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 Decreasing Risk of Coronary Artery Disease in Schizophrenia by Omega-3 Fatty Acid Supplementation (NCT00167310), a randomized phase 2 study. The primary outcome is Plasma Levels of Triglycerides and Lipoprotein Cholesterol.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00167310 |
| Phase | Phase 2 |
| Condition | Schizophrenia, Schizoaffective Disorder, Major Depression |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 57 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Pittsburgh |
| Results posted | Yes |
2. Clinical Question
Population
The study description concerns clinically stable people with schizophrenia or schizoaffective disorder, major depression, or bipolar disorder in the depressed phase, who were being treated with lipid-lowering drugs. The registry lists schizophrenia, schizoaffective disorder, major depression, bipolar disorder, and coronary artery disease as conditions. It does not report the detailed eligibility criteria or how many participants had each diagnosis.
Intervention
The active regimen was eicosapentaenoic acid, an omega-3 fatty acid, described as 2 g daily in 4x500 mg softgels. The study description also refers to antipsychotic treatment selected by the participant’s doctor. The record describes assessments at baseline, 1 month, 2 months, and 4 months.
Comparator
The comparison group received placebo described as soybean oil, also 2 g daily in 4x500 mg softgels, alongside antipsychotic treatment selected by the doctor. The study was randomized, and masking was quadruple.
Primary question
The intended question was whether omega-3 supplementation was associated with changes in plasma triglycerides and selected lipoprotein cholesterol measures at 4 months. The registry names plasma triglyceride levels as the population measure, while the outcome description includes triglycerides, small dense LDL cholesterol, large buoyant LDL cholesterol, and HDL2-cholesterol. Numerical comparisons for these measures are not reported in the registry record, so the record does not establish the direction or size of any observed difference.
3. Trial Design
This was a phase 2, randomized, quadruple-masked, parallel-group study. The registry reports enrollment of 57 and a completed status. The study start is listed as 2005-09, and primary completion as 2015-12. These dates describe the registry record; they do not supply details about recruitment duration, follow-up after the primary endpoint, or the timing of individual participant visits.
Participants were assigned to eicosapentaenoic acid or placebo. Both regimens were described as daily softgels, alongside antipsychotic treatment chosen by the participant’s doctor. The placebo was soybean oil. The study summary places treatment in the context of lipid-lowering therapy, such as statins, and describes a population with specified psychiatric diagnoses. Detailed eligibility criteria, the randomization procedure, allocation concealment, and the operational details of masking are not reported in the registry record.
The parallel design means that the assigned groups were intended to be compared with one another, rather than each participant serving as their own treatment comparison. The listed assessment schedule includes baseline, 1 month, 2 months, and 4 months. The primary outcome timeframe is 4 months. The record does not report the number of participants assigned to each group for the primary outcome, the number with measurements at each visit, or whether participants changed or stopped assigned treatment.
The study description addresses both coronary artery disease risk and illness severity, but the listed primary outcome is biochemical: plasma triglycerides and selected lipoprotein cholesterol fractions. A secondary outcome concerns cholesterol levels in various lipoprotein fractions. The registry lists two outcome measures, but provides no analysis results for either. Thus, design information identifies the intended comparison and measurements, while leaving the observed outcome effects unreported.
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 | Omega-3 Fatty Acid | Placebo |
|---|---|---|
| STARTED | 29 | 28 |
| COMPLETED | 21 | 18 |
| NOT COMPLETED | 8 | 10 |
Reasons for not completing this period:
| Reason | Omega-3 Fatty Acid | Placebo |
|---|---|---|
| Protocol Violation | 5 | 3 |
| Withdrawal by Subject | 3 | 7 |
Analysis population for the primary outcome, as defined in the registry: Plasma triglyceride levels
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.
Population: The participants withdraw voluntarily after signing the consent form.
| Characteristic | Unit | Omega-3 Fatty Acid | Placebo | Total |
|---|---|---|---|---|
| Participants analysed | 28 | 24 | 52 | |
| Age, Continuous | years | 56 (SD 8) | 54 (SD 8) | 55 (SD 8) |
| Sex: Female, Male: Female | Participants | 2 | 0 | 2 |
| Sex: Female, Male: Male | Participants | 26 | 24 | 50 |
| Region of Enrollment: United States | participants | 28 | 24 | 52 |
| Body Mass Index | kg/m^2 | 31 (SD 7) | 31 (SD 6) | 31 (SD 6) |
6. Primary Endpoint
The registry lists the primary outcome as Plasma Levels of Triglycerides and Lipoprotein Cholesterol, measured over 4 months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | mg/dL |
| Endpoint classification | Continuous Endpoint |
The primary outcome is titled “Plasma Levels of Triglycerides and Lipoprotein Cholesterol.” It is a continuous biochemical measure, with results intended to be expressed in mg/dL as means with standard deviations. The description names plasma triglycerides, small dense LDL cholesterol (LDL3- and LDL4-), large buoyant LDL cholesterol (LDL1- and LDL2-), and HDL2-cholesterol. The specified timeframe is 4 months, and plasma triglyceride levels are identified as the population measure.
