This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Post Approval Study of the TS Feature With the 530G Pump System Supplemented With Commercial Patient Data (NCT02003898), a na na study. The primary outcome is Mean Change in A1C From Baseline to 1 Year.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02003898 |
| Phase | NA |
| Condition | Diabetes |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 372 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Medtronic MiniMed, Inc. |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned people aged 16 and older with insulin-requiring diabetes. The record lists 372 enrolled subjects; 298 had both baseline and end-of-study A1C measurements. The condition is listed as diabetes.
Intervention
All subjects received diabetes treatment using the Medtronic MiniMed 530G insulin pump. The study focused on the Threshold Suspend feature. The record describes the intervention as a device and the study as single-group.
Comparator
There was no randomized control group in the registry record. The primary-outcome description says the estimated A1C change would be compared by a non-inferiority test with the CEP 266 study population. Details of that population and how it served as a comparison are not reported in the registry record.
Primary question
The primary question was the mean change in A1C from baseline to 1 year. The planned non-inferiority comparison used an A1C margin of 0.4% and a one-sided significance level of 0.025. The numerical estimate, confidence interval, and test result are not reported in the registry record.
This is therefore a question about a change over time in a treated study population, alongside a stated comparison with the CEP 266 study population. It is not a randomized head-to-head question between two treatment arms. The title notes that commercial patient data supplemented the study, but how those data were incorporated into the primary analysis is not reported in the registry record. Nor does the record explain whether every enrolled subject contributed to each outcome analysis. For the primary endpoint, it specifically states that 298 subjects had both measurements. The record also lists secondary A1C outcomes according to baseline A1C categories: below 7%, from 7% to 9%, and > 9%. The results for those outcomes are not reported in the registry record.
3. Trial Design
The registry describes a completed, single-group device study of the Medtronic MiniMed 530G insulin pump. All subjects received diabetes treatment using that pump. Allocation is listed as NA, masking as none, and the study model as single-group. These details indicate that the record does not describe randomized assignment to competing treatment arms or a masked comparison. The enrollment listed in the record is 372.
The study’s stated purpose was to evaluate the Threshold Suspend feature in patients aged 16 and older with insulin-requiring diabetes. The primary endpoint was mean change in A1C from baseline to 1 year. The record’s endpoint description states that this change would be estimated and compared by a non-inferiority test with the CEP 266 study population. It specifies an A1C margin of 0.4% and a one-sided significance level of 0.025. Details of the CEP 266 population, its measurements, and the exact comparison procedure are not reported in the registry record.
The record lists a start date of 2013-11-26, a primary completion date of 2018-02-20, and a completed status. The title refers to the study being supplemented with commercial patient data, but the record does not explain how those data relate to the enrolled study population, whether they were used for the primary endpoint, or how they were analyzed. It also does not report a randomized comparator arm. The record lists one analysis and four outcome measures; it does not specify how the analyses correspond to individual outcome measures.
These design details matter when interpreting changes over time. A single-group study can describe the observed course of its participants, but it does not provide a randomized within-study contrast that separates treatment effects from other explanations for change. The stated comparison with CEP 266 is relevant to the planned non-inferiority question, but the available record does not provide enough detail to assess the comparability of the populations or the analysis. The numerical primary result is not reported in the registry record.
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
| Stage | Medtronic MiniMed 530G Insulin Pump |
|---|---|
| STARTED | 372 |
| COMPLETED | 305 |
| NOT COMPLETED | 67 |
Reasons for not completing this period:
| Reason | Medtronic MiniMed 530G Insulin Pump |
|---|---|
| Death | 3 |
| Lost to Follow-up | 12 |
| Withdrawal by Subject | 52 |
Analysis population for the primary outcome, as defined in the registry: Among the 372 enrolled subjects, 298 had both baseline and end of study A1c.
