Oral Sedation During Cervical Dilator Placement: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Oral Sedation During Cervical Dilator Placement (NCT03202550), a randomized phase 4 study. The primary outcome is Cervical Dilator Placement Pain as Assessed by VAS on a Tablet Device.

2. Clinical Question

The clinical question focuses on pain at a specified procedural moment, rather than pain across the entire course of care. The primary measure is a visual analog scale (VAS) completed on a tablet device. Its anchors are 0 for no pain and 100 for the worst pain ever. The registry reports the outcome as a median and inter-quartile range for each arm.

The record describes a randomized, placebo-controlled comparison. Its brief summary calls the study double-blind, while its masking classification is quadruple. These descriptions are both part of the registry record; further details about who was masked are not reported in the registry record. The comparison is specific to the stated medications, placebo capsules, procedure, and outcome timing. It does not directly answer questions about pain at other stages of the procedure or about other interventions.

3. Trial Design

The registry classifies this as a Phase 4, randomized, parallel-group trial with quadruple masking. Its brief summary describes a two-arm, double-blind, placebo-controlled comparison of placebo with 1 mg oral lorazepam and 5 mg oral oxycodone. The active drugs were encased in microcrystalline cellulose capsules; the placebo arm received two oral microcrystalline cellulose capsules. The record does not report additional details about the randomization sequence, allocation concealment, or which roles were included in the quadruple masking.

The trial concerns pain during cervical dilator placement before dilation and evacuation. The primary outcome was pain measured immediately after the last dilator was placed, up to 1 minute later. The registry records enrollment of 27 and lists the study as completed. The recorded start date is 2017-06-28 and the primary completion date is 2019-05-28. These are registry dates and do not, by themselves, explain how recruitment proceeded or when each participant received treatment.

The primary outcome record includes 13 participants in the placebo arm and 10 in the active drug arm. The registry notes that one participant assigned to the active drug arm was determined not to need cervical dilators and was not included in the active arm’s primary outcome population. Safety records list 13 participants at risk in the placebo arm and 11 in the active drug arm. These are outcome-specific counts; they should not be treated as interchangeable analysis populations.

The record lists eight secondary outcomes, including pain at several procedural stages and the number of participants with the desired number of dilators inserted. It lists no analysis records. Details of the trial’s statistical plan, sample-size justification, and any interim analyses 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.

Before assignment: Three participants who were enrolled but did not receive the intervention had either chosen not to proceed further with the study or were not able to swallow the study drugs.

Overall Study

Analysis population for the primary outcome, as defined in the registry: One participant in the active drug arm was determined to not need to have cervical dilators placed, so this participant was not included in the total number of active drug arm participants.

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 Cervical Dilator Placement Pain as Assessed by VAS on a Tablet Device, measured over Immediately after the last dilator is placed, up to 1 minute.

The primary endpoint is pain associated with cervical dilator placement, assessed using a visual analog scale on a tablet device. The participant’s score is recorded immediately after the last dilator is placed, within the stated window of up to 1 minute. The scale runs from 0, meaning no pain, to 100, meaning the worst pain ever. The registry reports each arm’s median score and inter-quartile range.

As a general measurement point, a VAS converts a participant’s subjective experience into a score that can be compared across groups. The specific timing matters: a score taken immediately after the last dilator is placed concerns pain at that point, not necessarily pain during earlier steps, pain afterward, or the overall experience of the procedure. The registry lists additional pain outcomes at other procedural stages, but those are secondary outcomes rather than the primary endpoint.

A median describes the middle of the observed scores when they are ordered. The inter-quartile range describes the spread of the middle portion of those scores. These summaries are useful when a score distribution may not be well represented by a mean and standard deviation. They do not, on their own, quantify uncertainty in the difference between arms. The registry record does not report a confidence interval or a hypothesis-test result for this endpoint.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is summarized with a median and inter-quartile range, rather than a mean and standard deviation. As a general statistical point, the median is the central value after observations are ordered. It is less affected by very high or low scores than the mean. The inter-quartile range describes the middle spread of observations, from the lower quartile to the upper quartile. It can help readers see whether scores are tightly clustered or dispersed, but it is not a confidence interval for the median or for a comparison between arms.

The posted summaries are 55.0, with an inter-quartile range of 33.0 to 82.0, in the placebo arm, and 44.0, with an inter-quartile range of 10.0 to 80.0, in the active drug arm. These are descriptive statistics. They convey the observed center and spread of scores in the respective outcome populations. They do not supply an estimated difference with a measure of its statistical uncertainty. The registry’s primary outcome record does not report a p-value, confidence interval, or model-based estimate.

As a general statistical point, a confidence interval expresses uncertainty around an estimate under the assumptions of the method used to construct it. It can help distinguish a relatively precise estimate from one with substantial uncertainty. Because no confidence interval for the arm comparison is reported, the precision of a treatment contrast cannot be assessed from the registry record. The inter-quartile ranges should not be read as if they were confidence intervals: they describe spread among observed scores, not uncertainty about the group contrast.

