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 Control-IQ Technology for High Insulin Users With Type 1 Diabetes (Higher-IQ) (NCT05422053), a na na study. The primary outcome is Number of Severe Hypoglycemic Events.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05422053 |
| Phase | NA |
| Condition | Type 1 Diabetes |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 34 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Tandem Diabetes Care, Inc. |
| Results posted | Yes |
2. Clinical Question
Population
Adults with type 1 diabetes who planned to use at least one basal rate greater than 3 units/hr. The registry record lists enrollment of 34 participants.
Intervention
Home use of the t:slim X2 insulin pump with Control-IQ technology 1.5. The arm description also notes meal and exercise challenges.
Comparator
There was no separate comparator arm. The study is listed as single-group, with allocation recorded as NA, so it does not provide a randomized between-group comparison.
Primary question
The primary endpoint was the number of severe hypoglycemic events during the study period. A severe event was defined as hypoglycemia with cognitive impairment requiring another person’s assistance for treatment.
The clinical question is descriptive: how many severe hypoglycemic events were recorded during use of this device in the enrolled group? Because there was no control group, the design cannot estimate a comparative treatment effect against another device, usual care, or no intervention. The registry record does not report the observed primary endpoint count, so the event experience cannot be described from the posted primary results.
The study summary describes 13 weeks of home use, while the primary endpoint timeframe is listed as 3 months. The arm description likewise describes 3-months of outpatient use. These are the time descriptions recorded for the study; the registry record does not provide further detail about how the endpoint window was operationalized. Meal and exercise challenges were also planned, but their results are not reported in the registry record.
3. Trial Design
This was a prospective, single-arm study of the t:slim X2 insulin pump with Control-IQ technology 1.5 in people with type 1 diabetes who planned to use at least one basal rate greater than 3 units/hr. The registry lists enrollment of 34 participants and describes outpatient home use. The study is marked completed. Its recorded start date is 2022-06-29, and its primary completion date is 2023-01-06.
The design has no separate control arm. Allocation is listed as NA, and masking is listed as none. The phase is listed as NA. A single-group design can describe outcomes observed during the intervention period, but it does not create a concurrent comparison for separating intervention-associated changes from changes that might occur over time or for other reasons. The registry record does not report a comparator group or a randomized treatment assignment.
The study summary describes 13 weeks of home use; the primary endpoint timeframe is 3 months, and the arm description refers to 3-months of outpatient use. The arm description also says that meal and exercise challenges would be performed. The registry record does not report the challenge procedures or their findings. The sponsor is Tandem Diabetes Care, Inc.
The primary endpoint concerns severe hypoglycemic events over the study period. The registry also lists secondary outcomes for continuous glucose monitoring time below 54 mg/dL and below 70 mg/dL, considered overall and separately for daytime and nighttime. These outcomes address time spent at low glucose levels, whereas the primary endpoint counts severe events requiring assistance. The record lists 32 outcome measures and one analysis, but does not explain how those listings map to particular analyses or provide results for the primary endpoint.
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 | t:Slim X2 Insulin Pump With Control-IQ Technology |
|---|---|
| STARTED | 34 |
| COMPLETED | 34 |
| NOT COMPLETED | 0 |
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.
