This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for MyoSure Hysteroscopic Tissue Removal System Registry Study (NCT01369758), a na na study. The primary outcome is Procedure Efficacy.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01369758 |
| Phase | NA |
| Condition | Uterine Fibroids, Polyps |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 290 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Hologic, Inc. |
| Results posted | Yes |
2. Clinical Question
The study’s central question was whether community gynecologists could use the MyoSure Hysteroscopic Tissue Removal System to remove intrauterine polyps and submucosal fibroids, with efficacy assessed by the percentage of pathology removed and safety also being an objective. The registry record describes a single-group study, not a comparison of MyoSure with another treatment or a control group.
Population
Patients with intrauterine fibroids and/or polyps undergoing hysteroscopic tissue removal. The primary outcome population is described as 278 patients, with 559 pathologies: 187 fibroids and 372 polyps.
Intervention
The MyoSure Tissue Removal System, used for intrauterine pathology removal through a myomectomy procedure.
Comparator
There was no registered comparator group. The study is listed as single-group, and allocation is recorded as NA.
Primary question
What was the mean percentage of pathology removed, based on hysteroscopic assessment immediately after the treatment procedure?
The registry record also names the percentage of subjects achieving 100% removal of target pathology as a secondary outcome. However, outcome values for either measure are not reported in the registry record. Thus, the record identifies the clinical question and measurement approach, but does not provide the numerical efficacy results needed to describe the amount of pathology removed or the proportion with complete removal.
3. Trial Design
This was a completed, single-group device registry study of the MyoSure Hysteroscopic Tissue Removal System for intrauterine pathology, including uterine fibroids and polyps. The listed enrollment is 290. The primary outcome population is separately described as 278 patients, from whom 559 pathologies were removed. The registry record does not explain the difference between the enrollment figure and the primary outcome population, so the reason for that difference is not reported in the registry record.
The intervention description specifies removal of intrauterine pathology using the device in a myomectomy procedure. The brief study description frames the objective around treatment initiated by community gynecologists. The study is not described as randomized: allocation is recorded as NA, and the design is single-group. Masking is listed as NONE. Consequently, there is no like-for-like control arm in the registry record from which to estimate a comparative treatment effect.
The study phase is listed as NA. The record gives a start of 2010-11, primary completion of 2013-05, and status of COMPLETED. These dates describe the registry entry’s study milestones; they do not establish the duration of follow-up for individual patients. A patient-level follow-up schedule is not reported in the registry record.
The primary endpoint is a continuous measure, the mean percent of pathology removed, assessed by hysteroscopy immediately after completion of the treatment procedure. Its stated timeframe is 1 hour post treatment. The secondary outcome concerns the percentage of subjects achieving 100% removal of target pathology. The registry record identifies two outcome measures but reports no analysis entries. Statistical procedures used for the results, if any, 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
| Stage | Intrauterine Pathology, Myomectomy |
|---|---|
| STARTED | 290 |
| COMPLETED | 290 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: 559 pathologies, 187 Fibroids and 372 polyps, were removed from 278 patients.
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.
Population: 290 Subjects enrolled. Nine (9) subjects removed from analysis because they did not meet the inclusion criteria. Three (3) subjects removed from analysis because they met the exclusion criteria.
| Characteristic | Unit | Intrauterine Pathology, Myomectomy |
|---|---|---|
| Participants analysed | 278 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 278 |
| Age, Categorical: >=65 years | Participants | 0 |
| Sex: Female, Male: Female | Participants | 278 |
| Sex: Female, Male: Male | Participants | 0 |
| Region of Enrollment: United States | participants | 278 |
6. Primary Endpoint
The registry lists the primary outcome as Procedure Efficacy, measured over 1 hour post treatment.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | percent of pathology |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the mean percentage of pathology removed, based on hysteroscopic assessment immediately following completion of the procedure. It is a continuous measure: it represents the extent of removal on a percentage scale, summarized across the pathologies in the stated outcome population. The registry record gives the assessment timeframe as 1 hour post treatment.
This endpoint is intended to quantify procedural removal directly rather than rely only on a broad judgment of success. A mean can describe the average extent of removal across assessed pathology, while the accompanying 95% confidence interval is intended to express uncertainty around that estimated mean. A confidence interval does not show the results for every patient or pathology, and it does not by itself establish how clinically important an estimate is.
