Urinalysis Results in Healthy Individuals: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Urinalysis Results in Healthy Individuals (NCT04055675), a registered phase not stated study. The primary outcome is False Positive Urine.

2. Clinical Question

The study asks how often adult volunteers without acute symptoms have leukocytes or nitrites detected by a urine dipstick. The registry record labels the primary outcome “False Positive Urine” and defines it as a urine sample with at least 1+ leukocytes or positive nitrites. That definition identifies a dipstick finding; it does not, by itself, establish whether the finding is a false positive against an independent diagnostic reference.

Incidental hematuria is listed as a secondary outcome. The registry record does not report its result either. Accordingly, the available record establishes the question and the operational definition, but does not establish the observed frequency of either finding.

3. Trial Design

NCT04055675, titled “Urinalysis Results in Healthy Individuals,” is a prospective, observational study. Its official title describes the frequency of leukocytes and nitrites in the urine of healthy adults. The brief summary says adult volunteers with no acute symptoms provide a urine sample for dipstick testing. The registry lists the sponsor as Kendall Healthcare Group, Ltd., an enrollment of 200, a start date of 2019-07-03, and a primary completion date of 2019-12-30. The status is completed.

The record describes asymptomatic male and female volunteer groups. The group descriptions specify adults over the age of 18, without acute symptoms, who volunteered to provide a urine sample. The safety listing gives 96 participants in the male group and 104 in the female group. These are the group counts in that listing; the record does not establish that every enrolled participant contributed to every outcome analysis.

The urine dipstick is the diagnostic test being assessed. According to the primary outcome timeframe, the urine is tested immediately, with results available two minutes after placing the reagent strip in the urine. The primary endpoint is a participant count under a stated dipstick definition. Incidental hematuria is the listed secondary outcome.

This is not a randomized trial. Allocation is not stated, and the registry explicitly cautions that the groups are not a like-for-like control comparison. Differences between male and female groups, if reported, would therefore be descriptive rather than evidence from randomized assignment. The registry record does not report the recruitment method beyond volunteering, eligibility exclusions beyond the group descriptions, a sample-size justification, or a detailed statistical analysis plan.

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.

6. Primary Endpoint

The registry lists the primary outcome as False Positive Urine, measured over The urine is tested immediately, and results are available two minutes after placing the reagent strip in the urine..

The primary endpoint is the count of participants whose urine sample meets the registry’s operational definition of “False Positive Urine”: at least 1+ leukocytes or positive nitrites on the dipstick. The endpoint is recorded in participants, and the stated timing is immediate testing, with results available two minutes after the reagent strip is placed in the urine.

This measure is used to describe how often the specified dipstick findings occur in the study’s volunteers without acute symptoms. It combines two possible findings: leukocytes at or above the stated threshold, or positive nitrites. The registry does not report separate primary counts for those components, so their individual frequencies cannot be described from this record.

The label “false positive” requires care. As a general statistical and diagnostic principle, a positive test is established as false only by comparison with an appropriate reference standard or other definition of the true condition. The registry record defines the endpoint by dipstick findings but does not describe an independent confirmation procedure or reference standard. The endpoint therefore supports a count of samples meeting the stated dipstick rule; it does not alone establish the diagnostic accuracy of the test or whether a particular finding was clinically false.

The primary endpoint result is not reported in the registry record. The number of participants meeting the rule, the number who did not meet it, and any estimated frequency or uncertainty are therefore not available from this record. Incidental hematuria is listed as a secondary outcome, but its result is also not reported.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes an observational study with a binary-style primary endpoint recorded as a participant count. Understanding the intended measure is possible from the endpoint definition, but the record does not include the outcome counts or an analysis entry. The statistical concepts below explain how such data are generally interpreted; they are not a description of analyses reported for this study.

What does a participant count represent?

For a binary outcome, each participant can be classified according to whether the defined event occurred. Here, the event is meeting the dipstick rule of at least 1+ leukocytes or positive nitrites. A count states how many participants meet that rule. To interpret the count as a frequency, an appropriate denominator is also needed: the number of participants whose samples were assessed for that endpoint. A proportion expresses the event count relative to that denominator. The registry record does not report the primary event count, the endpoint-specific denominator, or a proportion.

The registry’s endpoint is a combined rule. A sample qualifies if either of the specified dipstick findings is present. Such a combined endpoint can answer a broad question about meeting the rule, but it does not show which component drove the result. Separate component counts would be needed to distinguish leukocyte findings from nitrite findings. Those component results are not reported in the registry record.

What would uncertainty describe?

In general, a confidence interval gives a range of values compatible with the observed data under a specified statistical method. For a participant proportion, the interval reflects sampling uncertainty in estimating the frequency in a broader population from the participants observed. Its interpretation depends on the denominator, the event count, and the method used. The registry record reports no primary interval or method for calculating one, so no interval can be interpreted for the primary endpoint.

