One-step HCV RNA Testing Among SSP Participants (HOT Study): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for One-step HCV RNA Testing Among SSP Participants (HOT Study) (NCT06634342), a na na study. The primary outcome is Receipt of HCV RNA Test Results.

2. Clinical Question

3. Trial Design

The HOT Study, registered as NCT06634342, is described as an observational prospective study of a point-of-care HCV RNA testing approach in a U.S. syringe services program. The intervention is listed as HCV RNA rapid testing. Its stated purpose is to evaluate the clinical utility and feasibility of a one-step testing algorithm among program clients. The registry identifies University of Washington as the sponsor.

The study has a single-group design and no masking. Allocation is listed as not applicable. Participants are described as adults aged 22 or older who do not already know they have HCV infection and are clients of a syringe services program. Planned enrollment is 200. The record does not describe a randomized assignment process, a parallel control group, or an allocation ratio for actual participants.

The primary outcome is receipt of HCV RNA test results, with a timeframe of 6 months. The registry also lists testing results and testing willingness as secondary outcomes, and records 5 outcome measures overall. It does not list statistical analyses. The study status is completed; the recorded start date is 2025-02-05 and the primary completion date is 2025-05-31.

These design features mean the study is intended to describe testing in a service setting rather than estimate a randomized treatment contrast. The design can document whether participants complete testing and receive results, as well as implementation-related outcomes if those were collected and reported. Without a control group, observed outcomes cannot by themselves establish what would have occurred under a different testing strategy. Details about recruitment, follow-up procedures, data collection, and the 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.

6. Primary Endpoint

The registry lists the primary outcome as Receipt of HCV RNA Test Results, measured over 6 months.

The primary endpoint is receipt of HCV RNA test results. The registry describes it as the percentage of individuals who complete an HCV RNA test and also receive their results, with a timeframe of 6 months. In practical terms, this endpoint focuses on a step after test completion: whether a participant receives the result. That makes it relevant to the stated interest in how people move from testing toward information about their HCV status.

The endpoint is useful for describing an operational part of a testing pathway. A test can be completed without the result reaching the person tested, so documenting result receipt is distinct from counting tests performed. The record does not define the precise method for confirming receipt, such as whether it was self-reported or documented by staff. It also does not specify how participants who do not complete a test enter the endpoint denominator. Those details are not reported in the registry record.

No observed numerator, denominator, percentage, or uncertainty interval for this endpoint is reported in the registry record. As a result, its value and precision cannot be assessed from the registry information described. The outcome definition indicates what the study intended to measure; it is not evidence of the proportion who received results.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the single-group design estimate?

In a single-group observational study, an outcome can be described among the people observed in the study setting. For this study, the central outcome is receipt of HCV RNA test results among people who complete testing. Such a description can characterize the testing pathway at the participating syringe services program. It does not compare outcomes under randomized alternatives, because the registry record lists no randomized comparison and no control group.

General statistical interpretation distinguishes a descriptive outcome from a treatment or intervention effect. A descriptive estimate concerns what happened in the observed group. A causal effect asks what would have happened to comparable people under another strategy. Random assignment can help make those groups comparable, but it is not part of the design. Other observational methods can sometimes adjust for measured differences, but no such analysis is listed in the registry record. Therefore, the single-group result, if reported elsewhere, should be read as a description of this setting rather than a causal estimate of the benefit of testing.

How should a binary endpoint be understood?

The endpoint has a yes-or-no structure: a person who completes an HCV RNA test either receives the result or does not, according to the study's outcome definition. A group-level percentage summarizes the number meeting the outcome relative to the relevant denominator. The registry record describes the endpoint as a percentage but does not report its numerator, denominator, or estimate. It also lists the parameter as a count of participants. Those registry entries do not establish a numerical outcome value; no percentage should be reconstructed from planned enrollment.

General explanation: a confidence interval expresses the uncertainty around an estimated quantity under the assumptions of the analysis. A narrower interval indicates greater precision, while a wider interval indicates less precision. Its interpretation depends on the data and statistical method. No confidence interval for the primary outcome is reported in the registry record, so the precision of an outcome estimate cannot be assessed.

Why does the lack of a comparator matter?

A control group provides a reference outcome against which the intervention group's outcome can be compared. In a randomized study, assignment is designed to make the groups comparable on average. This study instead has one group offered point-of-care testing. A result in that group could describe the experience of testing and result delivery, but it would not show how the same participants would have fared with another testing approach. Differences in service context, staffing, follow-up, and participant characteristics could affect outcomes. The registry record does not report analyses addressing such factors.

