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 Thiamine and Acute Decompensated Heart Failure: Pilot Study (NCT00680706), a randomized phase 2 study. The primary outcome is Effect of Thiamine Supplementation on Dyspnea.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00680706 |
| Phase | Phase 2 |
| Condition | Heart Failure, Diabetes |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 131 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Baystate Medical Center |
| Results posted | Yes |
2. Clinical Question
Population
Patients presenting to the emergency department with acute decompensated heart failure were the intended study population. The brief summary says the pilot included diabetic and non-diabetic patients. The registry record does not report further eligibility details or the characteristics of participants in the posted outcome groups.
Intervention
The intervention was thiamine supplementation. The registry record does not report the dose, route, or duration of thiamine treatment.
Comparator
The comparator was placebo. The study is described as placebo-controlled in the brief summary, and the registry record lists thiamine and placebo as drug interventions.
Primary question
The study hypothesis was that thiamine supplementation would alter substrate use in energy metabolism. The posted primary outcome measures dyspnea at baseline while participants were sitting upright on oxygen, using a visual analog scale. The record does not post a between-group estimate of change in dyspnea or another treatment-effect estimate for this outcome.
3. Trial Design
The registry identifies this as a Phase 2, randomized, quadruple-masked, parallel-group study. It is described as a pilot study of thiamine supplementation in hospitalized patients with acute decompensated heart failure. The brief summary identifies diabetic and non-diabetic patients presenting to the emergency department as the intended population. Baystate Medical Center is listed as the sponsor.
The registry reports enrollment of 131. That enrollment figure is not the same thing as the number with data in a particular outcome analysis: the posted baseline dyspnea outcome lists 55.0 participants in the control group and 63.0 in the thiamine group. The record does not explain the relationship between the enrollment figure and those outcome counts, or report reasons for any difference.
The parallel design assigns participants to one of the study groups rather than having each participant receive both interventions in sequence. Random allocation can help balance measured and unmeasured characteristics between groups on average, while masking is intended to reduce the influence of treatment knowledge on care, measurement, and interpretation. The registry’s masking classification is quadruple; the identities of all masked roles and the procedures used to preserve masking are not reported in the registry record.
The registry lists a study start of 2008-01, primary completion of 2010-02, and status of completed. The treatment dose, treatment duration, allocation procedures, and follow-up schedule are not reported in the registry record. Although the trial is characterized as placebo-controlled in the brief summary, details of how the placebo was made or administered are not reported.
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: One subject was dropped by the PI after consent but before randomization because the subject did not meet the inclusion/exclusion criteria.
Overall Study
| Stage | Thiamine | Control |
|---|---|---|
| STARTED | 70 | 60 |
| COMPLETED | 63 | 55 |
| NOT COMPLETED | 7 | 5 |
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 | Thiamine | Control | Total |
|---|---|---|---|---|
| Participants analysed | 70 | 60 | 130 | |
| Age Continuous | years | 73 (SD 13) | 73 (SD 13) | 73 (SD 13) |
| Sex/Gender, Customized: Male | participants | 34 | 33 | 67 |
| Sex/Gender, Customized: Female | participants | 33 | 27 | 60 |
| Sex/Gender, Customized: Unknown | participants | 3 | 0 | 3 |
6. Primary Endpoint
The registry lists the primary outcome as Effect of Thiamine Supplementation on Dyspnea, measured over Baseline.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | mm |
| Endpoint classification | Continuous Endpoint |
The primary outcome is dyspnea measured in millimeters with a 10-centimeter visual analog scale. The stated measurement condition is sitting upright on oxygen, and the timeframe is baseline. The registry describes lower scores as less dyspnea and a better clinical outcome, and higher scores as more dyspnea. This direction makes the scale’s clinical interpretation clear: a higher measurement represents greater reported breathlessness.
A visual analog scale represents a participant’s symptom rating along a continuum. It can capture perceived symptom intensity in a way that a simple yes-or-no measure cannot. In general, a continuous scale can retain gradations in reported symptoms, although the interpretation of a score depends on how the scale is administered and on the clinical setting. The registry does not report additional details about instructions given to participants or how the measurement was obtained.
