Observational Study of Botox® Treatment for Patients With Upper Limb Adult Spasticity: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Observational Study of Botox® Treatment for Patients With Upper Limb Adult Spasticity (NCT01387074), a registered phase not stated study. The primary outcome is Muscle Tone as Measured by the Modified Ashworth Scale (MAS) in the Elbow at Baseline.

2. Clinical Question

This study was designed to collect information about botulinum toxin Type A use in a routine setting among patients with upper limb adult spasticity. Its primary outcome description focuses on muscle tone during elbow movement, classified against a scale ranging from no increase in tone to rigidity. The scale’s categories are ordered: higher scores indicate more severe stiffness, while lower scores indicate little or no stiffness.

The registry record does not report the number of participants in each baseline score category. It also does not report a treatment-effect estimate, a comparison with untreated participants, or a statistical test for the primary outcome. Accordingly, the record supports describing the clinical question and measurement, but not estimating whether muscle tone changed following treatment or attributing any change to treatment.

3. Trial Design

This was a prospective, non-interventional, observational study of botulinum toxin Type A use in a routine setting for patients with upper limb adult spasticity. It is identified as completed. The registry record gives a start date of 2011-06 and a primary completion date of 2013-01, and lists Allergan as sponsor. Enrollment is recorded as 108.

The intervention description says the physician determined the treatment dose at baseline. A second botulinum toxin Type A treatment was to occur approximately 12 weeks later if applicable. The record does not specify how many participants received a second treatment, how treatment decisions were made, or whether the timing and dose varied across participants. Further details of the routine-care setting are not reported in the registry record.

Because this was observational and non-interventional, treatment was not assigned through a randomized comparison as described in the registry record. No control group is described, and the record does not state an allocation method. These features matter for interpretation: a treatment-effect comparison requires a suitable contrast, and differences between people receiving different care can reflect their underlying characteristics or clinical circumstances as well as treatment.

The registry lists eight outcome measures and describes the primary measure as the number of participants in each elbow Modified Ashworth Scale category at baseline. The record reports no analyses. It does not report a statistical analysis plan, sample-size justification, interim analyses, or methods for handling confounding. These details should not be inferred from the observational design or from the outcome description.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Efficacy population included all participants who received BOTOX® not previously treated with botulinum toxin.

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 Muscle Tone as Measured by the Modified Ashworth Scale (MAS) in the Elbow at Baseline, measured over Baseline.

The primary outcome measures elbow muscle tone using the Modified Ashworth Scale (MAS). The assessment concerns the degree of tone during movement compared with normal muscle tone. The registry describes a six-category scale, with scores from 0 through 4 and a distinct 1+ category. A score of 0 means no increase in muscle tone; the higher categories describe increasing resistance, difficulty with passive movement, or rigidity. Lower scores indicate little or no stiffness, while higher scores indicate more severe stiffness.

The outcome is stated as the number of participants in each score category at baseline. Reporting category counts can show how participants were distributed across an ordered clinical measure, while retaining the distinction between categories rather than treating the scale as a continuous measurement. The scale is used to characterize muscle tone; it does not, by itself, establish the cause of a score or show that a treatment changed it.

The stated timeframe is baseline, so this primary outcome is a starting-point description rather than a change-from-baseline endpoint. The registry record does not report the category counts, a later MAS assessment for this primary outcome, or a comparison over time. It therefore does not provide a result from which the magnitude or precision of any change in elbow muscle tone can be assessed.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes the primary outcome as counts of participants in categories of an ordered clinical scale. A count reports how many participants fall into a category; it does not measure the distance between category scores. That distinction is relevant because the MAS categories convey an order of increasing muscle tone, but the registry record does not establish that the difference between adjacent categories is numerically equal. Describing category counts preserves the scale’s stated structure.

In general, a binary outcome records whether a participant experienced an event or did not. The posted serious adverse event summary uses counts of participants affected, alongside numbers at risk. Those counts are not a treatment-effect estimate when there is no comparison group. A group’s event count alone cannot show what would have happened to the same participants under a different treatment or without treatment.

In general, an estimate is more informative when accompanied by a measure of uncertainty, such as a confidence interval. A confidence interval describes a range of values compatible with the data and the statistical method used; it is not a guarantee that the true value lies within that range. The registry record does not report a confidence interval for the primary outcome or a treatment-effect estimate. No precision measure for the baseline category distribution is reported either.

In general, a p-value is calculated under a specified statistical model and null hypothesis. It does not give the probability that a treatment works, and it does not measure clinical importance. A p-value also cannot substitute for an effect estimate and its uncertainty. The registry record lists no analyses and reports no p-value for the primary outcome. A statistical test should not be reconstructed from the available description alone.

