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 Yes/No Questionnaire for Aphasic Patients (YNQ) (NCT03257696), a registered phase not stated study. The primary outcome is YNQ Score.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03257696 |
| Phase | Phase not stated |
| Condition | Stroke, Acute, Aphasia |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 152 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Groupe Hospitalier de la Rochelle Ré Aunis |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned people with acute stroke and aphasia. The registry record reports enrollment of 152 participants. Further participant characteristics, including the distribution of aphasia severity or other clinical features, are not reported in the registry record.
Intervention
The assessment was a close-ended questionnaire called the Yes/No Questionnaire for Aphasic Patients. It consists of 10 questions intended to assess whether a patient can provide a coherent answer. The questions use the auditory/verbal channel and focus on personal data, with simple syntax and familiar words.
Comparator
A comparator or reference standard for judging answer reliability is not reported in the registry record. The reliable and unreliable labels in the safety record are not a randomized treatment comparison, and the registry cautions that the groups are not like-for-like control groups.
Primary question
The study aimed to define an optimal score for classifying test positivity, balancing sensitivity and specificity while emphasizing negative predictive value. The primary outcome is the YNQ score, measured within 7 in-hospital days. The cutoff selected and the resulting accuracy estimates are not reported in the registry record.
In general, a diagnostic accuracy study asks how well an assessment distinguishes the condition or state of interest according to a reference standard. For this study, the central statistical question is whether a score on a short yes/no questionnaire can identify patients whose answers are reliable. The registry record states that the tool was proposed because available tools did not allow professional consensus about that ability. It does not report how reliability was independently established, how the score was assessed against that judgment, or the results needed to quantify classification performance.
3. Trial Design
The registry record describes a diagnostic accuracy study of an answer reliability assessment tool for aphasic patients. The study is marked completed. Its recorded start date is 2017-10-02, and its primary completion date is 2019-02-21. Enrollment is 152. The sponsor is Groupe Hospitalier de la Rochelle Ré Aunis.
The intervention is a close-ended questionnaire. Its ten questions were designed to assess a patient's ability to provide a coherent answer. The description specifies an auditory/verbal channel, questions about personal data, simple sentence construction, familiar and frequent nouns, and a limit of seven words per question. With the exception of two questions, each yes-response question had a no-response equivalent. The score ranges conceptually from zero for wrong answers to all questions to ten for correct answers to all questions.
The primary outcome is the YNQ score, recorded in participants within 7 in-hospital days. The study objective was to define a score threshold for test positivity as a compromise between sensitivity and specificity, with emphasis on negative predictive value. The record does not report the selected threshold, diagnostic accuracy estimates, or the reference standard used to establish answer reliability.
Allocation is not stated in the registry record. The reliable and unreliable categories in the safety information should not be interpreted as randomized arms or as a like-for-like control comparison. Details of recruitment, eligibility criteria, study setting beyond the in-hospital measurement timeframe, and follow-up after the assessment are not reported in the registry record. The record lists one outcome measure and no analysis records. It does not describe a statistical analysis plan, interim analyses, or a sample-size justification for the study.
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 | Reliable | Unreliable |
|---|---|---|
| STARTED | 123 | 29 |
| COMPLETED | 123 | 29 |
| NOT COMPLETED | 0 | 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 | Reliable | Unreliable | Total |
|---|---|---|---|---|
| Participants analysed | 123 | 29 | 152 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 25 | 7 | 32 |
| Age, Categorical: >=65 years | Participants | 98 | 22 | 120 |
| Age, Continuous | years | 72.3 (SD 12.8) | 75.4 (SD 14.7) | 72.8 (SD 13.2) |
| Sex: Female, Male: Female | Participants | 57 | 17 | 74 |
| Sex: Female, Male: Male | Participants | 66 | 12 | 78 |
| Race and Ethnicity Not Collected | Participants | — | — | 0 |
| Region of Enrollment: France | participants | 123 | 29 | 152 |
| Diagnostic: Ischemic stroke | Participants | 109 | 24 | 133 |
| Diagnostic: Hemorrhagic stroke | Participants | 11 | 4 | 15 |
| Diagnostic: Combination of both stroke subtypes | Participants | 3 | 1 | 4 |
| Thrombolysis: Thrombolysis | Participants | 29 | 6 | 35 |
| Thrombolysis: No thrombolysis | Participants | 94 | 23 | 117 |
6. Primary Endpoint
The registry lists the primary outcome as YNQ Score, measured over measured within 7 in-hospital days.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the YNQ score, measured in participants within 7 in-hospital days. The questionnaire contains 10 closed-ended questions intended to test whether a patient can provide a coherent answer. A score of zero represents wrong answers to all questions; a score of ten represents correct answers to all questions.