The posted results are group means with 95% confidence intervals at baseline. They are not measurements of change from baseline, and the registry record does not report a between-group treatment-effect estimate for dyspnea. A baseline score describes symptom levels at the stated assessment; by itself, it cannot establish whether scores changed after treatment or whether any change differed between the groups. The record does not report a later dyspnea measurement or a follow-up timeframe for this outcome.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
At baseline, the control group’s mean dyspnea score was 34.0 mm, with a 95% confidence interval from 28.0 to 40.0. The thiamine group’s mean was 32.0 mm, with a 95% confidence interval from 26.0 to 37.0. The scale description indicates that lower values correspond to less dyspnea. These figures describe the groups at baseline; they are not an estimate of what thiamine did to dyspnea.
A confidence interval communicates uncertainty around an estimated quantity. In general, a 95% confidence interval is constructed by a method that, over repeated sampling under its assumptions, would cover the target quantity in 95% of such intervals. It does not show the range of individual participants’ scores, nor does it directly give the uncertainty around a difference between groups. The posted intervals are for the separate group means. The registry record does not report a confidence interval for a between-group contrast.
Because the stated timeframe is baseline, these results do not show whether dyspnea improved, worsened, or remained stable after the intervention. Nor do they establish whether the groups differed in change over time. The record does not post an inferential test, p-value, or adjusted treatment-effect estimate for the primary outcome. The comparison values therefore should be read as descriptive baseline summaries, not as evidence of a treatment effect or of its absence.
The outcome counts are 55.0 for control and 63.0 for thiamine. The registry record does not describe why those counts differ from one another or from the reported enrollment of 131. It does not explain whether the outcome counts represent all participants assigned to each group, participants with an observed baseline score, or another analysis population. That missing context limits interpretation of how representative the posted summaries are of the randomized groups.
The study’s stated hypothesis concerns thiamine and energy metabolism, but the primary outcome reported in this record is a symptom measure. The posted baseline dyspnea summaries do not provide evidence about changes in biochemical, electrocardiographic, respiratory, or other outcomes. The record identifies two outcome measures but posts no secondary outcome results. Accordingly, conclusions should be limited to the reported baseline dyspnea values and the registry’s description of the study, without extending them to later symptoms, metabolic mechanisms, or clinical benefit.
9. Statistical Methods Explained
What does the reported mean describe?
The primary outcome is continuous: it is recorded on a millimeter scale rather than as a category such as present or absent. The posted summary statistic is the mean, a measure of the center of a set of measurements. In general, the mean is calculated by adding observed values and dividing by their count. It can provide a concise group-level description, but it does not show the distribution of individual scores or whether values are clustered or widely spread. The registry does not post a standard deviation or another measure of participant-level spread for this endpoint.
The reported means are 34.0 mm for control and 32.0 mm for thiamine. They are explicitly baseline measurements. As a result, they describe the groups at the stated starting assessment, not change during follow-up. A randomized comparison intended to estimate an intervention effect would ordinarily need a defined contrast, such as a difference in follow-up outcomes or in change from baseline, together with its uncertainty. Such a treatment-effect estimate is not reported in the registry record for this endpoint.
What do the confidence intervals convey?
Each group mean is accompanied by a 95% confidence interval: 28.0 to 40.0 for control and 26.0 to 37.0 for thiamine. In general, a confidence interval gives a range of values compatible with the data and the method used to calculate the interval, subject to the method’s assumptions. It is a measure of uncertainty in an estimate of a group mean. It is not a range containing 95% of individual symptom ratings, and it does not by itself answer whether two group means differ.
To assess a between-group effect, the relevant estimate is the contrast between groups, with its own standard error or confidence interval and an appropriate analysis. Separate intervals around the means cannot substitute for that contrast. The registry record does not report a between-group confidence interval, standard error, or hypothesis test for the baseline dyspnea means. No p-value for this comparison is posted. The reported intervals therefore support descriptive interpretation of the means, not a conclusion about statistical evidence for a treatment effect.
Why does the design matter?
Randomization is intended to make treatment assignment independent of participants’ characteristics, on average. When the design and implementation are appropriate, it supports causal comparisons between assigned groups. It does not guarantee that every baseline characteristic will be identical between groups, especially in a pilot study. The registry says allocation was randomized but does not describe the sequence generation, concealment, or allocation implementation. Those details are not reported in the registry record.
The parallel-group structure means participants are assigned to a thiamine or control group. Masking can help limit bias in treatment delivery, outcome assessment, and reporting when participants and relevant study personnel do not know the assigned intervention. The registry identifies quadruple masking, but does not say which roles were masked or how masking was maintained. The brief summary calls the study double-blinded; the registry’s listed masking classification is quadruple. The record does not explain the terminology or identify the masked parties, so the practical masking procedures cannot be assessed from the posted information.