These measures were selected to characterize blood lipids relevant to the study’s stated focus on coronary artery disease risk. General statistical context: a continuous endpoint retains information about the measured level, rather than reducing each participant to a yes-or-no event. A group mean describes the average level, while a standard deviation describes how spread out individual measurements are around that mean. Neither quantity alone describes the uncertainty in a comparison between group means.
The registry outcome is broader than a single biomarker comparison because it names several lipid measures. The record does not report their observed means, standard deviations, between-group estimates, confidence intervals, or p-values. It therefore does not show whether any measure changed over time or differed between assigned groups.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the trial’s intended primary outcome but does not report numerical primary-outcome results. It lists no outcome analyses, and its note indicates that the primary outcome includes several categories or time points rather than being reduced to one comparison. Consequently, there is no reported estimate of the difference between omega-3 fatty acid and placebo for plasma triglycerides or the named lipoprotein cholesterol fractions.
Without group-level measurements or a treatment-effect estimate, the direction and magnitude of the observed data cannot be described. The record also does not report confidence intervals or p-values for these outcomes. Statistical significance, precision, and compatibility with effects of different sizes therefore cannot be assessed from the registry record. This is not evidence that the groups had identical results, nor is it evidence that a difference was present; the relevant numerical comparisons are not reported.
Enrollment is reported as 57, but that figure alone does not show how many participants contributed to each outcome analysis. Group-specific outcome denominators, missing measurements, and analysis populations are not reported in the registry record. Without those details, the completeness of the endpoint data and the effect of missing observations cannot be evaluated.
The trial’s stated purpose included coronary artery disease risk and illness severity, but the named primary outcome is a set of biochemical measures. The record does not provide numerical clinical-event results, a reported analysis of illness severity, or a conclusion connecting lipid measurements to clinical outcomes. The listed secondary outcome concerns cholesterol levels in various lipoprotein fractions; its numerical findings are also not reported.
Accordingly, interpretation should remain limited to the design and outcome definitions: the study randomized participants to omega-3 fatty acid or placebo, and planned to measure blood lipids at 4 months. The registry record does not provide the evidence needed to characterize the treatment effect or its precision. No conclusion about benefit, lack of benefit, or clinical impact follows from the absence of posted outcome estimates.
9. Statistical Methods Explained
What does a mean represent?
The primary outcome is described as a mean of a continuous measure. In general, a mean is the arithmetic average of participant measurements within a group. It can be useful for summarizing a biomarker such as a plasma lipid level, but it does not show the full distribution: participants may have values clustered near the mean or spread widely around it. The registry specifies standard deviation as the dispersion measure. In general, a standard deviation describes variability among observations; it is not the same as the standard error, which describes uncertainty in an estimated mean.
The record does not give the group means or standard deviations for the primary outcome. Nor does it give a treatment-effect estimate comparing the assigned groups. Thus, the outcome’s intended summary format is known, but the posted record does not permit a numerical interpretation of the observed data.
How would a group comparison be interpreted?
General statistical context: a comparison of group means estimates how far apart the group averages are on the measurement scale. A confidence interval around that estimate expresses uncertainty in the estimate under the analysis assumptions. A narrower interval indicates greater precision, while a wider interval indicates less precision. A confidence interval is not a range containing every individual participant’s measurement, and it does not by itself establish clinical importance.
No confidence interval or comparison estimate is reported for the lipid outcomes. There is therefore no basis in the registry record for describing the magnitude, direction, or precision of a group difference. The absence of a reported estimate should not be read as a zero effect.
Why do several lipid measures matter?
The outcome description names triglycerides and several lipoprotein cholesterol fractions, and the registry note says the primary outcome has several categories or time points rather than one reduced comparison. General statistical context: when an analysis tests multiple outcomes or time points, the chance of at least one apparently unusual result can increase if each test is treated as an independent opportunity to declare a finding. Methods for handling multiplicity can include identifying a primary comparison in advance, adjusting inference across tests, or treating secondary results as exploratory. Which approach was planned for this study is not reported in the registry record.
