Evaluation of Labeling Comprehension and Performance of a New Blood Glucose Meter System: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluation of Labeling Comprehension and Performance of a New Blood Glucose Meter System (NCT00804596), a na na study. The primary outcome is Percentage of Participants Rated as <=3 (Comprehension of Labeling).

2. Clinical Question

The question is about whether participants could carry out blood glucose testing and other system tasks after reading the product labeling, and how much assistance they needed. The scale distinguishes completing tasks without help, completing them after consulting instructions, completing them after verbal help or review of instructions, and unsuccessful performance. Because the primary endpoint includes ratings through 3, it encompasses some participants who needed assistance; it is not limited to unaided task completion.

The study also lists a secondary outcome concerning capillary blood results within specified limits of a laboratory glucose method. Its numerical result is not reported in the registry record. Thus, the posted record states what the study set out to assess but does not provide the estimates needed to quantify either endpoint.

3. Trial Design

The registry describes NCT00804596 as a completed, single-group device study. It lists 74 participants as the enrollment, identifies diabetes as the condition, and names the Apollo Blood Glucose Monitoring System as the intervention. The arm description says that subjects with diabetes used the system with subject capillary blood. The study is not described as randomized; allocation is NA, and masking is listed as none.

The brief summary states that the study aimed to evaluate the acceptability of product user guides for untrained subjects and to evaluate system performance with lay users and healthcare providers. The arm description specifically refers to subjects with diabetes. The record does not explain the recruitment or role of any healthcare-provider participants, so those details are not reported in the registry record.

The primary endpoint is a participant percentage based on study staff ratings after participants read product labeling. The primary endpoint population is identified as per protocol. The primary timeframe is 1-2 hours. The scale rates whether tasks were completed independently, after consulting instructions, after verbal help or review of instructions, or unsuccessfully. The record also lists a secondary outcome comparing capillary blood results with a laboratory glucose method, but does not report its result.

The study phase is listed as NA. The record gives a start date of 2008-12, a primary completion date of 2009-01, and a completed status. A detailed protocol, eligibility criteria, site information, and a fuller account of study procedures are not reported in the registry record. No control group is described, which means the design addresses observed performance in the studied group rather than a between-group treatment contrast.

The record does not report a statistical analysis plan or analysis results. Although enrollment is listed, the basis for that enrollment and any sample-size justification are not reported in the registry record. The planning assumptions associated with the sample-size illustrations are not a substitute for the study's own design rationale.

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.

Before assignment: 5 subjects signed informed consents but did not meet inclusion/exclusion criteria so were not considered enrolled in the study.

Overall Study

Analysis population for the primary outcome, as defined in the registry: per protocol

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 Percentage of Participants Rated as <=3 (Comprehension of Labeling), measured over 1-2 hours.

The primary endpoint is titled as the percentage of participants rated 3 or lower for comprehension of labeling. Study staff rated participants on success with blood glucose testing and other system features after they read the product labeling. The registry gives a four-level scale: successful without assistance; successful after referral to user instructions; successful after verbal assistance or review of part of the instructions; and unsuccessful, including incorrect performance or the need for staff intervention.

This endpoint is used to describe whether participants could carry out the assessed tasks and the level of assistance associated with that performance. A cutoff of 3 includes the first three levels, so it does not mean that every participant in the endpoint met all tasks independently. The scale combines task performance with the type of support needed, and the resulting percentage would be a summary of that defined threshold.

The endpoint is classified as a percentage of participants, and the timeframe is 1-2 hours. Its population is described as per protocol. The registry record does not report the observed percentage, the number of participants meeting the threshold, uncertainty around the estimate, or details of how the per-protocol population was defined. Those omissions prevent assessment of the observed magnitude and precision of the primary endpoint.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods determine how observations are converted into estimates and how uncertainty is represented. For this study, the primary endpoint is a percentage based on a categorical staff rating. The registry record defines the rating scale and the threshold of 3 or lower, but does not report the observed percentage or an analysis method. Any interpretation must therefore separate the endpoint definition from an estimate of its value.

What does a participant percentage represent?

In general, a participant percentage is the number of people meeting a specified outcome definition relative to the number included in the analysis. The threshold matters: a percentage for ratings of 3 or lower combines the first three rating categories, including ratings that involve instruction or verbal assistance. It does not give the same information as a count in each category or a percentage limited to independent task completion. The registry record does not provide the underlying category counts or the analyzed denominator.

When an estimate is available, its precision depends in part on how much information supports it and on the amount of variability in the underlying observations. A confidence interval is a general way of expressing uncertainty around an estimate. A narrower interval indicates greater precision under the method's assumptions, while a wider interval indicates less precision. No confidence interval is reported for the primary endpoint in the registry record, so precision cannot be judged from the posted results.

