MDs on Botox Utility (MOBILITY): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for MDs on Botox Utility (MOBILITY) (NCT00535938), a registered phase not stated study. The primary outcome is Change From Baseline in the SF-6D Measure Health Utility (Quality of Life) Score Using the SF-12® Questionnaire for Patients With Cervical Dystonia.

2. Clinical Question

3. Trial Design

MOBILITY, or MDs on Botox Utility, is recorded as a prospective, non-randomized, observational, multi-centre evaluation of health utility among patients receiving BOTOX® for therapeutic use. The registry lists Allergan as the sponsor, enrollment of 1372, a start date of 2007-09, primary completion in 2013-09, and status COMPLETED. These details describe the study record and do not establish how many enrolled patients contributed data to the primary endpoint.

Patients were classified by treatment history at entry. The naïve group was initiating BOTOX® treatment upon entry to the project; the non-naïve group was receiving ongoing treatment upon entry. These are observational categories rather than randomized assignments. Differences between the groups could reflect treatment history or other differences among patients, and the record does not describe an adjustment strategy that would make them equivalent.

The main outcome focused on health utility for patients with cervical dystonia, while the record also lists conditions and secondary outcomes covering several disorders and resource utilization. The primary endpoint used baseline and SV1 measurements. The interval to SV1 was at the physician’s discretion, with a maximum of 505 days for patients with cervical dystonia. That flexible timing is part of the outcome definition and means the observation was not scheduled at one uniform follow-up interval.

The registry record does not report the allocation method, detailed visit schedule beyond the stated SV1 timing, or a protocol-level statistical analysis plan. It also does not report the primary numerical outcome or any listed analyses. Consequently, the design can be described as observational, but the record does not support a reconstruction of all procedures used to collect or analyze the data.

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

Analysis population for the primary outcome, as defined in the registry: Efficacy Cohort: all enrolled patients who had a valid SF-6D score at baseline and at least one valid SF-6D score at a subsequent visit within the prospective period and who had data at this time point

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 Change From Baseline in the SF-6D Measure Health Utility (Quality of Life) Score Using the SF-12® Questionnaire for Patients With Cervical Dystonia, measured over Baseline, SV1 (up to 505 days).

The primary endpoint was change from baseline in the SF-6D measure of health utility, using the SF-12® questionnaire, for patients with cervical dystonia. The SF-12 consists of 12 questions about health. Its responses are used to derive an SF-6D health utility sub-score based on physical functioning, role participation, social functioning, bodily pain, mental health, and vitality. The score ranges from 0, representing death, to 1, representing perfect health.

Health utility is a numerical indicator of preferences for a health state or outcome. As a general statistical concept, a utility score can express health status in a form that permits comparisons across health conditions and types of health outcome. It is not a direct count of symptoms or a disease-specific physical measurement. The endpoint’s stated interpretation is that a positive change from baseline indicates improvement and a negative change indicates worsening.

The specified follow-up was Subsequent Visit 1 (SV1), scheduled at the physician’s discretion and up to 505 days after baseline. The primary population was the Efficacy Cohort: enrolled patients with a valid baseline SF-6D score and at least one valid score at a subsequent visit in the prospective period, with data at this time point. The numerical mean change, standard deviation, and number of patients contributing to the endpoint are not reported in the registry record. Therefore, the endpoint definition is available, but its observed result and precision cannot be described from the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a continuous measure: a mean change in SF-6D health utility score from baseline to SV1. For a continuous measure, a mean describes the central value across the observations included in an analysis, while a standard deviation describes the spread of individual observations around that mean. The record specifies mean and standard deviation as the summary approach, but the numerical summaries are not reported in the registry record. No analysis estimate or uncertainty interval is available in the posted results.

What does a change score represent?

A change score is formed by comparing a participant’s follow-up measurement with their baseline measurement. In this endpoint, the registry defines positive change as improvement and negative change as worsening. The interpretation depends on paired measurements from the same participant and on the timing and validity of those measurements. The record identifies the required valid-score criteria for the Efficacy Cohort, but it does not report the number of participants with complete qualifying data or the observed distribution of their change scores.

As a general statistical concept, summarizing change can help account for differences in starting scores when describing within-person movement over time. It does not automatically remove differences between treatment-history groups or account for other factors that may influence follow-up scores. Whether any model adjusted for such factors is not reported in the registry record. The registry also does not report whether the mean was accompanied by a confidence interval. A confidence interval, as a general concept, describes the range of values reasonably compatible with the data and analysis assumptions; without one or other uncertainty information, precision cannot be judged from a point estimate alone.

Why does the observational design matter?

