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 Electromyography in Patients on Chronic Pyridostigmine Therapy (NCT02364180), a na na study. The primary outcome is Percent Change in the Amplitude of Evoked Compound Muscle Action Potential by Electromyography Between the First to Fifth Response.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02364180 |
| Phase | NA |
| Condition | Muscle Weakness |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 11 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Toledo Health Science Campus |
| Results posted | Yes |
2. Clinical Question
Population
People taking pyridostigmine bromide for more than 6 weeks for a condition other than myasthenia gravis. The condition field lists Muscle Weakness. The primary outcome’s population field is blank, so further eligibility or analysis-population details are not reported in the registry record.
Intervention
Electromyography (EMG), including repetitive nerve stimulation, was used to measure evoked responses. The registry describes observation rather than assigning a treatment.
Comparator
No separate comparator group is described. The study is listed as single-group, with allocation recorded as NA. The first and fifth responses are measurements within the same assessment, not responses from separate treatment groups.
Primary question
What is the percent change in the amplitude of the evoked compound muscle action potential between the first and fifth responses in people on chronic pyridostigmine therapy? The registry specifies a median and full range as the summary, but does not report the observed outcome value or an analysis result.
The clinical rationale in the registry is that successive compound muscle action potentials are normally expected to be of the same height during rapid nerve stimulation. The investigators hoped to examine whether chronic pyridostigmine therapy might be associated with a reduced margin of safety and, consequently, smaller successive responses. This is the stated rationale, not a reported finding.
The registered assessment was at baseline, with the first and fifth stimuli delivered 2 seconds apart on the same day. The registry says there were no additional days or times. That timing defines a short, within-assessment comparison; it does not establish a change over a course of treatment or compare people receiving different therapies. Since the record contains no outcome estimate or analysis, it does not answer whether the measured responses differed in this group.
3. Trial Design
This completed study is registered as a single-group study of Electromyography in Patients on Chronic Pyridostigmine Therapy. The intervention is a diagnostic test, not an assigned drug regimen. The arm description says that subjects taking pyridostigmine bromide for more than 6 weeks for a condition other than myasthenia gravis were observed with EMG. Allocation is recorded as NA, and masking is listed as NONE. The registry does not describe a randomized comparison or a like-for-like control group.
Enrollment is recorded as 11. This is the registry’s enrollment figure, not a reported count of participants with available primary outcome data. The primary outcome population field is blank, and the record gives no analysis results. The safety entry separately reports 10 at risk for serious adverse events and 10 at risk for other adverse events. Those safety denominators should not be assumed to define the primary outcome analysis population.
The start is recorded as 2013-12, primary completion as 2016-07, and status as COMPLETED. The registry identifies the sponsor as University of Toledo Health Science Campus. Phase is listed as NA, and the study kind is other. Further details about the protocol, participant flow, enrollment rationale, or the conduct of the assessment are not reported in the registry record.
The primary endpoint is a within-assessment comparison of the first and fifth evoked responses. The registered timeframe says baseline measurement only, with the stimuli 2 seconds apart on the same day and no additional days or times. This design can describe the responses measured during that assessment, but without a separate comparator it cannot isolate a treatment effect from other explanations for any observed difference. The registry record does not report an outcome value or a sponsor analysis.
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 | Pyridostigmine Bromide Treatment Group |
|---|---|
| STARTED | 11 |
| COMPLETED | 10 |
| NOT COMPLETED | 1 |
Reasons for not completing this period:
| Reason | Pyridostigmine Bromide Treatment Group |
|---|---|
| Screen Fail | 1 |
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.
| Characteristic | Unit | Pyridostigmine Bromide Treatment Group |
|---|---|---|
| Participants analysed | 11 | |
| Age, Continuous | years | 63 (18 to 89) |
| Sex: Female, Male: Female | Participants | 5 |
| Sex: Female, Male: Male | Participants | 6 |
6. Primary Endpoint
The registry lists the primary outcome as Percent Change in the Amplitude of Evoked Compound Muscle Action Potential by Electromyography Between the First to Fifth Response, measured over Baseline measurement only. First and Fifth stimuli delivered 2 seconds apart on the same day. There are no additional days/times..
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Full Range |
| Unit | percent change |
| Endpoint classification | not reduced to a single comparison |
The primary outcome is titled as the percent change in the amplitude of the evoked compound muscle action potential (CMAP) measured by EMG between the first and fifth response. A CMAP is the recorded muscle response following nerve stimulation. Repetitive nerve stimulation allows successive responses to be examined within an assessment. The registry’s rationale is that successive CMAPs are normally of the same height and that smaller later responses could be relevant to the investigators’ question about the margin of safety.
