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 Safety and Tolerability Study Comparing Sodium Oxybate Given as an Oral Solution to a Single-blinded Combination of Oral Tablets Plus Oral Solution in Subjects With Fibromyalgia (NCT00803023), a randomized phase 3 study. The primary outcome is Summary of Most Frequent Adverse Events (Per Arm) Experienced by Study Subjects.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00803023 |
| Phase | Phase 3 |
| Condition | Fibromyalgia |
| Allocation | Randomized |
| Design model | Single Group |
| Masking | Single |
| Enrollment | 129 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Jazz Pharmaceuticals |
| Results posted | Yes |
2. Clinical Question
Population
Subjects with fibromyalgia. The registry gives an enrollment of 129 and reports adverse-event results by study arm. Further eligibility criteria and details of the analysis population are not reported in the registry record.
Intervention
Sodium oxybate given as an oral solution, either at 4.5 grams or 6 grams, is compared with regimens described as oral solution combined with tablets. The arm descriptions specify placebo tablets, while the adverse-event group labels refer to tablets. The record does not clarify this difference in wording.
Comparator
The registry describes oral-solution regimens at the corresponding dose levels as the comparison for the solution-plus-tablet regimens. Its arm descriptions identify the combined regimens as oral solution plus placebo tablets. The extent to which participants, investigators, or other study personnel were masked is not detailed beyond the single-blind designation.
Primary question
The stated primary outcome is a per-arm summary of the most frequent adverse events experienced by study subjects during 4 weeks. The study summary frames the comparison as one of safety and tolerability. The registry does not reduce this outcome to a single event, contrast, or statistical test, so the primary question is descriptive rather than a reported inferential comparison.
3. Trial Design
The registry classifies this as a Phase 3 study with randomized allocation and single masking. Its stated purpose was to compare the safety and tolerability of sodium oxybate administered as a combination of oral solution and oral tablets over 4 weeks in subjects with fibromyalgia. The record also lists oral-solution regimens at 4.5 grams and 6 grams, alongside combination regimens at those dose levels.
There is a structural ambiguity in the registry: the model is recorded as single-group, while the arm descriptions and adverse-event results distinguish several treatment groups. The record does not explain this inconsistency. It also does not specify the randomization procedure, allocation ratio, masking procedures, or whether masking applied to participants, investigators, or both. The title refers to a single-blinded comparison, but further operational detail is not reported in the registry record.
The study enrolled 129 participants. Its recorded start was 2010-03, primary completion was 2010-07, and status is completed. These record details describe enrollment and timing, not the number analyzed for each outcome. The reported at-risk counts vary by arm, and the registry does not explain the reasons for those denominators or provide a participant-flow account.
The primary outcome is titled “Summary of Most Frequent Adverse Events (Per Arm) Experienced by Study Subjects,” with a timeframe of 4 weeks and the unit participants. Tolerability assessed by adverse events is also listed as a secondary outcome. The registry records two outcome measures but no analyses. It does not report a detailed statistical analysis plan, sample-size justification, interim monitoring approach, or prespecified rules for selecting the most frequent events.
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 | 4.5g SXB | 4.5g SXB + 6 Tablets | 6g SXB | 6g SXB + 8 Tablets |
|---|---|---|---|---|
| STARTED | 32 | 33 | 31 | 33 |
| COMPLETED | 27 | 25 | 20 | 25 |
| NOT COMPLETED | 5 | 8 | 11 | 8 |
Reasons for not completing this period:
| Reason | 4.5g SXB | 4.5g SXB + 6 Tablets | 6g SXB | 6g SXB + 8 Tablets |
|---|---|---|---|---|
| Adverse Event | 5 | 4 | 8 | 6 |
| Withdrawal by Subject | 0 | 2 | 0 | 0 |
| Lost to Follow-up | 0 | 1 | 2 | 1 |
| Lack of Efficacy | 0 | 1 | 1 | 1 |
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 | 4.5g SXB | 4.5g SXB + 6 Tablets | 6g SXB | 6g SXB + 8 Tablets | Total |
|---|---|---|---|---|---|---|
| Participants analysed | 32 | 33 | 31 | 33 | 129 | |
| Age Continuous | years | 48.3 (SD 12.31) | 49.6 (SD 11.69) | 49.3 (SD 12.76) | 50.7 (SD 12.24) | 49.5 (SD 12.13) |
| Age, Customized: 18 - 39 | Participants | 9 | 7 | 7 | 5 | 28 |
| Age, Customized: 40 - 49 | Participants | 6 | 6 | 8 | 8 | 28 |
| Age, Customized: 50 - 64 | Participants | 15 | 18 | 12 | 17 | 62 |
| Age, Customized: >=65 | Participants | 2 | 2 | 4 | 3 | 11 |
| Sex: Female, Male: Female | Participants | 31 | 29 | 27 | 32 | 119 |