In a randomized study, assignment is used to create comparison groups through a chance-based process. MOBILITY is explicitly described as non-randomized and observational, and its two groups were defined by whether patients were starting or already receiving treatment at entry. The groups therefore do not constitute a randomized control comparison. General statistical reasoning cautions that an observed group difference can reflect baseline differences, treatment history, clinical context, or other factors, not just the intervention. The registry record does not report a causal analysis or a method to address confounding.

The endpoint also has a physician-discretion visit window, with SV1 up to 505 days after baseline. As a general matter, differing follow-up intervals can complicate comparisons of change because the elapsed time represented by each score may vary. The record does not report how follow-up timing varied across participants or whether the analysis accounted for it. No assumptions about a uniform visit interval should be made from the stated maximum alone.

What do the planning illustrations mean?

The registry’s planning assumptions describe illustrations based on the observed effect, with two-sided significance level 0.05, equal allocation between two arms, and a normal approximation. The illustrated effect is a stated fraction of the observed effect. These are planning calculations, not observed study outcomes and not evidence that the study had a particular probability of detecting an effect. Sample-size illustrations are not observed power. The record does not report a sample-size justification for the original study, and it does not report the numerical effect estimates needed to interpret any planning illustration in relation to the primary endpoint.

As a general concept, planning calculations depend on the effect chosen for detection and assumptions about the analysis. If the target effect is smaller than the observed estimate used as a reference, the planning requirement may differ; the record’s stated approach is to consider fractions of that observed effect. These calculations should not be confused with an estimate of treatment benefit, nor should they be read as a substitute for uncertainty around the study’s actual result. The listed assumptions do not establish that these methods were used to plan enrollment of the completed project.

What is not documented?

The registry lists 16 outcome measures and 0 analyses. It does not report the model used for the primary endpoint, covariates, treatment of repeated observations, handling of missing scores, or any multiplicity procedure. This absence limits assessment of how the primary result would have been estimated and how uncertainty or multiple testing was handled. A specified outcome definition is not the same as a complete statistical analysis plan. The primary numerical result and its precision are not reported in the registry record, so no inferential conclusion can be reconstructed from the endpoint description alone.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 16 outcome measures and 0 analyses. Several secondary outcomes concern BOTOX® dose across named disorders, and another concerns concurrent procedure resource utilization patterns. The record therefore includes a range of outcome topics, but it does not report how many formal statistical tests were performed or how results were selected for presentation. A multiplicity adjustment or prespecified hierarchy is not reported in the registry record.

As a general statistical concept, testing many outcomes can increase the chance that at least one apparently notable result arises by chance. A prespecified testing strategy can clarify how evidence is evaluated across multiple outcomes. The absence of a reported strategy does not establish that no such procedure was used; it means the registry record does not document one. With no listed analyses and no primary numerical result, the record does not permit evaluation of multiplicity handling or a comparison of statistical evidence across endpoints.

The primary analysis population was defined by valid baseline and subsequent SF-6D scores, including data at SV1. The registry does not report how many enrolled patients met this definition, how many had missing measurements, or how missing data were handled. As a general matter, analyses restricted to people with qualifying follow-up data can differ from the experience of all enrolled patients if the availability of data is related to health, treatment, or other characteristics. No particular missing-data mechanism or imputation method is reported in the registry record.

The record does not report interim analyses, a detailed statistical analysis plan, or a justification for the enrollment target. Those details should not be inferred from the project’s outcome descriptions or from planning illustrations.

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: death (0.7%), dysphagia (0.5%), asthenia (0.2%), hip fracture (0.2%), myocardial infarction (0.2%).

The registry reports serious adverse event figures by treatment-history group. In the naïve-to-Botox® group, 506 were at risk and 5 were reported as affected by serious adverse events. In the non-naïve-to-Botox® group, 866 were at risk and 33 were reported as affected. Other adverse events are listed as 0 affected in each group, with 506 and 866 at risk, respectively. The death counts in the group fields are not reported in the registry record.

The listed serious terms include Death at 0.7%, Dysphagia at 0.5%, Asthenia at 0.2%, Hip Fracture at 0.2%, Myocardial Infarction at 0.2%, and Small Intestinal Obstruction at 0.2%. The registry does not give the denominators or further context for these term percentages in the record excerpt, so they should be read as reported rather than converted into counts or compared across groups.

These are descriptive safety figures from an observational study, not a randomized comparison. The groups differ in their treatment history, and the record does not report an adjusted analysis of adverse events. The serious-event counts do not establish that treatment caused an event or that one group had greater risk. The registry record also does not provide the event definitions, exposure duration by group, or a full account of follow-up for safety outcomes.

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

The record establishes that MOBILITY was designed to evaluate health utility among patients receiving BOTOX® for therapeutic use, and that its primary outcome concerned change in SF-6D score among patients with cervical dystonia. It also defines the score’s direction: positive change indicates improvement and negative change indicates worsening. These are meaningful elements of the measurement question, but they are not the numerical outcome.