For an observational study, comparison of outcomes may be affected by confounding. Confounding occurs when a factor related to treatment choice is also related to the outcome. In general, measured confounders can sometimes be addressed with an appropriately specified analysis, but the adequacy of adjustment depends on the data and assumptions. The registry record does not report an adjustment strategy, covariates, or an adjusted comparison. It is therefore not possible to determine whether or how confounding was addressed.

Repeated measurements, if collected, can require methods that account for observations from the same participant being related. The treatment description allows for a second treatment approximately 12 weeks after baseline if applicable, but the record does not describe repeated primary MAS measurements or a longitudinal analysis. It would be inappropriate to assume a particular follow-up schedule or model from the treatment description alone.

In general, multiplicity arises when several outcomes or several statistical tests are examined. With multiple tests, the chance of at least one apparently unusual result can increase unless the analysis plan accounts for the testing strategy. The registry lists eight outcome measures, but reports no analyses or multiplicity method. The number of outcomes alone does not establish how many tests were performed or whether any adjustment was planned.

Planning calculations are different from observed results. In general, a sample-size calculation uses assumptions about an effect, variability or event rate, significance level, allocation, and desired power to estimate the amount of information a future study may need. Such a calculation is not evidence that a completed study had a particular probability of detecting an effect. The record’s planning description refers to an observed effect and specifies a two-sided significance level of 0.05, equal allocation, and a normal approximation; it does not provide numerical planning outputs in the registry record. Any planning illustration should be read as a hypothetical design calculation, not as observed power or a treatment result.

Over-dispersion is a general issue for count data when the variability is greater than a chosen model assumes. If it is ignored, uncertainty can be understated and inferential conclusions may be too confident. Its relevance depends on the data structure and model; the registry record does not report an over-dispersion assessment or a count-model analysis. This concept does not change the fact that the primary endpoint is described as category counts, nor does it supply missing results.

Finally, a method’s assumptions need to match the design and the available measurements. The registry record does not report the analysis population size for the primary endpoint, missing-data methods, model specifications, or sensitivity analyses. No re-calculation of an effect is possible from the record because the required outcome summaries and analysis results are not reported. A statistical method cannot compensate for an absent comparison or absent endpoint data.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists eight outcome measures but reports no analyses. It does not state which outcomes, beyond the described primary baseline MAS measure, were included in any inferential testing, or whether a hierarchy of outcomes was planned. A multiplicity adjustment or other strategy for interpreting several tests is not reported in the registry record. The count of listed outcomes alone does not establish how many statistical tests were performed.

The record does not report missing-data methods, the amount of missing outcome data, or the number of participants contributing to the primary endpoint. Enrollment is recorded as 108, but this does not establish that every enrolled participant contributed a baseline MAS assessment or met the described efficacy-population definition. The registry defines that population as participants who received BOTOX® and had not previously been treated with botulinum toxin, but does not report its size.

The registry record does not describe how participants with unavailable measurements were handled, whether any sensitivity analyses were conducted, or how protocol deviations affected inclusion. These omissions make it impossible to assess whether missingness could have affected the reported outcome distribution. They also prevent a comparison between the enrolled group and the population contributing to any outcome analysis.

No statistical analysis plan, interim analysis procedure, or sample-size justification is reported in the registry record. These are not details that can be inferred from the prospective observational design. With no analyses listed and no primary endpoint counts reported, the record does not support an assessment of multiplicity control, missing-data impact, or analysis-population sensitivity.

11. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: status epilepticus (0.9%), bacteraemia (0.9%), pneumonia aspiration (0.9%), gastroenteritis norovirus (0.9%), clostridium difficile colitis (0.9%).

The registry safety summary lists 108 participants at risk for serious adverse events and one participant affected in the botulinum toxin Type A group. It lists 108 at risk for other adverse events and zero participants affected in that summary. The reported counts describe participants, not necessarily the total number of separate event episodes.

Six serious adverse event terms are listed: Status epilepticus, Bacteraemia, Pneumonia aspiration, Gastroenteritis norovirus, Clostridium difficile colitis, and Hypokalaemia. Each term is paired with 0.9% in the registry record. These entries should be read as reported terms and percentages; they do not establish a causal relationship to treatment. The record does not describe event timing, clinical course, or attribution.

The death count is not reported in the registry record. It should not be interpreted as zero. Safety figures are descriptive, and the record does not provide a randomized comparator for assessing relative risk. The absence of a reported event in a particular summary also does not establish that no such event occurred outside the recorded categories or reporting period.

