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 Fish Oil Versus Statins Versus Placebos in Reducing Atrial Fibrillation in Patients Undergoing Thoracic Surgery for Lung Cancer (NCT01259284), a randomized phase 2, phase 3 study. The primary outcome is Incidences of Atrial Fibrillation During First 4 Days After Lung Resection.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01259284 |
| Phase | Phase 2, Phase 3 |
| Condition | Advanced Cancers |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Triple |
| Enrollment | 2 |
| Arms in the primary outcome | n/a |
| Lead sponsor | M.D. Anderson Cancer Center |
| Results posted | Yes |
2. Clinical Question
Population
Patients with lung cancer undergoing lung resection. The registry record lists the condition as advanced cancers and describes the intended population as people having lung surgery for lung cancer. It does not report further eligibility details in the record.
Intervention
Atorvastatin, taken as 1 capsule daily with 3 placebo capsules twice a day, orally, for 5 days pre-surgery; or fish oil supplement, taken as 3 capsules twice a day with 1 placebo capsule daily, orally, for 5 days pre-surgery.
Comparator
Placebo, taken as 4 capsules orally every morning and 3 every evening for 5 days pre-surgery. The record describes three arms but does not report an allocation ratio.
Primary question
Whether atorvastatin or fish oil supplements could reduce new-onset sustained or clinically significant atrial fibrillation during the first 4 days after lung resection, and whether either intervention differed from the other. No comparative answer is available because the study ended without an analysis of the primary outcome.
3. Trial Design
The registry record describes a randomized, triple-masked, parallel-group study, listed as phase 2 and phase 3. The planned groups were atorvastatin, fish oil supplement, and placebo. The record identifies M.D. Anderson Cancer Center as the sponsor. The stated enrollment was 2 participants. The study status is terminated; the recorded start is 2011-01 and primary completion is 2011-09.
The treatment schedules were designed to use capsules before surgery. The atorvastatin arm received 1 atorvastatin capsule daily plus 3 placebo capsules twice a day, orally, for 5 days pre-surgery. The fish oil arm received 3 fish oil capsules twice a day plus 1 placebo capsule daily, orally, for 5 days pre-surgery. The placebo arm received 4 capsules orally every morning and 3 every evening for 5 days pre-surgery. These descriptions establish the recorded schedules, but do not give additional details about adherence or treatment received by each enrolled participant.
Triple masking indicates that the registry record labels the study as masked at three levels, but it does not identify the people or roles covered by masking. The allocation procedure beyond randomization, including how the sequence was generated or concealed, is not reported in the registry record. The intended primary outcome population was per protocol. The record states that no analysis was conducted because the number enrolled was inadequate, resulting in early termination. It does not report a completed comparison among the groups, so the design description should not be mistaken for evidence that the planned comparison was carried out.
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: The study was terminated with only 2 participants enrolled. The inability to find participants was predominantly due to current or recent use of statins or fish oils.
Overall Study
| Stage | Atorvastatin | Fish Oil Supplement | Placebo |
|---|---|---|---|
| STARTED | 2 | 0 | 0 |
| COMPLETED | 0 | 0 | 0 |
| NOT COMPLETED | 2 | 0 | 0 |
Reasons for not completing this period:
| Reason | Atorvastatin | Fish Oil Supplement | Placebo |
|---|---|---|---|
| Study Termination | 2 | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: Analysis was to be per protocol. There is no analysis due to an inadequate number of enrolled participants in study which resulted in early termination.
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 | Atorvastatin | Fish Oil Supplement | Placebo | Total |
|---|---|---|---|---|---|
| Participants analysed | 2 | 0 | 0 | 2 | |
| Age Continuous | years | 69 (68 to 70) | — | — | 69 (68 to 70) |
| Gender: Female | participants | 2 | — | — | 2 |
| Gender: Male | participants | 0 | — | — | 0 |
| Region of Enrollment: United States | participants | 2 | — | — | 2 |
6. Primary Endpoint
The registry lists the primary outcome as Incidences of Atrial Fibrillation During First 4 Days After Lung Resection, measured over Baseline to 4 days post surgery.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint was the incidence of atrial fibrillation during the first 4 days after lung resection, with the stated timeframe extending from baseline to 4 days post surgery. The registry definition covers new-onset sustained atrial fibrillation lasting 15 min or >, or atrial fibrillation considered clinically significant because it required intervention. The definition is attributed to the American College of Cardiology and American Heart Association Physician Consortium.
This endpoint captures postoperative rhythm events using duration and clinical-significance criteria. In general, a prespecified clinical endpoint helps define what events count toward a trial’s main question; the exact definition matters because different thresholds can classify events differently. Here, sustained events and events requiring intervention were both included, even if they did not meet the same criterion. The endpoint concerns occurrence during a specified postoperative period rather than a longer-term outcome.
