Long-Term Patient Satisfaction of Facial Aesthetic Treatment With BOTOX®: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Long-Term Patient Satisfaction of Facial Aesthetic Treatment With BOTOX® (NCT01608672), a registered phase not stated study. The primary outcome is Percentage of Participants Mostly or Very Satisfied With Their Glabellar Lines on the Facial Line Satisfaction Questionnaire (FLSQ).

2. Clinical Question

The clinical question is therefore descriptive: it concerns the satisfaction reported by eligible participants with available data after prolonged treatment. It does not ask whether treatment caused a change in satisfaction relative to no treatment or to another treatment. The record also lists patient and physician satisfaction outcomes about effectiveness as secondary outcomes. Those descriptions indicate additional perspectives of interest, but their results are not reported in the registry record.

3. Trial Design

This is a completed observational study sponsored by Allergan. Its brief summary describes assessment of patient satisfaction following at least 5 years of BOTOX® treatment for glabellar lines. The registry record lists enrollment of 207 participants and a single group, “All Participants,” treated with botulinum toxin Type A as prescribed by the Investigator.

Because the study is observational and no assigned comparison group is described, it is not a randomized efficacy comparison. The record does not state an allocation method, and the listed group should not be interpreted as one arm in a controlled trial. Participants’ treatment was prescribed by the Investigator; the registry description does not specify a common treatment schedule, dose, or treatment regimen beyond treatment over at least 5 years.

The primary outcome is a percentage based on responses to the Facial Line Satisfaction Questionnaire. Participants answered the question about satisfaction with the effect of treatment on their facial lines using a five-point scale. The endpoint counts those classified as mostly or very satisfied. Assessment was scheduled at Study Day 1, approximately 4-28 weeks following the last treatment.

The primary analysis population is described as the Per Protocol population, consisting of enrolled participants who met eligibility criteria and had data available for analysis. The number with endpoint data and the number included in that population are not reported in the registry record. The record lists three outcome measures and zero analyses. Results for the primary endpoint and the described secondary outcomes are not reported in the registry record. The study is marked completed, but completion status alone does not provide the missing outcome estimates or information about how data were handled.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: Eligible patients were identified by retrospective chart review. Demographic and Outcome Measure data were collected at a study visit on Day 1 (approximately 4-28 weeks following last treatment) for patients who received treatment with BOTOX® for ≥5 years. Adverse Event data was collected by retrospective chart review.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Per Protocol population included all enrolled participants who met eligibility criteria with data available for analysis.

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 Percentage of Participants Mostly or Very Satisfied With Their Glabellar Lines on the Facial Line Satisfaction Questionnaire (FLSQ), measured over Study Day 1 (approximately 4-28 weeks following last treatment).

The primary endpoint is the percentage of participants who were mostly or very satisfied with their glabellar lines on the Facial Line Satisfaction Questionnaire. The underlying question asks how satisfied participants are with the effect treatment had on their facial lines. Responses use a five-point scale from very dissatisfied through neither dissatisfied nor satisfied to very satisfied. The endpoint groups the two positive response categories and reports the percentage in those categories.

This type of endpoint expresses the share of assessed participants whose answers meet a stated satisfaction threshold. It provides an interpretable summary of participants’ reported views, while retaining a meaningful distinction between positive satisfaction and responses that are neutral or dissatisfied. It does not, by itself, describe the full distribution of answers across all five response categories. The record does not report that distribution.

The assessment is specified for Study Day 1, approximately 4-28 weeks following the last treatment. That timing matters when interpreting the response: it locates the assessment relative to the most recent treatment, rather than providing repeated satisfaction measurements over the entire treatment history. The record does not give an endpoint percentage, numerator, denominator, or uncertainty interval. Consequently, the defined measure can be explained, but the level and precision of observed satisfaction cannot be evaluated from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record defines a binary percentage endpoint: participants are classified according to whether their questionnaire response falls into the mostly or very satisfied categories. The endpoint is a proportion expressed as a percentage. No estimate or analysis output is reported, so the statistical concepts below explain how this type of measure is generally interpreted rather than describing calculations reported for this study.

What does a percentage summarize?

In general, a percentage for a binary endpoint is formed by identifying participants who meet the endpoint definition and relating that count to the participants with relevant outcome data. Its interpretation depends on the definition of both the response category and the analysis population. Here, the qualifying categories are specified by the questionnaire, and the primary population is described as eligible enrolled participants with data available for analysis. The actual count meeting the satisfaction threshold and the number with analyzable responses are not reported in the registry record. The enrollment count should not be substituted for that missing denominator.

Turning the five-point response scale into a binary endpoint makes the result easier to express as the share above a selected satisfaction threshold. It also discards information: participants classified as mostly satisfied and very satisfied are combined, while differences among the other response categories are not represented in the endpoint. General interpretation should therefore distinguish the percentage meeting the threshold from the full pattern of questionnaire answers. The full response distribution is not reported in the registry record.

Why does the analysis population matter?

