Evaluation of the Accuracy and Usability of the ACR | U.S. Urine Analysis Test System in the Lay User Hands: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluation of the Accuracy and Usability of the ACR | U.S. Urine Analysis Test System in the Lay User Hands (NCT04626271), a na na study. The primary outcome is Accuracy Evaluation: The Degree of Agreement (%) of the ACR | U.S. Urine Analysis Test System as Compared to the Comparator Device.

2. Clinical Question

3. Trial Design

This was a completed, single-group device evaluation, with no masking listed and allocation marked NA. The registry lists Healthy.io Ltd. as the sponsor, albuminuria as the condition, and enrollment of 250. The listed study dates are 2020-08-31 for the start and 2020-10-23 for primary completion. The registry identifies the study as completed. It does not report a randomized allocation or a parallel control group, so the comparator device should not be read as a like-for-like control arm.

The study placed the ACR | U.S. system in a simulated home-use setting. Participants were asked to complete tasks with the kit and smartphone application, including testing a urine sample on two mobile phones. Each participant first used their preferred platform, iOS or Android; that session assessed usability and accuracy. The participant then used the other platform, and that session assessed accuracy only. Study staff tested urine samples with the URiSCAN Optima Urine Analyzer after lay-user testing. The registry describes those comparator results as the “true value” for the accuracy assessment.

Usability information came from questionnaires completed by the participant and the observer, and from user-performance evaluation. This design can describe how lay users interacted with the device under the specified simulated conditions and how the device readings compared with comparator readings. It does not establish performance in every home-use situation, or outcomes beyond those measured in the study.

The registry gives a primary outcome timeframe of 2 months and lists completion status, but does not state how many participants completed all tasks or contributed data to each outcome. It also does not report a formal sample-size justification, a detailed statistical analysis plan, or the outcome estimates. Without those details, the design can be summarized, but its realized analysis and precision cannot be fully assessed from 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.

Before assignment: The study enrolled 250 subjects who met the inclusion criteria and performed a total of 546 tests at two U.S. clinical sites

Overall Study

Analysis population for the primary outcome, as defined in the registry: Each study participant was asked to perform the test twice: first, by using their preferred platform device (iOS or Android), in which usability and accuracy were evaluated; and secondly by using the other platform device, which was assessed for accuracy only. In addition, 23 spiked samples were used in order to achieve sufficient sample sizes for all analyte blocks, each sample on both platforms as well.

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 Accuracy Evaluation: The Degree of Agreement (%) of the ACR | U.S. Urine Analysis Test System as Compared to the Comparator Device, measured over 2 months.

The primary endpoint is the degree of agreement between results from the ACR | U.S. Urine Analysis Test System when operated by a lay user and results from the URiSCAN Optima Urine Analyzer when operated by a healthcare professional. The registry specifies two forms of agreement: the percentage of reported values that match exactly, and the percentage that match within ±1 block. The comparison covers all reported values, described as blocks, across different concentrations.

Agreement is relevant because the study evaluates whether readings from a lay-user-operated device correspond to readings from a comparator on the same urine samples. Exact agreement is the stricter measure. Agreement within ±1 block allows a nearby result to count as a match, so it addresses a less exact level of correspondence. These summaries answer related but distinct questions; one cannot substitute for the other.

In general, agreement describes the closeness of paired measurements under a defined matching rule. It does not by itself establish that either device is correct in an absolute sense, nor does it measure clinical outcomes. The registry treats the comparator result as the “true value” for this study, but does not report independent validation of that assumption.

The registry record does not report the observed exact-match or ±1-block agreement percentages, their confidence intervals, or the number of values contributing to each estimate. Thus the endpoint definition is available, but its observed magnitude and precision are not. The usability evaluation is listed separately as a secondary outcome and should not be conflated with the primary agreement endpoint.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The record describes an accuracy evaluation based on agreement between two devices used by different types of operators. Lay users operated the ACR | U.S. system, while study staff used the URiSCAN Optima Urine Analyzer. The registry says the same urine sample was tested on the two devices and identifies the comparator result as the “true value” for the evaluation. This makes the comparison paired at the sample level in the described procedure: each sample’s reading on one device is considered alongside its reading on the other.

What do the agreement measures mean?

In general, exact-match agreement is the share of comparisons in which the two reported values are identical under the study’s coding. The ±1-block measure counts results that are identical or within one block according to the stated matching rule. The second measure is more permissive than exact matching, so it can be higher without indicating a contradiction. Both are descriptive agreement measures; each summarizes a different threshold for considering two readings close enough to match.

The registry says that the primary objective concerns percent exact match and percent ±1-block match for all reported values, across different concentrations. It does not describe a more detailed model, such as how multiple values from a participant or sample would be combined, weighted, or accounted for statistically. Those analysis details are not reported in the registry record. The record also does not give the observed percentages, their denominators, or confidence intervals.

