A Study of the Quality of Life in Adults With Crohn's Disease With Complex Perianal Fistulas: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Study of the Quality of Life in Adults With Crohn's Disease With Complex Perianal Fistulas (NCT04876690), a registered phase not stated study. The primary outcome is Meta-Scores of the 12-Item Short Form Health Survey (SF-12) Questionnaire's Physical Component Score [PCS-12].

2. Clinical Question

The study asks about physical health-related quality of life among people with Crohn’s disease (CD) and complex perianal fistulas (CPF) assessed in Portuguese routine clinical practice. Its primary outcome is the physical component score of the 12-Item Short Form Health Survey (SF-12), measured at the inclusion visit. The registry record also lists other quality-of-life, symptom, work-productivity, sociodemographic, clinical-characteristic, and healthcare-resource outcomes.

This is a descriptive question about the measured quality of life in the enrolled group, not a randomized comparison of treatments. Without a comparator, the study cannot establish how the measured scores differ from scores under another treatment, in another population, or at another time. The registry record describes a single clinic visit for the questionnaire and retrospective review of medical records for healthcare-resource information from the previous three years.

3. Trial Design

The registry identifies this as an observational, cross-sectional study of quality of life in adults with CD and complex perianal fistulas. Enrollment was 15, and the study status is completed. The record gives a start date of 2021-07-09 and a primary completion date of 2022-05-27. Takeda is listed as the sponsor.

Participants were assessed in Portuguese routine clinical practice. The study description says participants would visit the clinic once to complete a quality-of-life questionnaire, while study doctors would review medical records from the previous three years. The group description likewise states that retrospective data on healthcare-resource use related to CPF management during the previous three years were obtained from medical records. Further details about the clinic setting, recruitment process, eligibility criteria, or how the records were reviewed are not reported in the registry record.

The registry names one participant group, CD Participants With CPF. It does not describe random assignment or a control group; allocation is not stated. Consequently, this design is not a like-for-like comparison of treatment groups. Its primary purpose, as reflected in the listed outcome, is to describe the SF-12 physical component score at the inclusion visit. The listed primary population is all eligible participants with CD and CPAF included in the analysis.

The registry lists 15 outcome measures and 70 analyses. Secondary outcomes include the Short Inflammatory Bowel Disease Questionnaire score; sex-specific sexual quality-of-life questionnaire scores; Wexner scores for fecal incontinence; work productivity and activity impairment; healthcare-resource use; sociodemographic and anthropometric characteristics; and clinical characteristics of participants with moderate to severe CD. The record does not provide further details about the analysis plan or how the listed analyses were conducted.

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: Participants with a diagnosis of Crohn's disease (CD) with complex perianal fistulas (CPF) were enrolled from the investigative sites' database and were observed in a cross-sectional way along with a retrospective component to collect data for healthcare resource utilization and on the pharmacological and surgical treatments in this study.

Overall Study

Analysis population for the primary outcome, as defined in the registry: All eligible participants with CD and CPAF were included in the 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 Meta-Scores of the 12-Item Short Form Health Survey (SF-12) Questionnaire's Physical Component Score [PCS-12], measured over At inclusion visit (Day 1).

The primary endpoint is the SF-12 physical component score (PCS-12) at the inclusion visit, identified as Day 1. The SF-12 is a self-report questionnaire that assesses physical and mental health-related general quality of life. It produces physical and mental component summary scores; the primary endpoint is the physical component. The registry describes the PCS score as ranging from 0 to 100, with higher scores indicating better physical functioning.

A physical component score offers a standardized way to describe participants’ reported physical health-related quality of life. Reporting the mean gives a measure of the group’s average score, while the standard deviation describes how much individual scores vary around that mean. These summaries address different questions: the mean characterizes the group’s central level, and the standard deviation characterizes the spread of participant scores.

