A Performance Evaluation of the Enlite Glucose Sensor to Support a Full 144 Hours(6Days) of Use: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Performance Evaluation of the Enlite Glucose Sensor to Support a Full 144 Hours(6Days) of Use (NCT01464346), a randomized na study. The primary outcome is Mean Daily Agreement (Percent of Sensor Values Within 30% of Reference Value) With Minimum Calibration, Combined Abdomen and Buttock Insertion Sites.

2. Clinical Question

3. Trial Design

The registry record describes a completed device-performance evaluation sponsored by Medtronic MiniMed, Inc. It lists an enrollment of 90, a start date of 2011-11, and a primary completion date of 2012-03. The phase is recorded as NA. The conditions listed are type 1 diabetes mellitus and type 2 diabetes mellitus.

The device under evaluation was the Enlite Sensor, used with the Revel 2.0 Pumps. The brief summary describes participants aged 18–75 years and sensor wear at the abdomen and buttock. The arm descriptions identify three two-sensor configurations: abdomen/abdomen, abdomen/buttock, and buttock/buttock. The primary endpoint combines abdominal and buttock insertion sites rather than reporting a site-specific primary comparison.

The registry lists allocation as randomized, masking as none, and the study model as single group. Those descriptors do not, by themselves, explain how participants were assigned to insertion-site configurations, or whether any assignment procedure was used. Details of the randomization process are not reported in the registry record. The primary endpoint is described as combining results across participants and days, with no separate comparator identified.

The title refers to supporting 144 hours, while the brief summary describes an entire calibration and wear period of 146 hours (6 days). Both descriptions are in the registry record; the reason for the difference is not reported. The primary endpoint timeframe is Days 1, 3 and 6 of sensor wear. A secondary outcome concerns mean daily agreement with 3–4 calibrations per day, combining abdomen and buttock insertion sites.

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 Mean Daily Agreement (Percent of Sensor Values Within 30% of Reference Value) With Minimum Calibration, Combined Abdomen and Buttock Insertion Sites, measured over Days 1, 3 and 6 of sensor wear.

The primary endpoint is the mean daily percentage of sensor readings that were close to a reference measurement. A sensor value counted as agreeing when it was within 30% of the reference value, with a separate absolute tolerance of 22.5 mg/dL when the YSI reference value was <75 mg/dL. The endpoint description specifies minimum calibration, defined as every 12 hours, and combines abdominal and buttock insertion sites across participants and days.

This type of endpoint expresses agreement as a proportion of paired readings meeting a prespecified criterion. It is used to describe how often sensor readings fall within a defined tolerance of the reference, rather than measuring a clinical outcome such as symptoms or complications. The mean daily agreement also gives a summary across the specified days of wear, rather than presenting only one day’s readings.

General statistical context: a mean summarizes the central value of repeated measurements, while a confidence interval describes uncertainty around an estimated quantity under the analysis assumptions. Neither the primary mean nor its 95% confidence interval is reported in the registry record. The endpoint definition alone therefore does not indicate the observed level of agreement or the precision of an estimate.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a continuous measure summarized as a mean, although its unit is a percentage of paired readings. For each relevant day, the endpoint concerns the share of sensor values meeting the agreement rule against a reference value. The primary endpoint description specifies Days 1, 3 and 6, minimum calibration every 12 hours, and pooled abdominal and buttock insertion sites. The registry record does not report the calculation details beyond that definition, such as the handling of incomplete days or the number of paired readings contributing to each participant’s daily value.

What does the agreement threshold mean?

The rule classifies a sensor value as within tolerance when it is within 30% of the reference value, or within 22.5 mg/dL if the YSI reference value is <75 mg/dL. This creates a binary classification for each pair of readings: a pair either meets the stated tolerance or does not. The daily percentage summarizes the qualifying pairs for that day. General statistical context: a threshold-based agreement measure is easy to interpret as a frequency, but it does not show how far outside the threshold the remaining readings fall. Two datasets can have the same agreement percentage while differing in the size or pattern of discrepancies among readings that do not meet the rule.

Why report a mean and confidence interval?

The registry specifies a mean and a 95% confidence interval for the primary outcome. General statistical context: the mean provides a central summary of the observed daily agreement values, while the confidence interval represents uncertainty around that summary under the assumptions of the analysis. The interval is not a range containing 95% of individual readings. The endpoint result and interval are not reported in the registry record, so their magnitude and precision cannot be described.

Why can repeated readings matter?