How should planning calculations be understood?
Sample-size planning calculations are prospective illustrations of the number of participants that might be required under specified assumptions. They are not observed trial results and are not a measure of the trial’s observed power. The registry describes planning illustrations based on the observed effect, two-sided significance level 0.05, equal allocation, and a normal approximation. The effect to detect is expressed as a stated fraction of the observed effect. The record does not report the trial’s own sample-size justification or design assumptions.
Those planning assumptions do not turn the posted baseline means into an observed treatment effect. The primary measurement is at baseline, and no treatment-effect estimate is reported. The registry record also does not post the calculated participant-per-arm values associated with the planning illustrations. A sample-size calculation depends on its target effect, variability assumptions, error rates, allocation, and analysis method; the interpretation must remain tied to the assumptions actually stated. It would be inappropriate to treat an illustrative calculation as proof that the study had adequate power or to infer an observed power value.
What analysis details are absent?
The registry lists zero analyses. It does not report an analysis model, a covariate adjustment strategy, a method for handling repeated measurements, or a primary comparison for dyspnea. The endpoint is given as a mean with a confidence interval, but the calculation method for those intervals is not reported in the registry record. Statistical assumptions, such as the distributional approach used for inference, are also not described. Without these details, the posted means and intervals can be described, but the underlying analysis cannot be fully reproduced or evaluated.
In general, a continuous outcome may be analyzed with methods that compare means, but the appropriate method depends on the design, distribution, missingness, and intended estimand. Over-dispersion is a concern when data vary more than a model assumes; in general, underestimating variability can make confidence intervals too narrow and tests too optimistic. The record does not report evidence of over-dispersion or a model for this endpoint, so no claim about its presence or effect is warranted.
10. Multiplicity, Missing Data and Analysis Populations
The registry identifies two outcome measures and reports zero posted secondary outcomes. It does not describe a prespecified hierarchy of outcomes, adjustment for multiple comparisons, or a multiplicity strategy. When several outcomes or analyses are tested, multiplicity can increase the chance of at least one apparently unusual result; in general, a planned approach helps clarify how such results should be interpreted. The available record does not establish which adjustment, if any, was planned or used.
The registry lists zero analyses and does not report a statistical analysis plan, analysis populations, or an estimand for the primary outcome. It does not state whether results were analyzed according to randomized assignment, according to treatment received, or under another rule. The reported outcome counts are 55.0 for control and 63.0 for thiamine, but the record does not explain how these analysis counts were determined.
Missing-data methods and the amount or pattern of missing primary outcome data are not reported in the registry record. There is no description of imputation, complete-case analysis, or sensitivity analysis. Without this information, it is not possible to assess whether missing measurements could have affected the group summaries or a treatment-effect analysis. The record also does not report interim analyses, stopping rules, or a plan for handling protocol deviations. None of these details should be inferred from the posted baseline summaries.
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 |
|---|---|---|---|
| Thiamine | 0 | 63 | 0.0% |
| Control | 0 | 55 | 0.0% |
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 |
|---|---|
| Thiamine | 0 of 63 |
| Control | 0 of 55 |
The adverse-event record lists 0 serious events among the 63 participants at risk in the thiamine group and 0 among the 55 participants at risk in the control group. It also lists 0 other adverse events among the 63 at risk in the thiamine group and 0 among the 55 at risk in control. These are the event counts and at-risk group sizes reported in the registry.
Zero reported events in these groups should be read narrowly. They describe what the registry records for the listed categories; they do not establish that no adverse effects occurred in any sense, or that the interventions have no safety risks. The record does not provide event definitions, ascertainment procedures, follow-up duration for safety, or additional detail about the event reporting process. Death counts are not reported in the registry record. The listed adverse-event counts also do not explain how the safety population was defined or whether all participants were monitored for the same length of time.
12. What the Result Does, and Does Not, Mean
The posted results establish that baseline dyspnea was summarized as a group mean with a 95% confidence interval for control and thiamine. The control mean was 34.0 mm, with an interval from 28.0 to 40.0; the thiamine mean was 32.0 mm, with an interval from 26.0 to 37.0. The registry’s scale description says lower values indicate less dyspnea. These results are useful as descriptions of the recorded baseline measurements.
