Assessing and Improving Patient Knowledge About Keloid Scars (Keloids): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Assessing and Improving Patient Knowledge About Keloid Scars (Keloids) (NCT01176877), a na na study. The primary outcome is To Assess the Impact of an Educational Lecture on Knowledge About Keloid Scars by Comparing Mean Scores Between Knowledge Assessment Questionnaires Administered Before an Educational Lecture and Immediately After an Educational Lecture.

2. Clinical Question

3. Trial Design

This was a completed, single-group study with 40 enrolled participants. The record describes the participants as people diagnosed with a keloid scar. It lists one behavioral intervention: a scripted educational information talk about keloids. There was no randomized allocation or separate control arm, and masking was listed as none. Accordingly, the main knowledge comparison is a before-and-after assessment in the same study group, rather than a comparison between two independently assigned groups.

Participants completed a written questionnaire before the lecture, immediately after it, and 3 months afterward. The primary outcome concerns the mean score before and immediately after the lecture. The secondary outcome concerns mean scores before the lecture and 3 months afterward. The stated study aims also include examining differences in knowledge and self-treatment between people who use the Internet for information and those who do not, and examining whether people at high risk of additional keloid scars are more or less likely to change behavior following the educational talk. The registry record does not report numerical findings for these additional aims.

The study is listed as completed, with enrollment of 40. It is not listed as a randomized trial, and the registry record does not describe a parallel comparison group. The record does not report a protocol-based sample-size justification, detailed eligibility criteria, or a statistical analysis plan. The stated enrollment is the number recorded for the study; it does not establish how many participants contributed data to each outcome 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

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 To Assess the Impact of an Educational Lecture on Knowledge About Keloid Scars by Comparing Mean Scores Between Knowledge Assessment Questionnaires Administered Before an Educational Lecture and Immediately After an Educational Lecture, measured over immediately before and after a 5 minute educational lecture.

The primary endpoint is the mean score on a written questionnaire about knowledge of keloid scars, comparing assessment immediately before the lecture with assessment immediately afterward. The questionnaire covered risk factors for developing keloid scars, prevention, and treatment. It contained 19 questions; each correct answer received 1 point, and the points were summed. The possible total score ranged from 0 to 19, with lower scores associated with worse knowledge and higher scores associated with better knowledge.

A total score gives a compact way to describe responses across the questionnaire’s topics. Comparing scores before and after the lecture addresses whether average questionnaire performance differed over that interval in this group. Because the same participants were assessed at both times, the natural interpretation is a within-person change summarized at the group level, not a contrast between separate treatment groups. The registry record does not report the observed mean scores, the amount of change, a measure of uncertainty, or a statistical test for this endpoint. Therefore, the stated measurement and intended comparison can be described, but the size and precision of any observed change cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record describes a repeated questionnaire assessment in one study group. In general, when the same participants answer an outcome measure at multiple times, the observations are related: each person’s later score is linked to that person’s earlier score. A suitable analysis would ordinarily account for this pairing. The registry record does not report the statistical test or model used, so no particular method should be attributed to the study.

What does the mean score describe?

In general, a mean is the arithmetic average of the scores included in an analysis. It offers a concise description of the group’s overall questionnaire performance, but it does not show how scores are distributed among participants. Two groups of scores can have the same mean while differing in how widely individual scores vary. The registry identifies the primary summary as a mean and the dispersion as the full range, but does not report the actual mean or range values.

The questionnaire score is built from correct answers, with 1 point for each correct response and points summed across the questions. The possible score range is 0 to 19. This defines the scale and its direction, but it does not reveal how participants scored. A change in the group mean would describe average score movement; it would not, by itself, show that every participant changed in the same way.

How should the before-and-after comparison be understood?

For each participant with measurements at both times, a within-person comparison focuses on the difference between that participant’s later and earlier scores. A group analysis can then summarize those changes. This approach is distinct from treating the before and after assessments as unrelated groups. General statistical practice accounts for the association between repeat measurements because ignoring it can affect estimates of uncertainty.