The registry record describes 559 pathologies removed from 278 patients: 187 fibroids and 372 polyps. It does not report the mean percentage removed or its 95% confidence interval. Therefore, the endpoint’s definition and assessment timing are available, but the numerical estimate and its precision are not reported in the registry record.
The secondary outcome is the percentage of subjects achieving 100% removal of target pathology. This asks about complete removal rather than the average extent of removal. Its numerical result is also not reported in the registry record. Because the two measures address different summaries, neither should be substituted for the other.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record makes the study question and design identifiable, but it does not report the primary endpoint’s numerical result. The stated endpoint is mean percent of pathology removed, with a 95% confidence interval, assessed immediately after the procedure. Neither the mean nor the interval is available in the registry record. The reported sample description—559 pathologies from 278 patients—does not reveal the extent removed, and should not be treated as an efficacy result.
The secondary outcome is the percentage of subjects achieving 100% removal of target pathology. No percentage or count for that outcome is reported in the registry record. It is therefore not possible to describe the frequency of complete removal from this record. Nor can the average-removal measure be inferred from a complete-removal outcome: an average and a threshold-based proportion answer different questions.
The design is single-group, with allocation listed as NA and masking as NONE. There is no registered control group, so the record does not support a controlled estimate comparing the device with another approach. Even if an outcome estimate were available, a single-group result would describe outcomes in the observed study population; by itself, it would not isolate the effect of the device from other influences on the observed outcome.
The registry record does report adverse-event counts for 278 participants at risk: zero affected by serious adverse events and five affected by other adverse events. These counts are a limited safety description, not a complete accounting of the nature, timing, severity, or attribution of all events. The serious-event terms list is empty, and deaths are recorded as null; death information is therefore not reported in the registry record. The follow-up period used for safety ascertainment is not reported in the registry record.
Precision cannot be evaluated for the primary endpoint because its estimate and confidence interval are absent. The registry record also lists no analysis entries, and does not provide a statistical analysis plan or details explaining how the outcome estimates were calculated. The available information supports a description of the registry design, endpoint definitions, population counts, and recorded adverse-event counts. It does not support a numerical conclusion about the amount of pathology removed, the frequency of complete removal, or a comparative treatment effect.
9. Statistical Methods Explained
The main outcome is a continuous measure: mean percent of pathology removed. A continuous outcome can take values across a measurement scale rather than being limited to categories such as complete versus incomplete removal. A mean condenses observations into an average, which can be useful for describing the overall extent of removal. However, an average does not show the spread of individual observations or how results differed among patients or pathology types.
The registry record says the endpoint was based on hysteroscopic assessment immediately after the treatment procedure and gives a timeframe of 1 hour post treatment. It identifies the reported dispersion measure as a 95% confidence interval. In general, a confidence interval conveys uncertainty in an estimated quantity under the assumptions of the analysis. A narrower interval indicates greater statistical precision than a wider interval, but an interval does not show every observed value and does not by itself establish clinical importance. Here, the numerical mean and confidence interval are not reported in the registry record, so their magnitude and precision cannot be assessed.
The unit is percent of pathology. The population description states that 559 pathologies—187 fibroids and 372 polyps—were removed from 278 patients. Pathologies and patients are distinct units: a patient may contribute pathology counts, and the registry record’s description does not give a patient-level distribution of those counts. Statistical analysis would need to account appropriately for the unit of observation and any dependence among multiple pathologies from the same patient. The exact analysis unit, handling of multiple pathologies per patient, and any adjustment for clustering are not reported in the registry record. No claim about how the analysis handled these features can be made.
The secondary outcome is the percentage of subjects achieving 100% removal of target pathology. This is a threshold-based proportion rather than a continuous mean. In general, a proportion answers how often a defined event or condition occurred in the population being analyzed. Interpretation depends on a clear numerator and denominator, as well as consistent outcome ascertainment. The numerical result and analysis details for this secondary outcome are not reported in the registry record.
The design is single-group. In general, an estimate from a single group describes the outcomes observed among participants in that group; it does not provide a concurrent comparison that controls for other explanations of the outcome. The record lists allocation as NA and masking as NONE. It does not identify a comparator, and the reasons for the absence of masking are not reported in the registry record. Thus, no between-group contrast or comparative estimate can be interpreted from the registered design.
