Prospective Study of the Impact of Insulin Pump Therapy in Young Children With Type 1 Diabetes: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Prospective Study of the Impact of Insulin Pump Therapy in Young Children With Type 1 Diabetes (NCT00727220), a registered phase not stated study. The primary outcome is Change in HgBA1c.

2. Clinical Question

The study description frames the comparison as an examination of glycemic and neuropsychological outcomes among young children starting pump therapy and children not using pumps. It also lists blood sugar variability, cognitive outcomes, parenting stress, and changes in diet as areas of interest. These aims describe the broader study, but the record lists one outcome measure and does not report results for the broader set of aims.

This is not a randomized comparison: the record says children and their primary diabetes physician chose the insulin regimen for clinical use. Allocation is not stated. Consequently, the study question is about outcomes in groups receiving different regimens in practice, rather than a comparison in which assignment to treatment is reported as randomized.

3. Trial Design

The registry describes a prospective study sponsored by Indiana University. Its title concerns insulin pump therapy in young children with type 1 diabetes, and its brief description says the study would examine glycemic and neuropsychological outcomes. The listed enrollment is 42. The study description proposes assessing 40 children, with groups defined by the regimen they were using or starting.

The arm descriptions identify children starting insulin pump therapy and children remaining on insulin injections. The brief description further outlines injection regimens involving basal glargine or NPH or Lente with rapid-acting insulin. It says the regimen would be chosen by the child’s family and primary diabetes physician, and that the study team would not change it. The registry’s skip note cautions that the comparison is not randomized and that the arms are not a like-for-like control comparison.

The study is listed as completed. The registry gives a start date of 1999-11 and a primary completion date of 2003-04. The brief description says the pump group would be examined before and 12 months after pump implementation. Separately, the registered primary outcome specifies a baseline and 6 months timeframe. The record does not explain how these timeframes relate to each other.

Only one outcome measure is listed, and no analyses are listed. The registry record does not report a statistical analysis plan, sample-size justification, interim analyses, or methods for handling missing observations. It also does not report numerical primary outcome results. The listed enrollment and the proposed number in the study description should therefore be read as separate registry statements, not as a reported analysis population.

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

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 HgBA1c, measured over Baseline and 6 months.

The registered primary endpoint is “Change in HgBA1c,” with the unit given as percentage of glycosylated hemoglobin. The registry specifies a mean as the parameter and standard deviation as the measure of dispersion, with a timeframe of baseline and 6 months. It does not give a numerical change, group means, standard deviations, or a comparison between groups.

As a general statistical point, a mean describes the central value of a continuous measurement across observations. A standard deviation describes how spread out individual observations are around that mean. Reporting both can help readers understand not only the average measurement but also how much participants’ measurements vary. Neither measure alone establishes whether a difference between groups is precise or whether it could plausibly reflect sampling variation.

The study description identifies glycemic outcomes as an aim, including overall control and blood sugar variability. The registered endpoint focuses on change in glycosylated hemoglobin; it is not a direct report of every glycemic measure named in the broader description. The registry record does not define the calculation of “change,” specify the analysis population, or explain how values from baseline and follow-up would be combined or compared. It also does not report the outcome data needed to interpret the magnitude or precision of any change.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The record identifies the primary measure as continuous, summarized by a mean with standard deviation. It does not report an inferential analysis for that outcome. The explanations below describe general statistical concepts; they are not a description of methods confirmed to have been used in this study.

What does a mean with standard deviation describe?

In general, the mean is a way to summarize the central value of a continuous measurement across participants. The standard deviation describes the spread of measurements around that mean. A mean can make group summaries easier to compare, while the standard deviation gives context about variability among participants. These summaries do not, by themselves, show how precisely a group difference has been estimated. Precision also depends on the amount of information contributing to the estimate and the analysis used.

The registry specifies a change outcome at baseline and 6 months but does not state whether the reported mean would be a mean of individual changes, a difference between group means at follow-up, or another contrast. These approaches answer related but not identical questions and can rely on different assumptions. The registry record does not report which approach was used, nor does it provide the underlying measurements or summary estimates from which to assess it.

What would a group comparison need to clarify?

In general, a comparison of two groups should make clear which quantity is being compared, how participants are included, and how uncertainty is quantified. A point estimate describes the estimated contrast, while a confidence interval gives a range of values compatible with the data and the method’s assumptions. A p-value, when reported, addresses compatibility with a specified null model; it is not a measure of effect size or clinical importance. The registry record lists no analysis results, confidence intervals, or p-values for the primary outcome.