The score is relevant to the stated diagnostic aim because the investigators sought a threshold that would classify a test as positive or negative. In general, sensitivity describes how often a test identifies people who have the state of interest, while specificity describes how often it identifies people who do not. Negative predictive value describes the chance that a negative test corresponds to the absence of the state of interest in the population being assessed. These measures answer different questions, and the balance among them depends on the chosen threshold and the way the reference state is defined.
The registry record says that the investigators emphasized negative predictive value while seeking a compromise between sensitivity and specificity. However, it does not report the score threshold, the reference standard, or any observed accuracy estimates. The endpoint definition alone therefore describes what was measured, not how well the questionnaire classified answer reliability.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record establishes the study’s purpose and the form of its primary measurement, but it does not provide the findings required to judge diagnostic performance. It describes a ten-question questionnaire and the goal of defining an optimal positivity threshold. It does not report the threshold selected, the distribution of scores, sensitivity, specificity, negative predictive value, or any confidence intervals. Consequently, the record does not show how accurately the questionnaire classified answer reliability or how precisely any accuracy estimate was determined.
The aim of balancing sensitivity and specificity while emphasizing negative predictive value is a design objective, not a result. In general, changing a diagnostic threshold can change the balance between false-positive and false-negative classifications. A threshold cannot be evaluated from the stated objective alone; interpretation requires the observed classifications and a clearly described reference standard. The reference standard and its application are not reported in the registry record.
Enrollment was 152, but the registry record does not state how many participants contributed to the primary outcome analysis or whether all enrolled participants completed the assessment. It also does not give the number of participants with each score, the number classified as reliable or unreliable for the primary analysis, or the number of indeterminate or missing assessments. Enrollment should therefore not be treated as the analyzed sample size for any diagnostic accuracy estimate.
The record lists reliable and unreliable categories in its safety information, with 123 participants at risk in the Reliable group and 29 in the Unreliable group. Those labels do not supply diagnostic accuracy findings. The record explicitly cautions that the groups are not a like-for-like control comparison, and the study is not described as a randomized comparison. No inference about the questionnaire’s accuracy follows from those group labels alone.
There are no analysis records listed. Statistical methods used to choose the threshold, estimate accuracy, or account for uncertainty are not reported in the registry record. The record also does not report whether accuracy was evaluated in the same participants used to select the threshold or in a separate validation sample. In general, evaluating a threshold in the same data used to select it can make performance appear more favorable than its performance in new participants; whether that issue applies cannot be determined from the registry record.
The appropriate reading is therefore limited: the study was designed to address an important measurement problem in aphasia, and it defined a structured questionnaire and a scoring concept. The posted registry information does not establish the score’s diagnostic performance, the precision of that performance, or whether the intended balance of classification measures was achieved.
9. Statistical Methods Explained
Diagnostic accuracy methods assess how closely a test’s classifications agree with a reference standard. In this study, the questionnaire produces a score from answers to closed-ended questions, and the stated objective is to choose a score threshold for test positivity. To interpret such an analysis, readers need to know both the threshold and how the underlying state of answer reliability was determined. Those details are not reported in the registry record.
What do sensitivity and specificity mean?
In general, sensitivity is the proportion of people with the state of interest who receive a positive test classification. Specificity is the proportion of people without that state who receive a negative classification. They describe different types of classification performance. A threshold that identifies more people with the state of interest may also classify more people without it as positive; the actual tradeoff depends on the observed data. The registry record states that the investigators sought a compromise between sensitivity and specificity, but does not provide estimates or the selected threshold.
What does negative predictive value add?
In general, negative predictive value is the proportion of negative test results that correspond to people without the state of interest. It is a predictive measure, not simply another name for sensitivity or specificity. Its value depends in part on how common the state of interest is in the population being assessed. The study summary says that negative predictive value was emphasized, but the registry record does not provide an estimate or the information needed to assess the population context for that estimate.
Why does a reference standard matter?
A diagnostic measure needs a basis for deciding which participants truly have the state being classified. That basis is commonly called a reference standard. It permits comparison between the questionnaire’s classification and an independent assessment of answer reliability. Without a description of that standard, readers cannot determine what the proposed score was intended to detect or how disagreements were handled. The registry record does not report the reference standard, who applied it, or whether assessment was blinded to questionnaire scores.