The registry identifies the endpoint as a mean with standard deviation and states that all eligible participants with CD and CPAF were included in its analysis. However, the numerical mean, standard deviation, and number of participants with an observed PCS-12 score are not reported in the registry record. The record also does not report whether any questionnaire items or complete scores were missing, or how missing responses were handled. Therefore, the endpoint’s definition and intended summary are available, but the observed score and its precision 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 continuous primary outcome summarized by a mean and standard deviation. It does not report the actual numerical summary, a confidence interval, a p-value, or a detailed statistical analysis plan. The explanations below describe general statistical concepts and how they relate to the listed study design; they do not fill in unreported methods or results.

What does the mean describe?

In general, the mean is the arithmetic average of observed scores in the analysis group. For this study, the intended quantity is the average SF-12 PCS-12 score at the inclusion visit among eligible participants with CD and CPAF. A mean is useful as a compact description of the group, but it does not show whether participants’ scores are tightly grouped or widely spread. It can also be affected by unusually high or low individual values. The registry record does not report the mean, so the group’s observed average cannot be characterized numerically.

What does the standard deviation describe?

In general, the standard deviation measures the spread of individual observations around their mean. A relatively larger standard deviation indicates more variation among observed scores, while a smaller one indicates less variation. It is a descriptive measure of participant variability, not a measure of uncertainty in the mean and not a confidence interval. The registry identifies standard deviation as the endpoint’s dispersion measure, but its numerical value is not reported in the registry record.

How is uncertainty different from variation?

General explanation: a confidence interval is an interval estimate for an underlying quantity, such as a population mean. Its width reflects statistical uncertainty under the assumptions of the analysis and the available data. It does not describe the range of individual participant scores. A standard error is commonly used in constructing an interval for a mean, but the registry does not report a standard error or confidence interval for the PCS-12 result. Without the estimate and an uncertainty measure, readers cannot assess how precisely the group mean was estimated.

What can a cross-sectional design estimate?

In general, a cross-sectional assessment describes measurements collected at a particular assessment point. This study’s primary endpoint is specified at the inclusion visit, Day 1. The design can describe the distribution of scores among assessed participants, but a single cross-sectional measurement does not by itself describe within-person change over time. It also does not establish a cause-and-effect relationship. Although the study description places the quality-of-life assessment after treatment for CPF, treatment details and a pre-treatment score are not reported in the registry record.

Why does the lack of a comparator matter?

General explanation: a comparison group can help distinguish an outcome under one condition from what might have occurred under another condition. In observational research, comparisons can still be affected by differences between groups, and statistical adjustment does not automatically remove all confounding. In this study, the registry describes one participant group and does not describe a control comparison. The posted design therefore supports a description of the measured group, not an estimate of a treatment contrast.

What do the analysis counts tell us?

The registry lists 15 outcome measures and 70 analyses. These counts indicate that the record includes multiple planned or listed outcome analyses, but they do not reveal the exact statistical procedures, which analyses were primary or exploratory beyond the stated primary endpoint, or how findings were handled across analyses. The analysis plan, including any model specifications, covariate adjustments, or hypothesis-testing procedures, is not reported in the registry record.

General explanation: when many outcomes or statistical tests are considered, the chance of at least one apparently noteworthy result can increase if each is interpreted in isolation. Multiplicity methods may address that issue, but they can also affect how estimates and tests are interpreted. The registry record does not state whether any multiplicity adjustment was planned or applied. No adjusted or unadjusted test results for the primary or secondary outcomes are reported.

How should planning illustrations be understood?

General explanation: a sample-size calculation is a planning exercise based on assumptions about the outcome, the effect to detect, and the desired operating characteristics of a statistical test. It is not a description of observed study results. The planning assumptions associated with this record describe an illustration based on a fraction of an observed effect, with a two-sided significance level of 0.05, equal allocation between two hypothetical arms, and a normal approximation. Those assumptions are not evidence that this observational study used two arms, and they are not a sample-size justification for its enrollment. The registry record does not report the trial’s own sample-size justification. Any planning illustration should not be read as observed power or as evidence that the study did or did not detect an effect.