| Sex: Female, Male: Male | Participants | 1 | 4 | 4 | 1 | 10 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 5 | 5 | 3 | 7 | 20 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 27 | 28 | 28 | 26 | 109 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 | 1 | 1 |
| Race (NIH/OMB): Asian | Participants | 2 | 0 | 0 | 1 | 3 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 1 | 1 | 2 | 1 | 5 |
| Race (NIH/OMB): White | Participants | 29 | 31 | 28 | 30 | 118 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 1 | 1 | 0 | 2 |
| Region of Enrollment: United States | participants | 32 | 33 | 31 | 33 | 129 |
6. Primary Endpoint
The registry lists the primary outcome as Summary of Most Frequent Adverse Events (Per Arm) Experienced by Study Subjects, measured over 4 weeks.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is a per-arm summary of the most frequent adverse events experienced by study subjects during 4 weeks. The unit is participants, so the posted results give counts of participants affected, rather than a measure of symptom severity or a rate of events over person-time. The results separate serious adverse events from other adverse events, with counts at risk and affected reported for each arm.
Safety and tolerability endpoints are used to describe unwanted events observed during a study and to compare their recorded occurrence across treatment groups. A participant-based count can be easy to interpret, but it does not capture how often an individual experienced an event, how long it lasted, or how severe it was unless those details are separately recorded. The registry does not report those details for this outcome.
The endpoint title refers to the most frequent adverse events, but the record does not define a frequency threshold or identify which events constitute the complete endpoint. It lists serious-event terms separately, while the arm-level counts summarize serious events and other adverse events. The primary outcome has several categories or time points and is not reduced to a single comparison in the posted results. Consequently, the record supports a descriptive reading of the arm-level counts, not a single estimate of an overall treatment contrast.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted safety results are descriptive. For serious adverse events, the registry reports 1 affected participant among 32 at risk in the 4.5g SXB group, 0 among 33 in the 4.5g SXB + 6 Tablets group, 1 among 31 in the 6g SXB group, and 0 among 33 in the 6g SXB + 8 Tablets group. These are participant counts in the registry, not estimates accompanied by a statistical comparison.
For other adverse events, the corresponding counts are 12 among 32, 13 among 33, 11 among 31, and 17 among 33. The group with the largest recorded affected-participant count is the 6g SXB + 8 Tablets group; that observation alone does not establish a difference between regimens. The counts are presented with different at-risk denominators, and the registry provides no confidence intervals, p-values, adjusted estimates, or analysis populations to quantify uncertainty or account for other factors.
The registry separately lists Suicidal Behavior and Major Depression at 3.2% each, and Diverticulitis at 3.1%, among its frequent serious-event terms. It does not specify the arm attribution for these listed terms in the registry record recorded. They should therefore not be used to infer which regimen had more of a particular event.
In general, an observed count is a description of what was recorded in the study. A comparison of counts alone does not establish that an observed difference is larger than would be expected from sampling variation. Confidence intervals, when reported, describe the uncertainty around an estimate under a statistical model; none are reported for these arm-level adverse-event results. A p-value, if available, would address a specified statistical comparison under stated assumptions, but the registry does not report one.
The posted results do not state whether the adverse-event counts were analyzed according to randomized assignment, treatment received, or another population definition. Nor do they report missing outcome data, follow-up completeness, or reasons for participants not being included in a particular denominator. Those omissions limit interpretation of how completely the arm-level counts represent the enrolled study population. No conclusion about comparative safety can be drawn from the raw counts alone.
9. Statistical Methods Explained
What kind of outcome is recorded?
General: A participant-based adverse-event outcome records whether participants experienced an event during a defined observation period. Such data are often treated as binary at the participant level: a participant is counted as affected or not affected for a specified event or event category. This differs from counting every occurrence, since one participant might experience an event more than once. The registry identifies the unit as participants and reports counts at risk and affected, but does not explain whether repeat events or multiple event types were handled in a particular way.
