This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for French Validation of an Interview Guide to Cancer Announcement : the Psycho Oncology Basic Documentation (NCT02874001), a registered phase not stated study. The primary outcome is Reliability of the Questionnaire in Terms of Internal Consistency.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02874001 |
| Phase | Phase not stated |
| Condition | Cancer, With Caregiver Support Time, 18 Years and Over |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 252 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Institut Bergonié |
| Results posted | Yes |
2. Clinical Question
Population
The record concerns people with cancer and describes the condition as including caregiver support time and adults aged 18 years and over. It records an enrollment of 252. The brief summary describes a validation process intended to include 450 patients; the registry record does not explain the relationship between that stated target and the recorded enrollment.
Intervention
This is a questionnaire-validation study, not a record of a treatment intervention. The brief summary identifies the PO-BADO interview guide in its short and long versions as the instruments being validated. Details of how participants completed the versions, how interviewers were trained, or how the questionnaires were administered are not reported in the registry record.
Comparator
A like-for-like control comparison is not described. The allocation is not stated, and the record cautions that the arms are not a randomized comparison. It does not report a comparator group or the way the short and long questionnaire versions were assigned or compared.
Primary question
The primary question is whether the questionnaire shows internal consistency, assessed with Cronbach’s alpha, at two weeks after diagnosis. The record describes alpha as a coefficient for consistency among questionnaire responses and notes that larger average correlations between items correspond to greater internal consistency. It does not report the resulting coefficient, its uncertainty, or a criterion for judging an acceptable value. Therefore, the record identifies the measurement property and timing under study, but does not establish what the analysis found.
3. Trial Design
The registry record identifies a completed study sponsored by Institut Bergonié, with a start in 2015-07 and primary completion in 2016-08. Its title concerns French validation of an interview guide for cancer announcement, the Psycho Oncology Basic Documentation, and the brief summary specifies validation of the PO-BADO in short and long versions. The recorded enrollment is 252.
This is a questionnaire-validation study rather than a randomized treatment trial. Allocation is not stated, and the registry record explicitly cautions that any arms are not a like-for-like control comparison. The record does not describe a randomization procedure, masking, recruitment sites, eligibility criteria beyond the recorded cancer and adult-related conditions, or the number of participants assigned to each version. The planned enrollment rationale and any changes to enrollment plans are not reported.
The primary outcome is reliability in terms of internal consistency, measured using Cronbach’s alpha two weeks after diagnosis. Two outcome measures are listed in total, but only the primary outcome is described in the record summarized for this study. The second measure’s definition and timing are not reported in the registry record. The record lists no statistical analyses. It does not provide a detailed protocol, a statistical analysis plan, or an account of how questionnaire versions were evaluated against one another. Thus, the design can be described as a completed validation study with a stated primary measurement property and assessment time, but many operational and analytic features remain unspecified.
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
| Stage | Cancer Patients |
|---|---|
| STARTED | 252 |
| COMPLETED | 252 |
| NOT COMPLETED | 0 |
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.
| Characteristic | Unit | Cancer Patients |
|---|---|---|
| Participants analysed | 252 | |
| Age, Continuous | years | 57 (SD 12.8) |
| Sex: Female, Male: Female | Participants | 192 |
| Sex: Female, Male: Male | Participants | 60 |
| Race and Ethnicity Not Collected | Participants | — |
| Region of Enrollment: France | participants | 252 |
6. Primary Endpoint
The registry lists the primary outcome as Reliability of the Questionnaire in Terms of Internal Consistency, measured over 2 weeks after diagnosis.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | alpha coefficient |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is Cronbach’s alpha, expressed as an alpha coefficient, for internal consistency of the questionnaire. The intended assessment time is two weeks after diagnosis. The registry description explains internal consistency as the degree to which questionnaire responses relate to one another, with higher average correlations between items corresponding to greater internal consistency. In general, alpha is used to assess whether items in a scale tend to move together as a set.
