Qingdao: Insulin Pump Follow-Up Program: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Qingdao: Insulin Pump Follow-Up Program (NCT02655666), a registered phase not stated study. The primary outcome is Change in Glycosylated Hemoglobin (A1C).

2. Clinical Question

The registry also lists continuous glucose monitoring measures, including average glucose, glucose variability, glycemic excursions, and events and area under the curve in hypoglycemic and hyperglycemic ranges. These are listed as secondary outcomes, but their results are not reported in the registry record. Consequently, the clinical question is described more clearly as a planned observation of device use and outcomes than as a test of efficacy against a comparator.

3. Trial Design

This registry record describes the Qingdao: Insulin Pump Follow-Up Program, sponsored by Medtronic MiniMed, Inc. The study began in 2015-04, had primary completion in 2016-09, and is marked TERMINATED. The registry lists enrollment of 16. The reason for termination and the number of participants who completed the study are not reported in the registry record.

The brief summary describes an observational aim: collecting clinical data, subject users’ feedback, and device data to better understand real-life usage and acceptance of the 722 Pump in people with type 1 diabetes younger than 18 years, and the role of insulin pump therapy in Qingdao, China. The described system includes an insulin pump, transmitter, and glucose sensor.

The primary outcome is change in glycosylated hemoglobin (A1C) from baseline to the end of the study, with the timeframe stated as 1 year. It is specified as a mean with standard deviation for subjects who completed the study. Secondary measures concern continuous glucose monitoring, including average glucose values, standard deviation and coefficient of variation of glucose values, mean amplitude of glycemic excursion, hypoglycemic and hyperglycemic events, and area under the curve in those ranges.

The registry lists 11 outcome measures and 0 analyses. It does not describe allocation, and it is not a randomized comparison; the arm descriptions do not establish a like-for-like control comparison. Details such as the recruitment process, follow-up schedule, protocol deviations, and reason for termination are not reported in the registry record. The design should therefore be read as a registry-described follow-up program, not as a controlled efficacy trial.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Subject completed the study.

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 Change in Glycosylated Hemoglobin (A1C), measured over Change in A1C from baseline to end of study (1 year).

The primary endpoint is change in glycosylated hemoglobin (A1C), with the unit recorded as percent Glycosylated Hemoglobin. The timeframe is change from baseline to the end of the study (1 year). The registry says the change will be presented as a mean with standard deviation, for subjects who completed the study.

In general, measuring change compares an outcome at follow-up with its baseline value; the resulting estimate describes the average change in the analyzed population. The standard deviation describes how much individual observations vary around that average. It is not the uncertainty around the estimated average: that requires an inferential measure such as a confidence interval, which is not reported in the registry record.

The registry identifies A1C change as the primary endpoint but does not give a rationale for selecting it, specify whether the change is calculated as follow-up minus baseline, or report an observed mean or standard deviation. It also does not report how many study completers had measurements at both time points. Without those results and analysis details, the direction, size, and precision of the endpoint change cannot be assessed.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean and standard deviation describe?

The primary outcome is a continuous measure, and the registry specifies a mean and standard deviation. In general, the mean describes the center of a set of measurements. The standard deviation describes the spread of individual values around that center. These answer different questions: a mean change characterizes the average shift in the analyzed group, while the standard deviation characterizes variability among participants. Neither statistic, by itself, communicates how precisely the mean has been estimated.

For an endpoint defined as change from baseline, each analyzed participant’s follow-up measurement is compared with that participant’s baseline measurement, and the group summary describes the resulting changes. In general, a confidence interval around the mean change would indicate the range of values reasonably compatible with the data under the analysis assumptions. No confidence interval or observed mean change is reported in the registry record, so the endpoint’s precision cannot be assessed.

What can be inferred from a change over time?

In general, a before-and-after change describes the observed course in the analyzed participants. A controlled comparison is needed to distinguish a treatment-related effect from other explanations, such as changes over time or differences among participants. This record is identified as not a randomized comparison, allocation is not stated, and a like-for-like control comparison is not described. Thus, even if a change estimate were reported, it would not by itself establish that the device caused that change.

The record specifies that the primary analysis population is subjects who completed the study. This is a population definition, not a complete description of the analysis. The registry does not report how completion was determined, how many participants completed, whether all completers had endpoint measurements, or how missing measurements were handled. These details matter because an analysis limited to completers can differ from an analysis that includes everyone enrolled.

Why do uncertainty and analysis details matter?

