Suction Cervical Stabilizer Compared to Standard Tenaculum for Intrauterine Procedures: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Suction Cervical Stabilizer Compared to Standard Tenaculum for Intrauterine Procedures (NCT06193590), a non-randomized na study. The primary outcome is Patient-perceived Pain.

2. Clinical Question

The clinical question is comparative in wording, but the study’s nonrandomized allocation limits how directly the groups can be compared. Differences in patient, procedure, or clinical circumstances could accompany device choice. The registry record does not report whether or how such factors were addressed in the analysis. Thus, the stated question identifies the outcomes of interest, while the available record does not establish a causal comparison or provide numerical evidence about the size or precision of any difference.

3. Trial Design

The registry describes a completed study of Carevix and the standard tenaculum in the clinic setting. It lists Indiana University as sponsor and reports enrollment of 73. The allocation is classified as nonrandomized, masking as none, and model as single-group. At the same time, the intervention descriptions and safety summaries identify Carevix and Tenaculum groups. This combination of registry classifications makes the design difficult to characterize as a conventional controlled comparison; the record itself cautions that the arms are not a like-for-like control comparison.

The stated purpose is to evaluate patient-reported pain, bleeding, and device efficiency, along with provider-perceived bleeding, ease of use, and satisfaction. The primary outcome is patient-perceived pain. The record identifies three analyses and four outcome measures, but does not report the results for the pain outcome or numerical findings for the other listed outcomes. It also does not provide the analysis details needed to determine which measures were analyzed together or how the reported analyses relate to each measure.

The study is marked completed. Its phase is recorded as not applicable. The record does not report a random assignment procedure, masking, a statistical analysis plan, or whether any interim analyses were conducted. It also does not provide enough information to determine the distribution of procedure types or how participants came to receive one device rather than the other. These omissions matter because device selection and clinical context may be related to the outcomes being measured.

The design can therefore support a description of the registry’s stated aims and classifications, but the registry record does not provide the numerical efficacy results needed to assess the primary comparison. The nonrandomized allocation and the explicit warning about unlike arms are additional reasons not to interpret the listed groups as if they were formed by random assignment.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: Patients were ineligible if they did not meet these criteria, as well as if they presented with vaginal bleeding of unknown origin, cervix less than 26 mm in diameter, Nabothian cyst on anterior lip of cervix, cervical myomas, cervical abnormalities/shape, or if they were pregnant. Patients were also designated ineligible if they did not receive any cervical stabilization. Patients were recruited in two waves corresponding with each arm.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Participants who underwent an intrauterine procedure with either the Carevix device or the Tenaculum.

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 Patient-perceived Pain, measured over Immediately after intrauterine procedure and scheduled appointment is complete (approx. 5-10 minutes after procedure completion).

The primary endpoint is patient-perceived pain after an intrauterine procedure. Participants are asked to rate pain using the Numeric Rating Scale, described in the registry as a 0-10 scale: zero means “no pain” and 10 means “the worst pain imaginable.” The survey is completed after the procedure and clinical appointment conclude, approximately 5-10 minutes after procedure completion.

A patient report captures the experience the study aims to measure rather than relying only on a provider’s assessment. Measuring pain soon after the procedure is intended to record the participant’s perception at that moment. It does not, by itself, describe pain at later times or other aspects of the procedure.

The registry specifies the median and inter-quartile range as the summary for this endpoint. In general, the median gives the middle of the observed scores, while the inter-quartile range describes the spread of the middle portion of those scores. These summaries can be useful when scores are not well represented by a mean and standard deviation. The registry record does not report the group medians, inter-quartile ranges, or a numerical comparison, so the endpoint’s observed values and precision cannot be assessed from the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a median and inter-quartile range describe?

The registry specifies that pain is summarized by a median and inter-quartile range. In general, the median is the central value after observations are ordered. The inter-quartile range describes the interval spanning the middle half of the observations and therefore communicates variability as well as a typical value. These summaries are often useful for ratings when the distribution may be skewed or when extreme values could pull a mean away from the center. They do not show every individual score, and the same median can occur with different amounts of spread.

For this study, the record gives the scale and summary approach but does not report the group medians or inter-quartile ranges. It also does not report a confidence interval for a group contrast. In general, a confidence interval conveys a range of values compatible with the data and the stated statistical procedure; its width reflects uncertainty. Without the estimated contrast and its interval, neither the magnitude nor the precision of the primary comparison can be evaluated.

Why does allocation matter?

The registry classifies allocation as nonrandomized and states that the arms are not a like-for-like control comparison. In general, random assignment helps balance measured and unmeasured characteristics across groups on average. Without random assignment, group differences may reflect not only the intervention but also who received it, the procedure being performed, or other clinical circumstances. This is a general concern, not evidence that a specific imbalance occurred in this study.