General statistical context: readings from the same participant, sensor, or day may be correlated rather than independent. Treating correlated observations as independent can make uncertainty appear smaller than it is. Analyses of repeated measurements may account for clustering or within-participant dependence, but the statistical model used for this endpoint is not reported in the registry record. The record also does not state how multiple sensors worn by one participant were incorporated into the estimate.

Over-dispersion is a general concern when observed variability exceeds what a statistical model expects. For a measure based on proportions, extra variability can arise when observations cluster within participants or when agreement differs across settings. A model that does not account for such variability may give confidence intervals that are too narrow. This is a general methodological consideration, not a claim about the analysis used in this trial; the model and over-dispersion assessment are not reported in the registry record.

What does the design information establish?

The registry lists randomized allocation, no masking, and a single-group model. It also describes three insertion-site configurations and an endpoint that combines abdomen and buttock data. These registry entries describe features of the record but do not explain the allocation procedure or establish that the primary endpoint was analyzed as a comparison among configurations. Those details are not reported in the registry record. The registry also lists fewer than two arms in the primary outcome as a reason to skip an arm-based primary comparison.

The registry gives sample-size planning assumptions for an illustrative calculation: a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect expressed as a stated fraction of the observed effect. Such calculations are planning illustrations, not observed power and not evidence that the trial used those assumptions for its design. A sample-size justification for the trial is not reported in the registry record. No numerical planning result is described in this explanation.

General statistical context: power calculations depend on assumptions about the effect to detect, variability, significance level, allocation, and analysis. Changing an assumption changes the planning result. An illustration based on an observed effect is retrospective and should not be read as proof that a study had a particular probability of detecting an effect before data collection. The record’s planning assumptions do not fill the gap left by the unreported primary result.

How should the calibration outcomes be distinguished?

The primary outcome concerns minimum calibration, defined as every 12 hours. A secondary outcome is listed for 3–4 calibrations per day and also combines abdomen and buttock insertion sites. These are distinct calibration conditions. The registry record does not provide the numerical results needed to compare them, and the difference in calibration frequency should not be treated as an observed difference in agreement.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists six outcome measures and two analyses. It identifies the primary endpoint and names a secondary agreement outcome, but the statistical plan for handling multiple outcomes or analyses is not reported in the registry record. In particular, it does not state whether any adjustment for multiple testing was planned, or how the primary and secondary analyses were prioritized beyond the endpoint designation.

Missing-data methods are also not reported. The record does not explain how missing sensor readings, reference readings, days, or participant-level measurements were handled, nor does it describe whether any participants or measurement periods were excluded from the primary analysis. The primary endpoint description says results were combined across participants and days, but that wording does not specify the rules for incomplete observations.

The analysis population is not described in detail. The record lists enrollment of 90 and an adverse-event group titled “All Completed Subjects,” with 90 at risk. It does not separately define the population used for the primary endpoint or state whether all enrolled participants contributed evaluable data.

The record lists randomized allocation but a single-group model, and the primary endpoint combines insertion sites. The details needed to understand any allocation-based or site-specific analyses are not reported. These omissions limit assessment of how outcomes were selected, how incomplete data may have affected estimates, and how broadly the analyzed population represents the enrolled group.

11. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry record reports safety counts for “All Completed Subjects,” with 90 at risk. It records 0 serious adverse events, 17 other adverse events, and 0 deaths. These are counts as reported in the record; they do not describe the nature, timing, duration, or severity of the 17 other events. The record does not list serious adverse event terms.

General statistical context: an adverse-event count is a descriptive safety summary, not by itself a determination that an event was caused by the device. Causal attribution and event-level details are not reported in the registry record. A count of 0 serious events means that none are recorded in this summary; it does not establish that the underlying risk is zero. The counts should be read within the recorded group and follow-up information, not as a complete account of every possible safety outcome.

The registry labels the group as completed subjects and reports 90 at risk. It does not describe the safety follow-up period or provide participant-level exposure time. The safety figures therefore cannot be used to infer rates over time or to compare risk between insertion-site configurations.

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

The registry record documents a study intended to evaluate Enlite sensor performance over a calibration and wear period, using abdominal and buttock insertion sites. It defines a primary agreement measure based on the percentage of paired readings within the stated tolerance, under minimum calibration, on Days 1, 3 and 6. These details clarify what the study set out to summarize.

