Pain Perception With Tenaculum Placement: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Pain Perception With Tenaculum Placement (NCT02969421), a randomized na study. The primary outcome is Pain With Tenaculum Placement.

2. Clinical Question

3. Trial Design

NCT02969421, titled “Pain Perception With Tenaculum Placement,” is a completed randomized controlled study of pain perception with tenaculum placement during in-office procedures. The registry lists Duke University as sponsor, the study phase as not applicable, and the condition as pain. The listed study start was 2016-01-10, and primary completion was 2017-02-23. The registry reports an enrollment of 66.

The study used a parallel-group design with no masking. Participants were assigned to slow tenaculum placement or the cough method, in which placement occurs at the time of a cough. The registry describes pain measured using a visual analog scale and identifies pain directly after tenaculum placement as the primary outcome. Its outcome description specifies a 100-mm scale, with 0 meaning no pain and 100 meaning worst imaginable pain.

The registry also lists overall pain with intrauterine device insertion and provider satisfaction with tenaculum placement as secondary outcomes. It reports satisfaction counts for both groups, but does not report values for overall pain that permit a two-arm comparison. The record does not describe the participant eligibility criteria, recruitment setting beyond the in-office procedure context, randomization sequence, allocation concealment, or the number of participants included in each outcome analysis. Those details are not reported in the registry record.

The registry’s primary outcome results are descriptive: group medians and inter-quartile ranges. No primary comparison analysis is reported. Therefore, the group summaries describe the recorded pain distributions, but do not by themselves establish the uncertainty around a between-group effect or whether a formal statistical test found evidence of a difference.

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 Pain With Tenaculum Placement, measured over Directly after tenaculum placement.

The primary endpoint is pain directly after tenaculum placement. The registry says pain was measured on a 100-mm visual analog scale, with 0 representing no pain and 100 representing worst imaginable pain. It summarizes the results using a median and inter-quartile range for each group.

Pain is the outcome the study set out to compare because the assigned placement methods differ in how tenaculum placement occurs, and the study question concerns participants’ pain at that moment. A visual analog scale records a participant’s reported position along a scale rather than categorizing pain into a small set of verbal categories. The median describes the middle of the observed ratings, while the inter-quartile range describes the middle portion of their distribution. These are descriptive summaries, not estimates of a treatment effect with a confidence interval.

The reported median was 44.0 for slow placement, with an inter-quartile range from 21.0 to 63.0. For the cough method, the reported median was 32.0, with an inter-quartile range from 19.0 to 54.0. These summaries show that the observed group medians differed, while the ranges of ratings in both groups were broad. The registry does not report a formal statistical analysis for this primary outcome, a confidence interval for the between-group difference, or an analysis population description. The precision and statistical uncertainty of the primary comparison therefore cannot be assessed from the reported summary statistics alone.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies this study as randomized, unmasked, and parallel-group. Randomization is intended, in general, to make assigned groups comparable on average with respect to characteristics that could affect an outcome. It does not guarantee identical groups, especially in an individual study. The registry record does not report the sequence-generation method, allocation concealment, or details of how assignment was implemented. Those features cannot be evaluated from the record.

What does the primary summary describe?

The primary outcome is summarized by a median and inter-quartile range in each group. In general, a median is the central observation after ratings are ordered. The inter-quartile range describes the interval from the lower quartile to the upper quartile, capturing the middle portion of the observed ratings. These summaries are useful for describing the location and spread of a distribution, particularly when a mean and standard deviation are not the chosen summaries. They do not, on their own, quantify the uncertainty in a comparison between groups.

The registry reports medians of 44.0 for slow placement and 32.0 for the cough method. The corresponding inter-quartile ranges are 21.0 to 63.0 and 19.0 to 54.0. A reader can see the descriptive pattern in these summaries, but a formal comparison would ordinarily need an effect estimate and an account of its uncertainty, or a specified statistical test. The registry does not report such a primary-outcome analysis. It also does not report a confidence interval for a difference between medians or another primary effect measure.

What would a confidence interval add?

In general, a confidence interval expresses the uncertainty associated with an estimated effect under the assumptions of the method used. A narrower interval indicates greater precision, while a wider interval indicates less precision. An interval that includes values corresponding to no difference may be compatible with no effect as well as with effects in either direction; the interpretation depends on the effect measure and the analysis. No confidence interval for the primary comparison is reported in the registry record, so its precision cannot be described in those terms.

How should the secondary comparison be read?

Provider satisfaction is reported as a count of participants in each group. The registry also lists an unadjusted risk-difference comparison and a p-value of 0.757. In general, a risk difference expresses the difference between the proportions experiencing an outcome in two groups. The posted unadjusted interval for this comparison spans negative and positive values, so it is compatible with different directions of association as well as no difference. The p-value is not a measure of the size or practical importance of an effect; it summarizes how compatible the observed data are with a specified null model under the method’s assumptions. It should not be read as the probability that the null hypothesis is true.

