Overcoming Barriers to the Uptake of Cascade Screening for Lynch Syndrome: Workbook Feasibility Study: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Overcoming Barriers to the Uptake of Cascade Screening for Lynch Syndrome: Workbook Feasibility Study (NCT04978350), a na na study. The primary outcome is Acceptability of Workbook Assessed Through Likert Score Scale.

2. Clinical Question

3. Trial Design

The registry record identifies NCT04978350 as a completed feasibility study of an educational workbook addressing cascade screening for Lynch syndrome. It lists a single-group model, allocation as not applicable, and no masking. The record lists enrollment as 20. Its brief summary describes a pilot among 15 patients diagnosed with Lynch syndrome and 5 genetic counselors; the registry record does not clarify whether those figures describe planned or actual participation. No randomized or concurrent control group is described.

The intervention is classified as behavioral and named the Educational Workbook. The arm description says enrolled patients receive an electronic PDF by email and that genetic counselors introduce the workbook. The brief summary characterizes the workbook as containing exercises and resources intended to improve family communication among people with Lynch syndrome and first-degree relatives of people with Lynch syndrome. The record does not provide a complete description of workbook use, counselor activities, or any additional intervention procedures.

The primary outcome is assessed after four weeks of workbook use. Participants evaluate the workbook on seven acceptability criteria using a five-point Likert scale. Their responses are summed into a total score, with a stated acceptable-intervention threshold of 28 or higher. The population for this endpoint is participants who joined the study and responded to the questionnaire, but the number who completed it is not reported in the registry record.

The record lists one outcome measure and no analyses. It does not report an observed endpoint value, the number meeting the threshold, or an inferential comparison. The study dates are listed as starting 2021-08-01 and reaching primary completion on 2024-05-02; its status is completed. Those record details describe the study's administrative timeline, not the timing or completeness of individual participant follow-up.

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: A total of 20 subjects consented and started to the study.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Participants who joined the study and responded to the questionnaire.

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.

Population: The participants consented and started the study activities.

6. Primary Endpoint

The registry lists the primary outcome as Acceptability of Workbook Assessed Through Likert Score Scale, measured over Post 4 Weeks of Workbook Use.

The primary endpoint concerns acceptability of the educational workbook, assessed through a Likert score after four weeks of use. Participants rate seven criteria: ease of use, clarity of exercises, enjoyment, usefulness for understanding Lynch syndrome, support for communicating genetic information, acceptability of the time required, and overall satisfaction. Each criterion uses a five-point scale, with 1 representing “Strongly Disagree” and 5 representing “Strongly Agree.” The responses are summed to a total from 7 to 35, and higher scores indicate greater acceptability.

The registry defines a total score of 28 or higher as an acceptable intervention. This turns a set of subjective ratings into a prespecified classification that can describe whether participants' evaluations reach the stated threshold. Acceptability is relevant to a feasibility study because it addresses participants' experience of the workbook, rather than establishing whether cascade screening occurred or whether health outcomes changed. The registry record does not report how many participants reached the threshold or the distribution of total scores.

The listed outcome population is participants who joined the study and responded to the questionnaire. Without a reported response count or missing-item procedure, the endpoint's observed denominator and handling of incomplete questionnaires are not known. The record lists the outcome as a count of participants, but does not report that count. Accordingly, the endpoint definition is available, while the observed acceptability result is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the acceptability score represent?

The endpoint combines responses to seven criteria into one total. Each criterion is rated on a five-point Likert scale, from 1, “Strongly Disagree,” to 5, “Strongly Agree.” The registry states that the total ranges from 7 to 35, with higher scores indicating greater acceptability. A score of 28 or higher is the defined cutoff for an acceptable intervention. This is a rule for classifying a participant's score, not an observed study result.

In general, a Likert response is an ordered category: agreement is ranked, but the distance between neighboring categories is not necessarily known to be equal. Summing several ratings creates a composite score that is easier to summarize, but its interpretation depends on treating the combined ratings as a meaningful measure of a common construct. Here, the registry specifies the criteria and scoring rule; it does not report evidence about how consistently the items behaved together or whether participants interpreted them as intended.

Why use a threshold?

A cutoff translates a score into a classification that can be counted. For this study, the stated rule classifies a total of 28 or higher as acceptable. Such a rule can make an operational feasibility target explicit. However, a cutoff also compresses information: scores on opposite sides of the boundary are treated as different classifications even if they are close, while scores on the same side can differ. General interpretation should therefore distinguish the threshold classification from the full score distribution. The registry record reports neither the distribution nor the number meeting the cutoff.