The registered summary measure is the median, with the full range as the measure of dispersion. In general, a median describes the middle of the observed values and is less affected by extreme values than a mean. The full range describes the span from the lowest to highest observed value, but does not show how values are distributed within that span. These are general statistical interpretations of the registered summary choices; the registry record does not state the actual median or range.
The timeframe is baseline only: the first and fifth stimuli were delivered 2 seconds apart on the same day, with no additional assessment times. The record does not state the formula used to calculate percent change, nor does it report individual observations, the endpoint estimate, or an uncertainty interval. As a result, the endpoint’s intended measurement can be described, but its observed magnitude and precision cannot be assessed from the registry results.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a primary endpoint and a measurement occasion, but it does not report the primary outcome result. It lists one outcome measure and zero analyses. There is no reported median percent change, full range, confidence interval, test statistic, or p-value. Accordingly, the registered question about the first-to-fifth CMAP response cannot be answered from the results recorded. The rationale in the outcome description should not be read as evidence that the expected pattern occurred.
The study is described as observational and single-group. Participants were already taking pyridostigmine for more than 6 weeks, and EMG was used to observe their evoked responses. There is no separate control group or randomized treatment assignment in the record. Even if a difference between successive responses had been reported, this design alone would describe an association or measurement pattern in the observed group; it would not establish that pyridostigmine caused the pattern. The registry does not provide results that permit even that descriptive assessment.
The time structure is also narrow: the registered endpoint compares responses from stimuli delivered 2 seconds apart on the same day at baseline, with no additional days or times. It therefore concerns a within-assessment response, not change in an outcome across follow-up. The record does not provide data on how stable the measurement was across assessments or whether it related to later clinical outcomes.
The enrollment figure is 11, while the safety record lists 10 at risk for each of the two adverse-event categories. The primary outcome population is not specified in its registry field. Those entries do not establish how many participants contributed primary endpoint data, and no outcome-level denominator is reported. It would be inappropriate to infer the analysis population from enrollment or safety figures.
The posted safety figures report zero serious adverse events among 10 at risk, zero other adverse events among 10 at risk, and zero deaths. These are registry counts for the stated group and categories. They do not establish that no adverse events occurred outside the recorded categories or observation, nor do they provide a comparison with another group. The record supplies no detailed event terms or further safety analysis.
Overall, the registry supports a description of the study question, design, timing, and recorded safety counts. It does not supply an efficacy or endpoint estimate, its uncertainty, or an inferential analysis. No conclusion about the direction, size, or statistical significance of the CMAP response can be drawn from the registry record.
9. Statistical Methods Explained
The registry identifies the primary outcome as a median percent change and its dispersion as the full range. These choices describe how a set of observed values would be summarized; they do not themselves provide the values. No median, minimum, maximum, participant-level observations, or analysis results are reported. The meaning of the chosen summary can therefore be explained, but the actual distribution of responses cannot be reconstructed.
What does a median convey?
In general, the median is the central value when observations are ordered. It can be useful when a small number of unusually high or low observations might pull a mean away from the typical value. A median does not show the shape of the distribution, and it does not by itself show how uncertain the estimate is. The registry does not describe why the median was selected or whether the outcome distribution was assessed.
What does the full range convey?
In general, the full range gives the lowest and highest observations in a set. It communicates the observed span, but it can be strongly influenced by extreme observations and does not indicate where most values lie. It is not a confidence interval. A confidence interval, in general, describes uncertainty around an estimated quantity under specified assumptions; no confidence interval is reported for this primary outcome.
What does the within-assessment comparison represent?
The primary outcome compares the amplitude of the first and fifth evoked CMAP responses. The registered timeframe places those stimuli 2 seconds apart on the same day at baseline. Thus, the question is about successive responses during one assessment, rather than a before-and-after treatment comparison across separate visits. The record does not specify the formula used for percent change, the exact measurement sites, or other details of the calculation beyond the outcome title and description.
General statistical interpretation of repeated measurements distinguishes a within-person contrast from a comparison between independent groups. A within-person contrast can account for some stable differences between people because both measurements come from the same assessment. It does not, on its own, account for measurement error, transient variation, or other factors that may affect the responses. The registry does not report reliability data or an analysis addressing those factors.
What can the design establish?
The study is recorded as single-group, with no randomized allocation and no masking. The described participants were taking pyridostigmine before the EMG observation; the registry does not describe assignment to treatment or a separate untreated comparator. A descriptive outcome could characterize responses in the measured group, but a single-group observation does not isolate the effect of a drug from other possible explanations. Here, no descriptive outcome estimate is reported either.
