Comparison of 3 Versus 6-Month Use of CGMS in Non-Insulin Using T2DM Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Comparison of 3 Versus 6-Month Use of CGMS in Non-Insulin Using T2DM Patients (NCT03067480), a randomized na study. The primary outcome is Time Spent in Target Range.

2. Clinical Question

This is a comparison of two CGM-use durations, not a comparison of CGM with no CGM. Both arms are described as receiving professional CGM; their named distinction is the 3-month or 6-month duration. The research question focuses on a glucose-monitoring measure rather than a clinical event or a patient-reported outcome.

The record describes the intended population as poorly controlled, non-insulin using patients with type 2 diabetes. It does not report how poor control was defined, how participants were recruited, or whether the posted outcome population retained the original eligibility characteristics. Those details are not reported in the registry record.

3. Trial Design

NCT03067480 is a randomized, parallel-group trial with no masking. Its title describes a comparison of 3 versus 6-month use of professional CGM in non-insulin using patients with type 2 diabetes. The listed intervention is the iPro2 Professional CGM, and the two arms are the 3-Month and 6-Month iPro2 Professional CGM groups. No separate usual-care or no-device arm is listed.

The registry record lists enrollment as 12. The posted primary outcome includes 2 participants in the 3-month arm and 2 in the 6-month arm. These outcome counts are smaller than the enrollment figure, but the record does not explain the difference or report why outcome values are absent for other enrolled participants. It also does not report the analysis population or how participants were allocated in practice.

The study start date is 2017-06-06, and primary completion is listed as 2019-09-30. The current status in the record is terminated. The reason for termination and whether termination affected the planned study procedures are not reported in the registry record. The phase is listed as NA.

The professional CGM description says interstitial glucose was measured every 5 minutes during a 3 day period. The wearer was blinded to the repeated measurements, and the data were stored for retrospective analysis. Both arm descriptions give this same device procedure. More detailed information about when device periods occurred, how often they were repeated, adherence, co-interventions, randomization procedures, or masking of outcome assessment is not reported in the registry record.

The record lists one outcome measure and zero analyses. It gives descriptive results for the primary outcome, but no inferential comparison, confidence interval, or analysis plan. The sample-size assumptions described for planning illustrations are not the trial's own design justification; the trial's sample-size justification 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

Reasons for not completing this 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.

6. Primary Endpoint

The registry lists the primary outcome as Time Spent in Target Range, measured over 6 Months.

The primary endpoint is time spent in the target range, recorded as a percentage. It is defined as the time sensor glucose is between 70-140mg/dl during a 72 hour collection period, with the timeframe listed as 6 Months. The device description states that professional CGM measures interstitial glucose every 5 minutes during a 3 day period, allowing a record of glucose values across the collection window rather than a single measurement.

A time-in-range measure describes how much of the monitored period falls within a prespecified glucose interval. As a general statistical interpretation, this can summarize patterns across repeated measurements and can distinguish groups whose averages of individual readings alone might not describe the same distribution over time. The endpoint is reported as a mean and standard deviation, so the posted group summaries describe an average percentage and the observed spread of participant values within each group.

The record does not explain why 70-140mg/dl was selected, how the measure was operationalized beyond the stated interval and collection period, or whether any sensor-data quality rules were applied. Such details are not reported in the registry record. The endpoint is a measure of sensor glucose exposure during a monitoring window; it is not itself a measure of a clinical event or of longer-term health outcomes.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a continuous measure summarized by a mean and standard deviation. A mean expresses the average outcome across the participants included in a group summary. A standard deviation describes the observed spread of individual values around that mean. It is not the same as the uncertainty in the mean, and it does not by itself provide a confidence interval or determine whether a group comparison is statistically significant.

The posted summaries are 38.5 with standard deviation 18.5 for the 3-month arm and 50.0 with standard deviation 40.0 for the 6-month arm. Each summary is based on 2 participants. Those small counts make the means and standard deviations especially sensitive to the observations included. A standard deviation calculated from a very small group may be a poor guide to the variability that would be seen in a larger population. The record does not post participant-level values, so the shape of the outcome distribution cannot be assessed.

What would a confidence interval add?

As a general statistical concept, a confidence interval gives a range of values compatible with an estimate under the assumptions of the analysis. For a randomized comparison, an interval around the between-group effect can communicate both the estimated direction and the precision of that estimate. A narrow interval indicates greater precision than a wide interval, while an interval spanning values on either side of no difference can indicate that the data do not pin down the direction or magnitude well. No confidence interval for the comparison is reported in the registry record.

Likewise, a p-value is not a measure of effect size or clinical importance. In general, it summarizes how unusual data at least as incompatible with a stated null hypothesis would be under a specified statistical model. Its interpretation depends on the test, the model, and the analysis plan. The registry record reports zero analyses and gives no p-value or statistical test for the primary outcome. The posted means and standard deviations should therefore not be treated as evidence of a statistically established difference.

