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 Decision Aid for Therapeutic Options In Sickle Cell Disease (NCT02326597), a randomized na study. The primary outcome is Acceptability of Decision Aid Education Assessed by the Acceptability Survey.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02326597 |
| Phase | NA |
| Condition | Sickle Cell Disease, Sickle Cell Anemia, Hemoglobin SS |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Single |
| Enrollment | 134 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Emory University |
| Results posted | Yes |
2. Clinical Question
The trial examined a web-based decision aid intended to help people with sickle cell disease consider treatment options using information about their risks and benefits. The registered primary question was whether education involving the decision aid was acceptable to participants, assessed after the first visit. The broader study aim was to support informed decisions that reflect patients’ values and preferences.
Population
Participants with sickle cell disease. The registry lists sickle cell disease, sickle cell anemia, Hemoglobin SS, Hemoglobin SC, and Hemoglobin Beta Thalassemia. The specific eligibility criteria and participant characteristics are not reported in the registry record.
Intervention
Standard practice and healthcare-team discussion, with access to a web-based decision aid tool.
Comparator
Education and discussion about treatment considerations from the healthcare provider or team as part of standard practice.
Primary question
How did participants rate the acceptability of education after the first visit? The registry describes a questionnaire but does not report the resulting ratings.
The primary outcome is an acceptability measure, not a direct comparison of treatment choices or clinical outcomes. The registry says the acceptability survey was completed by 106 participants across both groups together. Because that measure combines the groups, it does not by itself show whether acceptability differed between standard practice and standard practice plus the decision aid. The registry also lists outcomes concerning decisional self-efficacy, decisional conflict, values, preparation, knowledge, and regret. Numerical results for these measures are not reported in the registry record.
3. Trial Design
This was a randomized, parallel-group trial with single masking. The registry lists an enrollment of 134 and a status of completed. The start is recorded as 2015-01, and primary completion as 2017-04-17. The phase is listed as NA. Emory University is the sponsor.
Participants were assigned to standard practice or standard practice plus the decision aid. The standard-practice group received education about treatment considerations from their healthcare provider or team as part of usual care. The other group received standard-of-care teaching and discussion in addition to access to the web-based decision aid. The registry does not report the allocation ratio or the method used to generate or conceal the random assignment.
Randomization is intended to make the groups comparable, on average, with respect to factors that could affect outcomes. It does not guarantee that the groups are identical, particularly in an individual trial. A parallel-group design means that participants were assigned to one group rather than crossing between the two approaches. The registry’s single-masking label indicates that masking was used, but which people were masked and how masking was maintained are not reported in the registry record.
The registered primary outcome was acceptability of decision-aid education, assessed after Visit 1, up to 2 weeks. The registry describes an analysis in which participants from both groups were considered together, with 106 participants completing the survey. That combined analysis is not a randomized comparison between groups. The registry lists additional patient-reported outcomes, but does not provide their numerical results or describe their analysis populations.
The trial’s stated purpose was to assess a web-based aid for communicating information about treatment options in sickle cell disease. The record does not report details such as the number of study sites, participant demographic characteristics, or the identity of the party masked.
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: Of the 134 participants who signed consent, 120 began study participation and were included in the baseline analysis.
Overall Study
| Stage | Standard Practice | Standard Practice + Decision Aid |
|---|---|---|
| STARTED | 60 | 60 |
| COMPLETED | 18 | 28 |
| NOT COMPLETED | 42 | 32 |
Reasons for not completing this period:
| Reason | Standard Practice | Standard Practice + Decision Aid |
|---|---|---|
| Lost to Follow-up | 42 | 32 |
Analysis population for the primary outcome, as defined in the registry: Analysis was completed in both the standard practice and standard practice + decision aid groups together. There were a total of 106 participants who completed the survey.
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 | Standard Practice | Standard Practice + Decision Aid | Total |
|---|---|---|---|---|
| Participants analysed | 60 | 60 | 120 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 60 | 60 | 120 |
| Age, Categorical: >=65 years | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Female | Participants | 46 | 45 | 91 |
| Sex: Female, Male: Male | Participants | 14 | 15 | 29 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 60 | 60 | 120 |
| Race (NIH/OMB): White | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | Participants | 60 | 60 | 120 |
6. Primary Endpoint
The registry lists the primary outcome as Acceptability of Decision Aid Education Assessed by the Acceptability Survey, measured over Post Visit 1 (Up to 2 Weeks).