A confidence interval is not a guarantee that a particular value is correct, and its width does not address every source of uncertainty. In this volunteer study, selection into the sample and the applicability of the volunteers to other populations are distinct considerations from sampling uncertainty. Statistical precision cannot correct for selection or establish that the group represents people who were not enrolled.

What does the study design allow?

Prospective observation means the study assesses volunteers and collects urine dipstick results as described, rather than assigning participants to randomized treatment groups. The registry identifies male and female volunteer groups, but states that they are not a like-for-like control comparison. General comparisons between nonrandomized groups can be affected by differences in participant characteristics or other factors. A raw difference, if available, would be descriptive and would not by itself establish a causal explanation.

The record does not state an allocation procedure, adjusted model, or covariates for analysis. It also does not report a prespecified group-comparison analysis. The primary endpoint is described as a count, but the registry does not specify a statistical test or modeling approach for comparing groups. No such procedure should be inferred from the fact that two groups are listed.

How should planning assumptions be read?

The study’s registry record does not report a sample-size justification or a protocol-based power calculation. Planning assumptions described for illustrative sample-size calculations use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. They are planning conventions, not evidence that those choices were part of the study’s own design or analysis.

Those illustrations are described as based on fractions of an observed effect. But the primary outcome result is not reported in the registry record, so the observed effect for this endpoint cannot be established from the record. Planning estimates, even when available, are not observed power and do not show that the study had a particular probability of finding a result. They are conditional illustrations that depend on assumptions about the effect and analysis.

For time-to-event outcomes, a planning calculation may be expressed in total events; for other outcome types, it may be expressed as participants per arm. This study’s primary outcome is a participant count, not a time-to-event endpoint. No sample-size result for this study is reported in the registry record.

What can be concluded from the posted analysis information?

The registry lists two outcome measures and zero analyses. It does not provide a primary endpoint estimate, uncertainty interval, test statistic, p-value, or analysis population. Those omissions mean that inferential conclusions cannot be reconstructed from the registry entry. They do not mean that no analysis was conducted outside the registry; the record alone does not establish that. Likewise, no interim analysis plan or correction for multiple testing is reported.

In general, statistical significance addresses compatibility with a specified null model under stated assumptions; it does not measure the size or practical importance of a finding. Estimates and intervals are needed to describe magnitude and precision. Because these results are absent, the registry record supports explanation of the endpoint and design, but not a numerical assessment of its frequency, precision, or statistical significance.

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("Asymptomatic Male Volunteers", "Asymptomatic Female Volunteers")
n      <- c(96, 104)
events <- c(6, 40)
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  Asymptomatic Male Volunteers  96  6  6.2  2.3  13.1  2.9  13.0  3.0  13.0
ARM  Asymptomatic Female Volunteers  104  40  38.5  29.1  48.5  29.7  48.1  29.7  48.1

11. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome, “False Positive Urine,” and a secondary outcome, incidental hematuria. It reports two outcome measures in total, but does not report results for either outcome. No analysis entries are listed. The record does not state whether a formal hierarchy, familywise error control, false-discovery procedure, or other multiplicity strategy was specified.

As a general principle, examining multiple outcomes or multiple subgroup comparisons can increase the chance of finding an apparently notable result by chance. A prespecified approach can clarify which outcomes are confirmatory and how multiple tests are handled. No such approach is reported in the registry record, so it is not possible to assess how multiplicity was addressed or whether any reported finding was adjusted. No inferential findings are posted in any case.

The registry record also does not report missing-data counts, reasons for missing samples, how incomplete dipstick assessments were handled, or an analysis population definition. It therefore cannot establish whether every enrolled participant contributed a usable sample or whether the primary endpoint denominator differed from enrollment. The safety listing gives group counts, but those do not define the analysis population for the primary outcome.

These are reporting gaps, not proof that data were missing or that a particular analysis method was used. The record does not provide information on exclusions, imputation, sensitivity analyses, or interim analyses. Without those details, the completeness and handling of outcome data cannot be evaluated from the registry record.

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 registry’s safety listing reports the male volunteer group with 96 participants at risk, zero serious adverse events, zero other adverse events, and zero deaths. For the female volunteer group, it reports 104 participants at risk, zero serious adverse events, zero other adverse events, and zero deaths. No serious adverse-event terms are listed.

These entries should be read as the safety counts recorded in the registry, not as a complete account of every possible symptom or health event. The record does not describe the method or period of safety monitoring, whether all events were actively solicited, or how events were judged to be related to the study procedure. It also does not report a detailed safety narrative.

The safety counts are separate from the primary endpoint. Zero recorded adverse events does not indicate that no samples met the dipstick definition, because the primary result is not reported. Conversely, a positive dipstick finding under the endpoint rule is not itself listed as an adverse event. The registry provides counts, but does not explain whether the categories capture all events relevant to this observational urine-testing study.

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

The registry record establishes that this completed, prospective observational study enrolled adult volunteers without acute symptoms to assess urine dipstick findings. It defines the primary outcome as the number of participants whose sample showed at least 1+ leukocytes or positive nitrites, and states that the test result was available two minutes after the reagent strip was placed in urine. These details clarify what the study intended to count and when the test was read.

