An Explorative Pilot Study of a New Mobile Phone Application Measuring Eye Parameters of Eyes in Patients With SUD: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for An Explorative Pilot Study of a New Mobile Phone Application Measuring Eye Parameters of Eyes in Patients With SUD (NCT05737550), a na na study. The primary outcome is Usability Questionnaire - Question 1..

2. Clinical Question

The central clinical question is whether people with confirmed substance use disorder can use the Previct Drugs mobile phone application, including for self-administered pupillometry. The primary outcome asks how a study subject’s ability to use a mobile phone was evaluated during a test with the application. The response choices are Good, Manageable, and Less good.

The registry also identifies two secondary questions about whether self-administered pupillometry with the application can collect pupillograms from patients with substance use disorder, including after refinement. Those questions concern whether data collection is feasible; they are not a comparison of the application with another device or method. The record describes an exploratory, early-feasibility pilot intended to collect initial clinical data. It therefore addresses usability and data-collection feasibility in the study population, rather than a comparative treatment effect.

3. Trial Design

The registry describes an exploratory, pre-market, early-feasibility pilot of Previct Drugs. The stated purpose is to collect initial clinical data for the device. The study is marked completed, with an enrollment of 24 participants. The recorded start date is 2023-03-10, and the primary completion date is 2023-06-28.

The model is single group, allocation is listed as not applicable, and masking is none. Although the brief summary calls the investigation controlled, the registry does not describe a like-for-like control arm. Its own design fields and the listed arm describe an evaluation among subjects with confirmed substance use disorder. The record also flags that this is not a randomized comparison, so results should not be interpreted as a randomized estimate of a difference between groups.

The intervention is the device Previct Drugs. The listed arm description concerns evaluating its usability when used in the intended population. The primary outcome is a questionnaire item at Day 0 (Visit 1); the record lists additional questions about collecting pupillograms, including after refinement. The registry lists 13 outcome measures overall, but the individual results and analysis details are not reported in the registry record.

The registry lists phase as not applicable. It does not report a separate control group, random allocation procedure, or masking procedure beyond the entry that masking is none. These design features matter because they determine what the observations can establish. A single-group feasibility evaluation can describe participant responses and the conduct of data collection, but it does not by itself estimate how outcomes would differ under another device, usual practice, or an untreated condition.

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

Analysis population for the primary outcome, as defined in the registry: Full analysis set (FAS)

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: All eligible subjects = Full Analysis Set (FAS)

6. Primary Endpoint

The registry lists the primary outcome as Usability Questionnaire - Question 1., measured over Day 0 (Visit 1).

The primary endpoint is “Usability Questionnaire - Question 1.” It records participants’ evaluation of a study subject’s ability to use the mobile phone during a test with Previct Drugs. The questionnaire is described as containing 18 usability questions, and this endpoint is assessed at Day 0 (Visit 1). The registry identifies the endpoint unit as participants and the population as the full analysis set.

The response choices—Good, Manageable, and Less good—represent ordered descriptions of usability, rather than a direct measurement of pupillogram quality or a clinical outcome. The endpoint is relevant to an early-feasibility study because an application intended for use by patients must be usable by its intended users. A questionnaire response can describe perceived or observed ease of use, but it does not, by itself, establish that eye measurements are accurate, that pupillograms are successfully collected, or that the device improves a health outcome.

The registry record does not report how many participants selected each response, how responses were summarized, or whether the categories were combined for analysis. Accordingly, the endpoint’s results and precision cannot be assessed from the available registry entry.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a single-group, exploratory pilot, with allocation listed as not applicable and masking listed as none. These are important features when interpreting statistical methods. In general, a single-group study can describe observations within its enrolled participants, but it does not estimate a randomized difference between intervention and control groups. The registry explicitly warns that the study is not a randomized comparison. No detailed statistical analysis plan is reported in the registry record.

What kind of outcome is being measured?

The primary outcome is a participant count associated with a usability questionnaire response. The question asks for an evaluation of the study subject’s ability to use the mobile phone, and the listed responses are Good, Manageable, and Less good. The outcome description therefore defines categories that can be summarized by counting participants in each category. The registry classifies the outcome as binary, but the question description lists three response options. The way those categories were coded or analyzed is not reported in the registry record, so it is not possible to determine whether a binary summary was planned or used.

In general, categorical outcomes are often presented as counts, with denominators made clear. That approach lets readers see how observations are distributed across response categories. If categories are combined, the rule for combining them should be stated because it changes the meaning of the summary. The registry does not report category counts, a combined-category rule, or an estimate for this primary endpoint.

What would an estimate and its uncertainty mean?