The primary result is not reported in the registry record. There is no reported mean change, standard deviation, confidence interval, or p-value for the primary endpoint. As a result, the record does not show whether the average score increased or decreased, how large any change was, or how precisely it was estimated. No conclusion about the primary outcome can be drawn from an endpoint title or from the study’s completed status.

The observational design also defines what comparisons can mean. The naïve and non-naïve groups capture treatment status at entry; they are not randomized treatment and control groups. Even if group-specific outcomes were available, a contrast would not on its own identify a treatment effect because the groups may differ in ways related to their prior or ongoing care. The registry does not report an adjusted causal analysis.

Enrollment of 1372 describes the project overall, not necessarily the analysis population for the SF-6D endpoint. That endpoint required valid data at baseline and subsequent assessment, and the number meeting the criterion is not reported in the registry record. Nor are the missing-data methods documented. The project’s broad range of outcome measures and conditions should not be taken to mean that a result was reported for every outcome.

In short, the record describes a health-utility outcome and the observational context in which it was collected, but it does not report the primary estimate needed to judge direction, magnitude, or precision. The serious adverse event figures are descriptive and do not establish causation or comparative safety.

13. Why This Trial Matters Statistically

MOBILITY is statistically notable as a prospective observational project centered on patient health utility rather than only a disease-specific measurement. SF-6D summarizes health utility using domains derived from the SF-12® questionnaire, including physical functioning, role participation, social functioning, bodily pain, mental health, and vitality. This kind of outcome asks about health status and preferences in a way that can complement condition-specific measures.

The registry record also illustrates why outcome definition and result reporting are separate requirements for interpretation. The primary endpoint is described in detail, including the direction of change and the SV1 timing, but the numerical mean change and its uncertainty are not reported. A clear definition makes the intended estimand easier to understand; without the estimate and the number analyzed, it does not reveal what the observations showed.

The treatment-history groups highlight a second statistical issue. Patients initiating treatment and patients receiving ongoing treatment at entry may be clinically and historically different. Because assignment was not randomized, group labels do not create an unbiased treatment comparison by themselves. This distinction matters when reading observational evidence and when deciding what a reported contrast could support.

Finally, the project’s 16 outcome measures and 0 listed analyses illustrate the importance of transparent reporting about analysis populations, missing data, multiplicity, and statistical methods. The registry record does not document these details or the primary numerical result. That absence limits independent assessment of precision and robustness, while leaving the project’s measurement question and design features visible.

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 are specific to the information recorded for this study. The project was non-randomized and observational, and its two groups were defined by treatment history at entry. They are not a like-for-like control comparison. Consequently, any difference between these groups would be vulnerable to differences in patient characteristics or clinical context, and the registry does not report an adjustment strategy.

The primary outcome was restricted to patients with valid SF-6D data at baseline and at least one subsequent valid score, with data at the specified time point. The number meeting this definition is not reported in the registry record. Enrollment of 1372 therefore cannot be treated as the primary analysis sample. The record also does not describe how missing scores were handled or whether the analyzed patients differed from those without qualifying measurements.

SV1 was scheduled at the physician’s discretion, up to 505 days after baseline. The record does not report the actual follow-up time distribution or how differences in timing were handled in analysis. This limits interpretation of change over time because the timing of follow-up was not described as fixed.

The registry lists 16 outcome measures and 0 analyses. It does not report a statistical analysis plan, multiplicity strategy, interim analyses, model details, or a sample-size justification. Most importantly, the primary endpoint’s numerical result and precision are not reported in the registry record. These omissions prevent assessment of the estimated change, its uncertainty, and the robustness of any inferential analysis. The study’s completed status and enrollment do not fill those reporting gaps.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: MDs on Botox Utility (MOBILITY) — NCT00535938.
• Registry record last updated 2014-09-10; status last verified 2014-09.
• Results first posted 2014-09-10.
• 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

MOBILITY (MDs on Botox Utility; NCT00535938) is recorded as a completed, prospective, non-randomized, observational, multi-centre evaluation of health utility in patients receiving BOTOX® for therapeutic use. The registry lists Allergan as sponsor, enrollment of 1372, start in 2007-09, and primary completion in 2013-09.

The primary outcome was change from baseline in SF-6D health utility score using the SF-12® questionnaire for patients with cervical dystonia, measured at SV1 up to 505 days after baseline. The primary numerical result is not reported in the registry record. Treatment-history groups were naïve to Botox® at entry or receiving ongoing treatment, and were not randomized comparison groups.

The registry lists 16 outcome measures and 0 analyses. It does not report the primary result’s precision, the number analyzed for that endpoint, or methods for missing data, multiplicity, or covariate adjustment.