The record does not report a calculated change, confidence interval, or test result. A confidence interval, in general, is a range of values compatible with the observed data under a specified statistical procedure and assumptions. It communicates uncertainty around an estimate; it does not guarantee that the true value lies within the interval. Without an interval or other uncertainty measure in the registry record, the precision of an estimated score change cannot be evaluated.

What do the timing and follow-up measure?

The immediate assessment addresses scores just before and just after the 5 minute educational lecture. The secondary outcome description adds a comparison with the assessment 3 months afterward. These timings correspond to different questions: an immediate comparison concerns near-term questionnaire performance, while a later comparison concerns scores at follow-up. The registry record does not report the numerical results at either time or whether follow-up data were available for all enrolled participants.

A score measured after an educational talk is a measure of questionnaire performance at that assessment time. It should not automatically be treated as proof of retained knowledge beyond the time measured or as evidence of behavior change. The record separately identifies an aim related to behavior among people at high risk of additional keloid scars, but does not report an operational definition, numerical outcome, or analysis for that aim.

What do the sample-size assumptions mean?

The planning illustration assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a stated fraction of the observed effect. Those assumptions describe a planning illustration, not the actual design of this single-group study. The registry record does not report a protocol-based sample-size justification. The illustration assumptions should therefore not be read as evidence that participants were randomized between two arms or that the study was designed around those assumptions.

A sample-size planning calculation estimates how many participants might be needed under specified assumptions. It is not an observed finding, does not show the probability that a result is true, and is not a substitute for reporting estimates and uncertainty from the actual study. No observed-effect estimate or calculated planning counts are reported in the registry record. Consequently, no planning result can be interpreted from this record.

What statistical information is not reported?

The registry record does not report the analysis method, the observed outcome summaries, p-values, confidence intervals, adjustment for covariates, or missing-data procedures. It also does not describe interim analyses or a prespecified statistical analysis plan. These omissions prevent assessment of whether the reported results, if any, were analyzed according to a prespecified approach. They also mean that a reanalysis from summary statistics is not possible from the record: the necessary outcome summaries are not reported.

10. Multiplicity, Missing Data and Analysis Populations

The record lists a primary knowledge outcome and a secondary outcome concerning knowledge 3 months after the educational lecture. It also describes aims related to Internet use as an information source, self-treatment, risk of additional keloid scars, and behavior following prevention education. Considering multiple outcomes or comparisons can raise a multiplicity issue: in general, the more statistical tests conducted, the greater the chance of at least one apparently notable result arising by chance. The registry record does not report a multiplicity strategy, hierarchy among additional aims, or the results of statistical tests. It is therefore not possible to determine whether any adjustment was used or how multiple comparisons were interpreted.

The record says 40 participants were enrolled, but does not report the number included in each outcome analysis or the numbers with questionnaire data at each time. It does not describe whether participants missed assessments, how missing scores were handled, or whether any analysis used imputation or another approach. The description that participants completed questionnaires at the specified times describes the intended assessments; it does not provide an analysis-specific accounting of available data.

The analysis populations are not reported in the registry record. In particular, the record does not state whether the primary comparison included only participants with both before- and after-lecture scores, or how participants with incomplete follow-up were treated in the 3-month comparison. No statistical analysis plan or interim-analysis details are reported. These gaps limit evaluation of the outcome analysis and its susceptibility to selective reporting, but they do not establish that any particular method was or was not used.

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 0% reporting threshold.

The registry record lists 40 participants at risk for both serious and other adverse events in the keloid scar group. It records 0 serious adverse events and 0 other adverse events. These figures describe the event counts recorded for this group; they do not provide details about how events were collected, the observation period for safety, or the definitions applied.

The deaths field is not reported in the registry record, so it should not be interpreted as a count of zero. The record lists no serious adverse event terms. The event figures should also be read separately from the study’s knowledge outcomes: they do not provide information about questionnaire scores or knowledge change. With no further safety methods or event descriptions reported, these counts alone do not support broader conclusions about safety beyond what is recorded.