Population: adults with type 1 diabetes (T1D) who planned to use at least one basal rate \> 3 units/hour
| Characteristic | Unit | t:Slim X2 Insulin Pump With Control-IQ Technology |
|---|---|---|
| Participants analysed | 34 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 33 |
| Age, Categorical: >=65 years | Participants | 1 |
| Age, Continuous | years | 39.9 (20 to 66) |
| Sex: Female, Male: Female | Participants | 14 |
| Sex: Female, Male: Male | Participants | 20 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 3 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 31 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 32 |
| Race (NIH/OMB): More than one race | Participants | 2 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | participants | 34 |
| Socio-economic factors (income): Less than $25,000 | participants | 3 |
| Socio-economic factors (income): $25,000 to less than $35,000 | participants | 0 |
| Socio-economic factors (income): $35,000 to less than $50,000 | participants | 3 |
| Socio-economic factors (income): $50,000 to less than $75,000 | participants | 1 |
| Socio-economic factors (income): $75,000 to less than $100,000 | participants | 8 |
| Socio-economic factors (income): $100,000 to less than $200,000 | participants | 11 |
| Socio-economic factors (income): $200,000 or more | participants | 3 |
| Socio-economic factors (income): Unknown | participants | 5 |
| Socio-economic factors (education): Less than high school | participants | 1 |
| Socio-economic factors (education): High school graduate / diploma / GED | participants | 4 |
| Socio-economic factors (education): Some college but no degree | participants | 8 |
| Socio-economic factors (education): Associate degree (AA) | participants | 3 |
| Socio-economic factors (education): Bachelor's degree (BA, BS, AB) | participants | 13 |
| Socio-economic factors (education): Master's degree (MA, MS, MSW, MBA, MPH) | participants | 5 |
| Socio-economic factors (education): Professional degree (MD, DDS, DVM, LLB, JD) | participants | 0 |
| Socio-economic factors (education): Doctorate degree (PhD, EdD) | participants | 0 |
| Socio-economic factors (education): Unknown | participants | 0 |
| Socio-economic factors (education): Does not wish to provide | participants | 0 |
| Duration of Diabetes | years | 21.8 (SD 11.2) |
| HbA1c at Control-IQ Start | percentage of glycated hemoglobin | 7.7 (SD 1.1) |
| BMI | kg/m^2 | 37.6 (SD 5.2) |
| Total daily insulin | units/kg/day | 1.2 (SD 0.4) |
6. Primary Endpoint
The registry lists the primary outcome as Number of Severe Hypoglycemic Events, measured over 3 months.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | events |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the number of severe hypoglycemic events during the entire study period, with a timeframe listed as 3 months. The registry definition describes severe hypoglycemia as an event involving cognitive impairment such that another individual’s assistance is needed for treatment. This is an event-count endpoint, not a measure of glucose time below a threshold. It focuses on episodes meeting the stated severity definition rather than all low glucose readings.
As a general statistical concept, counting events can capture repeated episodes within a study period. A count may differ from the number of participants who experienced at least one event: one participant can potentially contribute more than one event. Interpretation therefore depends on knowing whether the reported value is a total event count, how follow-up time was handled, and how events were ascertained. Those details matter when describing event burden or comparing rates.
The registry record does not report the observed primary endpoint count, an uncertainty estimate, or a model for the endpoint. It also does not report the number of participants with at least one primary endpoint event. Consequently, the posted record does not establish the magnitude or precision of the primary endpoint experience. The endpoint is clinically interpretable by its definition, but its observed value is not available in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted registry information identifies the population, intervention, design, and primary endpoint, but does not report the primary endpoint result. In particular, the number of severe hypoglycemic events during the study period is not reported in the registry record. No confidence interval or other uncertainty estimate for that endpoint is reported either. It is therefore not possible to describe the observed event count or how precisely it was estimated from the registry record.
The study is single-group, with no separate comparator. Any event count, if available, would describe what was observed among participants during the stated use period. It would not, by itself, establish how the event experience compares with another treatment or what would have happened to the same participants without the intervention. This distinction is especially important when interpreting uncontrolled studies, because there is no concurrent group to help separate intervention-associated observations from other influences.
The registry lists 34 participants enrolled. Enrollment is not necessarily the same as the number contributing data to each endpoint; the number analyzed for the primary endpoint is not reported in the registry record. The record does not state whether participants completed the full follow-up period or how missing observations were handled. Without those details, the amount of outcome information supporting any analysis cannot be assessed.
The study also lists continuous glucose monitoring outcomes for time below 54 mg/dL and below 70 mg/dL, including overall, daytime, and nighttime measures. These are distinct outcomes from the primary count of severe events. The registry record does not report their values or describe how they were analyzed. A change in a glucose-time measure should not be treated as interchangeable with a count of severe events, because the definitions and units differ.
Safety information is posted separately. The registry lists one participant with a serious adverse event, 19 participants with other adverse events, and zero deaths in the treatment group. The serious-event term listed is new onset atrial fibrillation, with 2.9% reported. These figures describe the registry’s adverse-event entries; they do not supply the missing primary endpoint result or a comparison with another group.