The registry record does not report endpoint results or an analysis. It also does not provide a numerical endpoint unit, parameter, or dispersion measure. Consequently, the posted results cannot establish how many qualifying events occurred across the planned groups or quantify a treatment contrast. The record notes that the outcome was not reduced to one comparison because it had several categories or time points. The definition is available, but a single analyzed estimate is not.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central interpretive fact is that only 2 participants enrolled and the study was terminated early. The registry record explicitly says that there was no analysis because the number enrolled was inadequate. Therefore, the primary outcome does not have a reported treatment-effect estimate, confidence interval, or significance test in this record. There is no statistical basis in the posted outcome record for ranking atorvastatin, fish oil, and placebo on atrial fibrillation incidence.
This is not a result showing that the interventions had equal effects, nor is it a result showing that either intervention increased or reduced atrial fibrillation. Those conclusions would require outcome information and a comparative analysis. Instead, the trial record documents an intended comparison that did not yield an analyzed primary outcome. The absence of an estimate is distinct from an estimate near no difference: the former leaves the comparative effect unquantified.
Precision is also not assessable from the primary outcome record. A confidence interval describes a range of values compatible with an estimate under a statistical model and its assumptions. Since no primary outcome estimate is reported, there is no interval to interpret for this comparison. Likewise, no reported p-value can be used to assess compatibility with a null hypothesis. A small enrollment alone does not supply an effect estimate or its uncertainty.
The registry record indicates a per-protocol analysis was intended, but reports no analysis due to inadequate enrollment and early termination. It does not provide an analyzed population, an account of outcome data for the enrolled participants, or an estimated event rate. No conclusions about comparative efficacy can be drawn from the stated study design, the planned endpoint, or the treatment schedules alone.
The adverse-event information is separate from the primary outcome. The safety summaries list participants at risk and affected by serious and other adverse events by group, but those entries do not replace an atrial fibrillation analysis. Group counts with no participants at risk cannot be read as evidence of no risk. Nor does a serious adverse event entry by itself establish that a treatment caused the event. The record’s safety reporting needs to be interpreted as descriptive registry information, with the limited enrollment and missing outcome analysis in view.
Any broader statistical interpretation must remain bounded by the record: randomized parallel groups were planned, but no comparative endpoint result is reported. There is no basis to estimate the size, direction, or precision of a treatment difference, and no basis to characterize the trial as a positive or negative efficacy test.
9. Statistical Methods Explained
The design labels describe the intended framework rather than an analysis result. Randomization assigns participants to study groups using a chance-based process; in general, this is intended to reduce systematic differences between groups at assignment. The record identifies the design as randomized, parallel, and triple-masked. It does not describe the random sequence method, allocation concealment, or which study roles were masked. Those details are not reported in the registry record and should not be inferred from the labels.
In a parallel-group design, participants are assigned to a group and followed under that group’s intervention. The record names three groups: atorvastatin, fish oil supplement, and placebo. It does not report the allocation ratio or group enrollment as part of the primary outcome analysis. The safety entries list participants at risk by group, but do not provide a completed efficacy comparison. The intended per-protocol population refers to participants analyzed according to the protocol’s requirements; the requirements themselves and the final analysis population are not reported in the registry record.
What would an endpoint comparison estimate?
In general, a comparison of event outcomes would summarize how often the defined endpoint occurred in each group and estimate a contrast between groups. Depending on the statistical plan and outcome structure, such a contrast could be expressed in different ways. The endpoint record has no reported estimate, event rate, or statistical comparison. No particular contrast measure or model is reported in the registry record, so none can be attributed to the study.
A confidence interval, in general, communicates the uncertainty around an estimate under the chosen analysis and assumptions. A narrower interval indicates greater precision than a wider interval, while the interval’s location indicates which effect values remain compatible with the data and model. Since the record reports no primary outcome analysis, there is no interval from which to assess precision or compatibility. A p-value, in general, measures how unusual the observed data would be under a specified null model; it does not measure the probability that a treatment is effective. No primary outcome p-value is reported in the registry record.
Why does the missing analysis matter?
The number enrolled was inadequate for the planned analysis, according to the registry record, and the study was terminated. Statistical estimates depend on observed outcome information. Without a reported analysis, readers cannot determine the frequency of qualifying atrial fibrillation in the groups, the size or direction of any contrast, or how uncertain a contrast would be. A design can state what investigators intended to compare, but it cannot substitute for observations and analysis.