Overall, the registry provides enough information to identify the primary measure, its direction, its intended summary, and the general observational context. It does not provide the primary estimate or the details needed to reproduce or fully evaluate the statistical analysis.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("CD Participants With CPF")
n   <- c(15)
m   <- c(45.36)
sp  <- c(7.58)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  CD Participants With CPF  15  45.360  7.580  41.162  49.558

11. Multiplicity, Missing Data and Analysis Populations

The registry lists multiple outcomes, including the primary PCS-12 measure and secondary measures covering disease-related quality of life, sexual quality of life, fecal incontinence, work productivity, healthcare-resource use, and participant characteristics. It also lists 15 outcome measures and 70 analyses. These counts do not specify how many formal statistical tests were performed or which analyses were intended as confirmatory versus descriptive.

General explanation: when many outcomes or tests are examined, interpreting each result independently can make chance findings more likely to attract attention. A prespecified analysis hierarchy or adjustment for multiplicity can help clarify how evidence should be interpreted across outcomes. Whether a strategy of this kind was planned or used is not reported in the registry record. Numerical results for the secondary outcomes are also not reported in the registry record, so their findings cannot be assessed.

The primary-outcome description states that all eligible participants with CD and CPAF were included in the analysis, but the number with a completed PCS-12 score is not reported in the registry record. The record does not state whether questionnaire data were incomplete, how missing items were handled, or whether any participants were excluded from an endpoint analysis. It also does not report imputation procedures or sensitivity analyses for missing data.

The listed primary population is all eligible participants with CD and CPAF. Further definitions of eligibility and analysis populations are not reported in the registry record. The record does not clarify whether the outcome analysis included all enrolled participants or only those with a valid score. These reporting gaps prevent assessment of the effect of missing data, the exact endpoint denominator, and the consistency of analysis populations across outcomes.

12. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

For the listed group, the registry reports 15 participants at risk for serious adverse events and zero participants with a serious adverse event. It also reports 15 at risk for other adverse events and zero participants with an other adverse event. The reported death count is zero. No serious adverse-event terms are listed.

These figures are observed counts for the group in the registry record. A count of zero means that no events of the reported category were recorded among the participants counted as at risk; it does not establish that the risk is absent or that similar events could not occur in another group or setting. The counts should not be read as a comparison between treatments, because the study is observational and no comparator group is described.

The registry record does not report detailed safety follow-up duration, event definitions, event-collection procedures, or additional information about the completeness of safety reporting. The study description centers on a clinic visit and review of medical records, but it does not specify how safety surveillance was conducted. As a result, the zero counts can be reported as registry observations, while broader conclusions about safety cannot be drawn from them alone.

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

The study is designed to describe quality of life among adults with CD and complex perianal fistulas assessed in Portuguese routine clinical practice. Its primary endpoint is the SF-12 physical component score at the inclusion visit. The registry explains the scale’s direction and its intended summary as a mean with standard deviation, but it does not report the numerical score or standard deviation. The principal descriptive result therefore cannot be interpreted from the registry record.

The record also identifies a broad set of secondary outcomes, including other quality-of-life measures, work productivity, fecal incontinence, healthcare-resource use, and participant characteristics. Their numerical findings are not reported in the registry record. The listed outcomes identify the subjects of interest, but do not establish what participants scored or how healthcare resources were used.

Because the study is observational and cross-sectional, it can be understood as a description of participants at the specified assessment, with retrospective resource-use information drawn from medical records. It does not provide a randomized treatment comparison. No comparator is described, and treatment details are not reported. Consequently, the design cannot establish that a treatment caused a particular quality-of-life score or that the score changed because of treatment.

The enrollment of 15 describes the reported study enrollment, but the endpoint-specific number of observed scores is not reported. The registry also does not report a confidence interval or other numerical measure of precision for the primary score. Therefore, neither the size of the average score nor the precision of its estimation can be judged from the registry record.

The zero adverse-event and death counts are limited to the recorded observations in the listed group. They should not be interpreted as proof of no risk. Overall, the registry record identifies a descriptive research question and measurement approach, but its missing numerical outcome results and analysis details prevent a fuller assessment of what the study observed.