The fact that several measures are listed does not reveal how they were analyzed or whether any multiplicity adjustment was used. The registry does not report test statistics or outcome estimates for the listed measures.
What does over-dispersion mean in general?
Over-dispersion is a concern for count outcomes when observed variability exceeds what a simple model assumes. It is not the central issue for the listed primary outcome, which is continuous and summarized by a mean and standard deviation. The safety figures are counts, but the registry does not report a model-based safety analysis. General statistical methods for sparse event counts may need to account for uncertainty and unequal exposure, but no such analysis is reported.
What can the planning description establish?
The registry describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. It also states that the effect to detect is expressed as a fraction of the observed effect and that non-time-to-event planning values are participants per arm. These are descriptions of planning assumptions, not trial results and not observed power. Numerical planning outputs, the observed effect used in those calculations, and the trial’s own sample-size justification are not reported in the registry record. The planning description does not establish what effect the trial was designed to detect or whether the achieved data were sufficiently precise.
In general, a sample-size calculation is conditional on its assumptions about the target effect, variability, significance level, power, allocation, and analysis. It is a planning tool, not a result. It should not be used as a substitute for the observed estimate and its uncertainty. The registry’s planning description does not report an interim-analysis approach or a statistical analysis plan.
10. Multiplicity, Missing Data and Analysis Populations
The primary outcome covers several biochemical categories, including plasma triglycerides and multiple lipoprotein cholesterol fractions. The registry explicitly indicates that the primary outcome has several categories or time points and was not reduced to one comparison. The record does not identify a single primary contrast among those measures or report how multiple comparisons were handled. It does not state whether a hierarchy of outcomes, an adjustment procedure, or an exploratory interpretation was planned. The statistical plan for multiplicity is not reported in the registry record.
The registry lists two outcome measures, including a secondary outcome concerning plasma cholesterol levels in various lipoprotein fractions. The relationship between the listed secondary outcome and the individual components of the primary outcome is not explained in the record. No numerical results or analysis details are reported for the secondary outcome.
Missing-data handling is also not reported in the registry record. There is no account of how many participants had measurements at 4 months, whether all randomized participants were included in the outcome analysis, how missing values were handled, or whether sensitivity analyses were conducted. Group-specific analysis populations and outcome denominators are not stated.
The record does not report whether the analysis followed intention-to-treat, per-protocol, or another population definition. It also does not report an analysis plan, interim analyses, covariate adjustment, or model specification. These omissions limit assessment of how the outcome data were selected and analyzed; they do not establish 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 |
|---|---|---|---|
| Omega-3 Fatty Acid | 0 | 28 | 0.0% |
| Placebo | 0 | 24 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 3% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Omega-3 Fatty Acid | 2 of 28 |
| Placebo | 1 of 24 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Omega-3 Fatty Acid | Placebo |
|---|---|---|---|
| Patient experiences mental problem | Psychiatric disorders | 1 of 28 | 1 of 24 |
| EKG report indicated sinus bradycardia with HR of 39. Patient asymptomatic. | Cardiac disorders | 1 of 28 | 0 of 24 |
The registry reports zero participants affected by serious adverse events in the omega-3 fatty acid group, with 28 participants at risk, and zero in the placebo group, with 24 participants at risk. It separately reports 2 participants with other adverse events in the omega-3 fatty acid group and 1 in the placebo group. These are the counts as recorded; the registry does not provide descriptions of the other events or their severity.
The at-risk figures are specific to the adverse-event entries. They should not be treated as the number of participants in the primary outcome analysis. The record reports enrollment of 57 but does not explain the difference between enrollment and the group-specific safety denominators. It also does not report exposure time, event timing, withdrawal due to adverse events, or a statistical comparison of safety outcomes.
Death counts are not reported in the registry record. No serious adverse-event terms are listed. Zero serious events reported in these entries is a description of the posted counts, not proof that no safety concerns could occur or that the groups were equivalent. Sparse event counts are imprecise, and no confidence intervals or adjusted safety analyses are reported.
12. What the Result Does, and Does Not, Mean
The record establishes that a randomized, quadruple-masked, parallel-group phase 2 study compared eicosapentaenoic acid with placebo in a population described as clinically stable and living with specified psychiatric disorders. It identifies plasma triglycerides and several lipoprotein cholesterol measures at 4 months as the primary biochemical outcome. This information clarifies the study question and the kinds of data the investigators intended to collect.