Random allocation is intended, in general, to make treatment groups comparable on average with respect to factors that could affect the outcome. It does not ensure that the groups will be identical, particularly in a small study, and it does not replace a clear analysis plan or a report of uncertainty. The registry classifies this trial as randomized and parallel-group. The sequence-generation method, allocation concealment, and details of implementation are not reported in the registry record. The masking classification is quadruple, while the brief summary describes the trial as double-blind; further operational details are not reported.

What do the summaries establish?

They establish the posted arm-specific medians and inter-quartile ranges for the primary endpoint, along with the stated outcome populations. They show that the reported median is 55.0 in the placebo arm and 44.0 in the active drug arm. They also show broad, overlapping ranges of observed scores. Without a reported comparison estimate and its uncertainty, these summaries do not establish whether an arm difference is statistically distinguishable from chance or how precisely that difference is estimated.

Why does over-dispersion matter?

As a general concept, over-dispersion means that the variation in data is greater than a statistical model assumes. If an analysis assumes too little variability, it can understate uncertainty and make results appear more precise than they are. A median and inter-quartile range do not themselves diagnose over-dispersion, and the registry record does not report a model or an over-dispersion assessment for this endpoint. The issue is relevant when choosing and checking a model for outcome data, not a finding that can be attributed to this trial.

What details of analysis are available?

The primary endpoint is identified as a median with inter-quartile range, but a full statistical analysis plan is not reported in the registry record. The record lists no analysis records. It does not specify a test for comparing the arms, an adjusted model, covariates, or a method for handling missing outcome data. As a result, the descriptive summaries should not be presented as if they came with an unreported inferential analysis.

General statistical practice distinguishes the observed group summaries from the target effect a study seeks to estimate. An analysis might estimate a difference in medians, compare distributions, or use another prespecified approach; each answers a somewhat different statistical question and may rely on different assumptions. The registry record does not state which comparison was planned. No recalculated comparison is needed to interpret the arm-specific summaries, and no new effect estimate or significance claim should be inferred from them.

Finally, the outcome has a specific measurement window and an outcome-specific population. The endpoint concerns pain immediately after the last dilator was placed, up to 1 minute, and excludes one active-arm participant who did not need dilators. Those details define what the descriptive summaries represent. They do not automatically apply to secondary pain measures, safety outcomes, or participants beyond the recorded analysis population.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists eight secondary outcomes in addition to the primary endpoint. They cover the desired number of dilators inserted and pain scores at several procedural stages, including before drugs were administered, around speculum placement, at tenaculum placement, during paracervical block, after the first dilator, and after the last dilator. Examining multiple outcomes can raise a multiplicity concern: as a general statistical point, making many separate statistical tests can increase the chance of finding an apparently notable result by chance. The registry record does not report a multiplicity adjustment, a testing hierarchy, or a statistical plan specifying how secondary outcomes were to be interpreted.

The primary outcome population excludes one participant in the active drug arm who was determined not to need cervical dilators. The registry does not report additional details about missing primary outcome scores or explain how any other missing data were handled. It also does not report whether the analysis followed an intention-to-treat approach, a per-protocol approach, or another defined analysis population. Those details are important for understanding which participants contribute to an estimate and how exclusions could affect interpretation.

The posted primary outcome counts differ from the safety counts: the primary outcome includes 13 placebo-arm and 10 active-arm participants, while the safety record lists 13 and 11 participants at risk, respectively. These populations are outcome-specific. The registry does not provide a fuller account of the relationship between the populations beyond the note about the participant who did not need dilators. The record lists no analysis records, and details of missing-data methods, multiplicity procedures, and analysis populations are not reported in the registry record.

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.

Most frequent non-serious adverse event terms

The registry reports no serious adverse events in either arm: 0 among 13 participants at risk in the placebo arm and 0 among 11 participants at risk in the active drug arm. Deaths are also reported as 0 in each arm. The record lists one other adverse event in the placebo arm, among 13 participants at risk, and none in the active drug arm, among 11 participants at risk. No serious adverse event terms are listed.

These figures describe events recorded during the trial; they are not proof that an intervention has no risk. As a general statistical point, an absence of observed events in a trial does not rule out events that are uncommon, occur outside the observation period, or were not captured by the reported categories. The registry record does not provide further information about event definitions, follow-up duration for safety, severity of the other adverse event, or the method used to collect adverse-event reports. The safety counts should be read separately from the primary pain outcome populations.

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

The registry reports lower median pain scores in the active drug arm than in the placebo arm at the primary measurement time: 44.0 compared with 55.0. The corresponding inter-quartile ranges are 10.0 to 80.0 and 33.0 to 82.0. This describes the posted scores; it is not, by itself, a formal test of a treatment effect. No confidence interval, p-value, or analysis result for the primary comparison is reported in the registry record.