Why do paired readings matter?

In general, comparing readings from the same sample avoids treating distinct samples as if they were interchangeable: the sample itself is shared by the two device readings. However, repeated readings can still be related. Participants performed the test on two mobile platforms, and the primary outcome description includes 23 spiked samples. The registry does not explain whether or how these repeated or spiked-sample observations were handled in the statistical analysis. When observations are related, an analysis that assumes every reading is independent may give uncertainty estimates that are too small. Whether this issue was addressed is not reported in the registry record.

More generally, variation in measurements can exceed what a simple model assumes. Over-dispersion means the observed variation is greater than the model’s expected variation; if present and ignored, uncertainty estimates and tests may be misleading. The registry does not report whether over-dispersion was assessed or whether any model was used for agreement outcomes. This is a general statistical consideration, not a claim about the study’s data.

What can a confidence interval add?

In general, a confidence interval communicates the precision of an estimate, in addition to its central value. For an agreement percentage, it would help readers see how much uncertainty remains around the estimate. The registry record does not report confidence intervals for the primary endpoint, nor does it state the method that would be used to calculate them. No interval should be inferred from the enrollment count alone: precision depends on the observations contributing to the endpoint and on their structure, which are not fully described in the record.

How should planning illustrations be read?

The sample-size section contains planning illustrations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Those are illustrations for hypothetical planning, not observed power and not evidence that the trial was designed as a two-arm comparison. The study itself is described as single group, and the registry marks allocation NA. A planning illustration does not establish the study’s own sample-size rationale. That rationale is not reported in the registry record.

The record does not report an inferential statistical plan, a specified hypothesis test, an interim-analysis plan, or the handling of missing readings. It also lists no analyses. Consequently, explanations of pairing, precision, and model assumptions are general statistical context; they cannot be attributed to analyses actually performed for this evaluation.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures: the primary accuracy evaluation and a secondary usability evaluation. It does not report a plan for controlling multiplicity, such as how interpretation would account for examining more than one endpoint or more than one agreement definition. The primary outcome itself includes exact-match and ±1-block agreement. The record does not say whether these were treated as co-primary measures, whether one was designated as the main analysis, or whether any adjustment was planned. These details are not reported in the registry record.

The record lists no analyses. It also does not report a statistical analysis plan describing hypotheses, statistical tests, confidence-interval methods, or rules for interpreting results. The absence of those details means readers cannot determine from the registry how confirmatory or exploratory analyses were distinguished, or whether any planned methods changed.

Missing-data handling is also not described. The registry does not state how incomplete tests, missing device readings, questionnaire nonresponse, or unusable samples were handled. It does not report whether all enrolled participants were included in every outcome analysis, or give outcome-specific denominators. Enrollment of 250 should not be assumed to equal the number analyzed.

The record describes testing on a preferred mobile platform and then on the other platform, with different evaluation aims for the two sessions. It does not report the analysis populations for either platform, whether all participants completed both sessions, or whether incomplete platform data were excluded. The registry also does not explain how the 23 spiked samples were incorporated in the analysis.

In general, multiplicity, missing-data rules, and analysis-population definitions can influence estimates and uncertainty. Without these details and the outcome results, readers cannot assess how robust the findings might be to alternative analytical choices. The relevant plans and dispositions are not reported in the registry record.

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.

The registry lists 250 participants at risk for the ACR | U.S. Urine Analysis Test System group and reports zero participants affected by serious adverse events. It also lists 250 at risk for other adverse events and zero affected. Deaths are listed as zero, and no top serious adverse-event terms are listed.

These are the figures recorded for this evaluation; they should not be read as proof that adverse events are impossible or that no events could occur in other settings. A count of zero affected in the registry is a reported observation, not a guarantee of zero risk. The record does not give further detail about event definitions, the method of collection, follow-up completeness, or the relationship of any event to device use.

The safety figures also do not answer the primary accuracy question. Agreement between the ACR | U.S. system and the comparator is a separate outcome, and its results are not reported in the registry record. Likewise, these adverse-event counts do not summarize usability performance. The registry lists the study as completed, but does not state how many participants completed all study tasks or the safety follow-up. Read the counts as registry-reported event summaries, with those reporting limits in mind.

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

This study’s stated purpose was to evaluate the accuracy and usability of a lay-user-operated urine analysis system in a simulated home-use environment. The primary endpoint was defined using exact agreement and agreement within ±1 block between the ACR | U.S. system and the URiSCAN Optima Urine Analyzer. The secondary outcome concerned user performance. These endpoint descriptions clarify the questions, but the registry record does not report their results.