The statistical analysis plan is not reported in the registry record. The record lists two outcome measures and zero analysis entries, but does not specify any model, assumptions, missing-data procedure, subgroup analysis, or adjustment strategy. It also does not give an inferential test or p-value for the primary or secondary outcome. In general, an analysis plan clarifies how endpoints, populations, missing observations, and multiple outcomes are handled; without those details, the analysis choices cannot be reconstructed.
A sample-size planning illustration is described as based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; it also describes planning for a stated fraction of the observed effect. Those are illustration assumptions, not a description of this trial’s single-group design. The calculated planning values and effect estimate are not reported in the registry record. Such planning figures, when available, are not observed power and should not be mistaken for trial results. The registry record does not report its own sample-size justification.
Over-dispersion is a general concern when variability in observed data exceeds what a simple statistical model assumes. If present, it can make standard errors and confidence intervals too small unless the analysis accounts for the extra variability. The registry record does not report a model or a dispersion assessment, so whether over-dispersion was relevant or addressed is not reported in the registry record. More broadly, statistical precision and potential sources of bias cannot be evaluated fully without the endpoint estimates, analysis methods, and participant-level information.
10. Multiplicity, Missing Data and Analysis Populations
The registry record identifies two outcome measures: mean percent of pathology removed as the primary outcome and the percentage of subjects achieving 100% removal of target pathology as a secondary outcome. It does not report a multiplicity procedure or explain whether any adjustment was planned for evaluating more than one outcome. Whether multiplicity was addressed is not reported in the registry record.
In general, multiplicity matters when several outcomes or analyses are tested, because interpreting each result separately can affect the overall chance of a false-positive finding. The relevance of that issue depends on the analysis plan, the role assigned to each endpoint, and the inferences intended. The record labels one outcome primary and one secondary, but provides no statistical analysis plan, test results, or p-values. No conclusion about statistical significance or multiplicity adjustment can be drawn from the registry record.
Missing-data handling is also not described. The enrollment is listed as 290, while the primary outcome population is described as 278 patients. The registry record does not explain the difference or say whether any participants or outcomes were excluded, unavailable, or otherwise not analyzed. It does not give missingness counts by endpoint, reasons for missing data, or a method used to address missing observations. These details are not reported in the registry record.
The analysis population is not defined beyond the outcome population description. The record does not say whether analyses followed an intention-to-treat, treated, evaluable, or other population definition. Nor does it provide participant flow or a reconciliation of enrollment and outcome denominators. The effect of missing or excluded observations therefore cannot be assessed from the registry record.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Intrauterine Pathology, Myomectomy | 0 | 278 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Intrauterine Pathology, Myomectomy | 5 of 278 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Intrauterine Pathology, Myomectomy |
|---|---|---|
| Cervical Trauma | Reproductive system and breast disorders | 4 of 278 |
| Pedal Edema Post-operative | Reproductive system and breast disorders | 1 of 278 |
The registry record reports 278 participants at risk for serious adverse events and zero affected. For other adverse events, it reports 278 at risk and five affected. These are the recorded counts in the registry entry; they do not provide details about event types, severity beyond the serious/other classification, timing, duration, or relationship to the device or procedure. The list of top serious adverse-event terms is empty.
Deaths are recorded as null, so death information is not reported in the registry record. A null entry should not be read as a reported count of zero. The time period over which adverse events were collected and the method of surveillance are not reported in the registry record. The record also does not clarify how the safety population was defined or whether all enrolled participants contributed to safety follow-up.
In general, observed adverse-event counts describe what was recorded in the analyzed safety population and depend on the completeness and duration of ascertainment. They do not, by themselves, establish causation or fully characterize risk. The available figures should therefore be read as limited registry counts, not as a complete account of every possible adverse event.
12. What the Result Does, and Does Not, Mean
The registry record describes a study of MyoSure hysteroscopic removal of intrauterine fibroids and polyps, with the primary outcome defined as mean percent of pathology removed immediately after treatment. It also identifies complete removal as a secondary outcome. These definitions show what the investigators intended to measure, and the population description reports 559 pathologies from 278 patients.
However, numerical results for the primary and secondary outcomes are not reported in the registry record. The mean, its 95% confidence interval, and the percentage of subjects achieving 100% removal are all unavailable. Therefore, the record does not permit a quantitative statement about the amount removed, the precision of the mean estimate, or how often complete removal occurred.