14. Why This Trial Matters Statistically

Quality of life is an important descriptive outcome in a study focused on CD and complex perianal fistulas. This registry record specifies a standardized questionnaire-based primary measure and identifies a broader range of secondary domains, including symptom burden, work productivity, sexual quality of life, and healthcare-resource use. That range makes clear that the study’s interests extend beyond clinical characteristics alone.

Statistically, the record illustrates why an endpoint definition is only one part of interpreting a study. Knowing that the primary outcome is the SF-12 physical component score, that higher values indicate better physical functioning, and that the planned summary is a mean with standard deviation helps explain what was intended to be measured. But without the numerical result, its variability, and an endpoint denominator, the measurement cannot be evaluated as an observed finding.

The observational, cross-sectional design also matters. It is suited to describing the assessed group, but it does not supply a randomized treatment contrast. Recognizing that distinction prevents a descriptive score from being mistaken for evidence of treatment effect. The registry’s broad list of outcomes and analyses also highlights the value of transparent reporting about analysis plans, missing data, multiplicity, and which results are intended to answer the primary question.

Finally, the adverse-event counts show why zero observed events need careful interpretation. They document what was recorded for the participants at risk; they do not establish the absence of risk. Clear reporting of outcome estimates, uncertainty, denominators, and data-handling procedures would allow readers to judge both what was observed and how reliably it was estimated.

15. 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 main limitation for interpreting the primary endpoint is that the registry record does not report its numerical PCS-12 result. Although the endpoint is defined as a mean with standard deviation, neither summary is available, and the endpoint-specific number of participants with observed scores is not reported. A confidence interval or other measure of precision is also not reported.

The study has no described comparator group and is observational and cross-sectional. It can characterize the assessed group but cannot establish a treatment effect or attribute a quality-of-life score to a particular intervention. The study description refers to assessment after treatment, but treatment types, treatment timing, and treatment-specific results are not reported in the registry record. Baseline questionnaire scores and longitudinal change are not reported.

The record describes a single clinic visit and retrospective medical-record review for healthcare-resource use during the previous three years. Further details about recruitment, eligibility criteria, clinic context, record abstraction, and completeness of historical records are not reported in the registry record. The secondary outcome results are also not reported, despite the extensive list of outcome measures and analyses.

Missing-data handling, analysis-population definitions beyond the primary population statement, statistical models, and any multiplicity strategy are not reported in the registry record. These omissions limit the ability to assess potential bias, reproduce the analysis, or judge the reliability of results across the listed outcomes. The small enrollment of 15 is a further constraint on how broadly the descriptive findings might apply, although the numerical results and endpoint denominator needed for a more specific assessment are not available.

The safety record reports zero events in the listed categories, but detailed event definitions and safety follow-up procedures are not reported. Those counts should therefore be interpreted as recorded observations rather than definitive evidence about risk.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: A Study of the Quality of Life in Adults With Crohn's Disease With Complex Perianal Fistulas — NCT04876690.
• Registry record last updated 2024-08-05; status last verified 2024-02.
• Results first posted 2024-08-05.
• 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.

19. Record Summary

NCT04876690 is a completed observational, cross-sectional study sponsored by Takeda, with reported enrollment of 15. It assessed adults with CD and complex perianal fistulas in Portuguese routine clinical practice. The record gives a start date of 2021-07-09 and a primary completion date of 2022-05-27.

The primary outcome is the mean SF-12 PCS-12 score at the inclusion visit, with standard deviation as the stated dispersion measure. Higher scores on the 0 to 100 scale indicate better physical functioning. The study description includes a clinic visit for a quality-of-life questionnaire and retrospective medical-record review of healthcare-resource use during the previous three years.

The registry lists 15 outcome measures and 70 analyses. It does not report the numerical primary outcome result, its endpoint-specific denominator, or detailed statistical methods. The listed group has zero reported serious adverse events, zero other adverse events, and zero deaths among 15 participants at risk.