Evaluation of the MiniMed™ 780G System in Type 1 Adult and Pediatric Subjects Utilizing Insulin Fiasp®: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluation of the MiniMed™ 780G System in Type 1 Adult and Pediatric Subjects Utilizing Insulin Fiasp® (NCT05224258), a na na study. The primary outcome is Primary Safety Endpoint - Change in HbA1c.

2. Clinical Question

In practical statistical terms, the study asks how HbA1c changed during use of the system with insulin Fiasp, rather than whether that change differed from a concurrent control group. This distinction matters: without a control group, changes over the study period cannot be separated from other influences by a randomized between-group comparison. The registry describes safety and effectiveness as the study’s broad aims, but only the primary endpoint definition and selected safety counts are available in this record. The endpoint data needed to quantify the HbA1c change are not reported in the registry record.

3. Trial Design

This was a completed, single-group study listed as phase NA. The registry records enrollment of 240 and describes use of the MiniMed 780G system with insulin Fiasp. Participants with insulin-requiring type 1 diabetes aged 7-80 used the system for three months. The study was intended to evaluate the system in a home setting, and the registry describes it as global, with the United States, Canada, and Australia named as study locations.

The design has no randomized allocation listed and no masking. Allocation is recorded as NA, and masking is recorded as none. The single-group model means the registry does not describe a concurrent comparator group. It is therefore important to distinguish a within-participant change from a controlled estimate of a treatment difference. A change from baseline can describe what happened during the study period among participants with available measurements, but the record does not establish what would have happened over the same period under a different intervention.

The study start date is 2022-03-17, the primary completion date is 2024-06-21, and status is completed. These dates describe the registry timeline; they do not supply a numerical result for the primary endpoint. The registry identifies four outcome measures and eight analyses. Details of how those analyses were selected, prioritized, or adjusted for multiple testing are not reported in the registry record.

The endpoint description says that the primary analysis used an intention-to-treat population with available data. At the end of the study period, 104 participants aged 7-17 and 114 participants aged 18-80 were analyzed for the endpoint and change from baseline. The record also says that three participants aged 7-17 and two participants aged 18-80 did not collect A1C at the end of the study period. The implications of missing endpoint measurements depend on their reasons and on the analysis approach; further details are not reported in the registry record.

The record does not report a protocol-level sample-size justification or detailed statistical analysis plan. Planning illustrations based on an observed effect are a different kind of calculation from the trial’s design justification, and should not be read as observed power or as evidence that the study was designed around a particular effect. The stated assumptions for those illustrations include a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Since the study itself is single-group, those illustrations do not create a control group or change the design.

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: 240 subjects (115 with age 7-17 and 125 with age 18-80) enrolled at the beginning, with 14 (5 with age 7-17 and 9 with age 18-80) screen failure, 3 subjects with age 7-17 early withdrawn prior the study period, 223 subjects (107 with age 7-17 and 116 with age 18-80) started the study and became the Intention to Treat Population.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intention to Treat Population with available data. Three subjects aged 7-17 and two subjects aged 18-80 did not collect A1C at the end of the study period, so 104 subjects aged 7-17 and 114 subjects aged 18-80 were analyzed at end of study period and the change from baseline to end of study 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.

Population: Intention to Treat Population

6. Primary Endpoint

The registry lists the primary outcome as Primary Safety Endpoint - Change in HbA1c, measured over 3 months.

The primary endpoint is the overall mean change in HbA1c from baseline to the end of the 3-month study period. HbA1c is a continuous measure, and the registry specifies the outcome parameter as a mean with standard deviation as the dispersion measure. The endpoint is labeled “Primary Safety Endpoint - Change in HbA1c” in the record, while its description also specifies a non-inferiority test.

In general, a change-from-baseline endpoint describes how a measured value differs between the start and end of a defined period. A mean summarizes the average change across the analyzed participants; a standard deviation describes the spread of individual values around that average. These summaries answer different questions: the mean describes the group’s average change, while the standard deviation indicates how varied the observed changes were.

In general, HbA1c is used as a measure related to blood glucose over time. A change in this measure can therefore serve as an effectiveness outcome in a study of diabetes technology, while safety outcomes are assessed separately. The registry’s label and description should both be retained when interpreting this endpoint: the label calls it a safety endpoint, and the description calls for a non-inferiority test of the mean change.