General explanation: confounding occurs when factors related to both the exposure or strategy and the outcome can distort an observed association. In a single-group study without a comparison strategy, the main limitation is more basic: there is no reported counterfactual group that estimates the alternative outcome. Adjustment for recorded covariates cannot automatically remove unmeasured differences or replace a randomized comparison.

What does the planning illustration mean?

The registry's sample-size assumptions describe a planning illustration based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The stated effect to detect is a fraction of the observed effect. These assumptions describe hypothetical planning calculations, not the actual single-group design, which has no two-arm allocation. The registry record does not report the numerical observed effect used for that illustration in the registry record for this account.

General explanation: a sample-size calculation estimates how much information a planned study might need under specified assumptions. A calculation based on an observed effect is retrospective planning, not evidence that the completed study had a particular probability of detecting an effect. It is not observed power. Any resulting sample-size figure is an illustration under its assumptions; it does not demonstrate that the actual design was adequately powered, nor does it replace an estimate and uncertainty interval for the endpoint.

Why are the analysis details important?

Analysis choices determine which participants contribute to an estimate, how incomplete observations are handled, and how uncertainty is quantified. They can also affect whether an estimate describes all enrolled participants, only those who completed testing, or another defined group. The registry record does not report an analysis population, a statistical model, a missing-data method, or a confidence interval method. It lists no statistical analyses. These omissions limit what can be inferred about how any eventual result was calculated.

General explanation: over-dispersion matters when the observed variability in data is greater than a model assumes. It can make standard errors too small if not accommodated. That issue is more relevant to some clustered or count-data analyses than to a simple binary proportion, and the registry record does not identify an analysis model that would permit a study-specific assessment. No claim about over-dispersion or model adequacy can be made for this study from the record described.

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("Participants of a Syringe Services Program")
n      <- c(200)
events <- c(193)
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  Participants of a Syringe Services Program  200  193  96.5  92.9  98.6  93.0  98.3  93.0  98.3

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists 5 outcome measures, including receipt of HCV RNA test results as the primary outcome and testing results and testing willingness as secondary outcomes. It does not list statistical analyses or describe a plan for addressing multiplicity. When a study examines multiple outcomes or multiple comparisons, the chance of at least one apparently unusual result can increase if each is assessed separately. General approaches include prespecifying a primary outcome, adjusting significance thresholds, or treating secondary analyses as exploratory. The registry information does not say which, if any, approach was planned.

No primary outcome estimate, confidence interval, or p-value is reported in the registry record. As a result, multiplicity cannot be evaluated from reported inferential results. The record also does not describe subgroup analyses or repeated interim assessments; these details are not reported in the registry record, and their absence from the record should not be treated as proof that they did not occur.

Missing-data handling is also not reported in the registry record. The primary endpoint refers to people who complete an HCV RNA test and receive their results, but the record does not specify how participants with an incomplete test, unavailable result, or unknown result-receipt status would be classified or excluded. Nor does it state how many observations were missing. This matters because an estimate based only on participants with recorded outcomes may differ from an estimate that accounts for everyone eligible for follow-up.

The record does not define analysis populations, such as whether the primary analysis would include all enrolled participants or only test completers. It also does not specify a statistical model, adjustment variables, or sensitivity analyses. Without these details and the outcome data, the results cannot be independently interpreted as a fully specified analysis.

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 record lists one group, Participants of a Syringe Services Program. For serious adverse events, it records 200 at risk and 0 affected. For other adverse events, it records 200 at risk and 0 affected. The record also lists 0 deaths. These are the event figures recorded in the registry; they are not a comparative safety estimate because the study has no randomized control group.

Zero recorded events should be read as a report of zero affected participants in the registry fields, not as proof that no adverse events occurred in any broader population or that the testing approach has no risk. The record does not give further detail about event definitions, how adverse events were collected, the observation period for these safety fields, or whether all participants had complete safety follow-up. Those details are not reported in the registry record.

The study evaluates a diagnostic testing approach in a service setting. The listed safety figures should therefore be interpreted within that study context and alongside the outcome and follow-up information available. The registry record does not report serious adverse event terms or additional event descriptions. The figures alone do not establish a difference in safety compared with another testing strategy.

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

The study addresses an implementation-focused question: whether people who complete point-of-care HCV RNA testing at a syringe services program receive their results, and how testing may fit into pathways toward HCV care. Its prospective, single-group design is suited to describing the experience of participants in the setting studied. The registry record identifies a primary endpoint and a 6 months timeframe, and records the study as completed.