Why does the small outcome count matter?

With few observations, estimates of both the group average and its variability are unstable. General methods for comparing continuous outcomes often rely on assumptions about the outcome distribution, the independence of observations, and the way missing values are handled. The record does not state which method, if any, was planned for the primary comparison. It also does not report whether the assumptions of a particular model were checked. The difference between total enrollment and the number with posted primary outcome values makes information about missingness and analysis population important.

Random allocation is intended, in general, to make treatment groups comparable on average at the start of a study. It does not guarantee balance in every realized sample, especially when the number of participants is small. The registry record identifies the study as randomized but does not report the sequence-generation or allocation-concealment procedures. It is therefore not possible to assess those implementation details from the record.

How should planning calculations be understood?

Planning sample-size illustrations are distinct from the results of the trial. The stated planning approach uses a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the effect to detect defined as a fraction of the observed effect. These are assumptions for an illustrative calculation, not evidence that the trial was designed with those assumptions or that the target sample size was achieved. The trial's own sample-size justification is not reported in the registry record.

As a general principle, a planning calculation asks how many participants might be needed for a future study to have a specified probability of detecting an effect under chosen assumptions. It does not show the probability that the observed result is true, and it is not a measure of the evidential strength of this trial. Calculations based on an effect observed in a very small sample can be particularly uncertain because that observed effect may not closely represent the underlying effect. Such planning values should be interpreted as illustrations, not as observed power.

The registry record does not provide inferential analyses, uncertainty intervals, a statistical analysis plan, or details of any adjustment. The statistical methods actually used for the reported means are not reported in the registry record. In the absence of those details, the most defensible reading is descriptive: the two group means and their reported spreads characterize the participants with posted outcome values, while leaving the comparative effect and its precision unresolved.

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("3-Month iPro2 Professional CGM", "6-Month iPro2 Professional CGM")
n   <- c(2, 2)
m   <- c(38.5, 50)
sp  <- c(18.5, 40)
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  3-Month iPro2 Professional CGM  2  38.500  18.500  -127.716  204.716
CARM  6-Month iPro2 Professional CGM  2  50.000  40.000  -309.386  409.386

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists one outcome measure and zero analyses. It does not report secondary posted outcomes. With only one listed outcome, there is no record-based list of multiple endpoint tests to describe. However, the registry record does not state whether other outcomes were collected, whether additional analyses were conducted outside the registry, or whether any multiplicity adjustment was planned. Those details are not reported in the registry record.

Multiplicity is a general statistical concern when many outcomes, time points, subgroups, or analysis choices are examined. The more opportunities there are to select a result for emphasis, the greater the chance that a striking finding can arise by chance. Adjustments or a prespecified hierarchy can help manage this concern, but no such approach is reported for this trial. The absence of posted analyses does not establish that no analyses were performed; it means the registry record does not describe them.

The primary outcome is posted for 2 participants in each arm, while enrollment is listed as 12. The registry record does not state why outcome values are unavailable for the remaining enrolled participants, how missing data were handled, or whether those without posted values were excluded from the analysis. It does not report an intention-to-treat or per-protocol population, participant flow, or the number randomized to each arm. These details are not reported in the registry record.

As a general principle, missing outcomes can affect interpretation if the likelihood of missingness is related to the outcome or to group assignment. Even when missingness is unrelated, fewer observations generally mean less precise estimates. Without reasons for missingness and a defined analysis population, readers cannot determine whether the posted summaries represent all randomized participants or a subset selected by availability of outcome data.

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.

The registry record reports serious adverse events for 0 of 5 participants at risk in the 3-month arm and 0 of 7 participants at risk in the 6-month arm. It also reports other adverse events for 0 of 5 and 0 of 7 participants at risk, respectively. Deaths are reported as 0 in both groups. No top serious adverse event terms are listed.

These figures describe events recorded in the registry, not a guarantee that an event could not occur. The denominators for the safety figures differ from the primary-outcome counts of 2 participants per arm. The record does not explain the safety-population definitions or why these counts differ. The duration and completeness of safety follow-up, methods of event collection, and criteria for judging relatedness are not reported in the registry record.

As a general statistical point, observing zero events in a group does not prove that the underlying event risk is zero. Safety estimates based on small groups are imprecise, and the posted figures do not support a precise comparison of event risks between arms. They should be read as the recorded event counts and denominators, rather than as evidence that the groups have identical safety profiles.

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

The posted results establish that the registry record contains descriptive time-in-range summaries for two participants in each randomized arm. The reported mean is 38.5 percentage points in the 3-month arm and 50.0 percentage points in the 6-month arm, with standard deviations of 18.5 and 40.0, respectively. The summaries describe those participants' recorded sensor-glucose outcomes during the stated collection period.