For a comparison to support causal interpretation, design and analysis must address alternative explanations for differences in outcomes. General methods include random assignment and an appropriate concurrent comparator, among other features. Those features are not described in this record. This is not a judgment about what may have occurred outside the registry entry; unreported details are not reported in the registry record.
How should the planning assumptions be read?
The record’s planning-assumptions text describes an illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says that the effect to detect is a stated fraction of the observed effect. It also distinguishes illustrations expressed as participants per arm from time-to-event illustrations expressed as total events.
These are planning assumptions, not evidence that this study enrolled two arms or used that design. The registered study is single-group, and no observed effect or analysis is reported. The assumptions do not supply a sample-size justification for this study, and no actual planning values are reported in the registry record. Any sample-size illustration based on an observed effect should be understood as a planning scenario, not observed power or a result of the trial.
In general, a normal approximation relies on conditions that make a normal-based calculation reasonable. The record does not give details of any calculation, its inputs beyond the stated assumptions, or a protocol-based sample-size rationale. It does not report interim analyses, a prespecified statistical analysis plan, or any recalculated analysis. None should be inferred from the planning-assumptions text.
What is available for statistical inference?
The record lists zero analyses. It does not report a standard error, confidence interval, hypothesis test, or p-value. Statistical inference would require an estimate and information about its variability, together with a stated analysis approach. Without those results, it is not possible to judge whether the observed responses were close to one another, how variable they were, or how precisely a group-level quantity was estimated.
General concepts such as over-dispersion matter when observed variability is greater than a model assumes, because model-based standard errors and uncertainty estimates can then be too small. The registry does not report a model, a variance estimate, or evidence of over-dispersion for this outcome. That concept is therefore relevant only as general statistical context, not as a finding about this study.
The sponsor’s own analysis would take precedence over a simple recalculation from posted summary statistics if a discrepancy were documented. No sponsor analysis or recalculated result is reported in the registry record, so no such comparison can be made. The statistical methods that were actually used to analyze the primary endpoint are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one primary outcome measure, but it does not report an analysis for that measure. It does not describe a statistical analysis plan, the number of hypotheses tested, or any procedure for handling multiple comparisons. The presence of a single listed primary outcome does not establish that no other analyses were conducted; analysis details are not reported in the registry record.
In general, multiplicity arises when multiple outcomes, groups, time points, or statistical tests are considered. Repeated testing can increase the chance of a result appearing notable by chance, so a prespecified plan may define which comparisons are primary and how inference is controlled. The registry gives a baseline-only timeframe for the primary endpoint, but does not report any multiplicity adjustment or state how other analyses, if any, were treated.
Missing-data handling is also not described. The primary outcome population field is blank, and no participant-level flow or endpoint denominator is reported. Enrollment is recorded as 11, while the safety entry has 10 at risk for each adverse-event category. These counts do not establish how many observations were available for the primary endpoint or why any data might be absent. The record does not report imputation, exclusions, or a sensitivity analysis.
The analysis population is not reported in the registry record. It is not possible to determine whether the primary outcome was intended to include all enrolled participants or a defined subset. No analysis results are listed, so there is no basis to evaluate how missing measurements or analysis-population choices affected an estimate.
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 |
|---|---|---|---|
| Pyridostigmine Bromide Treatment Group | 0 | 10 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Pyridostigmine Bromide Treatment Group | 0 of 10 |
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 |
|---|---|
| Pyridostigmine Bromide Treatment Group | 0 of 10 |
The safety entry is for the Pyridostigmine Bromide Treatment Group. It reports 10 at risk for serious adverse events and zero affected, 10 at risk for other adverse events and zero affected, and zero deaths. These are counts as recorded; they are not comparative estimates and do not establish a difference from another group.
The registry record does not provide the duration of safety observation, detailed event terms, or further safety analyses. The listed zero counts should therefore be read as no events recorded in these categories for the stated group and denominators, rather than proof that no event of any kind occurred. The record does not say how the safety denominators relate to the primary outcome population. Enrollment is recorded as 11, so the separate safety figures should not be substituted for enrollment or treated as the primary endpoint sample size.
In general, safety counts depend on how events are defined, collected, and observed. Without additional detail or a comparator, these figures do not quantify relative safety or establish whether the treatment caused or prevented events.
12. What the Result Does, and Does Not, Mean
The record establishes that the study was designed to observe EMG responses in people taking pyridostigmine chronically for a condition other than myasthenia gravis. Its primary question concerned the percent change in CMAP amplitude between the first and fifth evoked responses. The timing was a baseline assessment, with stimuli 2 seconds apart on the same day and no additional assessment times.