The record does not report the primary outcome count, its denominator, or an estimated frequency. It therefore cannot show how common the defined finding was among these volunteers. It also cannot show the precision of such an estimate, because no confidence interval or other uncertainty measure is reported. The listed secondary outcome, incidental hematuria, likewise has no result reported.

The term “False Positive Urine” is the registry’s endpoint label, but the operational definition is based on dipstick findings. As a general diagnostic principle, determining that a test result is false requires a reference standard or another means of establishing the true condition. The registry record does not describe independent confirmation for this endpoint. The record therefore does not establish diagnostic sensitivity, specificity, predictive values, or the clinical meaning of a positive result.

The male and female groups are observational volunteer groups, not randomized arms. The registry cautions that they are not a like-for-like control comparison. The record cannot establish that any difference between those groups, if one were reported elsewhere, was caused by sex or by an intervention. It also does not establish how representative the volunteers are of other adult populations.

The posted safety counts show zero serious adverse events, zero other adverse events, and zero deaths in the listed groups. Those entries describe the registry’s safety reporting, but do not establish the completeness of event collection. In short, the record defines a measurable question and reports basic study structure, while leaving the primary and secondary outcome findings unreported.

14. Why This Trial Matters Statistically

This study raises a useful statistical distinction between defining an outcome and reporting its result. The registry gives a concrete rule for classifying a dipstick sample: at least 1+ leukocytes or positive nitrites. Yet a definition alone cannot answer the frequency question. Interpretation also requires the number meeting the rule, the number assessed, and appropriate measures of uncertainty. Those primary result details are not reported in the registry record.

The distinction matters because an endpoint label can sound more conclusive than its operational measurement. “False Positive Urine” is defined by dipstick readings, while the record does not describe an independent reference standard. A count of samples meeting a rule is a valid descriptive target, but it is not automatically a measure of diagnostic accuracy. Statistical reporting should make clear both what was observed and what the measurement can support.

The study also illustrates why group labels do not create a controlled comparison. Male and female volunteers are listed separately, but the registry identifies the design as observational and says the groups are not like-for-like controls. A numerical contrast between them would need careful descriptive framing, and the record does not report such an analysis.

Finally, the registry demonstrates the limits of interpreting a completed status as evidence of available results. The study is marked completed, but its primary endpoint result, secondary outcome result, and analyses are not reported in the registry record. For biostatistical interpretation, study completion and result availability are separate details. A transparent account of endpoint counts, denominators, uncertainty, analysis populations, and missing-data handling would be needed to assess the frequency and precision of the findings.

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 main limitation for interpreting this record is the absence of the primary endpoint result. Although the study specifies a dipstick rule and enrolls 200 participants, the registry does not report how many participants met the rule, how many had an assessable sample, or an estimated frequency. It is therefore not possible to quantify the primary outcome from this record.

The endpoint combines leukocyte and nitrite findings. Separate component results are not reported, so the record cannot show whether one component or both contributed to any observed endpoint count. The “false positive” label is not accompanied by a described independent reference standard, limiting interpretation of the measure as diagnostic error rather than a dipstick-defined finding.

The volunteers are described as adults without acute symptoms, but the record does not provide further detail about recruitment, demographic composition, or representativeness. Results from volunteers could not automatically be generalized beyond the participants even if the outcome counts were available. The male and female groups are observational, and the registry explicitly warns they are not like-for-like control groups.

The record does not report the primary analysis population, endpoint-specific denominators, missing-sample counts, exclusion criteria beyond the group descriptions, or methods for handling missing data. It also does not report an analysis plan, multiplicity handling, interim analyses, or a sample-size justification. Incidental hematuria is registered as a secondary outcome, but its result is not reported.

The safety listing provides event counts but not details of ascertainment or monitoring. These limitations concern what can be concluded from the registry record; they do not establish that data were missing, that procedures were inadequate, or that no further analyses exist elsewhere.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Urinalysis Results in Healthy Individuals — NCT04055675.
• Registry record last updated 2020-06-18; status last verified 2020-06.
• Results first posted 2020-06-18.
• 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

NCT04055675, “Urinalysis Results in Healthy Individuals,” is a completed prospective observational study sponsored by Kendall Healthcare Group, Ltd. It enrolled 200 adult volunteers without acute symptoms and assessed urine dipstick results. The registry lists male and female volunteer groups, with safety-listing group counts of 96 and 104.

The primary endpoint, “False Positive Urine,” counts participants whose sample has at least 1+ leukocytes or positive nitrites. The registry states that results are available two minutes after placing the reagent strip in urine. Incidental hematuria is listed as a secondary outcome.

The primary and secondary outcome results are not reported in the registry record, and no analyses are listed. The record cautions that the groups are not like-for-like controls. Its safety listing records zero serious adverse events, zero other adverse events, and zero deaths in each group.