How does the single-group structure affect analysis?

In general, a single-group analysis can describe outcomes observed among participants in that group. It does not, by itself, estimate a contrast with a concurrent control group. A comparative estimate requires a defined comparison and suitable data for both groups. This registry record lists a single-group model and no comparator. Its design description therefore supports a question about observed performance, not a randomized between-group effect.

Allocation and masking are listed as NA and none, respectively. These entries describe the registry's design information; they do not provide additional detail about how ratings were assigned, how staff were trained, or whether any other safeguards were used. Such details are not reported in the registry record. The rating outcome involves staff assessment, so a full appraisal would ordinarily benefit from knowing the assessment procedures, but those procedures cannot be inferred from the scale description alone.

What is the role of an analysis population?

The primary outcome population is identified as per protocol. In general, a per-protocol analysis includes participants who meet protocol-defined conditions for the analysis, but the exact conditions vary by study and must be specified. The registry record does not define those conditions or report the size of that population. Enrollment is listed as 74, but that figure should not automatically be treated as the primary endpoint denominator.

Missing outcome data can affect an estimate if participants with unavailable results differ from those with observed results. General methods may describe the amount and reasons for missingness and how it was handled. Here, missing-data counts, reasons, and handling methods are not reported in the registry record. It is therefore not possible to assess whether the endpoint analysis included all enrolled participants or how unavailable ratings were treated.

What do the planning illustrations mean?

In general, sample-size planning asks how much information a future study would need to detect a specified effect under stated assumptions. The listed planning assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a stated fraction of an observed effect. Those assumptions concern planning illustrations, not the observed single-group design described for this study.

Planning values are not observed power and do not establish that this study was designed with those assumptions. The registry record does not report the study's own sample-size justification. The planning illustration also refers to two arms, whereas this trial is registered as single-group; it should not be interpreted as evidence that the study had two randomized arms. No planning output or numerical sample-size target is reported in the record details.

Why might a model account for over-dispersion?

In general, over-dispersion means that observations vary more than a chosen statistical model expects. If a model ignores that extra variability, its uncertainty estimates can be too small and statistical evidence can appear more precise than warranted. Whether over-dispersion is relevant depends on the outcome and analysis structure. The registry record does not report a model, repeated-measure structure, or analysis that would establish whether this issue arose in this study.

Likewise, adjustments for covariates, clustering, or multiple outcomes require an analysis plan and relevant data. No such methods are reported. Because the registry lists no analyses and provides no outcome estimates, there is no basis for reconstructing an inferential method or recalculating an estimate from summary statistics. General statistical concepts can clarify what such methods would do, but they cannot replace missing study results.

10. Multiplicity, Missing Data and Analysis Populations

The record lists two outcome measures, including the primary comprehension-rating endpoint and a secondary outcome concerning capillary blood results within stated limits of a laboratory glucose method. It does not report an analysis for either outcome. A multiplicity strategy, such as a prespecified ordering of outcomes or an adjustment to account for several statistical tests, is not reported in the registry record.

Multiplicity is a general concern when several outcomes or comparisons are tested: the chance of at least one apparently notable result can increase as the number of tests grows, depending on the testing strategy. This concept does not establish that any particular result is misleading. In this record, no p-values or outcome analyses are reported, so the implications of multiplicity cannot be evaluated.

Missing-data information is also absent. The record does not report the number of participants with available primary ratings, the number with missing ratings, reasons for missingness, or a method for handling missing values. The listed enrollment of 74 is not enough to establish the denominator for the per-protocol primary endpoint.

The primary population is labeled per protocol, but the criteria for that population are not reported in the registry record. No sensitivity analysis or alternative analysis population is described. Consequently, the robustness of any endpoint estimate to missing data or population definitions cannot be assessed from the posted information. These are reporting gaps, not evidence that missing data or multiplicity did or did not affect the findings.

11. 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.

Most frequent non-serious adverse event terms

For the group titled Subjects With Diabetes, the registry lists 74 subjects at risk for serious adverse events and 0 affected by serious adverse events. For other adverse events, it lists 74 at risk and 4 affected. These are the safety counts recorded for this group. The record does not provide further detail about the nature, timing, severity, or attribution of the other events.

No top serious adverse-event terms are listed. Deaths are not reported in the registry record. The safety figures should be read as counts associated with the registry's stated group and categories; they do not describe the primary comprehension endpoint or the laboratory-comparison outcome.

