Use of Ocular Point of Care Ultrasound in Diagnosing Retinal Detachment in the Emergency Department: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Use of Ocular Point of Care Ultrasound in Diagnosing Retinal Detachment in the Emergency Department (NCT03106025), a non-randomized na study. The primary outcome is Number of Participants With Retinal Detachment Per Ultrasound Assessment.

2. Clinical Question

The study title frames the work as an evaluation of ocular point-of-care ultrasound for diagnosing retinal detachment in the emergency department. Its brief description says data are being collected along with other academic institutions regarding ultrasound accuracy. This context identifies the broad diagnostic question, but the registry does not report details about other institutions or their contributions. The record also does not report a protocol-defined diagnostic threshold, a prespecified accuracy target, or a clinical decision rule.

3. Trial Design

The registry identifies this as a completed, non-randomized study with no masking and a crossover model. Enrollment is 5, and the condition is retinal detachment. The listed interventions are Ultrasound, classified as a device, and Ophthalmology Assessment, classified as other. The record gives the study start date as 2018-02-05 and the primary completion date as 2018-03-25. Phase is listed as NA.

The design labels need to be interpreted alongside the registry’s explicit caution: allocation was non-randomized, and the arms are not a like-for-like control comparison. The crossover label does not establish how participants were assigned, the order in which assessments took place, whether every participant received both assessments, or whether assessment results could influence one another. Those details are not reported in the registry record. In particular, it would be unwarranted to treat the two listed intervention descriptions as randomized parallel groups or to infer a specific within-person comparison procedure.

The ultrasound description says each participant will receive an ocular ultrasound and that its results will be compared with a final diagnosis. The ophthalmology-assessment description refers to the number of subjects with retinal detachment per formal ophthalmology assessment and describes that assessment as a composite measurement. The components named in that description include chief complaint, primary impression, visual acuity, ultrasound diagnosis, whether a diagnosis changed, and ophthalmology diagnosis. The exact operational definitions and adjudication process are not reported in the registry record.

The sponsor is Loma Linda University, and the registry status is completed. Completion indicates the recorded study status; it does not establish that all planned assessments or analyses were completed or posted. The registry lists one outcome measure and zero analyses. A protocol, recruitment details, analysis populations, and the statistical analysis plan are not reported in 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.

Overall Study

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: Same criteria as participant flow assignment.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Retinal Detachment Per Ultrasound Assessment, measured over at baseline.

The primary endpoint is titled “Number of Participants With Retinal Detachment Per Ultrasound Assessment.” Its unit is participants, its parameter is a count of participants, and its timeframe is at baseline. The description specifies the number of participants with retinal detachment according to ocular ultrasound results. This endpoint therefore records a count classified by ultrasound assessment rather than a direct measure of diagnostic accuracy.

A count can describe how many participants meet an outcome definition in the assessed group. On its own, it does not show how many ultrasound assessments were correct, how many were incorrect, or how often ultrasound and an independent reference assessment agreed. Diagnostic performance is usually described using information about both disease-positive and disease-negative classifications against a defined reference standard. Measures such as sensitivity, specificity, and predictive values require those classification details and suitable denominators. Those results are not reported in the registry record.

The endpoint may be relevant to the stated diagnostic purpose because it records ultrasound findings of retinal detachment. However, the endpoint title does not state that the outcome is the number correctly identified, and the description does not provide a cross-tabulation against final diagnosis. It would therefore be inaccurate to interpret the endpoint count as a count of confirmed cases, correct diagnoses, or successful examinations. The numerical endpoint result is not reported in the registry record, so the observed count and its precision cannot be described.

The registry specifies baseline as the timeframe. Further rules for classifying an ultrasound result, handling an indeterminate examination, or defining the final diagnosis are not reported in the registry record. These details matter because endpoint interpretation depends on consistent definitions and an appropriate reference assessment.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies one binary outcome measure, described as a count of participants with an event. In this setting, the event is retinal detachment according to ocular ultrasound assessment. The endpoint is a count, not a continuous measurement such as a laboratory value. For a count to be interpretable, the event definition, assessment method, timeframe, and population counted need to be clear. The record specifies the baseline timeframe and ultrasound-based classification, but further classification rules are not reported in the registry record.