The summaries do not show whether the difference between medians is statistically distinguishable from chance, how precisely an arm comparison is estimated, or whether any difference is clinically important. They also do not show each participant’s score or establish that participants in one arm consistently experienced less pain. The inter-quartile ranges describe the spread of observed scores and overlap; they are not uncertainty intervals for the difference between arms.

The result pertains to pain measured immediately after the last dilator was placed, up to 1 minute later. It should not be taken as a result for pain at every procedural stage, for the overall D&E experience, or for any outcome other than the endpoint described. The record also notes that one participant in the active drug arm was not included in the primary outcome because cervical dilators were not needed. How other missing data were handled is not reported in the registry record.

These results do not establish what would happen in other settings, with different medication regimens, or among people outside the study population. Nor do the safety counts establish that serious adverse events cannot occur. A careful reading keeps the scope narrow: the registry supplies descriptive arm-level primary outcome summaries and adverse-event counts, but does not report the inferential analysis needed to quantify uncertainty in the primary comparison.

13. Why This Trial Matters Statistically

This trial illustrates why the statistical description of an outcome matters alongside its observed values. Pain is recorded on a visual analog scale, but the registry summarizes it with medians and inter-quartile ranges. That choice communicates a center and spread without implying that scores follow a particular distribution. It also helps distinguish a description of observed participants from an estimate of uncertainty about the comparison between treatment arms.

The record makes the measurement time explicit: immediately after the last dilator is placed, up to 1 minute. Procedural pain can be measured at multiple stages, and the registry lists secondary measures at several such points. Keeping the primary endpoint’s timing clear prevents readers from treating a score at one moment as a measure of the entire procedure. It also highlights why multiple outcomes require a clear analytic plan; the registry does not report a multiplicity strategy.

The study is randomized and placebo-controlled, but a design label is not a substitute for information about analysis, missing data, and precision. The registry’s primary outcome summaries allow a descriptive comparison, while the lack of a reported inferential result limits what can be said about uncertainty. The participant excluded from the active arm’s primary outcome also demonstrates why analysis populations must be stated and why outcome-specific counts matter.

For clinical researchers and biostatisticians, the record is a useful example of separating observed summaries from conclusions about an intervention. Reporting arm-level values is informative, but interpretation also depends on the planned estimand, comparison method, uncertainty, missing-data handling, and scope of the measured endpoint. Several of those analytic details are not reported in the registry record, so the posted numbers should be read with that boundary in mind.

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 primary outcome is reported only through arm-specific medians and inter-quartile ranges. The registry record does not report a confidence interval, p-value, or formal comparison for the primary endpoint, so the precision and inferential meaning of the observed contrast cannot be assessed from the posted summaries alone. No analysis records are listed, and the statistical analysis plan is not reported.

The active drug arm’s primary outcome population excludes one participant who was determined not to need cervical dilators. The registry does not report whether other outcome data were missing, how missing values were handled, or whether the analysis population was defined in advance. The different counts in the primary outcome and safety records emphasize that the populations for these outcomes are not identical, but the record gives limited detail about their relationship.

The trial has a recorded enrollment of 27, with smaller outcome-specific group counts. The registry record does not provide information about the rationale for the planned enrollment or a sample-size justification. It does not report whether interim analyses were planned or conducted. Randomization and masking are identified, but details about sequence generation, allocation concealment, and the practical implementation of masking are not reported. The brief summary says double-blind, while the masking classification says quadruple; the record does not explain that difference.

The endpoint is restricted to pain immediately after the last dilator was placed, up to 1 minute. Although several other outcomes are listed, results for them are not reported in the primary outcome information. The record also does not report details needed to assess the multiplicity strategy for the listed secondary outcomes. Safety reporting gives event counts but limited detail about definitions, ascertainment, and follow-up. These limitations restrict interpretation to the descriptive endpoint and safety figures that the registry reports.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Oral Sedation During Cervical Dilator Placement — NCT03202550.
• Registry record last updated 2020-03-30; status last verified 2020-03.
• Results first posted 2020-03-06.
• 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

NCT03202550, titled “Oral Sedation During Cervical Dilator Placement,” is recorded as a completed, randomized, parallel-group Phase 4 trial sponsored by Johns Hopkins University. The registry records enrollment of 27, a start date of 2017-06-28, and a primary completion date of 2019-05-28. The brief summary describes a placebo-controlled comparison with 1 mg oral lorazepam and 5 mg oral oxycodone.

The primary outcome is VAS pain immediately after the last dilator was placed, up to 1 minute later. The reported median is 55.0 in the placebo arm and 44.0 in the active drug arm, with the respective inter-quartile ranges of 33.0 to 82.0 and 10.0 to 80.0. The primary outcome population excludes one active-arm participant who did not need dilators. A formal comparison and its uncertainty are not reported in the registry record. The registry lists eight secondary outcomes and no analysis records.