The record does not report the primary mean or its 95% confidence interval. Therefore, the posted information does not establish the observed agreement level, its precision, or whether agreement differed by day or insertion site. The endpoint definition and the study’s stated purpose cannot be substituted for numerical results.

The registry describes a secondary calibration condition and three insertion-site configurations, but the numerical outcomes for those configurations are not reported. It also does not report the statistical model, missing-data procedures, analysis population for the primary endpoint, or a detailed allocation process. Those gaps prevent a fuller assessment of how the pooled endpoint was formed and how uncertainty was handled.

The safety summary records 0 serious adverse events, 17 other adverse events and 0 deaths among 90 at risk in the group labeled “All Completed Subjects.” These counts are descriptive and do not establish causation, comparative safety, or the risk over a specified duration.

General statistical context: a study objective is a question, not a result. A well-defined endpoint helps readers understand what an estimate would represent, while the estimate and its uncertainty are needed to assess what the collected data show. Without the primary estimate and its interval in the registry record, conclusions about the measured agreement should remain limited to the endpoint definition and reported design details.

13. Why This Trial Matters Statistically

This trial is statistically useful as an example of how a device-performance endpoint can be defined around agreement with a reference measurement. The outcome is not simply a device reading or a clinical event: it is a mean daily percentage of paired values meeting a stated tolerance. Understanding the threshold, calibration condition, days of assessment, and pooling across insertion sites is essential to interpreting the intended summary.

The record also illustrates why design labels and analysis descriptions need to be read together. It lists randomized allocation and a single-group model, while describing several sensor-placement configurations and a pooled primary endpoint. Without allocation details or site-specific estimates, the reader cannot treat the record as a reported comparison among configurations.

General statistical context: repeated measurements can contain more information than a single observation per participant, but that information is useful only when the analysis accounts appropriately for dependence and uncertainty. The model used for the primary endpoint is not reported, so its handling of repeated observations cannot be assessed. Similarly, missing-data rules and multiplicity procedures matter when several outcomes and analyses are listed, but those procedures are not reported.

The missing numerical primary result is consequential: a clearly defined endpoint does not show the outcome by itself. This record can support discussion of measurement definitions, repeated data, and the limits of registry summaries, but it cannot support a quantitative conclusion about observed sensor agreement from the information recorded.

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 primary endpoint’s mean and 95% confidence interval are not reported in the registry record. Without them, the central performance summary and its precision cannot be assessed. Numerical results for the listed secondary outcome and other outcome measures are also not reported in the registry record.

The registry describes three sensor-placement configurations but gives no configuration-specific primary results. The primary outcome description combines abdominal and buttock insertion sites across participants and days. This pooled description does not reveal whether agreement varied by site, day, or participant.

The record lists randomized allocation and a single-group model but does not report the allocation process or explain how the configurations relate to the analysis model. The statistical model, handling of repeated observations, missing-data procedures, and primary analysis population are not reported. These omissions make it difficult to assess the source of uncertainty or the consequences of incomplete data.

There is also a duration wording difference in the record: the title refers to 144 hours, while the brief summary refers to 146 hours (6 days). The reason is not reported. The primary endpoint timeframe is described as Days 1, 3 and 6 of sensor wear, but the registry does not provide further detail about measurement availability on those days.

Finally, the safety summary provides counts but no event descriptions, follow-up duration, or attribution details. The record therefore gives a limited descriptive safety picture and does not support comparisons across placement configurations.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Performance Evaluation of the Enlite Glucose Sensor to Support a Full 144 Hours(6Days) of Use — NCT01464346.
• Registry record last updated 2018-05-30; status last verified 2018-05.
• Results first posted 2018-05-30.
• 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.

18. Record Summary

The record describes a completed evaluation of the Enlite Sensor in people aged 18–75 years with type 1 or type 2 diabetes mellitus. It lists enrollment of 90, randomized allocation, no masking, and a single-group model. Participants wore two sensors in abdomen/abdomen, abdomen/buttock, or buttock/buttock configurations with the Revel 2.0 Pumps.

The primary endpoint is mean daily agreement within the specified tolerance under minimum calibration, combining insertion sites and assessing Days 1, 3 and 6. The primary estimate and 95% confidence interval are not reported in the registry record. The record also lists a secondary outcome with 3–4 calibrations per day.

The safety summary reports 0 serious adverse events, 17 other adverse events and 0 deaths among 90 at risk. Statistical analysis details, missing-data methods, and the reason for the 144-hour versus 146-hour wording difference are not reported in the registry record.