What would a participant count tell the reader?

The registry records the primary outcome as a count of participants and identifies the population as participants who joined the study and responded to the questionnaire. If reported, a count meeting the threshold would describe how many respondents were classified as rating the workbook acceptable. To interpret such a count fully, readers would also need the number of respondents assessed and information about missing questionnaires or incomplete item responses. Those details are not reported in the registry record. No count or denominator should be inferred from the enrollment listing.

What can a single-group design estimate?

In general, a single-group study can describe observations among its participants. Without a comparator group, it cannot estimate a between-group treatment contrast. This record lists one group, no allocation, and no masking. Its primary acceptability measure can address reported experience among respondents if results are available, but the record does not report those results. The design also cannot establish that the workbook caused any change in communication or screening uptake. The registry's stated feasibility aim should not be conflated with a causal efficacy question.

How should precision be judged?

A confidence interval is a statistical range used to express uncertainty around an estimated quantity. In general, the width of an interval reflects both the amount of information and variability in the data; a point estimate alone does not show that precision. The registry record does not report an estimate or confidence interval for the acceptability endpoint, and it lists no analyses. Thus, the precision of the primary outcome cannot be evaluated from the posted results.

Likewise, a hypothesis test would require a defined statistical question and an analysis result, such as a test statistic or p-value. None is listed for the primary outcome. The registry record does not report a statistical analysis plan, a comparison against a benchmark, or an inferential procedure. The cutoff of 28 or higher defines acceptability, but it should not be mistaken for a statistical test or evidence that a target was met.

What do the study status and event fields show?

The record lists the study as completed and gives the study start and primary completion dates. These administrative entries do not indicate the number of participants with complete outcome data or establish when each respondent completed the questionnaire. The adverse-event fields show zero entries for the listed categories in the Educational Workbook Arm. Those registry entries should be read as recorded fields, not as a basis for a broader safety conclusion or a claim about unreported events.

In general, counts of events and counts of participants are different quantities: one participant can experience more than one event. The record's event fields do not provide a narrative account of monitoring, ascertainment, or reporting procedures. Such procedures are not reported in the registry record. The primary endpoint is an acceptability measure, and the adverse-event entries do not substitute for its missing results.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists one outcome measure and identifies the acceptability assessment as primary. It does not report a multiplicity procedure or explain whether other outcomes were collected. In general, multiplicity arises when several outcomes or tests are considered: the more opportunities there are to declare a result, the more important it can be to specify how those analyses will be interpreted. With no analysis listed, there is no reported testing strategy to assess. The record does not state whether interim analyses were planned or conducted.

The endpoint is defined among participants who joined the study and responded to the questionnaire. The record does not give the number of respondents, the number with complete item responses, or the number included in the endpoint count. It also does not describe how partially completed questionnaires were scored, whether any item could be omitted, or how missing responses were handled. These details are not reported in the registry record, so the completeness of the endpoint data cannot be evaluated.

The enrollment listing and the brief summary describe study participation, but they do not establish the denominator used for the primary endpoint. Enrollment should not be treated as equivalent to questionnaire response. No analysis population beyond the outcome's stated respondent population is described, and the record does not specify whether all participants who began workbook use were included in an analysis. There is no reported participant flow for the primary endpoint.

These gaps limit assessment of both bias and precision. If response to the questionnaire differed according to participants' experiences, results among respondents might not represent the experience of everyone who joined. That is a general possibility, not a finding about this study. Because the respondent count and missing-data handling are not reported, the degree of concern cannot be determined from the registry record.

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

The record establishes that the study was designed to assess workbook feasibility and intermediate outcomes, with acceptability measured after four weeks of workbook use. It specifies the rating criteria, scale anchors, score range, and threshold for classifying a total score as acceptable. It also identifies a single-group design and states that participants who joined and responded to the questionnaire form the outcome population.

The record does not report the observed acceptability score, the number of participants meeting the threshold, the respondent denominator, or an uncertainty estimate. It therefore does not show what proportion of respondents found the workbook acceptable or how precisely that quantity could be estimated. The study's completed status is not itself a result for the primary endpoint.

The endpoint is about participants' ratings of the workbook. It does not directly measure whether relatives underwent cascade screening, whether family communication changed, or whether clinical outcomes improved. Although the study rationale concerns screening uptake and communication, those aims should not be treated as outcomes demonstrated by the acceptability measure. Results for those questions are not reported in the registry record.