Adjustment for recorded characteristics can sometimes address measured differences, but it cannot ensure balance in factors that were not measured or not included in the analysis. The registry record does not report participant characteristics, allocation details, adjustment variables, or an adjusted primary analysis. Consequently, it is not possible to determine how potential confounding was handled. The record’s warning about unlike arms should remain central when reading any comparison.

What does a significance level mean for planning?

The sample-size assumptions describe a two-sided significance level of 0.05, equal allocation between groups, and a normal approximation. In general, a significance level is a planning threshold used to define how unusual data would need to be under a specified null hypothesis to meet a statistical testing rule. It does not measure the probability that a hypothesis is true, the size of an effect, or the clinical importance of a finding.

The assumptions also describe planning illustrations based on a stated fraction of the observed effect. Such illustrations ask how many participants per arm might be needed under specified assumptions to detect an effect of that size with a chosen power. They are planning scenarios, not observed power and not evidence that the completed study was designed around those assumptions. The registry record does not report the trial’s own sample-size justification, and the numerical effect estimate and planning outputs are not reported in the record. The stated assumptions therefore do not establish the study’s actual design rationale.

In general, sample-size calculations depend on the target effect, variability, allocation, significance threshold, power target, and analysis method. A change in any of these assumptions can change the planning result. A calculation based on an observed effect is especially dependent on that estimate: if the estimate is uncertain, the planning illustration inherits that uncertainty. No numerical planning result or observed effect size is reported in the registry record, so no required sample size or study power can be inferred.

Why can over-dispersion matter?

In general, over-dispersion occurs when observed variability is greater than a statistical model assumes. If a model underestimates variability, its standard errors can be too small and uncertainty intervals too narrow. This is relevant whenever the chosen outcome model makes assumptions about the distribution of observations. The registry record does not report a model for the primary outcome, a variance estimate, or diagnostics that would establish whether over-dispersion was assessed. It would therefore be speculative to claim that it occurred or that any particular correction was used.

The primary endpoint is a bounded rating scale, and the registry names a median and inter-quartile range for descriptive reporting. That information alone does not specify how an inferential comparison was conducted. A descriptive summary and a statistical test answer different questions: the summaries characterize observed scores, while a test or interval requires a defined comparison method and its assumptions. The registry record does not report the inferential method, adjustment strategy, or confidence interval for the primary contrast.

These methods concepts explain what the recorded endpoint and planning assumptions mean, but they do not fill gaps in the analysis record. The record does not report the statistical analysis plan, handling of missing outcome data, analysis populations, multiplicity procedure, or interim analyses. Those details are important for understanding how outcomes were selected and how uncertainty was assessed. Their absence prevents a fuller evaluation of the statistical analysis.

10. Multiplicity, Missing Data and Analysis Populations

The registry identifies a primary pain endpoint, several additional patient- and provider-focused outcomes, four outcome measures, and three analyses. It does not report a multiplicity procedure or explain how the analyses relate to the outcomes. When multiple outcomes or comparisons are examined, general statistical practice distinguishes a prespecified primary question from secondary or exploratory questions; testing many questions without accounting for multiplicity can increase the chance of at least one apparently notable result. The record does not say whether any adjustment or prioritization was used.

Missing-data handling is not reported in the registry record. The record does not state whether every participant completed the pain survey, how incomplete responses were treated, or whether any imputation or sensitivity analysis was performed. Thus, the available outcome description cannot establish how many ratings contributed to a particular analysis or whether missing responses could affect interpretation.

Analysis populations are also not reported. The registry does not specify whether analyses included all enrolled participants, only participants who received a procedure, or another defined group. Nor does it report protocol deviations or exclusions. These omissions prevent assessment of how the analyzed participants correspond to the population described for the endpoint.

The registry record does not report an interim analysis or a statistical analysis plan. Their absence from the record does not establish whether such plans or procedures existed outside it. Without these details and the numerical outcome results, it is not possible to evaluate the prespecification, completeness, or multiplicity of the reported analyses.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry safety summaries list 36 participants at risk in the Carevix group and 37 in the Tenaculum group. In each group, the reported counts are zero for serious adverse events, zero for other adverse events, and zero deaths. No serious adverse-event terms are listed.

These figures describe the registry’s recorded counts; they should not be read as proof that the devices have no risks. The record does not report the safety observation period, how events were solicited or verified, the event definitions, or whether participants with incomplete safety follow-up were included. A zero count in a registry summary means that no events in the stated category were recorded in that summary, not that the possibility of an event has been ruled out.

The counts also do not resolve the nonrandomized design limitation. The registry warns that the groups are not a like-for-like control comparison. Therefore, the safety figures are descriptive and do not establish a causal difference between devices. The record does not report a statistical safety comparison or uncertainty interval. These safety summaries should be considered separately from the unreported pain and other outcome results.