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.
| Characteristic | Unit | Medtronic MiniMed 530G Insulin Pump |
|---|---|---|
| Participants analysed | 372 | |
| Age, Continuous | Years | 45.5 (SD 15.9) |
| Sex: Female, Male: Female | Participants | 201 |
| Sex: Female, Male: Male | Participants | 171 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 15 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 351 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 6 |
| Region of Enrollment: United States | participants | 372 |
6. Primary Endpoint
The registry lists the primary outcome as Mean Change in A1C From Baseline to 1 Year, measured over 1 year.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | percentage |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is mean change in A1C from baseline to 1 year, measured in percentage units. A1C is a continuous measure, so the endpoint summarizes the average within-person change over the specified interval among the participants included in the analysis. The record states that the overall mean change would be estimated and compared with the CEP 266 study population using a non-inferiority test.
Using change from baseline focuses the analysis on how the measurement differs over time rather than only describing an endpoint value. A mean gives a single summary of the group’s average change, while a confidence interval communicates uncertainty around that estimate. General explanation: a confidence interval gives a range of values compatible with the data and the method used; it is not a guarantee that the true value lies within that particular interval.
The stated non-inferiority margin was 0.4%, with a one-sided significance level of 0.025. In general, a non-inferiority margin defines how much difference the study is designed to rule out in the direction relevant to the question. The margin alone does not establish non-inferiority: interpretation requires the estimated contrast and its uncertainty, along with the specified analysis. Those numerical results are not reported in the registry record. The record states that 298 enrolled subjects had both baseline and end-of-study A1C, but does not report the endpoint estimate or its 95% confidence interval.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The primary endpoint is clearly identified as mean A1C change from baseline to 1 year, and the registry record specifies a non-inferiority framework, a margin of 0.4%, and a one-sided significance level of 0.025. However, the numerical primary estimate, its 95% confidence interval, and the non-inferiority test result are not reported in the registry record. Consequently, the record does not permit a numerical assessment of the size or precision of the observed change, or a determination of how the result relates to the stated margin.
This absence is important because a non-inferiority conclusion depends on the estimated comparison and its uncertainty, not merely on the existence of a prespecified margin. General explanation: the confidence interval helps show which values remain compatible with the data under the analysis method. For a non-inferiority question, its position relative to the margin is central. Without the interval and test result, the direction and precision of the comparison cannot be evaluated from this record.
The study is listed as single-group, with all subjects receiving the same pump. The primary description refers to comparison with the CEP 266 study population, but the record does not provide details of that population or the comparison data. Thus, the record does not support treating this as a randomized comparison between concurrent treatment arms. Even if a numerical change over time were available, change in a single group by itself would not establish that the device caused the change. Other explanations for temporal change cannot be separated by a randomized control contrast in the design.
The record states that 372 subjects were enrolled and that 298 had both baseline and end-of-study A1C measurements. It does not report the endpoint analysis population beyond that statement, explain why some enrolled subjects lacked paired measurements, or describe how missing measurements were handled. That limits assessment of whether the analyzed participants represent the enrolled population. Commercial patient data are mentioned in the study title, but their role in the outcome analysis is not reported in the registry record.
The registry lists secondary A1C outcomes for baseline categories below 7%, from 7% to 9%, and > 9%. Their numerical results are not reported in the registry record. The record also does not describe adjustment for multiple outcome analyses. The overall interpretation is therefore constrained by missing outcome estimates, incomplete detail about the comparison population and analysis, and the absence of a randomized control group described in the record. No conclusion about the size, precision, or clinical importance of the A1C change can be drawn from the posted registry information alone.
9. Statistical Methods Explained
What does a mean change describe?
The primary endpoint is the mean change in A1C from baseline to 1 year. A continuous outcome can take values across a measurement scale, and a mean summarizes the average value of that outcome or its change in a group. Here, the intended summary is a change over time for the study population. The registry record identifies the unit as percentage and the parameter as a mean. It does not report the numerical mean change.
General explanation: a group mean can describe the center of the observed changes, but it does not show how much individual participants varied. The mean also does not, by itself, show the precision of the estimate. A confidence interval is used to express statistical uncertainty around an estimate, based on the data and the method used. The record identifies a 95% confidence interval as the dispersion measure, but its numerical limits are not reported in the registry record.
How is non-inferiority different from a difference test?