But the available registry information does not report the observed primary outcome result. It gives no numerator, denominator, percentage, or interval describing result receipt. It also does not report numerical findings for testing results, testing willingness, linkage to care, or treatment initiation and completion. Therefore, the record as described cannot establish how often results were received or how precisely that outcome was estimated.

The design does not support a direct causal comparison with another testing strategy. No randomized control group is listed, so any measured outcome would describe the study group rather than the difference between testing approaches. The study's aims include questions about how point-of-care testing may affect care engagement, but aims are not findings. No conclusion about a treatment effect or a change in care engagement follows from the design description alone.

The registry status of completed indicates that the study is recorded as completed; it does not supply its missing outcome estimates or analysis details. Planned enrollment is not an observed endpoint result. The listed safety fields report no affected participants or deaths, but do not establish that there were no unrecorded events or provide a comparative safety assessment.

In short, the record characterizes the population, testing approach, and intended outcomes. It does not report enough outcome data to quantify the primary result, assess its precision, or judge whether it differs from an alternative strategy. Those conclusions would require outcome and analysis information not reported in the registry record.

14. Why This Trial Matters Statistically

This study is statistically important because it focuses on a step that is easy to overlook when evaluating a diagnostic service: whether a person who completes testing actually receives the result. Counting tests alone would not describe that entire pathway. The stated endpoint therefore targets an operational outcome that can be relevant to evaluating how testing is delivered in a syringe services program.

The setting also makes the distinction between feasibility evidence and comparative effectiveness important. A prospective observational study can describe what happens in a service context and may help identify implementation questions. A single-group design does not, by itself, show that the observed outcome was caused by the testing approach. Recognizing this distinction helps prevent a descriptive result from being interpreted as a controlled treatment effect.

The registry information also illustrates why endpoint definitions and reporting details matter. A percentage needs a clear numerator and denominator; an estimate needs an account of uncertainty; and an analysis needs a defined participant population and approach to missing data. Those quantities and methods are not reported in the registry record. Without them, the study question can be understood, but the precision and magnitude of its findings cannot be judged.

The listed secondary outcomes and broader aims point to a pathway extending beyond test completion to care linkage and treatment. Reporting each step separately would help readers see where information is available and where it is not. The registry record does not include numerical results for those steps. This limits conclusions, while leaving the study's implementation questions recognizable as its central motivation.

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 results from the registry record is that it does not report observed outcome estimates. The primary outcome is defined, but its numerator, denominator, percentage, and uncertainty are absent. Results for the secondary outcomes and the broader questions about linkage and treatment are also not reported in the record described. This prevents assessment of outcome magnitude and precision.

The design is single-group and observational, with no randomized comparator listed. Consequently, an outcome measured among participants would not estimate a controlled difference between testing strategies. The record does not report a comparison group, a method for adjusting for confounding, or a causal analysis plan. The study's results, if reported elsewhere, would need to be interpreted in light of this design.

The population is limited to syringe services program clients who are adults aged 22 or older and do not already know they have HCV infection. Recruitment methods, eligibility screening, reasons for declining, and participant characteristics are not reported in the registry record. The extent to which the enrolled group reflects other settings or populations therefore cannot be assessed from this information.

The endpoint description does not specify how receipt of results was verified or how incomplete tests and unknown result status were handled. Follow-up procedures, missing-data methods, analysis populations, and statistical methods are not reported in the registry record. These gaps matter for understanding who contributed to an estimate and how it was calculated. The listed adverse event counts likewise lack details on event collection and follow-up. Finally, a completed status does not fill these reporting gaps or establish that all planned outcomes were available.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: One-step HCV RNA Testing Among SSP Participants (HOT Study) — NCT06634342.
• Registry record last updated 2026-06-24; status last verified 2026-05.
• Results first posted 2026-06-24.
• 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

NCT06634342, the HOT Study, is a prospective observational study of point-of-care HCV RNA testing among clients of a U.S. syringe services program. University of Washington is listed as the sponsor. The study is single-group, with no masking and no randomized allocation. The eligible participants are described as adults aged 22 or older who do not already know they have HCV infection.

Planned enrollment is 200. The primary outcome is receipt of HCV RNA test results, with a 6 months timeframe. Testing results and testing willingness are listed as secondary outcomes. The registry records the study as completed, with a start date of 2025-02-05 and a primary completion date of 2025-05-31.

The registry record does not report the observed primary outcome estimate, its denominator, or uncertainty. It lists no statistical analyses. The available information therefore describes the study design and intended questions, but not the quantitative primary result.