The numerical mean change, standard deviation, confidence interval, test result, and non-inferiority margin are not reported in the registry record. Without those details, the endpoint definition alone cannot show the size or precision of the change or whether a non-inferiority criterion was met.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The endpoint is a continuous outcome summarized as a mean, with standard deviation specified as its measure of dispersion. In general, a mean is the arithmetic average of the observed values, and a standard deviation describes how spread out those values are around the average. A mean change from baseline summarizes the average within-participant difference between the starting and ending measurements for the participants included in the analysis. The registry gives this endpoint a 3-month timeframe and describes the comparison as baseline to the end of the study period.

What does a confidence interval add?

In general, a confidence interval describes the statistical uncertainty around an estimated quantity under the assumptions of the analysis. It helps readers judge which values remain compatible with the observed data and method. A point estimate alone does not convey that uncertainty. For a non-inferiority question, the interval is usually considered in relation to a prespecified margin, but the margin and interval for this study are not reported in the registry record. No confidence interval for the primary endpoint is reported in the registry record.

What does non-inferiority mean in general?

In general, a non-inferiority analysis asks whether an outcome is not worse than a comparator by more than a prespecified amount. The margin is central: it defines the largest difference that would still count as non-inferior under the study’s chosen criterion. A statistical test result cannot be interpreted fully without knowing the comparison, margin, analysis population, and uncertainty around the estimate. Here, the endpoint description says “Non-inferiority test,” but the comparator, margin, and test result are not reported in the registry record. The single-group design also means the registry does not describe a separate randomized arm for a direct between-group comparison.

How should the single-group design affect interpretation?

In general, an observed change within one group is not the same as a treatment contrast. A treatment contrast compares outcomes under different assigned conditions, often using a concurrent control group. A single-group before-and-after comparison can describe the direction and distribution of change over time, but other time-related influences may also affect the measurements. Because allocation is listed as NA and the model as single-group, the record does not describe random assignment between treatment groups. Masking is listed as none. These design features do not prevent descriptive reporting, but they limit what can be attributed to the intervention.

The record states that the primary endpoint analysis used an intention-to-treat population with available data. The wording combines an intention-to-treat label with an availability condition; the exact operational definition and analysis procedures are not reported in the registry record. In general, intention-to-treat refers to analyzing participants according to their assigned group, while a requirement for an observed endpoint can mean that not every enrolled participant contributes to a particular outcome analysis. In a single-group study, details of how the analysis population was defined remain important even without a randomized assignment.

What is the role of missing-data information?

The registry reports missing end-of-study A1C collection for three participants aged 7-17 and two participants aged 18-80. It reports that 104 participants aged 7-17 and 114 aged 18-80 were analyzed for the endpoint at the end of the study period. These statements describe the available endpoint data, but do not specify why measurements were unavailable, whether missingness was related to observed outcomes, or whether any imputation or sensitivity analysis was used. In general, missingness can affect an estimate if the participants with observed measurements differ systematically from those without them. Without details on reasons and handling, the direction and extent of any effect cannot be judged.

Why do multiple outcomes and analyses matter?

The registry lists four outcome measures and eight analyses. In general, evaluating multiple outcomes or conducting multiple tests can increase the chance that at least one result appears notable by chance. Methods such as prespecifying a hierarchy or adjusting for multiplicity can help control the interpretation of a family of tests, but the statistical plan and any multiplicity procedure are not reported in the registry record. It is therefore not possible to determine from the record whether the analyses were adjusted, ordered, or treated as separate descriptive results.

The record describes the primary outcome as a mean with standard deviation. It does not give the numerical mean change, standard deviation, confidence interval, test statistic, or p-value. No recalculated estimate can be derived from the registry entries. In general, recalculation from summary statistics is an unadjusted analysis and may not reproduce a sponsor’s prespecified model; if a discrepancy is identified between such a recalculation and the sponsor’s analysis, the sponsor’s own analysis takes precedence. No recalculated primary result is reported in the registry record.