Internal consistency is relevant to questionnaire validation because it addresses whether items intended to contribute to a measure show a coherent pattern of responses. It is one measurement property, not a complete assessment of validity. A high alpha alone would not show that a questionnaire measures the intended concept, is stable over time, or is useful for every population or setting. Interpretation also depends on such factors as the number and content of items and whether the instrument is intended to represent one construct or several.
The record identifies the endpoint and assessment time but does not report an alpha estimate, confidence interval, item-level results, or a threshold for interpretation. Consequently, the endpoint’s role is clear, while the observed degree of internal consistency cannot be determined from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record defines a focused measurement question: internal consistency of the PO-BADO questionnaire, assessed with Cronbach’s alpha two weeks after diagnosis. It identifies validation of the short and long versions as the study purpose. However, no numerical alpha result is reported. There is therefore no posted estimate from which to describe the observed consistency, its precision, or whether it differs between versions.
The record reports enrollment of 252 and describes the validation process in its brief summary as needing inclusion of 450 patients. These entries do not, on their own, explain the enrollment plan or its rationale. The record does not state whether the enrollment target changed, whether the recorded enrollment represents all eligible participants, or how many participants contributed usable questionnaire data at the primary assessment. Those details are not reported in the registry record.
The record lists two outcome measures but describes only the primary outcome in the information available. It lists zero analyses, so no analysis method beyond the endpoint’s stated use of Cronbach’s alpha is described. There are no posted inferential results, confidence intervals, hypothesis tests, or comparisons between the short and long versions. The absence of a reported result should not be mistaken for evidence that internal consistency was low, high, or equivalent across versions.
Because allocation is not stated and the record warns that the arms are not a like-for-like control comparison, this is not a basis for a randomized between-group treatment interpretation. The listed endpoint is a measurement property, not a clinical outcome or treatment effect. Any planning illustrations associated with the record are based on an observed effect under stated assumptions; they are not observed power, and the record does not provide an alpha estimate to interpret in this discussion.
Overall, the posted information establishes the study’s purpose, primary measurement property, timing, recorded enrollment, sponsor, and completion status. It does not establish the numerical reliability result or the analytic basis for a validation conclusion. A reader can identify what the investigators intended to assess, but cannot judge the magnitude or precision of the primary result from the registry record.
9. Statistical Methods Explained
Cronbach’s alpha and internal consistency. Cronbach’s alpha is a summary measure used to describe how strongly items in a questionnaire relate to one another as a group. In general, it is relevant when multiple items are intended to contribute to a scale or score. The registry record identifies alpha as the primary endpoint and describes greater average correlation among items as indicating greater internal consistency. The record does not give the observed alpha value, so no conclusion about the PO-BADO’s measured consistency can be made from the posted results.
Alpha is not a direct test of whether a questionnaire measures the right concept. In general, items can correlate with one another while still failing to capture the intended construct. A coefficient also depends on the item set and its structure: a larger value does not automatically establish that the scale is unidimensional, valid, or suitable for every use. The number and wording of items, scoring rules, and any checks of the scale’s structure are not reported in the registry record. The result also cannot be interpreted against an acceptance threshold because no such threshold is reported.
Timing and measurement context. The stated timeframe is two weeks after diagnosis. Timing matters because responses can depend on when a questionnaire is administered and on the circumstances in which it is completed. In general, a clearly specified assessment time helps define what a reliability estimate describes. Here, the registry gives the timeframe but does not report the exact administration process, whether timing was consistent across participants, or how missing or late assessments were handled. These details are not reported in the registry record.
Short and long versions. The brief summary identifies both short and long PO-BADO versions for validation. In general, evidence for one version cannot automatically be transferred to another: a change in item content or item count may alter the scale’s behavior and its reliability estimate. A comparison between versions would require clear information about who completed each version, the allocation or selection process, and the planned analytic comparison. Those details and any version-specific alpha estimates are not reported in the registry record. The allocation is not stated, and the registry cautions that the arms are not a like-for-like control comparison.