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Standard Deviation |
| Unit | units on a scale |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is acceptability of decision-aid education, assessed with an 8-item questionnaire after Visit 1, up to 2 weeks. Each item is scored from 1-4, with 1 meaning poor, 2 fair, 3 good, and 4 excellent. The registry says items are rated individually and that there is no overall total score. It describes the endpoint parameter as a median, with standard deviation as the dispersion measure.
Acceptability is used to assess how participants appraise the education they received. In this study, it offers information about the experience of the educational material, including comprehension as described in the registry. Such a measure can help characterize whether an educational approach is acceptable to participants; it is not itself a measure of clinical benefit, treatment effectiveness, or whether choices match a person’s values.
The registry reports that 106 participants completed the survey and that analysis included the standard-practice and standard-practice-plus-decision-aid groups together. It does not report the item-level medians or standard deviations. Because the measure was analyzed across both groups together, the recorded analysis does not estimate a difference in acceptability between the randomized groups. The registry record also does not report how incomplete questionnaire items, if any, were handled.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the trial’s primary outcome and how it was intended to be measured, but it does not include the numerical acceptability ratings. It is therefore not possible to describe the observed level of acceptability or the precision of that estimate from the record. The listed median and standard deviation are the planned descriptive summaries; their values are not reported in the registry record.
The survey was completed by 106 participants, with the standard-practice and decision-aid groups analyzed together. This combined result, even if numerical ratings were available, would describe the survey responses across the analyzed participants rather than estimate the effect of adding the decision aid. A treatment contrast requires outcomes reported separately by randomized group or a suitable between-group analysis. Neither a numerical group comparison nor an effect estimate for the primary outcome is reported in the registry record.
The trial’s randomized design is relevant to comparisons between assigned groups, because randomization is intended to reduce systematic differences at the outset. But design alone cannot establish the direction or size of a result. Interpretation depends on the outcome data, the way missing observations were handled, and the analysis used. Those details are not reported for the primary outcome.
The registry lists seven secondary outcome descriptions, including measures of decisional self-efficacy, decisional conflict, values, preparation for decision making, knowledge, and regret. It also records eight outcome measures overall. Numerical findings for these measures are not reported in the registry record, and the record lists no analyses. No conclusions about changes in knowledge, confidence, conflict, preparation, values, or regret can be drawn from the outcome titles alone.
The registry’s adverse-event listings report zero serious adverse events, zero other adverse events, and zero deaths in each group. These figures describe the counts entered in those listings; they do not provide details on event definitions, collection procedures, or follow-up completeness. They should not be taken as proof that no events occurred beyond what was recorded.
Overall, the available record supports a description of the design, intervention, comparator, and measurement plan. It does not provide the outcome values needed to assess the acceptability ratings or estimate a comparative effect. The record also does not report a sample-size justification or a detailed statistical analysis plan, so those elements cannot be used to interpret the absence of numerical results.
9. Statistical Methods Explained
The registry describes a randomized, parallel-group comparison. Random assignment is a design approach intended to balance known and unknown prognostic factors between groups, on average. It supports a causal interpretation of a between-group contrast when allocation is implemented as intended and outcomes are analyzed appropriately. Randomization does not remove the need to examine missing outcomes, adherence, and the analysis population. Details of the randomization procedure and allocation concealment are not reported in the registry record.
What does the primary summary describe?
The acceptability outcome is described using a median and standard deviation. A median identifies the middle of an ordered set of responses. It can be useful when a measure is ordinal or when the distribution is not well represented by a mean. A standard deviation describes the spread of observations around a mean; paired with a median, it should be read as the registry’s specified dispersion summary, not as a confidence interval or a measure of uncertainty in the median.
The survey uses individual item ratings on a 1-4 scale, and the registry says there is no overall total score. Therefore, the primary measure is not a single summed questionnaire score. The registry does not report the item-specific summaries or explain whether any items were omitted from the reported analysis.
Why is the combined-group analysis important?
The registry says the acceptability analysis included participants from both groups together. Combining groups can describe responses across the analyzed sample, but it does not preserve the randomized contrast needed to estimate the added contribution of the decision aid. A between-group estimate would require group-specific results or a model that directly compares the randomized groups. Such an estimate is not reported in the registry record. The total of 106 survey completers is reported, but group-specific completion counts are not.
How should precision be assessed?