The primary outcome concerns adverse events over 4 weeks. The posted results distinguish serious adverse events from other adverse events and provide group-specific affected counts. The record does not define the full event-coding rules, severity criteria beyond the serious classification, or the method used to select the “most frequent” events. Those definitions matter because they determine which observations are included and how consistent classification is across groups.
How should counts and denominators be read?
General: A count describes the observed number of participants meeting an outcome definition, while the denominator describes the number considered at risk or eligible for that outcome. Reading the two together is important: the same count can have a different meaning when the number at risk differs. The registry’s figures are counts and denominators, not an inferential comparison. No percentages need to be inferred from them to understand the results as posted.
These denominators are arm-specific and are not identical. The registry does not explain whether this reflects enrollment to each arm, outcome availability, exposure, or another rule. A denominator can change the interpretation of an observed count, and a clear report would ordinarily specify its definition and describe missing observations or exclusions. That explanation is not reported in the registry record.
What does randomization contribute?
General: Random assignment is intended to make treatment groups comparable, on average, with respect to factors known and unknown at baseline. It does not guarantee identical groups, particularly in a study with limited enrollment, and it does not remove the need to report the analysis population and statistical methods. This record identifies the allocation as randomized but does not describe the allocation sequence, concealment, or implementation.
The registry also lists the model as single-group despite describing several arms and presenting arm-level results. This is a reporting inconsistency. Without clarification, it is not possible to determine how the registry’s model label relates to the stated randomized design and the recorded results.
What does masking mean for interpretation?
General: Masking can reduce the influence of expectations on behavior, outcome reporting, or assessment. The amount of protection depends on who is masked and whether the assigned regimens can be distinguished. The registry identifies the study as single-blind, but does not state who was masked, how masking was maintained, or whether the different formulations could reveal assignment. The label alone is not enough to assess the effectiveness of masking.
What statistical comparisons are available?
The registry reports no analyses. The primary outcome is described as having several categories or time points and is not reduced to one comparison. There are no reported estimates of treatment differences, confidence intervals, p-values, or model-based results for the adverse-event counts. It is therefore not possible to assess statistical uncertainty around contrasts between arms from the record.
General: For binary outcomes, analysts may estimate a difference or ratio between groups and attach a confidence interval to communicate uncertainty. Choice of measure and model depends on the design, outcome definition, and assumptions. Comparisons can also be affected by sparse data, especially when some groups have few affected participants. Methods suited to sparse outcomes may behave differently from large-sample approximations. The registry does not report a chosen comparison measure or method for this endpoint, so none should be attributed to the study.
The sample-size assumptions recorded for planning illustrations specify a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and detection of a stated fraction of the observed effect. These are planning assumptions, not evidence that the study was designed or analyzed using that approach. Planning illustrations are not observed power, and the registry does not report the study’s own sample-size justification. In addition, the primary endpoint is not reduced to one comparison, so a single endpoint contrast cannot be matched to those assumptions from the registry record.
Why can over-dispersion matter?
General: Over-dispersion occurs when observed variability is greater than a statistical model expects. It can make uncertainty estimates too small if the model assumes less variability than the data contain. It is relevant to some count-data analyses, but the posted endpoint is reported as participants affected, and the registry gives no fitted count model or dispersion estimate. It would be inappropriate to claim that over-dispersion was tested or adjusted for in this study.
Overall, the available statistical information supports a descriptive account of recorded participant counts. It does not support reconstruction of an adjusted analysis, uncertainty interval, or treatment-effect test. Any interpretation beyond the posted arm-level summaries would require analysis details that are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists two outcome measures and identifies adverse-event tolerability as a secondary outcome. It does not report a multiplicity strategy, such as a hierarchy of outcomes, an adjustment for multiple comparisons, or a rule for interpreting results across event types. The primary outcome itself includes multiple categories or time points and is not reduced to one comparison. Without a stated analysis plan, the treatment of multiple event categories and comparisons is not reported in the registry record.
Missing-data handling is also not described. The arm-specific at-risk counts are reported, but the record does not explain why they differ, whether any participants lacked outcome information, or how missing observations were treated. It does not state whether follow-up was complete through 4 weeks for everyone included in the study, or how participants who discontinued were handled.
The analysis population is not specified. The registry does not say whether results use randomized assignment, treatment received, or another population definition. Nor does it report how participants were assigned to denominators or whether any exclusions occurred before analysis. These details affect how the counts should be interpreted, particularly when they are used to compare randomized groups.