Precision and uncertainty. A confidence interval, in general, describes a range of values compatible with the data under the analysis method and conveys uncertainty around an estimate. It is useful alongside a point estimate because the same estimate can have differing precision in different datasets. No confidence interval or other uncertainty measure for alpha is reported. Without an estimate and its uncertainty, readers cannot assess how precisely internal consistency was measured or whether apparent distinctions between versions could reflect sampling variation.
Analysis reporting. The record lists no analyses. Apart from naming Cronbach’s alpha as the method for assessing internal consistency, it does not report an analysis plan, assumptions, handling of item-level missingness, subgroup analyses, or adjustment for multiple outcomes. In general, a pre-specified analysis plan clarifies which results were planned and how they would be interpreted. Since such details are not reported in the registry record, the posted information cannot establish whether the analysis followed a protocol or whether additional analyses were undertaken.
Planning illustrations. Any sample-size planning illustrations associated with this study are described as based on the observed effect rather than the trial’s own design. Their stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect set as a stated fraction of the observed effect. These are planning assumptions, not evidence that the study used that design or achieved a particular probability of detecting an effect. Sample-size calculations are planning illustrations, not observed power. The registry record does not report the study’s own sample-size justification, and no specific planning values are repeated.
10. Multiplicity, Missing Data and Analysis Populations
The record lists two outcome measures, while the primary outcome described is Cronbach’s alpha for internal consistency at two weeks after diagnosis. The other outcome’s definition, timing, and role in the analysis are not reported in the registry record. With more than one outcome, multiplicity can matter because testing several hypotheses can increase the chance of at least one apparently notable result. In general, a statistical plan may identify a primary outcome, specify which additional outcomes are confirmatory or exploratory, and state whether any adjustment is intended. No such multiplicity plan is reported.
The record lists zero analyses. It does not state how the alpha estimate was calculated from item responses, whether analyses were planned separately for the short and long versions, or whether any subgroup or sensitivity analyses were intended. No confidence interval, test result, or analysis population is reported. As a result, the registry record does not support an assessment of statistical significance, precision, or consistency across analysis choices.
Missing-data handling is not reported in the registry record. This includes whether participants without a two-week assessment or with incomplete item responses were included, excluded, or handled in another way. The number contributing data to the primary endpoint is also not stated. In general, missingness can affect a reliability estimate if the responses available for analysis differ systematically from those not available. Without an account of missingness and the analysis population, readers cannot tell how representative the estimate would be of all enrolled participants—even if an estimate were posted.
The record also does not describe an intention-to-treat or per-protocol population, terms more commonly associated with intervention comparisons. For this validation study, the relevant analysis set would need to be defined in relation to questionnaire completion and the primary measurement. That definition is not reported.
11. What the Result Does, and Does Not, Mean
The registry record establishes that the study was intended to validate the short and long PO-BADO versions and identifies internal consistency at two weeks after diagnosis as the primary measurement question. It also reports a completed status and an enrollment of 252. These registry entries describe the study’s purpose and recorded scale; they do not themselves show that the questionnaire achieved a particular level of reliability.
No numerical Cronbach’s alpha result is reported. Therefore, the posted information does not show whether internal consistency was low or high, how precise the estimate was, or whether the short and long versions differed. It also does not show whether the measure captured the intended concept, whether results were reproducible, or whether the questionnaire performed similarly in other populations or settings. Internal consistency is one aspect of measurement, not a complete validation conclusion.
The study is not described as a randomized treatment comparison, and allocation is not stated. The registry cautions that arms are not a like-for-like control comparison. Thus, the record does not support conclusions about the effect of a treatment. Nor should an absent result be interpreted as a null finding: no posted alpha estimate is not the same as an estimate near zero or evidence of no relationship among items.