The primary-outcome description specifies a non-inferiority test, an A1C margin of 0.4%, and a one-sided significance level of 0.025. General explanation: a conventional superiority question asks whether evidence supports a difference in a specified direction or whether groups differ. A non-inferiority question instead asks whether the data rule out a disadvantage larger than a prespecified margin. The margin is a boundary for the question; it is not an observed effect and does not show what the study found.
Evaluating a non-inferiority result requires the estimated contrast, its uncertainty, and clarity about the direction in which the contrast is defined. The record names CEP 266 as the population for comparison, but does not describe that population, the contrast’s sign convention, or the numerical result. It therefore does not allow the non-inferiority assessment to be reconstructed. The stated significance level is part of the planned test, not a result.
What does the single-group design imply?
The registry lists a single-group model, allocation as NA, and masking as none. All subjects received the Medtronic MiniMed 530G insulin pump. General explanation: a single-group study can estimate the observed outcome in the group and describe change over time. Without a randomized concurrent comparator, it cannot use random assignment to balance other causes of change between treatment groups. A comparison with a separate population may be informative under suitable assumptions, but the registry record does not give enough detail to assess those assumptions for CEP 266.
Masking is listed as none. The record does not explain whether outcome measurement or analysis involved any additional safeguards against influence. It is not appropriate to infer unreported procedures from the device or study description.
How should the confidence interval be read?
The primary endpoint lists a 95% confidence interval. General explanation: a confidence interval represents the uncertainty associated with an estimate under a specified statistical procedure. A narrower interval indicates greater precision than a wider interval, but precision is not the same as clinical importance. The interval’s location relative to a decision boundary also matters for a non-inferiority question. Because neither the interval nor the estimate is reported in the registry record, its width, direction, and relation to the margin cannot be assessed.
What are the planning illustrations for?
The planning assumptions describe illustrations computed from the observed effect, rather than the original trial design. They specify a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. General explanation: such calculations explore the sample size that would be needed under chosen assumptions for a future two-arm study. They are not observed power and do not change the design of this single-group study. The registry record does not report the observed effect needed to judge those illustrations, and their planning assumptions should not be mistaken for the study’s actual allocation or analysis.
For continuous outcomes, planning calculations depend on assumptions about the effect and the variability of measurements, among other design choices. General explanation: if the underlying data are more variable than assumed, a study may be less precise than anticipated. The registry record does not report the variability used for any planning calculation, the original sample-size justification, or a protocol-based power calculation. These details are not reported in the registry record.
What can be inferred from the analysis description?
The record lists one analysis and four outcome measures. It identifies the primary endpoint and three secondary A1C changes grouped by baseline A1C category. It does not report the statistical model, covariate adjustments, distributional checks, sensitivity analyses, or handling of repeated or incomplete measurements. General explanation: these choices can affect how an estimate is calculated and how robustly it can be interpreted. They should not be assumed when the registry record does not state them.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists four outcome measures: the primary mean A1C change from baseline to 1 year and secondary mean changes in baseline A1C categories below 7%, from 7% to 9%, and > 9%. It lists one analysis. The record does not state whether the outcomes were tested as a family, whether any adjustment was made for multiple comparisons, or how the secondary outcomes were intended to inform interpretation. Multiplicity handling is not reported in the registry record.
The primary endpoint description specifies a non-inferiority test with an A1C margin of 0.4% and a one-sided significance level of 0.025. The registry record does not describe whether this testing plan was part of a broader hierarchy or how any additional analyses related to the primary test. A prespecified significance level does not, on its own, explain the handling of multiple outcomes.
For missing data, the record states that 298 of the 372 enrolled subjects had both baseline and end-of-study A1C. It does not state why the remaining enrolled subjects lacked both measurements, whether other observations were available, or what methods were used to address missingness. The endpoint analysis population, beyond the paired-measurement statement, is not reported in the registry record. It also does not report sensitivity analyses exploring how missing measurements might affect the result.