In general, an estimate summarizes the observed data, while a confidence interval describes uncertainty around that estimate under the chosen statistical model and assumptions. For a categorical usability response, the estimate might describe the observed share or count in a category, depending on the analysis plan. No such estimate or confidence interval is reported for the primary outcome. It would not be appropriate to reconstruct one without the outcome counts and a specified method.

Confidence intervals are not guarantees about an individual participant’s experience. They characterize uncertainty in a population-level quantity under the statistical procedure used. Their interpretation depends on how participants were sampled, how outcomes were measured, and which analysis was specified. The registry does not provide enough information to assess those choices for the primary endpoint.

What does the planning note describe?

The registry’s planning note describes an illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It also states that the effect to detect is a specified fraction of the observed effect. For time-to-event outcomes, the note says its illustrations concern total events; for other outcomes, they concern participants per arm. This is a general planning description, not a report of the study’s own design assumptions.

That distinction is especially important because the recorded trial model is single group, not a two-arm randomized comparison. The note’s equal-allocation premise does not describe the listed study design. The observed effect, the fraction used in any particular illustration, and the resulting participant requirements are not reported in the registry record. Thus the planning note cannot establish how the actual enrollment was chosen or whether the study was designed to test a particular hypothesis.

In general, sample-size planning depends on the outcome, the target effect, variability, the significance threshold, desired power, and the analysis method. A planning calculation is conditional on those assumptions; it is not a result from the trial. In particular, a calculation based on an observed effect does not make that effect reliable, and a planned sample size should not be described as observed power. The registry record does not report a study-specific sample-size justification.

What does over-dispersion mean in general?

For count outcomes, some statistical models assume that variation follows a particular distribution. Over-dispersion means the observed variability is greater than that model expects. If it is ignored, standard errors and confidence intervals can be too small, making results appear more precise than warranted. This is a general statistical consideration, not a finding about this pilot: the primary outcome is described as a participant count, but the registry does not report a count model, a dispersion estimate, or an analysis of over-dispersion.

Likewise, a normal approximation is a modeling choice rather than an automatic property of the data. Its suitability depends on the outcome and the assumptions used in the calculation. The planning note mentions that approximation for its illustration, but the record does not say that it was used to analyze the primary questionnaire outcome.

What analyses are documented?

The registry lists zero analysis entries. That means no statistical analysis details or numerical analysis results are presented in the analysis records. It does not establish that no work was performed outside the registry; any such work is not reported in the registry record. In the absence of analysis methods, estimates, and uncertainty measures, the primary usability result cannot be independently assessed from the posted registry information.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 13 outcome measures, including the primary usability question and secondary questions concerning collection of pupillograms, with and without refinement of the application. When a study examines several outcomes, multiplicity can arise: in general, conducting multiple statistical tests can increase the chance that at least one result appears notable by chance. Researchers may address this through a prespecified hierarchy, adjusted thresholds, or a primarily descriptive approach. The registry record does not report a multiplicity strategy, a testing hierarchy, or adjusted analyses.

The record lists zero analysis entries. It does not report a primary-outcome result, secondary-outcome results, or statistical tests. Therefore, there is no basis for evaluating how multiple outcomes were handled or for interpreting any nominal significance claims. The absence of analysis entries should be read as absence of analysis details in the registry record, not as proof that analyses were never conducted elsewhere.

The primary outcome names the full analysis set as its population, but the membership rules for that set are not reported in the registry record. The record does not state how missing questionnaire responses, incomplete visits, or unusable pupillograms were handled. It also does not report the number of participants with evaluable data for each outcome. In general, missing-data handling can affect both the analyzed population and the interpretation of results; methods such as excluding incomplete observations or imputing values rely on assumptions that should be made explicit.

Without participant-level completeness information, outcome denominators, and missing-data rules, the amount and potential influence of missing information cannot be assessed. No assumptions about these procedures should be inferred from the full analysis set label alone.

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 5% reporting threshold.

For subjects with confirmed substance use disorder, the registry lists 24 participants at risk for serious adverse events and zero participants affected. It also lists 24 at risk in the other serious-event field and zero affected. Deaths are listed as zero, and no serious adverse-event terms are listed.

These entries are counts in the registry’s safety record. “At risk” is the listed group denominator; “affected” is the count recorded for the corresponding event category. The figures should not be read as a detailed account of every symptom or event, because the record does not provide event narratives or broader adverse-event results. In particular, zero serious adverse events does not establish that no non-serious events occurred, nor does it address risks that were not recorded or reported.

The entry is limited to this study group and the recorded safety categories. It is descriptive and does not compare safety with another intervention or population. The registry does not report additional detail on how safety events were collected or adjudicated.

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

The record describes a completed exploratory pilot of Previct Drugs in participants with confirmed substance use disorder. It identifies usability and self-administered pupillometry as areas of interest, and it records a primary questionnaire item about ability to use a mobile phone. It also documents enrollment and selected serious adverse-event counts. These registry entries describe the study’s purpose and recorded outcomes, but the primary response distribution is not reported in the registry record.