No analyses are listed in the registry, and a detailed statistical plan is not reported. Consequently, there is no documented basis for determining how multiplicity, missing outcomes, or analysis populations were addressed. Absence of these details in the registry should be read as information not reported in the registry record, rather than evidence that a particular method was or was not used.
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 |
|---|---|---|---|
| 4.5g SXB | 1 | 32 | 3.1% |
| 4.5g SXB + 6 Tablets | 0 | 33 | 0.0% |
| 6g SXB | 1 | 31 | 3.2% |
| 6g SXB + 8 Tablets | 0 | 33 | 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 |
|---|---|
| 4.5g SXB | 12 of 32 |
| 4.5g SXB + 6 Tablets | 13 of 33 |
| 6g SXB | 11 of 31 |
| 6g SXB + 8 Tablets | 17 of 33 |
Most frequent serious adverse event terms
| Event term | Organ system | 4.5g SXB | 4.5g SXB + 6 Tablets | 6g SXB | 6g SXB + 8 Tablets |
|---|---|---|---|---|---|
| Diverticulitis | Infections and infestations | 1 of 32 | 0 of 33 | 0 of 31 | 0 of 33 |
| Suicidal Behavior | Psychiatric disorders | 0 of 32 | 0 of 33 | 1 of 31 | 0 of 33 |
| Major Depression | Psychiatric disorders | 0 of 32 | 0 of 33 | 1 of 31 | 0 of 33 |
Most frequent non-serious adverse event terms
| Event term | Organ system | 4.5g SXB | 4.5g SXB + 6 Tablets | 6g SXB | 6g SXB + 8 Tablets |
|---|---|---|---|---|---|
| Nausea | Gastrointestinal disorders | 4 of 32 | 3 of 33 | 2 of 31 | 7 of 33 |
| Dizziness | Nervous system disorders | 3 of 32 | 1 of 33 | 4 of 31 | 2 of 33 |
| Headache | Nervous system disorders | 2 of 32 | 3 of 33 | 2 of 31 | 3 of 33 |
| Insomnia | Psychiatric disorders | 2 of 32 | 3 of 33 | 0 of 31 | 3 of 33 |
| Edema Peripheral | General disorders | 1 of 32 | 2 of 33 | 1 of 31 | 1 of 33 |
| Back Pain | Musculoskeletal and connective tissue disorders | 1 of 32 | 0 of 33 | 2 of 31 | 2 of 33 |
| Vomiting | Gastrointestinal disorders | 0 of 32 | 1 of 33 | 1 of 31 | 2 of 33 |
| Fatigue | General disorders | 1 of 32 | 0 of 33 | 0 of 31 | 3 of 33 |
| Sinusitus | Infections and infestations | 0 of 32 | 1 of 33 | 1 of 31 | 2 of 33 |
| Anxiety | Psychiatric disorders | 1 of 32 | 1 of 33 | 0 of 31 | 2 of 33 |
Serious events with the highest arm-level rate: suicidal behavior (3.2%), major depression (3.2%), diverticulitis (3.1%).
The serious adverse-event figures are participant counts, reported as affected participants among those at risk in each arm: 1 among 32 for 4.5g SXB, 0 among 33 for 4.5g SXB + 6 Tablets, 1 among 31 for 6g SXB, and 0 among 33 for 6g SXB + 8 Tablets. These figures describe the registry’s recorded results over the stated 4-week timeframe. They do not indicate the number of separate event occurrences, and the record does not provide event-level timing or participant-level detail.
The registry also lists Suicidal Behavior and Major Depression at 3.2% each, and Diverticulitis at 3.1%, as frequent serious-event terms. The registry entries recorded do not identify which arm each term belongs to, so these percentages should not be assigned to individual regimens. Death counts are not reported in the registry record.
General: A serious-event count is not a complete measure of safety. Interpretation can depend on event definitions, duration of observation, completeness of reporting, and the number of participants observed. These arm-level counts are descriptive; no statistical uncertainty or comparative analysis is reported. They should not be treated as proof that a regimen is safer or less safe than another.
12. What the Result Does, and Does Not, Mean
The record describes a randomized, single-blinded study in subjects with fibromyalgia, with safety and tolerability assessed over 4 weeks. It reports counts of participants affected by serious and other adverse events in each arm. The counts provide a compact account of what was recorded, and the listed serious-event terms provide additional descriptive information.