In general, an analysis population determines which participants contribute to an estimate. A Per Protocol population typically applies eligibility and data-availability conditions, but the registry description specifically states that it includes enrolled participants who met eligibility criteria with data available for analysis. Because the number meeting those conditions is not reported, the relationship between enrollment and the endpoint population cannot be assessed. The record also does not explain how missing questionnaire responses were handled, whether partial responses could be included, or whether any sensitivity analysis was conducted.

For a percentage, the denominator is essential to interpreting precision as well as the estimate. A percentage without a denominator does not indicate how much information supports it. General statistical methods may quantify uncertainty around a proportion with a confidence interval; the interval’s width depends in part on the amount of information and on the method used. No interval or method is reported for this endpoint, so its precision cannot be evaluated.

What would a confidence interval add?

In general, a confidence interval gives a range of values compatible with the observed data under a particular statistical procedure and its assumptions. It is not a guarantee that the true value lies in that range, and it does not by itself establish clinical importance. For a satisfaction percentage, an interval would help readers judge whether the estimate is tightly or loosely determined. The registry record does not provide an interval, a point estimate, or the analysis details needed to interpret one. No uncertainty estimate should be inferred from the enrollment figure alone.

What does the observational design imply?

In general, an observational study describes outcomes among people whose exposure or treatment is not assigned by random allocation within the study. Without a concurrent comparison group, the observed outcome cannot be contrasted with what would have happened under a different treatment or no treatment. In this study, the record describes one group receiving treatment as prescribed by the Investigator. It does not describe randomization or a control group. Even if a satisfaction percentage were available, it would describe the analyzed participants’ reported satisfaction, not establish a causal treatment effect.

The assessment timing is also part of the endpoint definition. Study Day 1 is described as approximately 4-28 weeks following the last treatment. The resulting measure would pertain to responses at that assessment window. It would not, without repeated measurements, characterize how satisfaction changed over the full treatment history. The registry record does not describe repeated primary endpoint assessments.

What can be inferred from the listed analyses?

The record lists zero analyses. It does not give a statistical model, confidence-interval method, hypothesis test, covariate adjustment, or sensitivity analysis for the primary endpoint. These details are not reported in the registry record. General methods for binary outcomes can include simple proportions or models that account for other variables, but no particular method should be attributed to this study in the absence of a reported analysis. Likewise, no sample-size justification or interim-analysis plan is reported in the registry record.

The registry record includes assumptions for planning illustrations: a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with an effect defined as a stated fraction of the observed effect. Those are planning assumptions, not evidence that this observational study used that design. The study description lists one participant group and no like-for-like control comparison. Planning illustrations are not observed power and do not establish what the study was designed or able to detect. The registry record does not report a sample-size justification for the study itself.

General statistical interpretation should keep the endpoint definition, analysis population, missing-data handling, and study design distinct. A percentage answers a descriptive question only for the people included in its denominator. An uncertainty interval would address precision, while a comparator would be needed for a direct between-group contrast. The registry record does not report the primary estimate, its denominator, an uncertainty interval, or a comparator-based analysis. Accordingly, no numerical conclusion about satisfaction or comparative effect can be drawn from the endpoint specification alone.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists three outcome measures, including the primary satisfaction endpoint and two described secondary satisfaction outcomes. The secondary outcomes concern the percentage of participants mostly or very satisfied with treatment effectiveness using a patient questionnaire, and the percentage for which the physician was mostly or very satisfied using a physician questionnaire. Their results are not reported in the registry record.

When a study evaluates multiple outcomes, general statistical practice may specify in advance which outcome is primary, how secondary outcomes will be interpreted, and whether any adjustment or hierarchy will be used to address the chance of false-positive findings across multiple tests. The registry record does not report a multiplicity strategy, analysis hierarchy, or inferential tests. It lists zero analyses. No adjustment method or unadjusted analysis result can therefore be attributed to this study.

The primary population is described as participants who met eligibility criteria and had data available for analysis. The count included in that population is not reported. The registry record does not explain the extent or pattern of missing questionnaire data, the handling of incomplete answers, or whether missingness was addressed through an imputation or sensitivity method. These omissions matter because a reported percentage would apply to the analyzed responses, and the available responses may not represent all enrolled participants if data are missing.

The registry record also does not report a sample-size justification or a prespecified statistical analysis plan. A planning illustration based on an observed effect is not a substitute for those details and is not observed power. With no endpoint results or analysis details reported, neither multiplicity nor missing-data assumptions can be evaluated from the registry information.

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 non-serious adverse event terms

For the “All Participants” group, the safety figures list 207 participants at risk for serious adverse events and zero participants with a serious adverse event. The corresponding figures for other adverse events are 207 at risk and 23 affected. The record lists no serious adverse event terms. These counts describe the registry’s safety reporting; they do not establish a causal relationship between treatment and an event, or the absence of risk.

The serious adverse event count should be read as a recorded count in the stated group, not as proof that serious events could not occur. The registry record does not provide additional detail about event definitions, observation duration for safety, event severity beyond the serious/non-serious distinction, or the methods used to collect and classify events. Deaths are not reported in the registry record.