The comparison is unadjusted. In general, an unadjusted comparison uses the observed group data without controlling for other variables. Randomization can support a between-group comparison, but the details of any analysis and the handling of missing outcome data still matter. The registry does not report a sponsor analysis for provider satisfaction. The posted comparison should therefore be read as limited secondary evidence, not as a substitute for a prespecified, fully documented analysis.

What does the planning illustration mean?

The registry includes a planning illustration based on the observed provider-satisfaction effect. It assumes a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. The illustration gives participants per arm for 80% and 90% power when planning for 100%, 75%, or 50% of the observed effect. For example, planning for 100% of the observed effect gives 2,703 participants per arm for 80% power and 3,618 participants per arm for 90% power. Planning for 75% gives 4,876 participants per arm for 80% power and 6,526 participants per arm for 90% power. Planning for 50% gives 11,125 participants per arm for 80% power and 14,893 participants per arm for 90% power.

These are planning illustrations, not observed power and not the trial’s original design justification. In general, sample-size calculations depend on the assumed effect, outcome variability or event frequency, allocation, significance threshold, and analysis method. Here, the record states the assumptions used for the illustration, but the trial’s own sample-size justification is not reported in the registry record. The observed effect may be unstable, especially when estimated from a small study, so planning directly around it should be interpreted cautiously.

What can be concluded from the analysis record?

The registry reports no primary analyses and no sponsor-reported secondary analyses. The posted secondary satisfaction comparison is an unadjusted calculation, while the primary outcome is available only as group summaries. The registry also indicates that values for overall pain with intrauterine device insertion were missing or not estimable for a two-arm comparison. In general, missing or unestimable results restrict what can be inferred, and the reason for missingness can matter. The record does not explain why these values are unavailable or report an analysis addressing them.

Accordingly, the available statistics support descriptive interpretation of the primary pain ratings, a limited unadjusted secondary comparison, and a description of reported event counts. They do not support a complete assessment of the planned statistical approach, primary-outcome uncertainty, multiplicity handling, or missing-data assumptions.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome and two secondary outcomes, but does not report a statistical plan for managing multiple outcomes or comparisons. When several outcomes are examined, the chance of at least one apparently unusual result can increase. In general, a prespecified hierarchy or an adjustment method can clarify how evidence across outcomes should be interpreted. Without a reported approach, secondary findings are best treated cautiously and should not be presented as though they independently confirm the primary result.

The record reports no formal primary-outcome analysis and no sponsor-reported secondary analyses. It does include an unadjusted provider-satisfaction comparison. The registry says values for overall pain with intrauterine device insertion are missing or not estimable for a two-arm comparison. It does not give the reason these values are unavailable, describe whether data were missing for individual participants, or report a method for handling missing outcomes. The extent and possible consequences of missing data therefore cannot be assessed.

The registry does not describe analysis populations, such as whether outcomes were analyzed according to randomized assignment or only among participants with available measurements. It also does not report whether any participants were excluded from an outcome analysis or how any protocol deviations were handled. These details are not reported in the registry record. Without them, it is not possible to determine whether the outcome summaries reflect all randomized participants or a subset with observed data.

These gaps matter because the interpretation of a randomized comparison depends not only on group summaries but also on how participants and outcomes were included in the analysis. The record supports reporting the statistics that are available, but it does not permit a full evaluation of multiplicity, missing-data assumptions, or analysis populations.

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 reports zero serious adverse events in the slow-placement group and zero in the cough-method group. It also reports zero other adverse events and zero deaths in both groups. The record lists 33 participants at risk for each of these event categories in each group.

These figures describe the events recorded in the registry; they are not proof that the procedures carry no risk. With no reported events, the data cannot estimate a comparative event rate beyond the observed counts, and the record does not provide a formal safety comparison or uncertainty interval. The registry also does not describe adverse-event collection methods, definitions, follow-up duration, or how completely events were ascertained. Those details are not reported in the registry record.

Accordingly, the appropriate reading is limited: no serious or other adverse events and no deaths were recorded for either group in the listed safety results. The counts should not be interpreted as evidence that such events are impossible or that the groups have equivalent safety profiles.

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

The results describe pain ratings recorded directly after tenaculum placement in a randomized comparison of slow placement and the cough method. The observed median was 44.0 for slow placement and 32.0 for the cough method, with inter-quartile ranges of 21.0 to 63.0 and 19.0 to 54.0, respectively. These values show the location and spread of the reported ratings in each group. They do not quantify the uncertainty in the difference between groups.