A confidence interval is a statistical range used to express uncertainty around an estimated quantity under a specified method. Its width depends on factors such as variability and the amount of information available. For a treatment comparison, an interval around the difference or other contrast helps readers assess both the plausible effect sizes and the precision of the estimate. No confidence interval or other uncertainty interval for the primary outcome is reported in the registry record. The listed standard deviation alone would not provide that interval.
The registry’s sample-size description refers to planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between groups, and a normal approximation. It states that the effect to detect is a stated fraction of the observed effect. These are described as planning illustrations, not the trial’s own design calculation. No sample-size illustration values are reported in the registry record for this analysis, and the registry does not report the trial’s sample-size justification. Such planning calculations are not observed power and cannot replace an estimate with an uncertainty interval.
What does over-dispersion mean in general?
In general, over-dispersion means that observed variability is greater than a statistical model assumes. If a model ignores over-dispersion, standard errors can be too small and uncertainty can appear narrower than it should be. Whether over-dispersion is relevant depends on the outcome and model. The registry record does not report a model for the primary outcome or an assessment of over-dispersion.
What can be inferred from zero event counts?
In general, an observed count of zero is not the same as proof that the underlying event risk is zero. Interpretation depends on the number of people observed, the duration and completeness of follow-up, and how events were identified and recorded. The registry lists 60 participants at risk in each group for serious and other adverse events, with zero events and zero deaths in both. It does not provide event definitions, follow-up duration for safety, or a detailed ascertainment method.
The registry lists no analyses and does not report model specifications, covariate adjustments, hypothesis tests, or confidence intervals. Recalculated estimates are not available in the registry record for this record. Consequently, there is no basis for describing an adjusted or unadjusted treatment effect, or for comparing a recalculation with a sponsor analysis.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists eight outcome measures, including the primary acceptability outcome and measures of decisional self-efficacy, decisional conflict, values, preparation for decision making, knowledge, and decisional regret. It does not report a multiplicity plan, such as a hierarchy of outcomes, an adjustment for multiple testing, or a distinction between confirmatory and exploratory analyses. The record lists zero analyses. Without reported inferential results and an analysis plan, the extent to which multiplicity was addressed is not reported in the registry record.
The registry reports 106 participants completing the primary survey, analyzed across both groups together. It does not report how many participants were assigned to each group for that analysis, group-specific survey completion, or reasons for noncompletion. The enrollment is 134, but the record does not explain the difference between enrollment and the number completing this survey. It also does not state whether participants were analyzed according to their randomized group, whether any participants were excluded, or how missing questionnaire items were handled.
In general, missing data can affect an estimate when the likelihood of missingness is related to participant characteristics or outcomes. Reporting the amount, pattern, and handling of missing data helps readers judge this risk. The registry does not report those details for the primary or secondary outcomes. The analysis population for the secondary outcomes is also not reported in the registry record.
The record does not describe interim analyses, stopping rules, or a prespecified statistical analysis plan. Their presence or absence cannot be inferred from the trial design or the listed outcome measures.
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 |
|---|---|---|---|
| Standard Practice | 0 | 60 | 0.0% |
| Standard Practice + Decision Aid | 0 | 60 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Standard Practice | 0 of 60 |
| Standard Practice + Decision Aid | 0 of 60 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Standard Practice | 0 of 60 |
| Standard Practice + Decision Aid | 0 of 60 |
The registry lists the same safety counts for the two groups: 60 participants at risk for serious adverse events and 60 at risk for other adverse events in each group. It records zero serious adverse events, zero other adverse events, and zero deaths in both groups. These are the counts entered in the registry’s adverse-event listings.
Zero recorded events should be interpreted as a report of the listed counts, not as evidence that the risk of an event is absent. Counts alone do not show how safety events were defined, how actively they were sought, how long participants were followed for safety, or whether follow-up was complete. Those details are not reported in the registry record.
The enrollment is listed as 134, while the safety listings report 60 participants at risk in each group. The record does not explain the relationship between these figures, so they should not be combined or reconciled by assumption. The registry also does not report event-level descriptions or separate results for particular types of events. The safety figures therefore describe the posted adverse-event counts and should not be read as a full account of safety assessment.
12. What the Result Does, and Does Not, Mean
The record documents a randomized comparison of standard practice with standard practice plus access to a web-based decision aid for people with sickle cell disease. It also describes an acceptability survey administered after the first visit and reports that 106 participants completed it. These details establish what the study set out to compare and how its primary outcome was defined.