In general, a count of affected participants is a descriptive safety summary. It does not, on its own, establish whether an event was caused by the device or whether the observed count differs from what would occur under another condition. A comparator and fuller event details would be needed for such assessments. The record does not report a comparative safety analysis.

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

The registry record establishes that the study evaluated labeling comprehension and blood glucose meter performance, and it defines a primary staff-rating threshold for task performance after reading the product labeling. It also identifies a secondary laboratory-comparison outcome. These details clarify the questions the study was designed to address.

The record does not report the primary endpoint percentage, the scale-category counts, or the secondary outcome result. It therefore does not quantify how participants performed, how often assistance was needed, or how capillary results compared with the laboratory method. No confidence interval or inferential analysis is reported, so the precision of an outcome estimate cannot be described.

The endpoint's threshold includes ratings that required consulting instructions or receiving assistance. In general, a favorable result under that threshold would not necessarily mean that every task was completed without help. Because the observed result is absent, even this endpoint-specific interpretation cannot be applied to the study's participants.

The single-group design provides no randomized control-group contrast. It does not establish a comparative effect, and the registry record does not support claims that the device works or does not work. The completed status and enrollment figure do not fill the gap in outcome reporting. The safety counts are separately reported, but they do not supply evidence about the primary endpoint or its precision.

In short, the posted information describes the study's purpose, design, endpoint definition, and limited safety counts. It does not provide the numerical findings needed to judge the observed performance or the strength of evidence around it. Conclusions about the results must remain limited to what the registry record actually reports.

13. Why This Trial Matters Statistically

This study is statistically useful as an example of why endpoint definitions and outcome reporting need to be considered together. A label such as comprehension can sound broad, but the registry defines it through staff-rated task performance and a specific threshold. That threshold includes participants who needed instructions or verbal assistance, so the endpoint's meaning depends on the rating rules rather than on the label alone.

The record also illustrates the distinction between a study question and a reported result. The registry explains what the study aimed to evaluate and how the primary rating scale was structured, but it does not report the observed percentage or an analysis. Without those data, readers cannot assess the size or precision of the outcome, regardless of how clearly the question is described.

The single-group design makes the intended descriptive focus especially important. A single group can be characterized, but a control-group contrast is not available in this record. The study should therefore be read according to its registered design rather than as a randomized comparison. The listed planning assumptions involving two arms do not change that design.

Finally, the record shows why analysis-population and missing-data details matter. The primary population is labeled per protocol, but the definition and denominator are absent. Without those details and the observed result, even a basic assessment of how much information supports the primary endpoint is not possible. These are general lessons about statistical interpretation, not claims about unreported study procedures.

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 main trial-specific limitation in the registry record is the absence of numerical outcome results. The primary percentage and secondary laboratory-comparison result are not reported, and the record lists no analyses. As a result, the observed performance, its uncertainty, and any statistical evidence cannot be evaluated from the posted information.

The primary endpoint is based on a staff rating with multiple levels, but the record provides neither category counts nor details about assessor procedures. The endpoint's per-protocol population is named without a definition or reported denominator. The enrollment figure alone does not clarify how many participants contributed to the primary analysis.

The study is registered as single-group, without allocation to a comparator and with no masking. It therefore does not offer a randomized control-group comparison in the registry description. The record's stated purpose mentions lay users and healthcare providers, while the arm description identifies subjects with diabetes; the roles and contributions of any healthcare-provider participants are not detailed.

The registry does not report eligibility criteria, missing-data handling, a multiplicity strategy, a statistical analysis plan, or a sample-size justification. It also does not report detailed safety-event descriptions or death counts. These missing details limit assessment of methods and interpretation; they do not establish that particular problems occurred.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Evaluation of Labeling Comprehension and Performance of a New Blood Glucose Meter System — NCT00804596.
• Registry record last updated 2016-02-29; status last verified 2016-01.
• Results first posted 2010-03-09.
• 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.

18. Record Summary

NCT00804596 is a completed, single-group device study of the Apollo Blood Glucose Monitoring System, also identified in the official title as CONTOUR® USB. The registry lists diabetes as the condition, enrollment of 74, no masking, and allocation as NA. The study aimed to assess acceptance of product user guides and system performance.

The primary endpoint is the percentage of participants rated 3 or lower for comprehension of labeling after reading product information, with a 1-2 hours timeframe and a per-protocol population. A secondary outcome concerns capillary blood results within stated limits of a laboratory glucose method. Neither outcome's numerical result is reported, and the registry lists no analyses.

The safety record lists 0 serious adverse events among 74 at risk and 4 other adverse events among 74 at risk. The record gives a start date of 2008-12 and a primary completion date of 2009-01. Its outcome and methodological reporting is insufficient to assess the magnitude or precision of the study findings.