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

The record provides a description of the study’s observational design, its treatment approach, and the intended primary measure. It indicates that physicians determined the treatment dose at baseline and that a second treatment was planned approximately 12 weeks later if applicable. It also defines the MAS categories used to characterize elbow muscle tone and reports summary counts for serious and other adverse events.

It does not provide the primary endpoint’s category counts, a follow-up MAS result, or an estimate of change. There is no reported statistical comparison or confidence interval for muscle tone. As a result, the posted information does not quantify the size or precision of a treatment-associated outcome, and it cannot establish whether the baseline measure changed over time.

The study’s non-interventional design and the absence of a described control group also mean that the record does not support a causal comparison. In general, observational findings can be influenced by treatment selection and other differences among participants. The registry record does not report an adjusted analysis that would address such differences.

The adverse event entries provide a descriptive safety record, not proof that treatment caused or did not cause any event. One participant is listed as having a serious adverse event, and zero are listed for other adverse events in the summary; the listed serious-event terms each carry 0.9%. The registry does not report a death count or enough detail to assess causality, timing, or comparative risk.

Overall, this entry is informative about the study’s purpose and measurement framework, but limited for evaluating outcomes. Missing results do not mean that an effect was absent; they mean the registry record does not report the information needed to characterize one. No treatment recommendation or conclusion about effectiveness follows from these registry entries alone.

13. Why This Trial Matters Statistically

This study illustrates a useful distinction between describing care and estimating a treatment effect. A prospective observational study can document how treatment is used in routine settings and define outcomes of interest. But a baseline outcome description, without reported follow-up results or a comparator, cannot by itself quantify change or separate treatment effects from other influences.

The primary outcome also illustrates why measurement scale matters. The MAS is described through ordered categories, and the registry presents the intended result as participant counts in each category. Those categories have a clinical order, but the record does not report results or establish that the scale should be analyzed as though each step represents an equal numerical change. Keeping the scale’s structure clear is important for choosing and interpreting an analysis.

The entry also shows why registry completeness affects statistical interpretation. Enrollment and a defined outcome are not enough to assess precision when the endpoint counts, analysis population, missing-data handling, and inferential results are not reported. A reader cannot recover an effect estimate from a design description alone.

Finally, descriptive safety counts and serious-event terms require careful boundaries. They can communicate what the registry records, but without comparative analysis they do not estimate relative risk or establish causation. Distinguishing descriptive evidence from comparative inference helps prevent the study’s purpose and available information from being overstated.

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 specified at baseline, and the registry record does not report its category counts. No later primary MAS assessment or change estimate is reported. This leaves the main muscle-tone outcome without a posted result that can be interpreted for magnitude or precision.

The study is observational and non-interventional. No control group or random allocation method is described, so the record does not provide a like-for-like comparison. The registry does not report methods for controlling confounding, nor does it provide enough information to evaluate treatment selection or differences among participants.

The treatment dose was determined by the physician, and a second treatment was planned approximately 12 weeks later if applicable. The record does not report actual doses, how many participants received a second treatment, or the reasons for treatment decisions. These details limit interpretation of variation in exposure.

Although enrollment is listed as 108, the record does not report the number contributing to the primary outcome or the size of the defined efficacy population. Missing-data amounts and handling are not reported. The registry lists eight outcome measures but no analyses, and does not describe multiplicity procedures, a statistical analysis plan, interim analyses, or a sample-size justification.

Safety reporting is also limited: the registry gives affected-participant counts and serious-event terms but does not report event timing, attribution, or a death count. These limitations are specific to the information reported in the registry record; they do not establish that unreported procedures or data were absent from the study itself.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Observational Study of Botox® Treatment for Patients With Upper Limb Adult Spasticity — NCT01387074.
• Registry record last updated 2014-02-03; status last verified 2013-12.
• Results first posted 2014-02-03.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

The registry record describes a completed prospective, non-interventional observational study of botulinum toxin Type A for upper limb adult spasticity. Enrollment is recorded as 108. Physicians determined the treatment dose at baseline, with a second treatment planned approximately 12 weeks later if applicable.

The primary outcome is the number of participants in each elbow MAS category at baseline. The record explains the scale but does not report the category counts or a treatment-effect analysis. It lists eight outcome measures and no analyses.

The safety summary records one participant with a serious adverse event and zero with other adverse events; six serious-event terms are listed, each with 0.9%. A death count is not reported in the registry record. The observational design and absence of a reported comparator limit causal interpretation.