These gaps matter because the analyzed population and missing-data assumptions can affect an estimate and its uncertainty. General explanation: an analysis restricted to participants with measurements at both time points can differ from an analysis that uses additional partial information or makes explicit assumptions about missing values. The record does not identify which approach was used beyond reporting the number with both measurements. Details of interim analyses, if any, are not reported in the registry record.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Medtronic MiniMed 530G Insulin Pump | 19 | 372 | 5.1% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Medtronic MiniMed 530G Insulin Pump | 3 of 372 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Medtronic MiniMed 530G Insulin Pump | 37 of 372 |
Most frequent serious adverse event terms
| Event term | Organ system | Medtronic MiniMed 530G Insulin Pump |
|---|---|---|
| Diabetic ketoacidosis | Metabolism and nutrition disorders | 5 of 372 |
| Hyperglycaemia | Metabolism and nutrition disorders | 4 of 372 |
| Acute myocardial infarction | Cardiac disorders | 1 of 372 |
| Altered state of consciousness | Nervous system disorders | 1 of 372 |
| Bile duct obstruction | Hepatobiliary disorders | 1 of 372 |
| Cellulitis staphylococcal | Infections and infestations | 1 of 372 |
| Chest pain | General disorders | 1 of 372 |
| Death | General disorders | 1 of 372 |
| Gastric ulcer | Gastrointestinal disorders | 1 of 372 |
| Hypoglycaemia | Metabolism and nutrition disorders | 1 of 372 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Medtronic MiniMed 530G Insulin Pump |
|---|---|---|
| Hyperglycaemia | Metabolism and nutrition disorders | 10 of 372 |
| Puncture site haemorrhage | General disorders | 9 of 372 |
| Hypoglycaemia | Metabolism and nutrition disorders | 4 of 372 |
| Contusion | Injury, poisoning and procedural complications | 2 of 372 |
| Skin infection | Infections and infestations | 2 of 372 |
| Skin irritation | Skin and subcutaneous tissue disorders | 2 of 372 |
| Abscess limb | Infections and infestations | 1 of 372 |
| Cellulitis | Infections and infestations | 1 of 372 |
| Convulsion | Nervous system disorders | 1 of 372 |
| Dermatophytosis | Infections and infestations | 1 of 372 |
Serious events with the highest arm-level rate: diabetic ketoacidosis (1.3%), hyperglycaemia (1.1%), acute myocardial infarction (0.3%), altered state of consciousness (0.3%), bile duct obstruction (0.3%).
The adverse-event record lists one group, the Medtronic MiniMed 530G Insulin Pump group, with 372 subjects at risk for serious adverse events and 372 at risk for other adverse events. It reports 19 subjects affected by serious adverse events, 37 affected by other adverse events, and 3 deaths. These figures describe the registry’s safety entries; they do not by themselves establish that the device caused an event or death.
The registry also lists serious adverse-event terms with percentages: Diabetic ketoacidosis, 1.3%; Hyperglycaemia, 1.1%; Acute myocardial infarction, 0.3%; Altered state of consciousness, 0.3%; Bile duct obstruction, 0.3%; and Cellulitis staphylococcal, 0.3%. These are the terms and percentages recorded; the registry record does not explain the calculation or denominator for each listed percentage. The term-level entries should not be treated as a complete account of each participant’s clinical course.
General explanation: adverse-event counts describe events reported during a study period, while causal attribution requires a separate assessment. The record does not provide detail about event timing, severity criteria, relatedness assessments, or the circumstances of the deaths. It also does not describe a concurrent control group for comparing safety outcomes. The figures therefore provide a descriptive account of reported safety events in the study group, not a causal comparison.
12. What the Result Does, and Does Not, Mean
The registry record establishes that the study evaluated the Threshold Suspend feature of the Medtronic MiniMed 530G insulin pump in a single-group study of people with insulin-requiring diabetes. It identifies mean change in A1C from baseline to 1 year as the primary endpoint and states that the intended comparison used a non-inferiority test against the CEP 266 study population. It also gives the margin and significance level for that test.
The record does not report the numerical primary A1C change, its 95% confidence interval, or the non-inferiority result. It therefore cannot show the observed direction or size of the change, how precisely it was estimated, or whether the comparison met the stated criterion. The secondary A1C results are also not reported in the registry record. Without those outcome results, the posted information does not support a conclusion about the endpoint’s statistical or clinical meaning.