Overall, the registry supports a description of the study setup and certain safety counts, but not a quantitative conclusion about the primary endpoint. A lack of a posted primary result is not evidence that the endpoint count was zero. Nor does the completed status supply an outcome result. The endpoint value and its precision remain not reported in the registry record.
9. Statistical Methods Explained
The registry identifies a single-group study and a count-based primary endpoint, but it does not report the statistical method used to analyze that endpoint. The explanations below describe general statistical concepts; they should not be read as a description of the analysis actually performed in this study.
What does a count endpoint represent?
As a general matter, a count endpoint records how many qualifying events occur over a defined observation period. It differs from a binary endpoint, which records whether a participant did or did not experience at least one event. Counts preserve information about repeated events, while a binary measure collapses all participants with one or more events into the same category. For this study, the definition specifies severe hypoglycemic events requiring another individual’s assistance, and the timeframe is listed as 3 months. The observed count is not reported in the registry record.
When event counts are analyzed, statistical methods often account for the amount of time participants were observed. Such approaches can estimate an event rate rather than just a total count. That distinction can matter if follow-up duration differs across participants. The registry record does not report an event-rate analysis, an exposure-time adjustment, or the handling of differing follow-up.
Why can count data be more variable than expected?
As a general explanation, a simple count model may assume that the variability in counts follows a particular relationship to their average. In practice, participants may differ in event susceptibility or observation time, and events may cluster within some participants. When the observed variability is greater than a basic model expects, this is called over-dispersion. Ignoring over-dispersion can make uncertainty estimates too small. Other methods can allow more variability, but the registry record does not identify a count model or report a dispersion assumption for this endpoint.
What would an uncertainty estimate add?
In general, a confidence interval communicates a range of values compatible with the data under a specified statistical procedure. It helps readers judge precision: a narrower interval indicates greater precision under that procedure, while a wider interval indicates more uncertainty. A point estimate alone does not convey the full uncertainty. The registry record does not report a confidence interval or another uncertainty estimate for the primary event count, so its precision cannot be assessed from the posted primary endpoint information.
What does the single-group design allow?
In general, a single-group study can describe outcomes observed during a defined period, but a treatment comparison requires an appropriate comparator. Without a concurrent control group, an observed endpoint value cannot distinguish intervention-associated effects from other influences with the same protections that a randomized comparison can offer. This is a design limitation, not a claim about the direction or size of any observed outcome. Here, the registry identifies no separate comparator arm and lists allocation as NA.
The registry also lists sample-size planning assumptions for illustrations. These are described as planning illustrations computed from an observed effect, not as the trial’s own design justification. The listed assumptions are 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. For time-to-event illustrations, the stated output is the total number of events using the Schoenfeld approach; other illustrations are stated in participants per arm. These planning assumptions do not change the actual single-group design. The registry record does not report a trial-specific sample-size justification, and the observed primary endpoint result needed to assess an effect-based illustration is not reported in the registry record.
As a general concept, a planning sample size is not observed power. It is a calculation under assumptions about the effect, variability, allocation, and statistical procedure. It does not show the probability that a completed study found a particular result, and a planning illustration does not substitute for an observed estimate with an uncertainty interval. No numerical planning outputs are described in the registry information summarized by these registry entries.
The registry lists one analysis and 32 outcome measures. Those counts alone do not identify the model, test, adjustment variables, analysis population, or multiplicity procedure. They also do not establish whether each measure was analyzed, or how the listed analysis relates to the outcomes. Those details are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 32 outcome measures and one analysis. It also names secondary continuous glucose monitoring outcomes for time below 54 mg/dL and below 70 mg/dL, each considered overall, during daytime, and during nighttime. The record does not explain how these measures relate to the total count of outcome measures or to the listed analysis.
As a general statistical issue, examining many outcomes can increase the chance of finding an apparently notable result by chance if each is tested separately. A prespecified hierarchy, an adjustment for multiple testing, or a clear distinction between confirmatory and exploratory outcomes can help readers interpret a family of tests. The registry record does not report whether any such approach was planned or used, and no multiplicity adjustment is reported. With no primary result posted, the role of the primary endpoint in any testing hierarchy also cannot be assessed.
The registry record does not report how missing outcome data were handled, whether imputation was used, or whether sensitivity analyses were performed. It does not report the number of participants contributing data to the primary endpoint or to the secondary outcomes. Enrollment of 34 does not establish the analysis population for each outcome.