The sample-size assumptions describe planning illustrations based on a fraction of the observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. In general, such illustrations explore how sample size might relate to a chosen effect and statistical assumptions. They are not the same as the study’s own sample-size justification, and they are not observed power. The registry record does not report the trial’s sample-size justification. Since the trial is single-group, an equal-allocation, two-arm planning illustration should not be mistaken for the actual design or for a randomized comparison. Numerical planning estimates are not reported in the registry record.

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("Subjects 7-17 Years of Age", "Subjects 18-80 Years of Age")
n   <- c(104, 114)
m   <- c(-0.2, -0.4)
sp  <- c(0.7, 0.6)
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  Subjects 7-17 Years of Age  104  -0.200  0.700  -0.336  -0.064
CARM  Subjects 18-80 Years of Age  114  -0.400  0.600  -0.511  -0.289

11. Multiplicity, Missing Data and Analysis Populations

The registry lists four outcome measures and eight analyses. It does not report the relationship between those analyses, a hierarchy among endpoints, or a procedure for adjusting for multiple comparisons. In general, multiplicity matters when several outcomes or statistical tests are interpreted together, because the chance of at least one apparently notable finding can increase as more tests are considered. Without a stated strategy, the record does not establish whether the analyses were adjusted or how any collection of results should be interpreted. The numerical primary-endpoint test result is not reported in the registry record.

The primary-endpoint analysis is described as using an intention-to-treat population with available data. The record states that three participants aged 7-17 and two aged 18-80 did not collect A1C at the end of the study period. It reports 104 analyzed participants aged 7-17 and 114 aged 18-80 for the endpoint and change from baseline. The reasons for missing end-of-study measurements are not reported in the registry record. The record also does not describe imputation, a missing-data model, sensitivity analyses, or whether participants with missing measurements contributed to any other analyses.

In general, available-case analysis uses observed outcome data, whereas imputation or model-based methods may incorporate information differently. The appropriate interpretation depends on the assumptions and implementation. The phrase “with available data” indicates that endpoint availability is relevant, but does not provide enough detail to determine the missing-data assumptions. The registry does not report a full statistical analysis plan or multiplicity strategy, so both the handling of missingness and the scope of confirmatory inference remain uncertain. Those omissions prevent a complete assessment of how robust a primary endpoint conclusion would be to alternative analysis choices.

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 non-serious adverse event terms

The registry reports serious and other adverse-event figures separately for participants aged 7-17 and participants aged 18-80 during the study period. In the 7-17 age group, 0 serious adverse events were reported among 107 at risk; 26 were affected by other adverse events among 107 at risk; and 0 deaths were reported. In the 18-80 age group, 0 serious adverse events were reported among 116 at risk; 30 were affected by other adverse events among 116 at risk; and 0 deaths were reported.

These are descriptive counts recorded for the study groups, not comparisons against a control group. The record’s serious adverse-event term list is empty. The details of the other adverse events, including their types, severity, timing, and relationship to the system or insulin, are not reported in the registry record. The counts therefore do not explain what events occurred or how they were assessed.

In general, a count of zero recorded events does not by itself establish that an event is impossible or that risk is absent. It describes what was recorded in the specified groups during the stated study period. The registry does not report further safety analyses or a comparator that would support a relative safety estimate.

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

The record establishes that a completed, single-group study evaluated the MiniMed 780G system with insulin Fiasp in a home setting over three months. It identifies change in HbA1c as the primary endpoint and gives an analysis population by age group. It also records age-specific counts for serious adverse events, other adverse events, and deaths. These details clarify what was studied and what aspects of the study are documented.

The primary endpoint’s numerical result is not reported in the registry record. The mean change, its variability and uncertainty, and the non-inferiority test outcome are unavailable in the record. The non-inferiority margin and comparator are also not reported in the registry record. Accordingly, readers cannot determine from this record whether the observed HbA1c change met a non-inferiority criterion, how large the change was, or how precisely it was estimated.

The study has no randomized comparison listed. In general, a single-group change over time cannot establish what would have happened under an alternative condition during the same period. It can describe the measured experience of participants with available data, but it cannot by itself isolate the intervention’s effect from other influences. The registry’s design description should therefore guide interpretation of any endpoint result that may be reported elsewhere; no such result is available in this record.

