic ketoacidosis (0.0%), other serious adverse event (0.0%).

The registry lists serious adverse events, other adverse events, and deaths separately for the Humalog and Novolog groups. For Humalog, 128 participants were listed as at risk for serious adverse events and 0 were affected; 128 were listed as at risk for other adverse events and 14 were affected. For Novolog, 132 were listed as at risk for serious adverse events and 1 was affected; 132 were listed as at risk for other adverse events and 29 were affected. Deaths are listed as 0 in each group.

These counts are descriptive safety summaries. They do not establish that the groups had comparable risk, because the study was not randomized and the registry does not describe the groups as a controlled comparison. The counts also do not provide event timing, duration, relatedness to the device, or the number of recurrent events for an affected participant.

The record separately lists Severe Hypoglycemia at 0.8%, Diabetic Ketoacidosis at 0.0%, and Other Serious Adverse Event at 0.0% among top serious-event terms. The denominator and group context for those percentages are not reported in the registry record. They should not be treated as directly reconcilable with the group counts without that context. A count of zero in a listed category does not establish that the risk is absent.

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

The study is registered as a completed, open, prospective, multicenter, single-group study of an investigational extended-wear infusion set during home use in people with type 1 diabetes. The registry states the intended wear schedule, the equipment used, the primary endpoint definition, and selected adverse-event counts. Those details describe what was studied and how the primary question was framed.

The primary endpoint asks about the mean percentage of infusion set wears surviving 7 days without a protocol-defined reason for ending the wear. However, the numerical mean and its standard error are not reported in the available registry record. No primary estimate or confidence interval can therefore be discussed. A study's completed status is not a substitute for its outcome results.

The single-group design does not provide a randomized control comparison. It can describe observations in the study group, but it cannot determine how those observations would compare with a separate control group under the same study conditions. The Humalog and Novolog safety listings should not be read as a randomized comparison.

The safety counts offer a limited account of reported events. They do not alone establish the full safety profile, event attribution, or comparative risk. The registry-listed percentages for serious-event terms also lack reported denominator and group context.

These limits do not make the registry information uninformative. The record identifies a specific home-use setting and a defined 7-day survival question, and it presents selected safety counts. It does mean that conclusions about the magnitude and precision of the primary outcome, the contribution of individual endpoint components, and comparative performance are not supported by the available information.

14. Why This Trial Matters Statistically

This study raises a statistical question that depends on both the definition of a successful wear and the structure of the observations. The primary outcome is expressed as a percentage of wears, while participants could contribute multiple consecutive wear periods. In general, repeated observations from the same person may be related. The analysis approach and its treatment of that dependence matter for estimating uncertainty around a mean.

The endpoint also combines several protocol-defined reasons for a wear not to meet the survival definition. A composite measure can give a concise summary of a practical outcome, but its interpretation depends on the component criteria. Without component-specific results, a reader cannot tell which reasons contributed most to the reported endpoint even if an overall estimate is available.

Study design is another central issue. An open, single-group study can characterize outcomes during home use, but it lacks a randomized control comparison. This distinction prevents a descriptive result from being interpreted as a controlled estimate of the device's comparative effect. The separate Humalog and Novolog safety summaries do not supply such a comparison.

Finally, statistical interpretation requires the estimate and its uncertainty, as well as information about the analysis population, missing data, and analysis methods. The registry record defines the primary endpoint and gives the qualifying insertion criterion, but it does not report the numerical primary result or these additional details. The distinction between an outcome definition and a reported outcome estimate is therefore especially important for this study.

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 primary limitation for interpreting the registered endpoint is that its numerical result is not reported in the available registry record. The mean percentage of wears meeting the 7-day survival definition and its standard error are not stated. No confidence interval is reported, so the magnitude and precision of the primary result cannot be assessed.

The primary analysis applies to participants using Humalog who successfully inserted at least 6 sets under the protocol. The registry does not report how many participants met that criterion, how many wear periods contributed to the analysis, or how observations were distributed across participants. The registered enrollment of 260 should not be treated as the primary endpoint denominator.

The single-group design is a further limitation for comparative interpretation. There is no randomized control group, and the Humalog and Novolog safety groups are not described as randomized arms. The open design also means masking was absent. The registry does not report whether outcome assessment or event attribution used additional safeguards.

Details needed to evaluate the analysis are not reported in the registry record, including the full statistical plan, handling of missing wear outcomes, treatment of repeated observations, and multiplicity procedures. The seriousness-term percentages are listed without their denominator or group context. Safety counts do not describe timing, recurrence, relatedness, or severity beyond the categories presented.

These are limits of the information reported in the registry record. They do not establish that a particular analysis method was not used or that a particular outcome occurred.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Investigational Extended Wear Insulin Infusion Set in People With Type 1 Diabetes — NCT06273124.
• Registry record last updated 2025-09-24; status last verified 2025-09.
• Results first posted 2025-09-24.
• 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

NCT06273124 is a completed, open, prospective, multicenter, single-group study of an investigational extended-wear insulin infusion set for people with type 1 diabetes. The registered enrollment is 260, and the study dates are 2024-03-07 through primary completion on 2024-12-11.

Participants were asked to wear the set for up to 7 consecutive days over 12 consecutive wear periods. The primary endpoint concerns mean 7-day infusion set survival as a percentage of wears among Humalog users meeting the protocol insertion criterion. The primary outcome estimate and its standard error are not reported in the available registry record.

The registry lists serious and other adverse-event counts for Humalog and Novolog groups and reports 0 deaths in each. Because the study has no randomized control group, these group listings are descriptive rather than a like-for-like comparison. Details of the full statistical plan, missing-data handling, and multiplicity procedures are not reported in the registry record.