The enrollment figure and the brief summary’s stated need for inclusion of 450 patients do not explain how the target was set or how many participants contributed to the primary outcome. Analysis details, missing-data procedures, and uncertainty estimates are also not reported. These gaps limit how much can be inferred from the record. The appropriate statistical reading is narrow: the registry names the validation aim, endpoint, and timing, but does not provide the primary numerical evidence needed to judge the result.
12. Why This Trial Matters Statistically
Questionnaire validation asks a different statistical question from a clinical treatment trial. Rather than estimating a treatment contrast, this study focuses on whether responses to questionnaire items show internal consistency. Identifying that distinction helps prevent the endpoint from being misread as a clinical outcome or a comparison of treatment efficacy.
The record also illustrates why an endpoint definition is not a result. It names Cronbach’s alpha and a measurement time, but no coefficient or uncertainty estimate is reported. Without those values, the statistical question is identifiable but the measured degree and precision of consistency remain unknown. This distinction matters when readers assess registry records: design intentions and observed findings are separate kinds of information.
Validation of short and long versions also raises a general measurement issue. Evidence about one version does not automatically establish how another version behaves. A clear account of version assignment, item content, scoring, and version-specific results would be needed to understand any comparison; those details are not reported in the registry record. The stated enrollment and the brief summary’s stated patient need likewise do not substitute for a reported analysis population or a sample-size rationale.
Finally, the record’s caution about allocation signals that the study should not be read as a randomized, controlled comparison. The central statistical value of the record is therefore in specifying a validation objective and a primary reliability measure, while also showing how important results and analysis details are for drawing conclusions. In the absence of the numerical outcome, the record cannot establish the degree of internal consistency achieved.
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 interpretation is the absence of a reported Cronbach’s alpha estimate. No confidence interval or other measure of uncertainty is reported either. Since alpha is the primary endpoint, this omission prevents readers from judging the observed internal consistency or its precision.
The brief summary identifies validation of both short and long versions, but version-specific results and the process used to assign or select versions are not reported in the registry record. Allocation is not stated, and the record cautions that arms are not a like-for-like control comparison. This limits any interpretation of differences between versions. The record also does not report item content, scoring procedures, or information about the questionnaire’s underlying structure.
Recorded enrollment is 252, while the brief summary says the validation process needs inclusion of 450 patients. The record does not explain the relationship between these figures, provide a sample-size justification, or state how many participants contributed complete responses at the primary assessment. No missing-data procedure or analysis population is described.
Two outcome measures are listed, but the registry entries only the primary outcome in the available record. It reports no analyses and does not describe a statistical analysis plan, multiplicity handling, subgroup analyses, or sensitivity analyses. The registry record also does not report participant recruitment details, administration procedures, or whether the instrument was evaluated against other measurement properties. These limitations concern what can be established from the posted record; they do not determine what analyses may have been conducted outside it.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: French Validation of an Interview Guide to Cancer Announcement : the Psycho Oncology Basic Documentation — NCT02874001.
- Registry record last updated 2025-10-06; status last verified 2025-09.
- Results first posted 2025-10-06.
- 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.
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17. Record Summary
NCT02874001 is a completed study sponsored by Institut Bergonié. The record gives a start date of 2015-07, primary completion in 2016-08, and enrollment of 252. Its stated purpose is validation of the PO-BADO interview guide in short and long versions for the French context.
The primary outcome is internal consistency assessed with Cronbach’s alpha at two weeks after diagnosis. The record lists two outcome measures but describes only the primary one, and it lists zero analyses. No alpha estimate, uncertainty measure, detailed analysis plan, or missing-data approach is reported. Allocation is not stated, and the record cautions that the arms are not a like-for-like control comparison.
The brief summary describes a need to include 450 patients, but the record does not explain that target in relation to the recorded enrollment. The registry identifies the validation question and its primary measurement, but does not report the numerical result needed to judge internal consistency.