The record therefore does not establish how participants rated usability across the listed response categories. It also does not report whether pupillograms were successfully collected, how often collection succeeded, or how results changed after refinement. The secondary outcome descriptions indicate that these questions were of interest, but outcome descriptions alone are not findings.

Even if questionnaire counts were available, a single-group pilot would be primarily informative about observations in the enrolled study population and setting. It would not, on its own, show that the application performs better than another device or method. There is no like-for-like control comparison in the recorded design, and no randomized comparison is described. The pilot’s pre-market and early-feasibility framing also differs from a confirmatory test of a comparative clinical effect.

The serious adverse-event entry reports zero affected participants in the listed categories, but this should not be expanded into a claim that all adverse effects were absent. The posted record does not provide comprehensive safety detail or a comparative safety analysis.

In general, evidence about usability, successful measurement, measurement accuracy, and clinical benefit answers different questions. A questionnaire response can inform usability; it does not by itself validate the accuracy or clinical meaning of an eye measurement. The registry record does not report results that would resolve those separate questions. Its findings should therefore be interpreted within the narrow scope of the reported design and outcomes, without inferring unreported efficacy, accuracy, or broader safety conclusions.

13. Why This Trial Matters Statistically

This study is statistically notable because it focuses on feasibility and usability rather than a randomized treatment comparison. For a device intended to be used by patients, whether participants can operate it is a relevant early question. The primary questionnaire item makes that aspect explicit, while the secondary outcome descriptions address whether pupillograms can be collected through self-administered use.

At the same time, feasibility questions require clear reporting of what was attempted and what was successfully completed. Participant counts by usability response, denominators for each outcome, and information about incomplete or unusable measurements would help readers understand how the application performed in the intended population. Those results and details are not reported in the registry record.

The single-group design also clarifies the appropriate scope of inference. Descriptive observations can characterize the participants’ experience in the study, but a randomized comparator would be needed for a like-for-like estimate of differences between approaches. The registry explicitly identifies that this is not a randomized comparison, so the design should not be interpreted as one.

Finally, the record lists multiple outcomes but no analysis entries. This makes the distinction between planned questions and reported findings particularly important. An outcome’s presence in a registry is not evidence that it was successfully measured or that a specific result was obtained. Transparent reporting of analysis methods, missingness, and uncertainty would be needed to judge the strength and limits of any future claims. The pilot’s statistical importance lies in the questions it is designed to explore, while the available registry record leaves the primary result unresolved.

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 direct limitation is that the primary outcome’s response counts are not reported in the registry record. The questionnaire provides three response options, but without the distribution across them, the usability result cannot be described or its precision assessed. The record also does not give an analysis method for that outcome.

The design is single group, with allocation listed as not applicable and no masking. There is no like-for-like control comparison, and the registry explicitly notes that the study is not a randomized comparison. As a result, the record cannot support an estimate of a difference between Previct Drugs and an alternative. The brief summary’s use of “controlled” does not supply details of a control group that are absent from the recorded design.

The registry lists 13 outcome measures but zero analysis entries. It does not report a multiplicity approach, a detailed statistical analysis plan, or an analysis population rule beyond identifying the full analysis set for the primary outcome. The handling of missing questionnaire responses and incomplete pupillogram collection is not reported in the registry record. These omissions limit assessment of both the results and the process that produced them.

The planning note describes a two-arm illustration, while the recorded trial is single group. It does not report the study’s own sample-size justification or the effect and assumptions underlying any particular planning value. The safety entry is also limited to recorded event categories and does not provide broader adverse-event detail. Together, these reporting limits mean the registry supports a description of the pilot’s purpose and design, but not a full statistical evaluation of its usability findings.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: An Explorative Pilot Study of a New Mobile Phone Application Measuring Eye Parameters of Eyes in Patients With SUD — NCT05737550.
• Registry record last updated 2024-10-08; status last verified 2024-07.
• Results first posted 2024-10-08.
• 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

NCT05737550 is a completed, exploratory, pre-market pilot of the Previct Drugs mobile phone application in participants with confirmed substance use disorder. The registry lists 24 enrolled participants, a single-group model, allocation as not applicable, and no masking. The recorded study dates are 2023-03-10 for start and 2023-06-28 for primary completion.

The primary outcome is a usability questionnaire item at Day 0 (Visit 1), asking about the study subject’s ability to use a mobile phone, with responses of Good, Manageable, or Less good. The registry does not report the response counts or analysis results. It lists 13 outcome measures and zero analysis entries. For the safety group, 24 participants are listed at risk, with zero serious adverse events and zero deaths recorded. The design and available results support only a limited, descriptive reading of the registry record.