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

The registry record establishes that the study was designed to evaluate pain and other patient- and provider-reported outcomes during intrauterine procedures using Carevix or the standard tenaculum. It also specifies how the primary pain measure was collected and summarized. Those details describe the question and intended measurement, not the observed result.

The primary pain scores and numerical results for the other listed outcomes are not reported in the registry record. Accordingly, the record does not establish whether the groups had different pain ratings, how large any difference was, or how precisely it was estimated. It does not support a conclusion about the direction or magnitude of an outcome contrast.

Even if numerical group differences were available, the nonrandomized allocation and the registry’s warning that the groups are not like-for-like would be important. In general, differences in who receives each device or in the circumstances of the procedure can influence comparisons. The record does not report enough about those circumstances or the analysis to assess that possibility. A group contrast in a nonrandomized study is not automatically an effect caused by the device.

The safety summaries record no serious adverse events, other adverse events, or deaths in either listed group. Those counts are limited to what the record reports and do not establish the absence of risk. The registry does not report the safety follow-up window or detailed event ascertainment methods.

In short, the registry describes a completed study and a clearly stated patient-reported primary endpoint, but does not report the primary outcome values needed to judge the result. The study status, endpoint definition, and safety counts should not be treated as substitutes for an efficacy estimate or its uncertainty.

13. Why This Trial Matters Statistically

This study raises a practical statistical question: how should patient-reported pain be compared when use of the devices was not randomized? The registry’s explicit nonrandomized classification and warning about unlike arms make the design limitation visible. That matters because a numerical difference, if available, would need to be interpreted in light of possible differences between the groups, rather than attributed automatically to the device.

The endpoint also illustrates the importance of reporting both a measure and its observed results. The registry defines a 0-10 pain rating, the timing of the survey, and median with inter-quartile range as the summary. Those choices help readers understand what was intended to be measured. But without the scores, group summaries, and an estimate of uncertainty, readers cannot judge the size or precision of the primary contrast.

The study lists several outcomes beyond pain, which makes clear why transparent reporting of outcome definitions and analysis choices matters. When several questions are examined, readers need to know which outcome was primary, how secondary outcomes were treated, and whether multiplicity was addressed. The registry record does not report those analysis details or the numerical outcome findings.

The safety counts provide a separate example of descriptive results that require context. Zero recorded events in a group is informative about the registry summary, but without follow-up and ascertainment details it cannot establish that the risk is absent. Together, these features show why design, measurement, analysis, and reporting all shape what clinical researchers can infer from a trial record.

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 main limitation for interpreting outcomes is that the registry record does not report the primary pain results or numerical results for the other stated outcomes. It provides no group medians, inter-quartile ranges, effect estimate, or confidence interval for the primary comparison. The direction, magnitude, and precision of the outcome findings therefore cannot be assessed.

The design is classified as nonrandomized, and the record cautions that the groups are not a like-for-like control comparison. The registry does not report how device allocation occurred, the characteristics of participants in each group, the types of procedures represented, or adjustments for potential differences. This limits interpretation of any group contrast and prevents assessment of confounding.

The registry also classifies the model as single-group while listing Carevix and Tenaculum intervention groups in the safety summaries. The record does not explain this combination of classifications. This makes the study structure less clear than a fully described comparative design.

Other analysis details are not reported in the registry record, including the statistical analysis plan, analysis populations, missing-data handling, multiplicity approach, interim analyses, and the trial’s sample-size justification. Safety summaries lack reported follow-up duration and event ascertainment details. These gaps limit assessment of both the completeness of outcome reporting and the precision or scope of the safety findings.

These limitations describe what can be evaluated from the registry record; they do not establish that the investigators failed to collect or analyze information outside that record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Suction Cervical Stabilizer Compared to Standard Tenaculum for Intrauterine Procedures — NCT06193590.
• Registry record last updated 2025-06-10; status last verified 2025-05.
• Results first posted 2025-06-10.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

The registry describes a completed, nonrandomized study of Carevix suction cervical stabilization and standard tenaculum use for intrauterine procedures. It lists Indiana University as sponsor, enrollment of 73, and identifies patient-perceived pain as the primary outcome. Pain was to be rated on a 0-10 Numeric Rating Scale immediately after the procedure and appointment were complete, with median and inter-quartile range specified as summaries.

The registry also lists patient- and provider-focused secondary outcomes and reports zero serious adverse events, zero other adverse events, and zero deaths in each safety group. It cautions that the groups are not a like-for-like control comparison. Numerical primary and secondary outcome results, detailed analysis methods, and missing-data procedures are not reported in the registry record.