Because the study is not described as randomized, a group contrast may reflect both regimen differences and pre-existing differences between children. In general, adjustment for measured baseline characteristics can address some differences, but cannot guarantee removal of confounding, especially from characteristics that were not measured or included. The record does not report a model, covariates, adjustment procedure, or other strategy for dealing with such differences. It would be inappropriate to infer that any particular adjustment was performed.

How should the planning assumptions be understood?

The record includes assumptions for a planning illustration: two-sided significance level 0.05, equal allocation between the two arms, and a normal approximation. It describes the effect to detect as a stated fraction of the observed effect. These are assumptions for a planning calculation, not a report of the trial’s own design justification or an analysis of the observed data. The record does not report a sample-size justification from the study team, and the planning assumptions should not be treated as evidence that the study achieved a particular level of power.

In general, sample-size planning estimates how much information might be needed to detect a chosen effect under stated assumptions. The result depends on the effect targeted, variability, allocation, and statistical method. A planning illustration based on an observed effect is not the same as observed power and does not establish the precision of the actual trial estimate. The registry record does not report numerical primary outcome estimates alongside which to interpret the planning illustration.

Why can variability matter?

In general, greater variability in a continuous outcome makes a group contrast harder to estimate precisely when other features are unchanged. If a measure has a distribution with more variation than a simple model assumes, methods that rely on that model may understate uncertainty. This is the general concern behind over-dispersion: observed variation exceeds what a model expects. The record does not report an over-dispersion assessment or indicate that such a model issue arose in this study.

For a mean-based outcome, the standard deviation is one descriptive way to show variation. For a count outcome, an analysis might need to account for how counts vary relative to model assumptions. The registered primary outcome is continuous, so the registry’s description does not establish that a count model or an over-dispersion correction was used. No such model details are reported.

What can be concluded from the analysis listing?

The registry lists one outcome measure and zero analyses. This means the record does not contain a posted statistical analysis of the primary outcome. It does not establish whether analyses were conducted outside the registry record. No statistical model, test, treatment-effect estimate, confidence interval, p-value, or sensitivity analysis is reported. Consequently, general explanations of statistical methods should not be mistaken for methods documented as used by the study.

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("Insulin Pump Therapy", "Insulin Injections")
n   <- c(20, 17)
m   <- c(8.5, 8.7)
sp  <- c(0.6, 0.7)
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  Insulin Pump Therapy  20  8.500  0.600  8.219  8.781
CARM  Insulin Injections  17  8.700  0.700  8.340  9.060

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one outcome measure, titled “Change in HgBA1c,” and zero analyses. The study description names broader areas of interest, including blood sugar variability, cognitive outcomes, parenting stress, and changes in diet, but the record does not list those as additional outcome measures with results. It does not report a multiplicity strategy, such as a prespecified hierarchy or adjustment for testing multiple outcomes. No claim can be made about whether multiplicity was addressed outside the registry record.

In general, multiplicity arises when multiple outcomes, timepoints, subgroups, or statistical tests are examined. Considering many results can increase the chance that at least one appears notable by chance. A prespecified analysis plan can help readers distinguish primary questions from exploratory ones, while an adjustment may be used for some families of tests. The registry record does not report which outcomes or comparisons were prespecified beyond identifying the primary outcome.

The record does not report missing-data counts, reasons for missingness, or a method for handling missing observations. It also does not state how many children contributed baseline and 6-month values, whether follow-up was complete, or whether any participants were excluded from the primary analysis. Therefore, the listed enrollment cannot be assumed to be the analysis population.

In general, missing outcome data can affect both the amount of information available and the interpretation of a group comparison. Complete-case analysis, imputation, and other approaches rely on different assumptions; no approach is identified in the record. The analysis population is also not reported, so it is not possible to determine whether participants were analyzed according to their original group, their regimen during follow-up, or another definition.

12. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

The adverse-event record lists two groups: Insulin Pump Therapy and Insulin Injections. For each group, 21 participants are listed as at risk for serious adverse events, with 0 affected. The record also lists 21 at risk for other adverse events in each group, with 0 affected. These are counts as reported in the registry record; they are not an analysis of comparative risk.

The deaths field is null for both groups, and the registry record does not report deaths. A null entry should not be read as a reported count of zero. The record lists no serious adverse-event terms among the top serious terms.

In general, “at risk” describes the group size used for the adverse-event listing, while “affected” is the reported count with an event in the corresponding category. Zero affected in a registry entry does not establish that no events occurred outside the reporting scope or period represented by the entry. The record does not provide further detail about collection, event definitions, follow-up duration for safety reporting, or completeness of reporting.

These figures should be read separately from the primary endpoint. They do not provide numerical results for change in HgBA1c, and the registry record does not report a statistical comparison of adverse events between groups.