Definitions of analysis populations, such as which participants were included in each endpoint analysis, are not reported in the registry record. The record also does not describe exclusions, adherence requirements for analysis, or the handling of participants who did not complete the intended observation period. These omissions limit assessment of how complete and comparable the analyzed data would be, even though the study is listed as completed.
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 |
|---|---|---|---|
| t:Slim X2 Insulin Pump With Control-IQ Technology | 1 | 34 | 2.9% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| t:Slim X2 Insulin Pump With Control-IQ Technology | 0 of 34 |
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 |
|---|---|
| t:Slim X2 Insulin Pump With Control-IQ Technology | 19 of 34 |
Most frequent serious adverse event terms
| Event term | Organ system | t:Slim X2 Insulin Pump With Control-IQ Technology |
|---|---|---|
| New onset atrial fibrillation | Cardiac disorders | 1 of 34 |
Most frequent non-serious adverse event terms
| Event term | Organ system | t:Slim X2 Insulin Pump With Control-IQ Technology |
|---|---|---|
| Upper respiratory tract infection | Infections and infestations | 7 of 34 |
| COVID-19 | Infections and infestations | 2 of 34 |
| Influenza | Infections and infestations | 2 of 34 |
| Otitis media | Ear and labyrinth disorders | 1 of 34 |
| Tympanic membrane perforation | Ear and labyrinth disorders | 1 of 34 |
| Nausea | Gastrointestinal disorders | 1 of 34 |
| Tooth fracture | Gastrointestinal disorders | 1 of 34 |
| Vomiting | Gastrointestinal disorders | 1 of 34 |
| Influenza like illness | General disorders | 1 of 34 |
| Bronchitis | Infections and infestations | 1 of 34 |
Serious events with the highest arm-level rate: new onset atrial fibrillation (2.9%).
The registry lists one participant with a serious adverse event among 34 at risk in the t:Slim X2 insulin pump with Control-IQ technology group. It lists 19 participants with other adverse events among 34 at risk and zero deaths. The serious adverse-event term listed is new onset atrial fibrillation, with 2.9% reported. These are the safety figures recorded for this single group; there is no separate comparator group for a between-group safety comparison.
The serious-event count and the other adverse-event count are different registry categories and should not be combined. The term and percentage describe the serious-event listing; the record does not provide further event-level detail in the registry record. A percentage attached to a term is not, on its own, enough to establish causation or compare risk between groups. The registry record does not report a causal assessment or a comparative risk estimate.
As a general statistical point, adverse-event counts are descriptive and depend on the observation period, event definitions, ascertainment, and the number of participants observed. The study’s home-use period is described as 13 weeks and its primary endpoint timeframe as 3 months. The registry does not provide further detail about the timing of the listed adverse events or whether participants had complete safety follow-up. These figures should therefore be read as the posted safety entries, not as a complete assessment of all possible risks.
12. What the Result Does, and Does Not, Mean
The record establishes that this completed study evaluated home use of the t:slim X2 insulin pump with Control-IQ technology 1.5 in a single group of adults with type 1 diabetes who planned to use at least one basal rate greater than 3 units/hr. It identifies a primary endpoint focused on severe hypoglycemic events requiring assistance and lists additional glucose-time outcomes. It also reports selected adverse-event figures.
The registry record does not report the observed primary endpoint count. It therefore does not support a statement about how many severe events occurred during the study period, how precisely that count was estimated, or how the event experience compared with another approach. The absence of a posted count cannot be interpreted as a count of zero. The study’s completed status does not fill that reporting gap.
Because there is no separate control arm, the study does not provide a randomized estimate of a difference between groups. Even if an outcome value were available, a single-group observation would describe the enrolled participants during the study period; it would not by itself establish what would have happened under a different intervention or without the device. This is a limit of the design, not a conclusion about the direction of an outcome.
The adverse-event entries provide a limited descriptive view of safety reporting in the registry. They are not a comparative safety analysis and do not establish that an event was caused by the device. The secondary glucose-time outcomes are also not substitutes for the primary severe-event endpoint. Their values and analysis details are not reported in the registry record.