The count for other adverse events is a participant count, not a measure of event frequency or severity. The record does not list the corresponding event terms in the registry record describing this outcome. The safety figures also do not supply a comparison group. They therefore cannot support a comparative risk estimate or an attribution of events to treatment.

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

This study addresses a specific descriptive question: how participants with at least 5 years of BOTOX® treatment for glabellar lines rated satisfaction at an assessment approximately 4-28 weeks after their last treatment. The registry record defines the questionnaire item and the threshold used to classify a participant as mostly or very satisfied. That definition makes clear what the primary endpoint was intended to measure.

The endpoint result itself is not reported in the registry record. The information therefore does not establish what percentage met the satisfaction threshold, how many responses contributed, or how precise an estimate would be. Enrollment of 207 participants does not fill those gaps because the primary population is limited to participants meeting eligibility criteria with available data, and its size is not reported.

Even with a reported percentage, this observational single-group description would not establish that treatment caused the reported satisfaction. There is no control group described for comparison, and no random allocation is reported. Satisfaction is a patient-reported assessment at a specified time; it is not equivalent to an objective measurement of facial-line change, nor does the endpoint establish the treatment’s comparative effectiveness or safety.

The question also concerns satisfaction at one specified assessment window, not the trajectory of satisfaction throughout at least 5 years of treatment. The record does not provide a baseline satisfaction measure, repeated assessments, or a reported comparison over time. The secondary patient and physician satisfaction outcomes are described, but their results are not reported in the registry record.

Thus, the record clarifies the study’s population, treatment context, endpoint definition, and timing. It does not provide the primary outcome estimate or the information needed to judge its precision, nor does it support a causal or comparative conclusion.

13. Why This Trial Matters Statistically

Statistically, this study is a useful example of why an endpoint definition and an endpoint result are different kinds of information. The registry record describes a clear patient-reported measure: a specified questionnaire response, a defined satisfaction threshold, a stated assessment window, and a named analysis population. Those details tell readers what the intended percentage would represent.

At the same time, the outcome estimate is not reported. Without the numerator, denominator, or uncertainty estimate, readers cannot assess the observed satisfaction level or its precision. The enrollment count alone cannot supply those missing elements because not every enrolled participant necessarily meets the endpoint’s stated analysis-population criteria or has available data. The record does not report how many participants contributed to the endpoint.

The observational design is also central to the statistical reading. A single treated group can describe reported experience, but it cannot offer a like-for-like contrast with another treatment or no treatment. The study’s question should therefore remain descriptive rather than causal. This distinction is important when satisfaction outcomes are considered alongside the treatment history that precedes them.

The record further illustrates the importance of transparent reporting around multiple outcomes, missing responses, and analysis methods. Three outcome measures are listed, but no analyses are listed. Details about multiplicity, missing-data handling, statistical procedures, and the sample-size rationale are not reported in the registry record. Without those details and the results themselves, the study record supports careful interpretation of what was planned to be measured, not a statistical conclusion about what participants reported.

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 principal limitation for interpreting the primary outcome is that its result is not reported in the registry record. There is no endpoint percentage, numerator, denominator, or confidence interval. As a result, neither the observed satisfaction level nor its precision can be assessed.

The primary analysis population is defined as eligible enrolled participants with data available for analysis, but its size is not reported. The record does not explain whether any participants lacked questionnaire data, how incomplete responses were handled, or whether the analyzed participants differed from those without available data. This limits assessment of how representative the reported population would be, even if an endpoint estimate were available.

The study is observational and describes a single group treated as prescribed by the Investigator. No comparator is described, so the design does not provide a direct contrast with another treatment or no treatment. The record also does not report a baseline measure or repeated primary assessments that would characterize change over time. The primary assessment is tied to Study Day 1, approximately 4-28 weeks following the last treatment.

The registry record lists three outcome measures and zero analyses, but does not report statistical methods, a multiplicity plan, a missing-data strategy, or a sample-size justification. Secondary outcome results are also not reported. These gaps prevent review of the analysis choices and the relationship between the intended outcomes and reported evidence. The listed planning assumptions do not establish the design or statistical plan of the observational study.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Long-Term Patient Satisfaction of Facial Aesthetic Treatment With BOTOX® — NCT01608672.
• Registry record last updated 2019-04-16; status last verified 2019-04.
• Results first posted 2013-12-23.
• 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

NCT01608672 is a completed observational study sponsored by Allergan concerning patient satisfaction after at least 5 years of BOTOX® treatment for glabellar lines. The registry record lists enrollment of 207 participants and one group receiving botulinum toxin Type A as prescribed by the Investigator.

The primary endpoint is the percentage mostly or very satisfied on the Facial Line Satisfaction Questionnaire, assessed at Study Day 1, approximately 4-28 weeks following the last treatment. The primary population is described as eligible enrolled participants with data available for analysis. The endpoint estimate and analysis-population size are not reported in the registry record.

Three outcome measures and zero analyses are listed. The registry record does not report the primary result, secondary results, statistical analysis methods, or missing-data handling. Safety figures list zero participants with serious adverse events and 23 with other adverse events among 207 at risk for each category.