The record does not report a statistical model, covariate adjustment, handling of repeated measurements, or a method for missing outcome data. These omissions matter because an analysis plan specifies how observations are converted into estimates and how incomplete information is handled. They do not establish that any particular method was or was not used outside what the registry record states; the record simply does not report those details.
How should planning illustrations be understood?
General sample-size calculations are planning tools. They use assumptions about the effect to detect, variability or event frequency, significance level, allocation, and analysis method to illustrate the amount of information a design might need. The planning note associated with this record describes a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. It specifies that time-to-event calculations use total events and other calculations use participants per arm.
Those assumptions are not a reported sample-size justification for the trial. The registry record does not report the trial’s own sample-size rationale. A planning illustration is not observed power: it does not tell readers what the completed study detected, and it cannot turn an unanalysed outcome into a treatment result. In particular, a planning calculation based on an effect does not provide an effect estimate from this trial. The record gives no analyzed primary outcome from which to judge the realized precision of the planned comparison.
In general, the significance level is a design or analysis convention governing a threshold for evaluating data under a specified test; it is not a measure of clinical importance. Equal allocation is an assumption about how participants are distributed between two groups for an illustration, not a report of the actual group allocation in this three-arm study. A normal approximation is a mathematical approach, whose suitability depends on the problem and data. Since the record does not report the trial’s actual analysis method, these illustration assumptions should not be presented as its efficacy-analysis plan.
Over-dispersion is a general issue that can arise when observed variability exceeds what a statistical model assumes, potentially making uncertainty estimates too small if it is ignored. The registry record does not report a model or variance estimate for the endpoint, so over-dispersion cannot be assessed for this trial. More generally, statistical methods need observed data and a defined estimand; method descriptions alone do not establish a result.
10. Multiplicity, Missing Data and Analysis Populations
The primary outcome record indicates that the outcome had several categories or time points and was not reduced to one comparison. This is important because multiplicity arises when more than one outcome, time point, subgroup, or statistical test is considered. In general, multiple opportunities to identify a result can raise the chance of at least one apparently noteworthy finding under a null situation. Statistical plans may address multiplicity by defining a primary contrast, ordering tests, or adjusting interpretation. No multiplicity strategy is reported in the registry record.
The record identifies a per-protocol analysis as intended, but says there was no analysis because enrollment was inadequate and the study ended early. It does not report an analysis population actually used, how participants were assigned in an efficacy analysis, or whether an intention-to-treat analysis was planned or performed. The meaning of per protocol depends on eligibility and adherence rules, which are not reported.
Handling of missing outcome data is also not reported in the registry record. It does not describe whether all enrolled participants had endpoint assessment, how incomplete assessments were treated, or whether any imputation or sensitivity analysis was planned. These points cannot be resolved by the enrollment total or by the safety summaries.
Interim analyses, stopping boundaries, and other monitoring procedures are not reported in the registry record. Early termination is recorded, and the reason given is inadequate enrollment; it should not be interpreted as evidence of a favorable or unfavorable interim efficacy result. The record also does not state whether the endpoint definition or analysis plan changed. Without these details and without an outcome analysis, readers cannot assess how multiplicity, missingness, or analysis-population choices might have affected a comparative result.
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 |
|---|---|---|---|
| Atorvastatin | 2 | 2 | 100.0% |
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 |
|---|---|
| Atorvastatin | 2 of 2 |
| Fish Oil Supplement | 0 of 0 |
| Placebo | 0 of 0 |
Most frequent serious adverse event terms
| Event term | Organ system | Atorvastatin | Fish Oil Supplement | Placebo |
|---|---|---|---|---|
| decreased hemoglobin | Blood and lymphatic system disorders | 2 of 2 | 0 of 0 | 0 of 0 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Atorvastatin | Fish Oil Supplement | Placebo |
|---|---|---|---|---|
| Pain in extremity | General disorders | 1 of 2 | 0 of 0 | 0 of 0 |
| hypotension | Blood and lymphatic system disorders | 1 of 2 | 0 of 0 | 0 of 0 |
| atrial fibrillation | Cardiac disorders | 1 of 2 | 0 of 0 | 0 of 0 |
| nausea | Gastrointestinal disorders | 1 of 2 | 0 of 0 | 0 of 0 |
| dyspnea | Respiratory, thoracic and mediastinal disorders | 1 of 2 | 0 of 0 | 0 of 0 |
| fatigue | General disorders | 1 of 2 | 0 of 0 | 0 of 0 |
| anorexia | Gastrointestinal disorders | 1 of 2 | 0 of 0 | 0 of 0 |
Serious events with the highest arm-level rate: decreased hemoglobin (100.0%).