A point estimate alone gives a single summary of the observed data. A confidence interval adds information about statistical uncertainty, while a test statistic or p-value addresses compatibility with a specified null hypothesis under a specified model. Neither replaces judgment about study design, measurement, or relevance. The registry record reports no analyses, so it provides no inferential result for the primary endpoint or secondary outcomes. The analysis method, model, covariate adjustment, and handling of repeated measurements are not reported in the registry record.

For continuous glucose monitoring outcomes, the record lists measures of central tendency, variability, excursions, event counts, and area under the curve. In general, glucose measurements can be variable, and repeated observations from the same person are not necessarily independent. Statistical methods may need to account for that structure. The registry does not report the data-aggregation rules, monitoring duration, event definitions, or analysis method, so those features cannot be evaluated for this study.

How should the planning illustrations be read?

The stated planning assumptions describe illustrations based on an observed effect, rather than the study’s own design justification. They specify a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect to detect expressed as a stated fraction of the observed effect. Such calculations are prospective planning aids: they illustrate the number of participants per arm that might be needed under those assumptions. They are not observed power and do not establish that the study was adequately sized.

The registry record does not report its own sample-size justification. It also does not report a primary endpoint effect estimate from which to evaluate the planning illustrations. In general, sample-size calculations depend on assumptions about the effect, variability, significance level, allocation, and analysis. When those assumptions differ from the eventual study or the actual analysis, the resulting planning figure may not describe the information available in the completed study. The trial’s stated enrollment of 16 does not convert a planning calculation into evidence about statistical power or the endpoint result.

What does the safety summary measure?

Adverse-event summaries are descriptive counts of events or participants meeting the registry’s reporting definitions. The record lists 16 at risk for serious adverse events, 2 affected, and 0 deaths in the system group. It separately lists 16 at risk for other adverse events and 0 affected. These figures do not establish whether an event was caused by the device, and the registry does not describe event adjudication, severity criteria, or exposure time. General statistical caution is warranted when interpreting event counts from a follow-up program without a comparator and without fuller event-level information.

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("Medtronic MiniMed Paradigm® REAL-Time System")
n   <- c(4)
m   <- c(0.9)
sp  <- c(2.22)
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  Medtronic MiniMed Paradigm® REAL-Time System  4  0.900  2.220  -2.633  4.433

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 11 outcome measures, including the primary A1C change endpoint and secondary continuous glucose monitoring measures. When multiple outcomes are examined, the chance of at least one apparently notable result can increase if each is tested without accounting for the number of analyses. In general, a prespecified testing strategy or multiplicity adjustment can help address that issue. The registry does not report whether any adjustment was planned, which outcomes were formally tested, or how outcome priority was handled beyond identifying the primary endpoint.

The record lists 0 analyses. It therefore reports no outcome estimates, tests, or intervals for the primary or secondary measures. Interim analyses and stopping rules are not reported in the registry record. The TERMINATED status does not, by itself, establish whether an interim analysis occurred or why the study stopped.

The primary population is described as subjects who completed the study, but the number of completers and the number with observed endpoint measurements are not reported. The registry does not describe missing-data patterns, reasons for missingness, imputation, sensitivity analyses, or whether participants were analyzed according to any alternative population definition. These omissions limit assessment of selection and missing-data bias. Enrollment of 16 cannot be treated as the endpoint analysis denominator without a reported analysis population.

In general, missing-data methods rely on assumptions about why measurements are unavailable. If those assumptions are not described, the robustness of an estimate to missing outcomes cannot be evaluated. For this record, the missing-data approach and the analysis populations beyond the stated completer population are not reported in the registry record.

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

Serious events with the highest arm-level rate: severe hyperglycemia (6.2%), hyperglycemia (6.2%).

The registry lists the Medtronic MiniMed Paradigm® REAL-Time System group with 16 at risk for serious adverse events and 2 affected. It reports 16 at risk for other adverse events and 0 affected, with 0 deaths. These are descriptive registry counts. They should not be read as a comparison between treatment groups, because the record does not describe a like-for-like control comparison.

The top serious-event terms are Severe Hyperglycemia at 6.2% and hyperglycemia at 6.2%. The record does not explain the denominators or event-counting details behind these term percentages. It also does not report whether the terms overlap, so they should not be added together or interpreted as separate participant groups. No event-level timing, duration, outcome, or causal attribution is reported in the registry record.

In general, safety counts describe reported events under the registry’s definitions; they do not alone establish causation or characterize risk relative to another treatment. The posted counts are limited by the follow-up information and event details available in the record.