How should a confidence interval be read?
In general, a confidence interval expresses the uncertainty around an estimated quantity under the assumptions of the method used. A narrower interval indicates greater precision, while a wider interval indicates less precision. No confidence intervals for diagnostic accuracy are reported in the registry record, so the precision of any such estimates cannot be assessed from the posted information.
What is the role of the score threshold?
A score threshold turns a graded score into a positive or negative classification. In general, selecting a threshold involves a decision about the relative importance of different classification errors. The study summary describes a compromise between sensitivity and specificity, with emphasis on negative predictive value. It does not state the rule used to select the threshold, whether the rule was prespecified, or whether a separate dataset was used to evaluate the selected threshold. Those details are not reported in the registry record.
What do the sample-size assumptions mean?
In general, a sample-size calculation is a planning exercise based on assumptions about the effect to be detected and the analysis. It is not evidence that an effect was observed, and it is not a measure of observed power. The record describes a planning illustration using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect defined as a stated fraction of the observed effect. It also says that the illustration is not the trial's own design. These assumptions do not establish that the diagnostic accuracy study was planned or analyzed using a two-arm comparison. The registry record does not report the study's own sample-size justification, or the diagnostic accuracy parameters that would be needed to evaluate one.
More generally, diagnostic accuracy analyses should make clear how missing or indeterminate results are handled, which participants enter each estimate, and how uncertainty is calculated. The registry record does not report these methods. It also lists no analysis records, so no analysis approach can be attributed to the study from this record.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists one outcome measure, the YNQ score, and no analysis records. It does not report a statistical analysis plan, a hierarchy of outcomes, or how multiple analyses might have been handled. The stated goal of selecting a positivity threshold could involve evaluating more than one possible threshold, but the record does not describe the selection procedure or any adjustment for the repeated evaluation of alternatives. It is therefore not possible to assess whether multiplicity was relevant or addressed.
Missing-data handling is also not reported in the registry record. The record does not state whether all enrolled participants completed the questionnaire, whether any scores were unavailable, how incomplete questionnaires were treated, or whether participants with missing measurements were excluded from analysis. Enrollment of 152 does not by itself establish the number included in an endpoint analysis.
The analysis population is not defined in the registry record. There is no reported count for participants included in the primary outcome analysis, nor a description of eligibility or exclusions specific to analysis. It is also not reported whether diagnostic accuracy estimates would use every enrolled participant or a subset with a complete questionnaire and a reference assessment.
In general, these details matter because changes in the analyzed population or in the treatment of missing classifications can affect estimated accuracy. Without the analysis population and missing-data rules, readers cannot determine how representative any analysis would be of the enrolled group. The registry record does not report interim analyses or a prespecified approach to multiplicity, missing data, or analysis populations.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Reliable | 0 | 123 | 0.0% |
| Unreliable | 0 | 29 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Reliable | 0 of 123 |
| Unreliable | 0 of 29 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Reliable | 0 of 123 |
| Unreliable | 0 of 29 |
The registry record lists serious and other adverse-event counts for two categories labelled Reliable and Unreliable. In the Reliable group, 123 participants were at risk; the listed counts for serious events, other events, and deaths are all 0. In the Unreliable group, 29 participants were at risk; the listed counts for serious events, other events, and deaths are also all 0. No serious adverse-event terms are listed.
These figures describe the safety record as entered; they are not evidence of a randomized comparison. The registry explicitly cautions that the groups are not like-for-like control groups, and allocation is not stated. The group labels therefore should not be interpreted as treatment assignments or as evidence that one group had a different safety experience because of the questionnaire.
The record does not explain the meaning of these group labels for safety reporting, the method used to collect adverse events, or the period during which events were monitored. It also does not report additional detail about event definitions or completeness of safety follow-up. The listed zero counts indicate that no events are recorded in these fields; they do not, on their own, establish that no unrecorded events occurred.
12. What the Result Does, and Does Not, Mean
The study addresses a practical assessment problem: whether people with aphasia can provide reliable answers to questions asked by caregivers. The registry describes a concise, structured instrument built around yes/no questions and a score that reflects the number of correct answers. Its stated objective was to identify a positivity threshold that balances sensitivity and specificity while emphasizing negative predictive value.
That objective should not be confused with a demonstrated result. The registry record does not report a selected threshold, diagnostic accuracy estimates, confidence intervals, or the reference standard used to determine reliability. It therefore does not establish how often the questionnaire correctly classified participants, how uncertain those estimates were, or how its performance might vary across patients or settings.