The safety counts describe recorded events in the study groups. They do not provide details of the other adverse events, and they do not establish a comparison with another treatment or a broader population. The missing A1C measurements and lack of reported missing-data methods also leave uncertainty about how endpoint availability may affect the primary analysis. Taken together, the record supports a clear account of the study’s design and available safety counts, but it does not support a numerical conclusion about the primary endpoint or a comparative claim about safety or effectiveness.

14. Why This Trial Matters Statistically

This study is statistically notable for the contrast between its stated endpoint framework and its single-group design. The primary endpoint description specifies a non-inferiority test, while the registry lists a single-group model, allocation as NA, and no masking. In general, non-inferiority requires a defined comparison and margin. Because these details and the numerical test result are not reported in the registry record, the endpoint label cannot be treated as evidence that a non-inferiority criterion was met.

The distinction between descriptive change and comparative effect is central to interpreting clinical studies. A baseline-to-end change can summarize observed measurements over time. A randomized comparison can address a different question by comparing outcomes under assigned conditions. The registry’s single-group design supports description of change among participants with available measurements, but does not supply the concurrent control needed for a randomized contrast.

The record also illustrates why analysis populations and endpoint availability matter. It specifies an available-data analysis and reports missing end-of-study A1C collection in both age groups. Yet it does not describe reasons for missingness or how missing data were handled. These details affect how readers assess the population represented by the endpoint result and the assumptions behind any estimate.

Finally, the registry lists multiple outcome measures and analyses without reporting a multiplicity strategy. In general, the interpretation of multiple tests depends on whether endpoints were prespecified, prioritized, or adjusted. The record does not state those methods. The study therefore offers useful design and safety information, while the absent primary numerical results and analysis details constrain statistical interpretation. Recognizing those boundaries is important: endpoint definitions, completion status, and observed safety counts are not substitutes for an estimate with uncertainty and a transparent analysis plan.

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 effectiveness is that the numerical HbA1c result is not reported in the registry record. The mean change, standard deviation, confidence interval, and non-inferiority test result are absent. The non-inferiority margin and comparator are also not reported in the registry record. Without these details, the endpoint cannot be evaluated quantitatively or against a defined criterion.

The study is listed as single-group, with no randomized comparison and no masking. This design does not provide a concurrent control group for separating change during the study from other time-related influences. Allocation is listed as NA. The registry does not report a detailed protocol or statistical analysis plan, sample-size justification, interim-analysis plan, or procedure for handling multiplicity.

Endpoint availability is another limitation. The record says that three participants aged 7-17 and two participants aged 18-80 did not collect A1C at the end of the study period, and it gives age-specific analyzed counts. It does not report reasons for missing measurements, imputation, sensitivity analyses, or missing-data assumptions. The endpoint population is described as intention-to-treat with available data, but the operational details of that analysis are not reported in the registry record.

The safety information is limited to counts by age group. Details of the other adverse events, including event types, severity, timing, and relationship to the intervention, are not reported in the registry record. An empty serious-event term list and zero recorded serious adverse events do not supply information about unreported event details or comparative risk. The registry lists four outcome measures and eight analyses, but does not explain their hierarchy or any adjustment for multiple testing. These limitations restrict both endpoint interpretation and assessment of the robustness of the analyses.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Evaluation of the MiniMed™ 780G System in Type 1 Adult and Pediatric Subjects Utilizing Insulin Fiasp® — NCT05224258.
• Registry record last updated 2025-06-22; status last verified 2025-06.
• Results first posted 2025-06-22.
• 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

The registry record describes a completed, single-group study of the MiniMed 780G system with insulin Fiasp in people with type 1 diabetes aged 7-80. Use took place in a home setting for three months. The study is listed as phase NA, allocation NA, and masking none. Its status is completed, with start date 2022-03-17 and primary completion date 2024-06-21.

The primary endpoint is mean change in HbA1c from baseline to the end of the study period, described as a non-inferiority test. The numerical result, uncertainty, comparator, and non-inferiority margin are not reported in the registry record. The endpoint analysis is described as intention-to-treat with available data; missing end-of-study A1C collection is reported in both age groups.

The registry reports 0 serious adverse events and 0 deaths in each age group, alongside other adverse-event counts of 26 in participants aged 7-17 and 30 in participants aged 18-80. Details of those other events are not reported in the registry record. The record lists four outcome measures and eight analyses, but does not report a multiplicity strategy or detailed statistical analysis plan.