What a count can and cannot say

A count tells the reader how many people in a defined group were classified as having the outcome. It does not, by itself, show how closely a diagnostic test matches a reference standard. For diagnostic assessment, each participant’s test classification is typically compared with an independent reference classification. The resulting joint pattern distinguishes participants classified positive or negative by each method. From that pattern, diagnostic measures can be estimated, with uncertainty. The registry does not report that joint pattern or any such accuracy estimates.

The primary endpoint title refers to participants with retinal detachment per ultrasound assessment, while the study description refers to comparison with a final diagnosis. These descriptions do not provide enough information to determine how the final diagnosis was made, whether ultrasound findings contributed to it, or how disagreements were resolved. Such details are important because using the test under evaluation as part of the reference can affect the interpretation of apparent agreement. Whether that occurred in this study is not reported in the registry record.

Allocation, masking, and crossover

Allocation is listed as non-randomized, masking as none, and the model as crossover. Randomization, in general, is used to make assigned groups comparable in expectation; it does not guarantee balance in every study. In a non-randomized design, differences between groups or assessment pathways may reflect how participants were selected or assessed as well as the intervention itself. The registry explicitly warns that the arms are not a like-for-like control comparison. Thus, the listed ophthalmology assessment should not be interpreted as a randomized control arm.

Masking, in general, can reduce the influence of knowledge about one assessment on another assessment or on outcome classification. The registry lists no masking. It does not report which people knew the ultrasound results, whether ophthalmology assessors were independent, or the order and timing of assessments. A crossover design generally involves more than one condition or assessment within a participant, but the label alone does not specify its conduct. Sequence, period, washout, and within-participant analysis details are not reported in the registry record.

Estimation and uncertainty

Statistical estimation uses observed data to describe an outcome, while an uncertainty interval communicates how imprecise that estimate may be under a stated model. A confidence interval is a general method for expressing uncertainty around an estimate; its width depends on the information available and the assumptions used. The registry record does not report an interval for the primary endpoint or a statistical model for estimating diagnostic performance. With no numerical primary result posted, neither the estimate nor its precision can be assessed.

For diagnostic accuracy, the relevant estimates depend on the reference classification and the number of participants in each disease and test-result category. Small datasets can produce especially imprecise estimates, and empty or sparse categories can make standard methods unsuitable. These are general considerations, not reported findings about the study’s unposted classifications. The registry’s enrollment of 5 underscores that the study record contains a limited participant count, but it does not establish the distribution of diagnoses or test results.

Planning illustrations

The stated planning framework describes an illustration computed from the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. The framework is identified as a planning illustration rather than the trial’s own design. The registry does not report a sample-size justification for the study, and the numerical primary outcome and analysis results needed to evaluate an effect-based illustration are not reported in the registry record.

A sample-size illustration estimates how many participants might be needed under specified assumptions. It is not an observed study result, and it is not observed power. Power is a design concept tied to a particular assumed effect, variability or event rate, test, and significance threshold. A post hoc calculation based on an observed effect does not establish the probability that the completed study would detect a true effect. The assumptions stated for an illustration should therefore be read as planning conditions, not as evidence that this study was designed or powered according to them.

Equal allocation is an assumption in the described planning framework; it does not override the registry’s non-randomized allocation or its warning that the arms are not comparable control groups. Likewise, the normal approximation is a general computational assumption, not a reported analysis of this endpoint. Details of any actual statistical test, multiplicity control, missing-data method, or analysis population are not reported in the registry record.

Multiplicity and analysis choices

Multiplicity concerns the increased chance of misleading findings when multiple hypotheses or outcomes are tested. A prespecified analysis plan can state which outcomes are primary and how multiple tests will be handled. The registry lists one outcome measure and zero analyses, but it does not report a multiplicity procedure, whether other outcomes were assessed, or a prespecified analysis plan. It is therefore not possible to evaluate how analysis choices were made or whether any adjustment was appropriate.