The design is single-group rather than a randomized comparison, with allocation listed as NA and masking as NONE. There is no control group from which to estimate a comparative effect. The record therefore describes a treatment cohort and its recorded outcomes, rather than a direct comparison with another procedure or strategy. The registry entry does not provide enough detail to determine how much any observed outcome might reflect factors other than the device and procedure.
For safety, the registry reports zero participants affected by serious adverse events among 278 at risk and five affected by other adverse events among 278 at risk. These figures do not describe event types or follow-up duration. Deaths are recorded as null and thus are not reported in the registry record.
In general, an absent result is not evidence that the outcome was zero or that no event occurred. The registry record’s missing efficacy values should not be replaced with assumptions or inferred from enrollment and pathology counts. The information supports a description of the design, measurement definitions, population counts, and limited recorded safety counts; it does not support a numerical conclusion about efficacy or a comparative claim.
13. Why This Trial Matters Statistically
This study illustrates why registry design and outcome reporting need to be considered together. The record identifies an important statistical distinction: it is a single-group study, not a randomized or controlled comparison. That design can describe outcomes in a treated population, but it does not provide a concurrent comparator for estimating a difference between treatment strategies.
It also distinguishes the unit of clinical description from the patient count. The primary outcome population is described as 278 patients and 559 pathologies, including fibroids and polyps. When multiple observations may come from one patient, the analysis needs to make clear whether the unit is the patient or the pathology and how within-patient dependence is handled. Those analysis details are not reported in the registry record.
The endpoint illustrates a further distinction between a continuous summary and a threshold-based outcome. Mean percent of pathology removed describes an average extent, while the percentage of subjects with 100% removal concerns complete removal. Both can be informative, but each answers a different question. In this registry entry, the definitions are available but the numerical results are not reported in the registry record. The difference highlights that endpoint registration alone is not enough to assess the findings; estimates and their uncertainty are essential.
The safety entries likewise show why counts require context. The registry reports participants at risk and affected, but the event details, ascertainment window, and death information are incomplete or not reported. For biostatistical interpretation, denominators, outcome definitions, analysis populations, and missing-data handling all affect what can be concluded from reported results.
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 most consequential limitation of the registry record for statistical interpretation is that it does not report the numerical results for either efficacy outcome. The mean percent of pathology removed and its 95% confidence interval are not reported in the registry record; neither is the percentage of subjects achieving 100% removal. The outcome definitions therefore cannot be paired with effect estimates or precision.
The single-group design provides no registered control arm. Allocation is listed as NA, masking as NONE, and the model as SINGLE GROUP. As a result, the registry does not provide a controlled estimate of comparative effectiveness. The record does not describe measures to address potential confounding or other sources of bias.
The enrollment figure is 290, while the primary outcome population is described as 278 patients. The reason for this difference, participant flow, and the analysis population criteria are not reported in the registry record. Missing-data amounts, reasons, and handling are also not reported. This prevents assessment of whether the outcome population represents all enrolled participants or whether missing outcomes could affect interpretation.
Although the population description gives counts of fibroids and polyps, the registry record does not explain the unit used for statistical analysis or how multiple pathologies within a patient were handled. It does not provide subgroup estimates by pathology type. The analysis method, statistical plan, multiplicity approach, and sample-size justification are not reported in the registry record.
Safety information is limited to counts of participants affected by serious and other adverse events. Event terms, timing, follow-up duration, attribution, and death information are not fully available; deaths are recorded as null. These gaps restrict the completeness of safety interpretation.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: MyoSure Hysteroscopic Tissue Removal System Registry Study — NCT01369758.
- Registry record last updated 2017-09-13; status last verified 2017-08.
- Results first posted 2017-09-13.
- 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.
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18. Record Summary
NCT01369758 is a completed, single-group registry study of the MyoSure Hysteroscopic Tissue Removal System for removal of intrauterine fibroids and polyps. The registry lists enrollment of 290, allocation as NA, and masking as NONE. The primary outcome is mean percent of pathology removed, assessed by hysteroscopy immediately after treatment, with a stated timeframe of 1 hour post treatment and a 95% confidence interval.
The outcome population is described as 278 patients with 559 pathologies: 187 fibroids and 372 polyps. A secondary outcome concerns the percentage of subjects achieving 100% removal. Numerical efficacy results and analysis details are not reported in the registry record. Safety entries report zero affected by serious adverse events and five affected by other adverse events among 278 at risk; deaths are recorded as null. The record does not provide a concurrent comparator or enough detail to evaluate comparative effects, missing data, or analysis methods.