The registry does not report a formal primary-outcome analysis, an effect estimate for the primary comparison, or a confidence interval. It is therefore not possible to assess the statistical precision of the primary comparison from the reported summaries alone. The descriptive difference between the medians should not be treated as proof of a causal effect or as a definitive finding about how the methods compare.

The secondary outcomes do not remove this uncertainty. Provider satisfaction has a posted unadjusted comparison, but this is a secondary measure and the registry does not report a sponsor analysis or multiplicity plan. Overall pain with intrauterine device insertion has no reported values estimable for a two-arm comparison. The results consequently do not establish a complete pattern across all listed outcomes.

The safety record lists no serious adverse events, other adverse events, or deaths in either group. This is a statement about the events recorded, not a guarantee of no risk. The registry’s reporting also does not provide enough detail to assess event ascertainment or the precision of safety comparisons.

Overall, the record permits a descriptive account of the recorded primary pain ratings and a limited account of the secondary and safety results. It does not establish whether the primary group difference is statistically reliable, how precisely it is estimated, or whether the findings generalize beyond the study participants and setting. The trial’s own sample-size justification and full statistical analysis plan are not reported in the registry record.

13. Why This Trial Matters Statistically

This study illustrates why the form of outcome reporting matters. A median and inter-quartile range provide useful descriptions of pain ratings, but they do not answer every question raised by a randomized comparison. Readers also need a clearly defined between-group effect and information about its uncertainty to judge how compatible the data are with different possible effects.

Here, the primary outcome is reported descriptively, without a formal primary comparison or confidence interval. That makes it possible to describe the observed group summaries but not to assess the precision of their difference from the registry record. The distinction is important: a visible difference in sample summaries is not itself an inferential result.

The record also shows how incomplete secondary reporting can limit synthesis across outcomes. Provider satisfaction has an unadjusted comparison, whereas the overall-pain outcome is not estimable for a two-arm comparison. Because the registry does not report a multiplicity plan or sponsor analyses, the secondary information should not be treated as a comprehensive statistical account.

Finally, the planning illustration demonstrates a general feature of sample-size calculations: the required study size depends on the effect planners aim to detect. Its estimates are based on the observed secondary effect and stated assumptions; they are not observed power and do not reveal the original rationale for the trial’s enrollment. The record’s omissions reinforce the value of reporting analysis methods, missing-data handling, and uncertainty alongside outcome summaries.

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 this trial is the absence of a reported inferential analysis for the primary pain outcome. Group medians and inter-quartile ranges are available, but no primary effect estimate or confidence interval is reported. This leaves uncertainty about the precision of the comparison unquantified.

The registry record also lacks important design and analysis details. It does not report participant eligibility criteria, the randomization sequence, allocation concealment, or the analysis population. It does not explain whether all randomized participants contributed to each outcome or how any unavailable measurements were handled. These omissions make it harder to assess the risk of selection or analysis-related bias.

The registry lists overall pain with intrauterine device insertion as a secondary outcome, but says its values are missing or not estimable for a two-arm comparison. The reason is not reported. Provider satisfaction has a posted unadjusted comparison, but no sponsor analysis or multiplicity plan is reported. The secondary findings consequently have limited interpretive weight and do not compensate for the missing primary analysis.

The safety results report no events in either group, but the record does not describe event definitions, ascertainment, or follow-up. The absence of recorded events cannot establish the absence of risk. The enrollment is reported as 66, and the group summaries list 33 participants for each outcome group; the registry does not provide further detail on outcome-specific analysis populations.

Finally, the planning illustration is based on the observed provider-satisfaction effect rather than a reported original design justification. Its assumptions are stated, but it should not be used to infer the trial’s planned power or to judge the primary endpoint’s adequacy. The trial’s sample-size justification is not reported in the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Pain Perception With Tenaculum Placement — NCT02969421.
• Registry record last updated 2019-03-18; status last verified 2018-12.
• Results first posted 2019-03-18.
• 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.

18. Record Summary

NCT02969421 is a completed randomized, unmasked, parallel-group study sponsored by Duke University. It compares slow tenaculum placement with placement at the time of a cough during intrauterine device insertion. The registry reports enrollment of 66 and lists pain directly after tenaculum placement as the primary outcome.

The primary outcome is summarized using medians and inter-quartile ranges on a 100-mm visual analog scale. The registry does not report a formal analysis of the primary comparison. Provider satisfaction is reported as a secondary outcome with an unadjusted comparison; overall pain with intrauterine device insertion has no values estimable for a two-arm comparison. The record reports no serious adverse events, other adverse events, or deaths in either group.

Key details, including the primary statistical analysis, analysis populations, missing-data handling, multiplicity plan, and original sample-size justification, are not reported in the registry record.