They do not establish whether differences among the arm counts are due to the regimens, random variation, or other factors. The registry provides no statistical comparisons, confidence intervals, or p-values for these results. It also does not report a single primary contrast, a detailed analysis population, or enough information about missing outcomes and denominators to assess those issues. The arm-level counts should therefore be read as descriptive findings rather than evidence of a statistically established difference.
General: A clinical trial’s observed results answer the question defined by its participants, treatment regimens, outcome definitions, and follow-up. They do not automatically apply to people or settings outside that study. Here, further eligibility details, the event-selection rules, and the analysis methods are not reported in the registry record, which limits assessment of how broadly to interpret the summaries.
The record also contains a model label of single-group alongside randomized allocation, arm descriptions, and results for several groups. That inconsistency remains unresolved in the registry. The distinction between oral solution and solution-plus-tablet regimens is described, but masking procedures and the discrepancy between arm descriptions and adverse-event group labels are not clarified.
Accordingly, the posted results show the recorded adverse-event counts for this study, not a complete comparative safety analysis. They do not establish a treatment effect, explain why any event occurred, or support a medical decision for an individual. The registry record does not report enough inferential or methodological detail to make those broader conclusions.
13. Why This Trial Matters Statistically
This study illustrates why safety results need both a clear outcome definition and a clear analysis plan. A label such as “most frequent adverse events” can cover multiple event types, while the registry’s arm-level summaries distinguish serious events from other events. Without a prespecified definition of which events are included, how frequency is determined, and how categories are handled, readers cannot tell whether the listed summaries represent the full intended endpoint or selected components of it.
It also illustrates the difference between descriptive counts and statistical evidence of a group contrast. Counts and at-risk denominators convey what was recorded in each arm, but they do not quantify uncertainty or establish that any observed variation is more than sampling variability. The registry reports no analyses, so the information does not support an inferential comparison.
The record’s combination of randomized allocation, multiple arm descriptions, and a single-group model label highlights the importance of consistent design metadata. Clear reporting of randomization, masking, analysis populations, denominators, and missing outcomes helps readers understand what was compared and which participants contributed to each result. Those details are not fully.
Finally, safety interpretation depends on more than a list of event counts. Event definitions, severity classification, follow-up completeness, and treatment of multiple event categories all matter. This record offers useful descriptive information about participant counts and selected serious-event terms, while also showing the limits of registry summaries when the statistical and operational details are sparse.
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 registry’s model is recorded as single-group even though the allocation is randomized and results are reported for several arms. This inconsistency makes the formal design description less clear. The record does not explain the discrepancy or specify the randomization procedure and allocation ratio.
Masking is listed as single, but the record does not identify who was masked or how the masking was maintained. The arm descriptions refer to placebo tablets, whereas the adverse-event group labels refer to tablets; the record does not clarify the difference. This limits precise understanding of the treatment regimens as represented in each part of the record.
The primary outcome is a summary of the most frequent adverse events per arm, but no selection rule or complete event definition is reported. The results give participant counts at risk and affected, but do not explain the differing denominators. Event-level details, including timing and recurrence, are not reported in the registry record.
No statistical analyses are listed. There are no reported confidence intervals, p-values, adjusted estimates, or stated analysis population for these outcomes. Multiplicity procedures, missing-data handling, reasons for different denominators, and follow-up completeness are also not reported. The registry does not provide a sample-size justification or explain whether interim analyses were planned or conducted.
These limitations restrict the results to a descriptive reading of the posted counts. They do not show that the study lacked additional procedures; those details are simply not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety and Tolerability Study Comparing Sodium Oxybate Given as an Oral Solution to a Single-blinded Combination of Oral Tablets Plus Oral Solution in Subjects With Fibromyalgia — NCT00803023.
- Registry record last updated 2011-08-19; status last verified 2011-08.
- Results first posted 2011-08-16.
- 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
NCT00803023 is recorded as a completed Phase 3 randomized, single-blinded study of sodium oxybate regimens in subjects with fibromyalgia. Enrollment was 129, with a recorded start of 2010-03 and primary completion of 2010-07. The stated study purpose was to compare safety and tolerability over 4 weeks.
The primary outcome summarizes the most frequent adverse events by arm. The registry reports counts of participants affected by serious and other adverse events, and lists selected serious-event terms. It records two outcome measures and no analyses. A single-group model label appears alongside the randomized, multi-arm descriptions, and this inconsistency is not explained. Statistical comparisons, analysis populations, missing-data methods, and a detailed statistical plan are not reported in the registry record.