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

This record establishes that a follow-up program was registered to collect clinical, user-feedback, and device data about real-life use of the 722 Pump system in people with type 1 diabetes younger than 18 years in Qingdao, China. It names change in A1C from baseline to the end of the study (1 year) as the primary endpoint and identifies subjects who completed the study as the primary population. It also lists continuous glucose monitoring outcomes.

It does not establish the observed size or direction of A1C change. No primary outcome estimate, standard deviation, confidence interval, or analysis result is reported. The record also does not report results for the listed secondary measures. Without those results, neither the magnitude nor the precision of any outcome change can be assessed.

The design information does not support a controlled causal comparison: the study is not randomized, allocation is not stated, and the arms are not a like-for-like control comparison. The listed safety counts and serious-event terms are descriptive and do not establish whether the device caused an event or how its safety compares with another approach.

The registry’s TERMINATED status is a record-status description, not an explanation of why the study ended or whether all planned observations were completed. The reason for termination and completion details are not reported in the registry record. The appropriate interpretation is therefore limited: the record describes a planned real-life follow-up program and reports selected adverse-event counts, but it does not provide efficacy estimates or comparative evidence.

14. Why This Trial Matters Statistically

Statistically, this study matters as an example of why registry aims and registry results must be distinguished. The record describes an observational follow-up program, names a primary endpoint, and lists secondary measures, but reports 0 analyses. A clearly specified endpoint does not itself supply an estimate, and enrollment does not show how many participants contributed outcome data.

The intended endpoint is a change measure summarized by a mean and standard deviation. Those statistics would describe the average change and the spread of individual changes, but interpretation also requires the analysis population, missing-data handling, and a measure of uncertainty. The record does not report those outcome results or analysis details. This leaves the reader unable to assess precision, clinical magnitude, or consistency across participants.

The design is also important to interpretation. A nonrandomized follow-up without a like-for-like control can describe observations during device use, but cannot isolate the device’s effect from other explanations for changes over time. The registry’s safety information is similarly descriptive; its counts and event terms are not comparative risk estimates.

Finally, a terminated study status cannot substitute for an explanation of study conduct. Without a reported reason for termination, completion information, or results, it is not possible to determine whether the planned observations were fully captured or why analyses are absent. These limitations make transparent reporting of participant flow, outcome estimates, uncertainty, and analysis methods essential for readers evaluating 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 record does not report the primary endpoint result, although it defines change in A1C as the primary outcome. No mean change, standard deviation, confidence interval, or p-value is available. The 0 analyses listed also mean that the secondary continuous glucose monitoring outcomes have no posted analysis results in the registry record.

The registry lists enrollment of 16 but does not state the number who completed the study or contributed measurements. Because the primary population is described as subjects who completed the study, the absence of completion and missing-data details makes it impossible to determine the analysis denominator or assess potential bias from incomplete follow-up.

The study is not a randomized comparison, allocation is not stated, and the arm descriptions do not define a like-for-like control comparison. As a result, the design information does not support attributing any possible change over time to the system. The record also does not report the reason for termination, the recruitment process, protocol deviations, or whether the planned follow-up was completed.

Outcome measurement and analysis details are limited. The registry does not report the A1C calculation convention, monitoring duration or data-processing rules for continuous glucose monitoring outcomes, event definitions, statistical model, missing-data approach, or multiplicity strategy. Safety reporting is limited to selected counts and terms; event-level descriptions and causal assessments are not reported. These gaps constrain assessment of both the outcome evidence and the completeness of reporting.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Qingdao: Insulin Pump Follow-Up Program — NCT02655666.
• Registry record last updated 2019-07-11; status last verified 2019-04.
• Results first posted 2018-09-21.
• 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 Qingdao: Insulin Pump Follow-Up Program is a terminated registry study sponsored by Medtronic MiniMed, Inc., with enrollment of 16. It describes collection of clinical data, user feedback, and device data for real-life use of the Medtronic MiniMed Paradigm® REAL-Time System in people with type 1 diabetes younger than 18 years.

The planned primary endpoint is change in A1C from baseline to the end of the study (1 year), summarized as a mean with standard deviation among subjects who completed the study. The registry lists 11 outcome measures and 0 analyses. It reports no primary or secondary outcome estimates.

The safety record lists 2 affected by serious adverse events among 16 at risk, 0 affected by other adverse events, and 0 deaths. Severe Hyperglycemia and hyperglycemia are each listed at 6.2%. The study is not a randomized comparison, allocation is not stated, and a like-for-like control comparison is not described.