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

This study was designed to assess knowledge about keloid scars around an educational lecture and at a later follow-up assessment. Its primary endpoint was a questionnaire score, with a defined set of topics and scoring rules. The study description also identifies questions about Internet information use, self-treatment, prevention, and behavior among people at high risk of additional keloid scars. These aims indicate what the investigators sought to assess, not what the observed results were.

The registry record does not report the numerical knowledge scores or statistical comparisons. It is therefore not possible to say whether mean scores increased, decreased, or remained similar, or to describe the size or precision of any change. Nor can the record establish whether questionnaire performance at follow-up reflected lasting knowledge or whether behavior changed. Those outcomes would require reported estimates and methods relevant to each question.

Even if a before-and-after difference were reported, the single-group design would be important context. In general, a change across two measurements without a separate comparison group cannot isolate the effect of the lecture from other influences over time. This does not negate the descriptive value of repeated measurements; it limits causal interpretation.

The enrollment of 40 does not by itself establish how precise an outcome estimate would be. Precision depends on the available outcome data and their variability, neither of which is reported. Likewise, a planning illustration is not evidence about the results observed among participants. The registry record supports a description of the study’s design, timing, questionnaire, and recorded adverse event counts, but not a conclusion about the magnitude or statistical reliability of knowledge or behavior findings.

13. Why This Trial Matters Statistically

This study illustrates why the research question, measurement schedule, and design need to be considered together. The primary question concerns a change in a defined questionnaire score from before to immediately after a brief educational lecture. Repeated measurements in the same participants are structurally different from comparisons between separate groups, and analyses should reflect that relationship. The registry record specifies the intended comparison but does not report the analysis method or numerical results.

It also distinguishes immediate questionnaire performance from knowledge measured at a later follow-up. These assessments address different time points and should not be treated as interchangeable. A defined questionnaire and scoring rule make the intended endpoint understandable, while the absence of observed scores and uncertainty measures prevents readers from assessing the result itself.

Finally, the study’s multiple stated aims extend beyond the primary score comparison. Internet information use, self-treatment, prevention, risk of additional scars, and behavior are separate topics, and each would need clear outcome definitions and reported analyses to support interpretation. The registry record documents these aims but does not provide findings for them. Statistically, the key lesson is that a clearly described question and endpoint are necessary, but they do not replace reporting the actual estimates, their precision, and the analytic methods used.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The most direct limitation for interpreting the posted results is that numerical outcome findings are not reported in the registry record. Although the primary and secondary knowledge outcomes are described, their means, ranges, changes, and measures of uncertainty are absent. No statistical analysis results are listed, so the size and precision of the knowledge comparisons cannot be evaluated.

The study was single-group and had no separate control arm. Thus, even with reported before-and-after findings, the design would not by itself separate change associated with the lecture from other possible influences over time. The record also does not report numerical results for the stated aims concerning Internet information use, self-treatment, or behavior change.

Enrollment was 40, but the record does not identify how many participants contributed data to each comparison, whether any questionnaire assessments were missing, or how missing data were handled. It does not report detailed eligibility criteria, participant characteristics, a statistical analysis plan, interim analyses, or a protocol-based sample-size justification. The record therefore leaves important questions about the analysis population and the prespecification of analyses unanswered. These are limitations of what can be evaluated from the registry record; they should not be taken as proof that particular procedures were absent from the study itself.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Assessing and Improving Patient Knowledge About Keloid Scars (Keloids) — NCT01176877.
• Registry record last updated 2013-01-03; status last verified 2012-11.
• Results first posted 2013-01-03.
• 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, single-group study enrolling 40 people diagnosed with a keloid scar. Participants received a scripted educational information talk, described in the primary outcome as 5 minutes long, and completed a 19-question knowledge questionnaire before, immediately after, and 3 months after the lecture. The primary outcome was mean score before versus immediately after the lecture; the secondary outcome concerned scores at 3 months.

The record also states aims related to Internet use as an information source, self-treatment, and behavior following prevention education. Numerical outcome results and statistical analyses are not reported in the registry record. The record lists 0 serious adverse events and 0 other adverse events among 40 participants at risk; deaths are not reported.