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

The registry record documents a prospective study of children with type 1 diabetes in which insulin regimens were chosen clinically. It identifies insulin pump therapy and insulin injections as the two arms and names change in HgBA1c at baseline and 6 months as the primary outcome. It also records adverse-event counts for both groups. These details describe the study and its registered outcome, but they do not include numerical efficacy results.

The record does not report the mean change in either group, the difference between groups, a measure of uncertainty, or a statistical test. Thus, the posted record does not show whether the primary outcome increased or decreased, how large any change was, or how precisely it was estimated. The outcome name and timeframe alone cannot answer those questions.

The comparison is not randomized according to the registry note. The study description says that families and their primary diabetes physician chose the regimen, and the record does not state allocation. In general, results from such a comparison can be influenced by differences between the groups beyond their regimen. Without reported outcome estimates and analysis details, even an association cannot be characterized from the registry record.

The listed serious and other adverse-event counts are zero affected in both groups, with 21 participants at risk in each. The deaths field is not reported in the registry record. These entries describe the recorded safety counts but do not resolve the missing primary outcome results or establish the completeness of adverse-event collection.

More broadly, the study description mentions cognitive outcomes, parenting stress, diet, and blood sugar variability, but no results for those aims are reported. The registry record therefore supports a careful account of the study’s question, group formation, endpoint, and reporting gaps. It does not support a conclusion about treatment benefit, lack of benefit, or comparative safety.

14. Why This Trial Matters Statistically

This study is statistically notable because its groups reflect treatment choices made in clinical care rather than a reported randomized assignment. That design can describe outcomes among children using different regimens, but interpretation of a between-group difference would need to consider how the groups came to receive those regimens. The registry note explicitly warns that the arms are not a like-for-like control comparison.

The record also distinguishes a broad study description from a narrower registered primary outcome. The brief description names glycemic, cognitive, parenting, and dietary aims, while the registry lists one outcome measure: change in HgBA1c. Keeping those distinctions clear helps readers avoid treating planned areas of inquiry as reported results.

Another statistical issue is the difference between a registered question and a reported answer. The outcome is described with a mean and standard deviation, but no numerical endpoint result or analysis is listed. Without an estimate and an uncertainty measure, readers cannot assess the size or precision of a group contrast. The absence of those statistics is itself important context for interpreting the record.

Finally, the study description mentions an assessment before and 12 months after pump implementation, while the registered primary outcome gives baseline and 6 months. The record does not reconcile these timeframes. Recognizing that unresolved timing detail is important because an outcome estimate is meaningful only when its measurement schedule and comparison are clear.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The main limitation for statistical interpretation is that the registry record reports no numerical primary outcome results and lists zero analyses. It is therefore not possible to assess the size, direction, or precision of change in HgBA1c, or to determine whether a group comparison was performed.

The study is not described as randomized, and allocation is not stated. The brief description says regimen choices were made clinically by families and their primary diabetes physician. This creates the possibility of differences between groups that could influence outcomes. The record does not report baseline group characteristics, adjustment methods, or an approach to confounding.

The record gives enrollment of 42, while the study description proposes assessing 40 children. It does not report how many participants were analyzed for the primary outcome, how many completed follow-up, or whether the analysis population differed from the enrolled population. Missing-data handling is not reported.

The registered primary outcome timeframe is baseline and 6 months, while the study description refers to assessment before and 12 months after pump implementation. The record does not explain the relationship between these timeframes. It also does not provide a definition of the change calculation or say how repeated measurements were analyzed.

The brief description names several broader outcome areas, but the registry lists one outcome measure and no analyses. Multiplicity methods and results for the broader aims are not reported. Adverse-event entries contain counts but little information about event definitions, collection, or completeness. These reporting gaps limit what can be concluded from the registry record, independently of the study’s stated objectives.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Prospective Study of the Impact of Insulin Pump Therapy in Young Children With Type 1 Diabetes — NCT00727220.
• Registry record last updated 2017-05-19; status last verified 2017-05.
• Results first posted 2017-05-19.
• 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 prospective study sponsored by Indiana University, with a listed enrollment of 42 and a start date of 1999-11. The primary completion date is 2003-04. The study concerns young children with type 1 diabetes and compares children starting insulin pump therapy with children remaining on insulin injections.

The study description says regimens were chosen clinically and would not be changed by the study team. The registry notes that this is not a randomized comparison and that the arms are not a like-for-like control comparison. The primary outcome is change in HgBA1c, measured as a mean with standard deviation, at baseline and 6 months.

The registry lists one outcome measure and zero analyses. It does not report numerical primary outcome results, analysis methods, missing-data handling, or a statistical analysis plan. Serious and other adverse-event entries list 0 affected in each group, with 21 at risk per group; deaths are not reported in the registry record.