They do not establish an effect of thiamine on dyspnea. The timeframe is baseline, and the registry record does not report a later measurement, change from baseline, between-group treatment-effect estimate, or inferential test for this primary outcome. The baseline summaries cannot determine whether symptoms subsequently changed or whether any change differed between groups. They also cannot establish whether thiamine altered energy metabolism, despite that being the study’s stated hypothesis.
The registry’s randomized, quadruple-masked, parallel design identifies the intended trial structure, but details needed to assess implementation and analysis are not reported. In particular, the record does not report a statistical analysis plan, missing-data approach, outcome-analysis population, or the relationship between enrollment and the outcome counts. These absences limit assessment of how the posted summaries were generated and how broadly they represent the trial population.
Likewise, the safety record reports zero serious and zero other adverse events in the listed at-risk groups, but does not provide enough information to interpret the completeness or duration of event monitoring. These data are not a basis for a general safety conclusion. The appropriate interpretation is limited to the specific counts and baseline dyspnea summaries recorded, with uncertainty about methods and follow-up kept explicit.
13. Why This Trial Matters Statistically
This pilot trial is statistically informative as an example of the distinction between a trial’s hypothesis and the results actually posted for its primary outcome. The study’s rationale concerns thiamine and myocardial energy metabolism, while the reported primary measure is baseline dyspnea. Recognizing the measurement timeframe prevents a descriptive starting-point summary from being mistaken for an estimate of treatment response.
The record also illustrates why an outcome estimate and its uncertainty need to match the scientific question. Confidence intervals around each group mean describe uncertainty in those means. A question about whether assigned groups differed in dyspnea after treatment would require a treatment-effect contrast and uncertainty around that contrast. The registry does not report such an estimate for this endpoint. Separate baseline means and intervals cannot fill that gap.
Registry transparency matters as well. Information about analysis populations, missing data, the statistical plan, follow-up, and the handling of multiple outcomes helps readers judge how robustly findings address the intended question. Several of these details are not reported in the registry record. Their absence does not establish that a method was not used; it means the posted record does not allow the method to be evaluated.
Finally, the safety counts demonstrate the importance of reading event totals alongside the population at risk and the information available about follow-up and ascertainment. The record lists zero events in the stated categories, but does not provide enough context for a broader interpretation. Taken together, the trial is best read as a pilot record with descriptive baseline symptom results, rather than as a posted test of a treatment effect on dyspnea.
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 primary endpoint is reported at baseline, so the posted data do not show symptom change during or after treatment. A between-group treatment-effect estimate, uncertainty interval for that estimate, and inferential test are not reported in the registry record. The results therefore cannot answer whether dyspnea changed differently between assigned groups.
The registry reports enrollment of 131, while the baseline outcome summaries list 55.0 control participants and 63.0 thiamine participants. The record does not explain the difference between these figures, define the outcome-analysis population, or describe missing outcome measurements. This prevents a clear assessment of how the posted scores relate to the randomized groups.
Important intervention details are not reported in the registry record, including the thiamine dose, route, and duration. Eligibility criteria, participant characteristics, follow-up schedule, and the procedures used to measure dyspnea are also not described in the posted information. These omissions limit assessment of who the findings describe and how the intervention and outcome were implemented.
Although the study is identified as randomized and quadruple-masked, the registry does not report details of allocation concealment, sequence generation, or which study roles were masked. It does not post an analysis plan, missing-data strategy, analysis population, or multiplicity approach. Secondary outcomes are not posted, and the record lists zero analyses. Safety reporting is limited to the listed counts and at-risk groups; event ascertainment, follow-up duration, and death counts are not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Thiamine and Acute Decompensated Heart Failure: Pilot Study — NCT00680706.
- Registry record last updated 2013-08-21; status last verified 2013-08.
- Results first posted 2012-09-28.
- 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 describes a completed, randomized, quadruple-masked, parallel Phase 2 pilot study sponsored by Baystate Medical Center. It lists thiamine and placebo interventions, enrollment of 131, and a study start of 2008-01 with primary completion in 2010-02. The brief summary describes patients with acute decompensated heart failure, including diabetic and non-diabetic patients.
The posted primary outcome is baseline dyspnea measured in millimeters with a visual analog scale while sitting upright on oxygen. The control mean is 34.0 mm (95% confidence interval 28.0 to 40.0); the thiamine mean is 32.0 mm (95% confidence interval 26.0 to 37.0). The registry does not report a treatment-effect estimate for change in dyspnea. It lists zero secondary outcomes and zero analyses. Serious and other adverse-event counts are zero in both listed groups; death counts are not reported in the registry record.