Accordingly, the posted record does not establish the observed level of agreement, the precision of that estimate, or the observed usability performance. It also does not show whether results differed between iOS and Android use, or how the readings from the two platform sessions were analyzed. Those findings cannot be reconstructed from the enrollment figure or study status.

The evaluation compares device readings on urine samples; it is not a randomized comparison of treatments and does not report patient health outcomes. The comparator provides a reference for the study’s accuracy comparison, but the record’s use of “true value” does not by itself demonstrate that the comparator is error-free. The results, if reported elsewhere, would need to be interpreted in light of the device procedures, outcome definitions, and analysis details.

In general, statistical evidence is more informative when the estimate, denominator, and uncertainty are all available. Here, those primary numerical results and precision measures are not reported in the registry record. It is therefore not possible from this record to decide how close readings were, how consistently users completed tasks, or how much uncertainty surrounds any estimate.

The study’s completion status indicates that the registry lists it as completed. It does not supply a statistical conclusion. The appropriate reading is that the registry documents a planned comparison and the broad evaluation procedures, while leaving the main outcomes unavailable. No conclusion about device performance should be inferred from the absence of posted outcome values.

13. Why This Trial Matters Statistically

This evaluation raises statistical questions that are important in device studies: what counts as agreement, how a reference device is treated, and how repeated measurements are summarized. The primary endpoint explicitly separates exact matching from matching within ±1 block. Keeping those definitions distinct matters because each represents a different tolerance for discrepancy, and the two measures may tell different parts of the measurement-comparison story.

The study also illustrates why unit of analysis matters. Participants used two platforms, and the same urine samples were tested with the study device and comparator. Readings from the same participant or sample may be related rather than independent. In general, recognizing that structure is important for valid uncertainty estimates. The registry record does not say how repeated readings or the 23 spiked samples were handled, so the actual analysis cannot be assessed on this point.

The design is also useful to distinguish from a treatment trial. It is a single-group evaluation with a device comparator, not a randomized, like-for-like comparison of clinical interventions. Its central statistical question concerns agreement and usability under the described conditions. Those outcomes do not, on their own, establish clinical benefit or performance in every setting.

Finally, the registry’s missing outcome estimates highlight the difference between a clearly stated endpoint and an interpretable result. Without observed agreement percentages, denominators, and uncertainty intervals, readers cannot judge either the size or precision of the primary findings. A completed study record can still leave the main statistical evidence unavailable for review. This makes transparent reporting of results and analysis details central to evaluating the study.

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 most consequential limitation of the registry record is that it does not report the primary accuracy results or the secondary usability results. There are no posted exact-match or ±1-block percentages, confidence intervals, or outcome-specific denominators. Therefore, neither the magnitude nor precision of the measured agreement can be evaluated from this record.

Enrollment is listed as 250, but the number who completed testing and the number included in each analysis are not reported in the registry record. The record also does not describe missing readings, incomplete questionnaires, exclusions, or the handling of unusable tests. These omissions make it difficult to understand whether the analyzed observations represent all enrolled participants.

The study used a simulated home-use environment, and the registry describes task completion with the kit and smartphone application. It does not report how closely that environment represented use outside the study setting. The recorded procedures therefore define the context of the evaluation but do not establish that the same user performance would occur in every home-use circumstance.

The comparator is described as the “true value,” but the record does not give further evidence about its validation or measurement uncertainty. It also does not explain how multiple reported values, repeated platform tests, or the 23 spiked samples entered the analysis. Platform-specific accuracy results are not reported, and usability was assessed only on the first, preferred platform session as described in the primary outcome population text.

Finally, no statistical analysis plan, sample-size justification, multiplicity approach, or missing-data plan is reported. These limitations concern what can be learned from the registry record; they do not establish that the study lacked those procedures, only that they are not reported there.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Evaluation of the Accuracy and Usability of the ACR | U.S. Urine Analysis Test System in the Lay User Hands — NCT04626271.
• Registry record last updated 2023-05-09; status last verified 2023-04.
• Results first posted 2023-05-09.
• 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

The registry describes a completed, single-group device evaluation sponsored by Healthy.io Ltd., with enrollment of 250 and no masking listed. Participants used the ACR | U.S. Urine Analysis Test System in a simulated home-use setting, and study staff tested urine samples with the URiSCAN Optima Urine Analyzer. The primary endpoint was exact-match and ±1-block agreement; user-performance analysis was listed as a secondary outcome.

The registry reports zero participants affected by serious adverse events, zero affected by other adverse events, and zero deaths among the listed group counts. It does not report the observed primary or secondary outcome results, confidence intervals, analysis populations, or a detailed statistical plan. Thus, the record defines the evaluation but does not provide the numerical performance findings needed to assess its results.