Accordingly, the strongest interpretation is about the study’s question and design, not an efficacy conclusion. The registry record describes what investigators set out to observe, but it does not provide the primary result needed to characterize the observed severe-event burden. Missing outcome details, analysis methods, and analysis populations further limit statistical interpretation.
13. Why This Trial Matters Statistically
This trial is statistically informative as an example of the distinction between describing outcomes and estimating comparative effects. The single-group design can provide observations about participants during device use, but without a separate comparator it cannot estimate a randomized between-group contrast. That distinction is important when readers encounter a completed study and want to know whether its design supports a causal comparison.
The primary endpoint also illustrates why endpoint definitions matter. A severe hypoglycemic event requiring assistance is different from time spent below a glucose threshold. One is an event count defined by clinical severity and need for help; the others are measures of time at specified glucose levels. These outcomes may address related aspects of glucose experience, but they are not interchangeable statistically or clinically.
Reporting the endpoint estimate and its uncertainty is central to interpreting a count outcome. The registry identifies the endpoint and timeframe, but does not report the observed count or an uncertainty estimate. Without those quantities, readers cannot assess the magnitude or precision of the primary endpoint experience. Likewise, the listed enrollment does not reveal how many participants contributed data to a particular endpoint.
The record also highlights the difference between planning assumptions and study results. Sample-size illustrations are planning calculations under stated assumptions; they are not observed power and do not replace reporting an endpoint estimate. The record’s listed planning assumptions do not make the single-group study a two-arm comparison.
Finally, the listing of many outcome measures makes transparent reporting of analysis choices important. The registry does not state how multiplicity, missing data, or analysis populations were handled. Those details help readers judge how robustly results can be interpreted. Here, the lack of a posted primary endpoint value makes those questions especially consequential for understanding what evidence the study can contribute.
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.
Several limitations follow directly from the registry record. The study is single-group and has no separate comparator, so it cannot provide a randomized comparison. Masking is listed as none, and allocation is listed as NA. The registry does not report the primary endpoint result, an uncertainty estimate, or a method for analyzing the event count. This prevents assessment of the endpoint’s observed magnitude and precision.
The study period is described as 13 weeks in the summary, while the primary endpoint timeframe is listed as 3 months and the arm description refers to 3-months of outpatient use. The registry record does not explain the operational details of the endpoint window or report participant-level follow-up. It also does not report how many of the 34 enrolled participants contributed to each outcome.
The record says meal and exercise challenges would be performed, but does not report their procedures or results. It lists secondary glucose-time outcomes but does not provide their values or analysis details. Missing-data methods, analysis populations, and multiplicity handling are not reported in the registry record. These gaps limit assessment of completeness and the interpretation of any outcome analysis.
Finally, the participant group is defined around type 1 diabetes and planned use of at least one basal rate greater than 3 units/hr. The record does not provide further detail about the enrolled participants beyond the stated study description. The findings, if reported, would need to be interpreted in light of that eligibility description and the study’s outpatient duration; the registry information does not support extending conclusions to populations or circumstances not described.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Control-IQ Technology for High Insulin Users With Type 1 Diabetes (Higher-IQ) — NCT05422053.
- Registry record last updated 2025-04-03; status last verified 2025-04.
- Results first posted 2024-04-17.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The registry record describes a completed prospective, single-group study of the t:slim X2 insulin pump with Control-IQ technology 1.5 in adults with type 1 diabetes who planned to use at least one basal rate greater than 3 units/hr. Enrollment was 34. The summary describes 13 weeks of home use; the primary endpoint timeframe is listed as 3 months. Meal and exercise challenges were planned.
The primary endpoint was the number of severe hypoglycemic events requiring another individual’s assistance during the study period. The observed primary endpoint value and its uncertainty are not reported in the registry record. The study has no separate comparator arm; allocation is listed as NA and masking as none. The sponsor is Tandem Diabetes Care, Inc. The recorded start date is 2022-06-29, and primary completion is recorded as 2023-01-06.
The registry lists one participant with a serious adverse event, 19 with other adverse events, and zero deaths. New onset atrial fibrillation is listed as a serious-event term at 2.9%. The record also lists secondary glucose-time outcomes and 32 outcome measures, but does not report the primary result or analysis details needed to assess it.