The record does not report the acceptability ratings, a treatment-group contrast, or an uncertainty interval. It therefore does not establish whether participants found the education acceptable, how ratings varied across questionnaire items, or whether access to the decision aid changed acceptability compared with standard practice. The combined analysis across groups cannot answer that comparative question.
The trial’s stated aim included helping patients understand treatment risks and benefits and make decisions consistent with their values and preferences. The registry lists related secondary measures, but their numerical results are not reported. The purpose of the intervention and the names of the outcomes do not establish that knowledge, decisional confidence, preparation, or values-concordant decision making changed.
The registry’s zero adverse-event counts describe what was entered in the safety listings. They do not establish that no events occurred outside the recorded counts, nor do they describe the completeness or duration of safety monitoring.
In general, a randomized design can support a fair comparison when the groups are analyzed appropriately, but conclusions still depend on actual outcome data and transparent methods. Here, the registry record supports a description of the design and measurement approach, not a conclusion about the decision aid’s effect. It also does not report enough detail to assess missing-data handling, multiplicity, or the precision of an estimated effect.
13. Why This Trial Matters Statistically
Decision aids are intended to make information about options and outcomes accessible during clinical decisions. In this trial, the registered intervention was added to standard teaching and discussion rather than replacing usual care. Studying an educational approach raises statistical questions distinct from simply measuring a clinical endpoint: what aspect of the decision process is being measured, whether the instrument is summarized appropriately, and whether the comparison preserves the randomized groups.
The primary outcome focuses on acceptability, with individual questionnaire items rated from 1-4 and no overall total score. The registry’s choice to describe a median and standard deviation is important to recognize when interpreting the endpoint. A single combined result would characterize responses across participants but would not isolate the contribution of the decision aid. The record states that both groups were analyzed together for this outcome, making the distinction between descriptive acceptability and comparative effectiveness especially important.
The study also lists outcomes that address decisional self-efficacy, conflict, values, preparation, knowledge, and regret. These outcomes reflect several different dimensions of decision making. Each requires a clear measurement and analysis approach; a favorable result on one dimension would not automatically imply a change in another. The registry does not report numerical findings for these measures.
Statistically, the record illustrates why design information and outcome results must be considered together. Randomization describes the intended basis for a fair group comparison, while the reported combined primary analysis does not present that comparison. Without estimates, uncertainty intervals, and details about missing data and multiplicity, readers cannot assess the size or precision of any effect. The design is informative about the question asked, but the registry record does not provide the results needed to answer it.
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.
Important limitations for interpreting this trial record arise from missing outcome and analysis details. The primary outcome is described, and the number completing its survey is reported, but the item-level results are not. No group-specific primary outcome summaries, treatment contrast, or confidence interval are reported in the registry record. The recorded analysis combines participants from both randomized groups, so it does not estimate the comparative effect of adding the decision aid.
The registry does not report the detailed eligibility criteria, participant characteristics, group allocation ratio, randomization procedure, or allocation concealment. It labels the study single-masked but does not identify who was masked or describe how masking was implemented. These omissions limit assessment of how the design was carried out and to whom the results might apply.
Missing-data handling is not described. Although 134 participants were enrolled and 106 completed the acceptability survey, the record does not state group-specific completion numbers or reasons for noncompletion. It also does not explain how incomplete items were treated. The relationship between enrollment and the safety listings of 60 participants at risk per group is not explained.
The registry lists multiple secondary outcomes but does not report their numerical findings, an analysis plan, or a multiplicity approach. It also does not report sample-size justification or interim-analysis details. These limitations concern what can be assessed from the registry record; they do not establish that the corresponding procedures were absent from the conduct of the trial.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Decision Aid for Therapeutic Options In Sickle Cell Disease — NCT02326597.
- Registry record last updated 2018-10-09; status last verified 2017-12.
- Results first posted 2018-10-09.
- 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
NCT02326597 is a completed, randomized, single-masked, parallel-group trial sponsored by Emory University. It enrolled 134 participants and compared standard practice with standard practice plus access to a web-based decision aid for sickle cell disease treatment discussions.
The primary outcome was acceptability of education assessed after Visit 1, up to 2 weeks, using an 8-item survey with individual ratings from 1-4 and no overall total score. The registry reports that 106 participants completed the survey and were analyzed together across groups, but does not report the outcome ratings or a randomized group comparison.
The registry lists secondary decision-making outcomes and adverse-event counts, including zero serious adverse events, zero other adverse events, and zero deaths in each group. Numerical results for the secondary outcomes and further safety-assessment details are not reported in the registry record.