Missing-data methods are also relevant because exclusions or unavailable assessments can change the group represented by an analysis. The enrollment is 5, but the record does not report a participant flow, missing assessment counts, exclusions, or analysis populations. No assumptions about complete follow-up or complete paired assessments should be made from enrollment alone. These unreported methods and data details limit reproducibility and the interpretation of any diagnostic comparison.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Patients Receiving Ultrasound")
n      <- c(5)
events <- c(5)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Patients Receiving Ultrasound  5  5  100.0  47.8  100.0  56.6  100.0  54.1  99.6

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one outcome measure and zero analyses. The primary measure is a baseline count of participants with retinal detachment according to ultrasound assessment. No numerical result, hypothesis test, confidence interval, or analysis model is reported in the registry record. The registry also does not report whether additional outcomes or exploratory analyses were performed outside the listed record.

Multiplicity arises when several outcomes, comparisons, or statistical tests are examined. In general, more testing can increase the chance that a result appears noteworthy by chance, so an analysis plan may specify a primary comparison and an adjustment strategy. The registry does not report a multiplicity plan or adjustment procedure. With zero analyses listed, there is no reported testing structure to assess.

Missing-data interpretation requires knowing which participants were enrolled, assessed, and included in each analysis, as well as how unavailable or indeterminate results were handled. The record reports enrollment of 5, but does not report participant flow, missing assessments, exclusions, incomplete ultrasound examinations, or indeterminate diagnoses. It also does not report whether the analysis population included all enrolled participants or only those with paired assessments.

The record does not specify an intention-to-diagnose or other analysis population, nor does it describe imputation or sensitivity analyses. Such methods should not be presumed. Since the numerical endpoint and diagnostic comparison are not reported, the effect of missing information on the estimate cannot be evaluated. These omissions concern reporting in the registry record; they do not establish what analyses or data-handling procedures may have been used elsewhere.

12. 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 safety figures list the Patients Receiving Ultrasound group with 5 participants at risk. The record reports 0 serious adverse events among those participants, 0 other adverse events among 5 participants at risk, and 0 deaths. These figures are counts, not estimates of an event rate adjusted for follow-up time. The registry does not report the duration or completeness of safety follow-up.

A zero count means that no event in the relevant category is recorded for the listed group in the registry results. It does not demonstrate that the event is impossible or that risk is absent. In general, safety counts from a small group provide limited information about uncommon or delayed events. The enrollment of 5 means that the safety experience recorded is limited in scale, and the registry does not give additional safety detail that would broaden its interpretation.

The record does not list serious adverse event terms, and the top serious adverse event terms list is empty. It does not report how adverse events were defined, actively collected, judged related to ultrasound, or followed over time. No inference about comparative safety is supported: the record lists no comparable randomized control group, and the registry cautions that the arms are not a like-for-like comparison. These counts describe the posted safety record only.

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

The registry record establishes that a completed, non-randomized study enrolled 5 participants and listed ocular ultrasound assessment for retinal detachment as its primary outcome. It also lists ophthalmology assessment, no masking, and a crossover model. The study description states that ultrasound results were to be compared with a final diagnosis. These details characterize the intended diagnostic setting and the methods as registered.

The record does not report the numerical primary endpoint result. It also does not report the cross-classification of ultrasound findings against a reference diagnosis or any formal diagnostic-accuracy estimate. As a result, the posted information cannot quantify how often ultrasound classifications agreed with a reference, how often they differed, or the precision of any such estimate. The endpoint count should not be interpreted as a number of correct diagnoses.

The study’s non-randomized allocation and the registry’s warning that the arms are not a like-for-like control comparison are important. The listed ophthalmology assessment cannot be treated as a randomized control arm. The crossover designation does not, by itself, establish the timing, sequence, independence, or analytic handling of assessments. Those details are not reported in the registry record.

The safety record reports zero serious adverse events, zero other adverse events, and zero deaths in the ultrasound group, with 5 participants at risk. These findings describe only the recorded counts and do not establish an absence of risk. The available safety information is limited and does not include detailed event definitions or follow-up.

In general, a diagnostic study can be informative even when it is not randomized, but interpretation depends on how participants were selected, how the test and reference were conducted, and how results were compared. The registry record does not provide enough outcome or methods detail to judge those features quantitatively. It therefore supports a description of the study and its reporting gaps, rather than a conclusion about the diagnostic performance of ocular ultrasound.