It does not establish the observed effect of omega-3 fatty acid on any named lipid measure. Numerical outcome values and comparisons are not reported in the registry record. Without those results, it is not possible to say whether the groups differed, in which direction, by how much, or with what precision. The absence of an outcome analysis is not evidence of no effect.
The study purpose mentions coronary artery disease risk and illness severity, but the record does not report results for clinical coronary events or illness severity. A biomarker measurement is not itself a reported clinical outcome, and no claim about clinical consequences can be drawn from the endpoint description alone.
The safety entries report zero serious adverse events in each group and a small number of other adverse events, but the event descriptions and fuller safety analyses are not reported. These counts do not establish equivalent safety, particularly without information about follow-up, exposure, and uncertainty.
Overall, the registry record supports a description of design, intended outcomes, and limited posted safety counts. It does not support a conclusion that the intervention did or did not change lipid levels or clinical risk. An estimate and its uncertainty, together with transparent information about analysis populations and missing data, would be needed to assess what the observed trial data indicate.
13. Why This Trial Matters Statistically
This study is statistically notable because its stated clinical aim spans both coronary artery disease risk and psychiatric illness severity, while the named primary outcome is biochemical. That distinction matters: a lipid measurement can address a biological or risk-marker question, but it is not interchangeable with a clinical event or a measure of illness severity. The registry record does not report numerical findings for either the lipid outcomes or those broader aims.
The primary outcome description includes multiple lipid measures. When a study considers several related outcomes, readers need to know which comparisons were primary and how multiplicity was addressed. Without a reported analysis plan or estimates, it is not possible to determine how the outcomes were prioritized or how the evidence should be interpreted across them.
The record also illustrates why study design information and outcome evidence are different kinds of information. Randomization and masking describe how a comparison was intended to be conducted; they do not provide the estimated treatment effect. Enrollment and a completed status likewise do not reveal the number of analyzed observations, the precision of results, or whether the data were complete.
Finally, planning calculations and observed findings answer different questions. A planning illustration is conditional on assumptions about an effect and a statistical method. It cannot replace a treatment-effect estimate with its uncertainty, and it is not observed power. In this record, the planning assumptions are described, while numerical outcome comparisons are not reported. This makes the distinction between a documented study design and an interpretable efficacy result especially important.
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 for statistical interpretation is that the registry record does not report numerical primary-outcome results or any outcome analyses. It therefore provides no group means, standard deviations, treatment-effect estimates, confidence intervals, or p-values for the lipid measures. The direction, size, and precision of any observed differences cannot be assessed.
The primary outcome is described across several lipid categories, but the record does not identify a single reported comparison or explain how the different measures were handled analytically. The multiplicity strategy is not reported. The number of outcome measures is listed, but no results are attached to them in the registry record.
The record reports enrollment but not group-specific primary-outcome sample sizes or the number of participants with measurements at the 4-month timeframe. It does not describe missing-data handling, analysis populations, adherence, treatment discontinuation, or any sensitivity analyses. These gaps prevent assessment of whether the analyzed data represent all randomized participants or how incomplete observations might affect interpretation.
Detailed eligibility criteria, the randomization procedure, allocation concealment, masking procedures, and the statistical analysis plan are not reported. The reported safety entries have limited detail: other adverse events are not characterized, deaths are not reported, and event timing and exposure are absent. These limitations concern what can be evaluated from the registry record; they do not establish that particular procedures or analyses were not conducted.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Decreasing Risk of Coronary Artery Disease in Schizophrenia by Omega-3 Fatty Acid Supplementation — NCT00167310.
- Registry record last updated 2017-04-10; status last verified 2017-02.
- Results first posted 2017-04-10.
- 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 describes NCT00167310, a completed phase 2 randomized, quadruple-masked, parallel-group study with enrollment of 57. It compared eicosapentaenoic acid with soybean-oil placebo, alongside antipsychotic treatment selected by the doctor. The study description concerns clinically stable participants with specified psychiatric diagnoses receiving lipid-lowering treatment.
The primary outcome was plasma triglycerides and selected lipoprotein cholesterol measures at 4 months, expressed as means and standard deviations in mg/dL. Numerical outcome comparisons and analyses are not reported in the registry record. Serious adverse events were reported for zero participants in each group; other adverse-event counts were 2 in the omega-3 fatty acid group and 1 in the placebo group. The record does not provide enough outcome detail to assess treatment effects or their precision.