In general, a diagnostic test's performance is distinct from the value of a care strategy based on the test. Even an accuracy estimate would not by itself establish effects on communication, care decisions, or patient outcomes. The registry record does not report those outcomes, nor does it describe a comparison of care strategies.
The recorded enrollment of 152 indicates the size of the enrolled study population, not necessarily the number analyzed for the primary endpoint. The registry gives no analysis population or missing-data account. The Reliable and Unreliable labels in the safety information do not substitute for accuracy results and should not be treated as comparison arms.
The defensible conclusion is narrow: the registry documents a completed diagnostic accuracy study intended to develop a scoring threshold for the YNQ. The posted information does not permit a conclusion about the questionnaire’s classification performance, its precision, or its applicability beyond the participants and assessment circumstances represented in the study.
13. Why This Trial Matters Statistically
Statistically, the study focuses on a common challenge in diagnostic assessment: turning a measurement into a classification rule. A questionnaire score can be easy to record, but choosing a threshold requires a clear definition of the state being identified and evidence about the consequences of different classification errors. The registry describes the aim of balancing sensitivity and specificity while emphasizing negative predictive value, making the threshold-selection question central to the study’s purpose.
The intended setting also makes the definition of the target state important. The study concerns whether patients can answer reliably, but the registry record does not explain how that judgment was established independently of the questionnaire. Without a described reference standard, it is difficult to interpret what a positive or negative classification would mean statistically.
The questionnaire’s construction is described in some detail: it uses the auditory/verbal channel, focuses on personal data, favors simple syntax and familiar words, and limits question length. These constraints define what the instrument asks. They do not, on their own, demonstrate that its score separates reliable from unreliable answers. That distinction between an instrument’s design and its measured performance is important when reading diagnostic research.
The registry also illustrates why reporting completeness matters. A study objective and endpoint description can explain the intended analysis, but readers need the threshold, reference standard, accuracy estimates, uncertainty, and analysis population to judge the evidence. Those items are not reported in the registry record. Accordingly, the study’s statistical importance lies in the question it set out to address, while the available registry information is insufficient to establish the answer.
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 main limitation of the registry record for interpreting this study is that it does not report the diagnostic accuracy findings. The chosen score threshold, sensitivity, specificity, negative predictive value, and confidence intervals are not reported in the registry record. Without these results, the stated goal cannot be evaluated.
The reference standard for answer reliability is not described. The record does not state how reliability was defined, who assessed it, whether assessors were blinded to questionnaire scores, or how disagreements were resolved. This limits interpretation of what the questionnaire was evaluated against.
Although enrollment is 152, the number included in the primary endpoint analysis is not reported. The record does not state how many participants completed the questionnaire, whether any scores were missing, or how missing or indeterminate assessments were handled. Participant characteristics and details of eligibility are also not reported, limiting assessment of who the results would represent even if accuracy findings were available.
The registry lists no analysis records and does not report the statistical analysis plan, threshold-selection method, interim analyses, or a study-specific sample-size justification. It does not say whether threshold selection and accuracy evaluation used separate data. Allocation is not stated, and the Reliable and Unreliable categories are not a like-for-like control comparison.
The in-hospital measurement timeframe is reported as within 7 in-hospital days, but further information about the timing and completeness of assessment is not given. The record is marked completed, yet that status does not fill the gaps in the posted results. These limitations concern what can be established from the registry record; they do not by themselves show that the study procedures were inadequate.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Yes/No Questionnaire for Aphasic Patients (YNQ) — NCT03257696.
- Registry record last updated 2022-06-10; status last verified 2022-06.
- Results first posted 2022-06-10.
- 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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18. Record Summary
The registry record describes NCT03257696, a completed diagnostic accuracy study of the Yes/No Questionnaire for Aphasic Patients. It lists 152 participants, acute stroke and aphasia as conditions, and Groupe Hospitalier de la Rochelle Ré Aunis as sponsor. The recorded study start date is 2017-10-02, and the primary completion date is 2019-02-21.
The primary outcome is the YNQ score, measured within 7 in-hospital days. The questionnaire has 10 closed-ended questions and was intended to assess the ability to provide a coherent answer. The stated objective was to identify a positivity threshold balancing sensitivity and specificity, with emphasis on negative predictive value.
The selected threshold, reference standard, diagnostic accuracy results, confidence intervals, analysis population, and missing-data methods are not reported in the registry record. The record lists no analysis records. Its safety information records zero serious events, other events, and deaths in both the Reliable and Unreliable categories, which are not randomized comparison groups.