14. Why This Trial Matters Statistically

This study raises a central statistical issue in diagnostic research: counting test-positive participants is not the same as measuring whether a test classifies participants correctly. A useful diagnostic assessment depends on comparing test results with a clearly defined reference diagnosis and reporting the full pattern of classifications. The registry lists a count-based primary endpoint, but the numerical result and the diagnostic comparison are not reported in the registry record.

The design labels also matter. Non-randomized allocation and no masking can affect the interpretation of comparisons, while the registry explicitly cautions that the listed arms are not a like-for-like control comparison. A crossover label alone does not specify how the assessments were sequenced or whether their interpretations were independent. Clear reporting of these details is necessary to understand what comparison the data can support.

Enrollment of 5 makes precision and transparent reporting especially important. In general, limited participant counts can leave diagnostic estimates uncertain, particularly when outcome categories are sparse. Here, the registry does not report the underlying classifications or uncertainty estimates, so readers cannot determine the amount of information available for diagnostic accuracy. The missing result is not repaired by the study’s completed status or by the description of its intended comparison.

The registry lists one outcome measure and zero analyses. This makes the distinction between a registered endpoint, an observed result, and an inferential analysis particularly visible. Statistical interpretation requires all three to be distinguishable: what was intended to be measured, what was observed, and how uncertainty or comparisons were analyzed. The record supplies the endpoint definition but does not report the latter results.

These points are broadly relevant to clinical researchers. A compact count can be easy to read but may not answer the clinical measurement question unless the reference standard, analysis population, missing data, and uncertainty are also clear. The record’s limitations illustrate why transparent outcome reporting is essential when a study concerns diagnosis rather than treatment assignment.

15. 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 registry record contains limited information for evaluating the diagnostic question. Although it describes comparison of ultrasound results with a final diagnosis, it does not report the final-diagnosis procedure, the reference standard, criteria for a positive ultrasound, or how discordant findings were resolved. The numerical primary endpoint result is not reported in the registry record, and neither are diagnostic-accuracy estimates or their uncertainty.

Enrollment is 5, and participant characteristics, eligibility criteria, recruitment methods, and the number with retinal detachment are not reported in the registry record. The record does not report a participant flow, the number completing each assessment, or how missing or indeterminate results were handled. These omissions prevent assessment of the population represented by any potential comparison.

The study is classified as non-randomized, unmasked, and crossover. The registry cautions that the arms are not a like-for-like control comparison. Details needed to interpret the crossover designation—including assessment sequence, timing, assessor independence, and within-participant analysis—are not reported in the registry record. The record also does not identify an analysis population or a statistical analysis plan.

There is one listed outcome measure and zero listed analyses. A sample-size justification, prespecified diagnostic performance target, and method for quantifying precision are not reported in the registry record. The stated planning framework is an illustration based on an observed effect, rather than the study’s own design, and should not be interpreted as observed power.

Safety reporting is also brief: the ultrasound group has 5 participants at risk and reports 0 serious adverse events, 0 other adverse events, and 0 deaths. Event definitions, collection procedures, and follow-up duration are not reported in the registry record. These limitations concern what the registry reports; they do not establish what may have been documented in study materials outside the registry.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Use of Ocular Point of Care Ultrasound in Diagnosing Retinal Detachment in the Emergency Department — NCT03106025.
• Registry record last updated 2022-10-18; status last verified 2022-09.
• Results first posted 2022-10-18.
• 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.

19. Record Summary

The registry record describes a completed study titled “Use of Ocular Point of Care Ultrasound in Diagnosing Retinal Detachment in the Emergency Department.” Loma Linda University is listed as sponsor. The study began on 2018-02-05, had a primary completion date of 2018-03-25, and enrolled 5 participants. Retinal detachment is the listed condition.

The design is classified as non-randomized, unmasked, and crossover, with phase listed as NA. Ultrasound and ophthalmology assessment are the listed interventions. The registry cautions that the arms are not a like-for-like control comparison. The primary endpoint is a baseline count of participants with retinal detachment according to ultrasound assessment.

The record lists one outcome measure and zero analyses. A numerical primary endpoint result and diagnostic-accuracy estimates are not reported in the registry record. In the ultrasound group, 0 serious adverse events and 0 other adverse events are reported among 5 participants at risk, with 0 deaths. The posted information therefore documents the study framework and limited safety counts but does not quantify diagnostic performance.