The study’s single-group design is another important boundary. The record says all subjects received the same pump and does not describe random assignment to a control group. The reference to CEP 266 indicates a planned comparison, but details needed to assess the comparability of the populations and the analysis are not reported. A change over time in one group is not equivalent to a randomized estimate of a treatment effect.
The record reports paired baseline and end-of-study A1C measurements for 298 enrolled subjects, but does not describe missing-data methods or the reasons measurements were unavailable. It also mentions commercial patient data without explaining their contribution to the analysis. These limits affect how completely the registry record can be used to interpret the primary question.
In short, the record describes the study question and some design and safety details, but not the primary efficacy result. It does not establish a treatment effect, nor does it allow a conclusion that the stated non-inferiority criterion was or was not met.
13. Why This Trial Matters Statistically
This study is statistically notable because its central question is framed as non-inferiority, while the study model is listed as single-group. A non-inferiority question depends on a clearly defined comparison and on estimates precise enough to evaluate a prespecified margin. The registry record names CEP 266 as the comparison population and specifies an A1C margin of 0.4%. Yet it does not describe the comparison population or report the result needed to evaluate the margin. This makes the relationship between the design and the stated question especially important to examine.
The record also highlights the distinction between enrollment and endpoint data. It lists 372 enrolled subjects and states that 298 had both baseline and end-of-study A1C. The difference between those records of participation cannot be interpreted without information about missing measurements, exclusions, and the analysis population. Those details are not reported in the registry record.
For clinical researchers, the case illustrates why a named endpoint and a planned test are not enough to establish what a trial found. The estimated change, confidence interval, comparator definition, and handling of incomplete measurements are needed to assess the result. Here, those primary numerical results are not reported in the registry record. The study title also refers to commercial patient data, but their role is not described, reinforcing the importance of transparent reporting about data sources and analysis populations.
The safety entries provide descriptive counts and listed event terms, but they are not a randomized comparison. Interpreting them requires caution about attribution, denominators, and event definitions, some of which are not detailed in the record. Overall, the registry record is useful for identifying the study’s question and key design features, while its missing outcome and analysis details limit statistical interpretation.
14. 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 central limitation for interpreting efficacy is that the registry record does not report the numerical primary endpoint result, its 95% confidence interval, or the non-inferiority test result. The stated margin and significance level describe the planned question, but they cannot establish the result. Secondary A1C results are not reported either.
The study is listed as single-group, with no randomized control arm described. Although the primary endpoint description refers to CEP 266, the record does not provide its population characteristics, outcome data, or the method used to make the comparison. The title mentions commercial patient data, but how those data were selected, combined, or analyzed is not reported in the registry record.
The record states that 298 enrolled subjects had both baseline and end-of-study A1C, but does not explain missing measurements, exclusions, or the final analysis population. It does not report a missing-data method or sensitivity analyses. Without this information, it is difficult to assess how incomplete measurements could affect the estimate.
Other analysis details are also not reported in the registry record, including the statistical model, covariate adjustments, multiplicity handling, and whether interim analyses occurred. The safety record gives counts and event terms but does not detail event timing, relatedness, or the denominator basis for the listed percentages. These limitations constrain assessment of both the study’s outcome findings and their precision. They should not be filled in by assumption.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Post Approval Study of the TS Feature With the 530G Pump System Supplemented With Commercial Patient Data — NCT02003898.
- Registry record last updated 2019-03-05; status last verified 2019-02.
- Results first posted 2019-03-05.
- 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.
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18. Record Summary
The registry record describes a completed, single-group study of the Medtronic MiniMed 530G insulin pump and its Threshold Suspend feature in people aged 16 and older with insulin-requiring diabetes. It lists 372 enrolled subjects and states that 298 had both baseline and end-of-study A1C measurements. The primary endpoint was mean A1C change from baseline to 1 year, with a stated non-inferiority comparison against the CEP 266 study population, a margin of 0.4%, and a one-sided significance level of 0.025.
The record does not report the numerical primary endpoint result, confidence interval, or non-inferiority test result. It also does not describe the role of commercial patient data, the comparison population in detail, or the approach to missing measurements and multiplicity. Safety entries include 19 subjects affected by serious adverse events, 37 affected by other adverse events, and 3 deaths. These are descriptive registry figures, not a randomized causal comparison.