The record does not report the primary endpoint result. It gives no median, full range, participant-level measurements, confidence interval, test statistic, or p-value. Therefore, it does not show whether the fifth response was smaller, larger, or similar to the first response, or how variable the measured changes were. The stated rationale about a possible reduced margin of safety is a motivation for the outcome, not a result.
The single-group observational design also limits what any descriptive pattern could establish. There is no separate control group or randomized assignment described. A difference between successive responses, if one were reported, would not by itself show that chronic pyridostigmine caused that difference. The registry does not report enough information to assess alternative explanations, measurement reliability, or clinical consequences.
The enrollment figure of 11 should not be read as the number contributing primary outcome data, because the outcome population and analysis denominator are not reported. The safety figures are separate: zero serious adverse events among 10 at risk, zero other adverse events among 10 at risk, and zero deaths. These counts do not provide a comparison or a complete account of safety beyond what the registry records.
Accordingly, this record supports a clear description of the measurement question and study structure, but not a conclusion about the observed EMG response, its precision, or its clinical significance. It neither establishes a treatment effect nor reports a result that could be interpreted as evidence for or against the proposed physiological explanation.
13. Why This Trial Matters Statistically
This study raises a statistical distinction between a measurement question and a treatment-comparison question. Its registered endpoint focuses on successive EMG responses within an assessment, while the study is described as a single-group observation of people already taking pyridostigmine. The design can frame a descriptive question about those responses, but it does not provide a randomized comparison of treatment strategies.
The choice of a median and full range signals that the registry intended to summarize both a central value and the observed spread. Those summaries can be useful for data that may not be well characterized by a mean and standard deviation. But summaries need actual observations to be interpretable, and the record does not report the endpoint estimate or its distribution. This makes the gap between a registered outcome and a reported result especially important.
The record also illustrates why populations and denominators should be kept distinct. Enrollment is 11, the safety denominators are 10, and the primary outcome population is blank. These figures serve different registry roles and cannot be combined to infer who contributed outcome data. Clear participant flow and endpoint denominators are necessary to understand how much information an estimate represents.
Finally, a planning illustration based on a fraction of an observed effect is not the same as a study’s documented design rationale, nor is it observed power. In this case the assumptions describe equal allocation between two arms even though the registered model is single-group. This underscores the need to distinguish generic planning scenarios from the design and analysis actually reported for a study. The registry gives no primary analysis with which to assess precision or uncertainty.
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.
Several limitations follow directly from the registry record. The primary outcome value and its full range are not reported, and the record lists zero analyses. There is therefore no estimate, uncertainty interval, or inferential result to evaluate. The primary outcome population field is blank, and the denominator for that endpoint is not reported.
The single-group observational design has no separate comparator described, and allocation is listed as NA. The record does not support a causal comparison of pyridostigmine with another treatment or no treatment. The single registered measurement occasion is baseline, with the first and fifth stimuli 2 seconds apart on the same day; the registry reports no additional assessment times. It cannot describe change across follow-up.
Important operational and analytical details are not reported in the registry record, including the formula for percent change, the primary endpoint analysis method, participant flow, missing-data handling, and the statistical analysis plan. The record also does not explain the difference between enrollment of 11 and the safety denominators of 10, or state how those denominators relate to outcome availability.
Safety reporting is limited to the listed counts: zero serious adverse events among 10 at risk, zero other adverse events among 10 at risk, and zero deaths. Event definitions, detailed terms, and duration of observation are not reported. These limitations restrict interpretation of both the unreported primary outcome and the recorded safety figures.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Electromyography in Patients on Chronic Pyridostigmine Therapy — NCT02364180.
- Registry record last updated 2017-05-09; status last verified 2017-03.
- Results first posted 2017-03-31.
- 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
The registry identifies NCT02364180, Electromyography in Patients on Chronic Pyridostigmine Therapy, as a completed single-group study sponsored by University of Toledo Health Science Campus. The recorded start is 2013-12 and primary completion is 2016-07. Enrollment is 11; allocation is NA, masking is NONE, and phase is NA.
The study observed people taking pyridostigmine bromide for more than 6 weeks for a condition other than myasthenia gravis. Its primary endpoint was the median percent change in evoked CMAP amplitude between the first and fifth responses, with full range as dispersion. The baseline stimuli were delivered 2 seconds apart on the same day.
The record lists one outcome measure and zero analyses. No primary outcome estimate or analysis result is reported. Safety counts are zero serious adverse events among 10 at risk, zero other adverse events among 10 at risk, and zero deaths. The outcome population, statistical analysis methods, and missing-data handling are not reported in the registry record.