More generally, a single-group feasibility study can describe experience within the observed group but cannot provide a randomized comparison with usual practice or another intervention. The absence of a comparator does not make descriptive information meaningless; it does limit causal interpretation. In this record, the absence of posted endpoint values adds a further limitation: even a descriptive conclusion about acceptability cannot be drawn from the information reported.

The appropriate conclusion is narrow. The registry describes how acceptability was intended to be assessed and what threshold was defined. It does not provide enough outcome information to determine whether that threshold was met or to quantify participants' ratings. No treatment-effect or clinical-benefit conclusion follows from the endpoint definition alone.

12. Why This Trial Matters Statistically

Feasibility studies address practical questions that can precede larger evaluations. In general, acceptability can indicate whether participants view an intervention's format, content, and demands favorably. The registry makes that construct concrete by identifying seven rating criteria and specifying how their responses form a total score. It also defines a threshold, rather than leaving the meaning of “acceptable” entirely open-ended.

That clarity is statistically useful because outcome definitions shape what a study can claim. A workbook rating is a participant-reported experience measure; it is not the same as a behavioral endpoint such as completed screening. Keeping those constructs separate helps readers avoid treating favorable impressions as evidence of uptake or clinical effect. This distinction is particularly relevant to an intervention whose stated purpose involves family communication and cascade screening.

The study's single-group design also highlights a common distinction in clinical research: description and causal comparison answer different questions. A single-group assessment may describe ratings in the participating group, whereas a controlled comparison is needed to estimate how outcomes differ between conditions. The record does not present a control group or a causal estimate. This is consistent with interpreting the study as a feasibility study, not as a randomized efficacy trial.

Finally, a well-defined measure is only one part of an interpretable result. The respondent denominator, observed score information, missing-data approach, and uncertainty all matter when judging what the data indicate. The registry record defines the outcome but does not report these result details. That makes the record useful for understanding the planned measurement while leaving the actual acceptability findings unresolved. Recognizing both what is specified and what is absent is central to sound statistical interpretation.

13. 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 this study is that the registry record does not report the primary endpoint result. It provides a scoring rule and a threshold but no observed total scores, count meeting the threshold, or respondent denominator. The outcome's precision therefore cannot be assessed. No analyses are listed, and no inferential estimates are reported.

The endpoint relies on participant ratings collected after workbook use. The record does not report questionnaire response completeness, the handling of missing items, or whether all enrolled participants completed the assessment. Because the stated endpoint population includes only participants who responded, the relationship between respondents and all participants cannot be evaluated from the registry information.

The design is single-group, with no allocation to a comparator and no masking. The registry therefore does not support a controlled estimate of a workbook effect. Acceptability ratings, even if available, would not by themselves establish an effect on family communication, cascade screening uptake, or clinical outcomes. Results for those outcomes are not reported in the registry record.

The brief summary describes a pilot among patients and genetic counselors, while the primary outcome population is described as study participants who responded. The record does not give role-specific endpoint results or clarify how the counselors' participation relates to the workbook assessment. The arm description is also incomplete, so the full intervention procedures and participant activities are not reported in the registry record.

The record lists adverse-event fields as zero, but does not describe event ascertainment or monitoring procedures. Those entries should not be used to make claims beyond the information recorded. Overall, the registry gives a defined outcome and basic design information, while leaving important result, missing-data, and implementation details unreported.

14. Related Tutorials

15. Related Statistical Calculators

16. Sources

• ClinicalTrials.gov: Overcoming Barriers to the Uptake of Cascade Screening for Lynch Syndrome: Workbook Feasibility Study — NCT04978350.
• Registry record last updated 2025-07-03; status last verified 2025-07.
• Results first posted 2025-07-03.
• 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.

17. Record Summary

NCT04978350 is listed as a completed, single-group feasibility study of an educational workbook about cascade screening for Lynch syndrome. The record lists enrollment as 20 and describes a pilot involving patients diagnosed with Lynch syndrome and genetic counselors. The intervention is an electronic PDF workbook introduced by genetic counselors to enrolled patients.

The primary outcome is acceptability assessed after four weeks of workbook use. Participants rate seven criteria on a five-point Likert scale; the responses are summed to a score from 7 to 35, with 28 or higher defined as acceptable. The outcome population is participants who joined and responded to the questionnaire.

The record does not report the observed endpoint result, respondent count, missing-data handling, or analysis results. It lists one outcome measure and no analyses. With no comparator group, the design does not provide a like-for-like control comparison. The registry defines how acceptability was to be measured, but the posted results do not establish whether the threshold was met.