They do not establish the size or precision of a population-level difference. No confidence interval, p-value, or inferential analysis is reported. The small outcome counts, the absence of participant-level values, and the unexplained difference between enrollment and outcome counts all constrain interpretation. The reason the trial is listed as terminated is not reported in the registry record.

The record also does not support conclusions about outcomes beyond the measured time in target range, about longer-term glycemic patterns, or about clinical events. The endpoint is a sensor-based measure during a 72 hour period; it is not a direct measure of every aspect of diabetes management or health. The record does not explain the relationship between the listed 6 Months timeframe and the timing of the collection period in relation to each arm's assigned duration.

As a general principle, a randomized design can support causal comparisons when implementation, follow-up, and analysis are appropriately described and conducted. The registry record identifies randomization but does not include enough methodological detail to assess these features fully. The descriptive results should therefore be separated from any stronger claim about the effect of assigning one duration rather than the other.

The most appropriate conclusion is limited: the posted outcome summaries differ numerically, but their uncertainty and representativeness are not established by the registry record. They do not by themselves show that one duration produces a reliably different result, nor do they show that the two durations are equivalent.

14. Why This Trial Matters Statistically

This trial is statistically notable because its registry record pairs a randomized two-arm design with a very small number of participants contributing to the primary outcome. Randomization is a useful design feature, but it cannot remove the uncertainty created by having only 2 outcome observations per arm. The posted means and standard deviations are therefore best understood as descriptive summaries rather than precise estimates of a comparative effect.

The contrast between total enrollment of 12 and the primary-outcome count of 2 per arm makes transparent reporting of participant flow especially important. Knowing who was randomized, who contributed outcome data, and why other values are absent can help readers assess missing-data risk and the relevance of the analyzed group. Those explanations are not reported in the registry record.

The endpoint also illustrates a common feature of continuous monitoring research: repeated sensor readings are summarized into an outcome for each participant, and the comparison is then made across participants. In general, many readings within one person do not replace the need for an adequate number of independent participants. The registry record does not describe the analysis of the repeated readings beyond defining the percentage of time in the target interval.

Finally, the record illustrates why planned sample-size calculations and observed results must be kept distinct. An illustrative calculation based on an observed effect is not a justification for the trial's enrollment and does not make a small observed sample more conclusive. Clear reporting of design assumptions, analysis populations, missing outcomes, and uncertainty would be needed to interpret the comparison more fully. These statistical considerations matter regardless of the direction of the posted means.

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 principal limitation of the posted outcome is the small number of observations: 2 participants in each arm contribute to the reported primary outcome, although enrollment is listed as 12. The record does not explain the gap, identify the participants represented in the summaries, or report reasons for missing outcome values. It is therefore not possible to assess whether the outcome population represents all randomized participants.

No inferential analysis is posted. There is no reported confidence interval, p-value, adjusted estimate, or model description for the primary comparison. The record also does not report a statistical analysis plan, the randomization procedure, allocation concealment, or the planned approach to missing data. These details are not reported in the registry record.

The trial is listed as terminated, but the reason for termination is not reported in the registry record. The record does not describe whether termination was related to recruitment, feasibility, safety, or another cause; no explanation should be inferred. The study start and primary completion dates are recorded, but dates alone do not explain the conduct or completion of follow-up.

The arm descriptions specify the same professional CGM measurement procedure, but give limited detail about the timing and repetition of collection periods in relation to the 3-month and 6-month assignments. The outcome timeframe is listed as 6 Months, and the endpoint describes a 72 hour collection period. The registry record does not give further details about the relationship between these time references, sensor-data processing, or criteria for usable data.

Safety counts use denominators of 5 and 7, while primary-outcome counts are 2 in each arm. Safety follow-up definitions and the relationship between these populations are not reported in the registry record. Taken together, the limited outcome counts and incomplete analysis and follow-up details constrain both efficacy interpretation and safety precision.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Comparison of 3 Versus 6-Month Use of CGMS in Non-Insulin Using T2DM Patients — NCT03067480.
• Registry record last updated 2026-01-09; status last verified 2025-12.
• Results first posted 2026-01-09.
• 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

NCT03067480 is a randomized, unmasked, parallel-group study listed as terminated. It compares 3-month and 6-month use of the iPro2 Professional CGM in poorly controlled, non-insulin using patients with type 2 diabetes. Enrollment is listed as 12, and the primary outcome is time spent with sensor glucose between 70-140mg/dl during a 72 hour collection period, assessed at 6 Months.

The posted mean outcome is 38.5 with standard deviation 18.5 for 2 participants in the 3-month arm, and 50.0 with standard deviation 40.0 for 2 participants in the 6-month arm. No inferential analysis is reported. Serious and other adverse event counts are 0 in both groups; the safety denominators are 5 and 7, respectively, and deaths are 0 in each group.

The reason for termination, explanation for the outcome counts, analysis population, missing-data handling, and statistical analysis plan are not reported in the registry record. The results are descriptive and do not establish the precision or statistical significance of the comparison.