The serious-adverse-event summary lists 2 participants at risk and 2 affected in the atorvastatin group. For fish oil supplement and placebo, it lists 0 participants at risk and 0 affected. The summary for other adverse events has the same group counts: 2 at risk and 2 affected for atorvastatin, and 0 at risk and 0 affected for each of the other groups.
Counts of 0 at risk do not provide a meaningful opportunity to observe events in those groups and should not be read as evidence that the interventions had no adverse events. The record identifies decreased hemoglobin as the top serious-event term, listed as 100.0%. The denominator and detailed basis for that percentage are not reported in the registry record, so it should be read as the registry’s displayed summary rather than expanded into a count or causal claim. Death counts are not reported in the registry record.
These are descriptive safety entries, not a comparative safety analysis. With 2 participants enrolled overall and no primary outcome analysis, the counts cannot establish relative safety or determine whether an event was caused by an intervention. The registry record does not provide further event-level detail or a statistical comparison of adverse events.
12. What the Result Does, and Does Not, Mean
The record describes a randomized comparison of atorvastatin, fish oil supplement, and placebo for preventing or reducing postoperative atrial fibrillation after lung resection in patients with lung cancer. It specifies the primary endpoint definition and the intended per-protocol analysis. It also records that the study enrolled 2 participants, was terminated, and had no analysis because enrollment was inadequate.
That combination means the intended clinical question remains unanswered by the posted primary outcome results. There is no reported estimate of atrial fibrillation incidence by group, no treatment contrast, and no uncertainty interval. As a result, the record cannot establish whether the groups differed or how large any difference might have been. It also cannot support a conclusion that the interventions were equivalent, because equivalence requires a defined margin and an analysis that is sufficiently informative to assess it; neither is reported.
The absence of an analyzed outcome is not evidence for a null effect. It is a lack of an estimate. Similarly, the fact that the study was randomized does not by itself guarantee that a reliable comparison can be made when the planned analysis did not occur. Randomization describes how allocation was intended to work, while conclusions depend on observed outcomes and an analysis appropriate to the question.
The safety entries can describe what the registry record lists, but they do not fill the efficacy gap. With no participants at risk listed for fish oil and placebo in the safety summary, zero affected in those groups does not establish absence of adverse events. The atorvastatin entries and the listed serious-event term also do not establish causality or comparative risk.
Accordingly, this record is most informative about the planned design, endpoint, and reason no primary analysis is available. It does not provide evidence for a treatment effect, a precise estimate, or a definitive safety comparison. Any interpretation should keep that distinction between a planned trial question and an analyzed result clear.
13. Why This Trial Matters Statistically
This study illustrates why the distinction between trial design and trial result matters in clinical research. A randomized, masked, parallel design can be intended to support a fair comparison, but the design alone does not answer the clinical question. The primary outcome must be observed and analyzed before readers can assess the direction, size, and precision of a difference. Here, the registry record says that enrollment was inadequate and no analysis was conducted.
The case also shows how endpoint definitions shape interpretation. The outcome includes new-onset sustained atrial fibrillation lasting 15 min or >, as well as clinically significant atrial fibrillation requiring intervention, during the first 4 days after surgery. This combination of duration and clinical significance criteria defines which events count. Without a reported event summary, however, a careful endpoint definition cannot yield a comparative estimate.
For biostatisticians and clinical researchers, the record highlights the importance of transparent reporting about analysis populations, missing data, multiplicity, and stopping procedures. Those details help readers understand how a planned question was translated into an analysis. Several of these methods are not reported in the registry record, and the absence of an endpoint analysis leaves no statistical result to interrogate.
Finally, low enrollment affects what can be learned, not only whether a significance threshold is crossed. Without an estimate and its uncertainty, readers cannot distinguish a small effect from a large but imprecisely measured effect. The record therefore serves as a useful example of a study whose documented design is clearer than its inferential yield: it records the intervention schedules and endpoint, but does not furnish an analyzed comparison.
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 most consequential trial-specific limitation is that only 2 participants enrolled, and the registry record states that inadequate enrollment led to early termination and no analysis. Consequently, the primary outcome has no reported group-specific event counts or treatment-effect estimate. The comparative question cannot be answered from the outcome record.
The registry record identifies the intended analysis as per protocol but does not provide the rules defining that population or identify a population used in a completed analysis. It does not report how missing endpoint observations were handled, whether any participants lacked endpoint data, or whether sensitivity analyses were planned. The actual allocation ratio and group enrollment for the efficacy analysis are not reported.
The outcome was recorded with several categories or time points and was not reduced to one comparison. The statistical plan for selecting or interpreting comparisons, including any multiplicity approach, is not reported. The model, covariate adjustment, interim monitoring, and stopping procedures are also not reported in the registry record. These omissions limit assessment of how the intended analysis would have been carried out; they do not justify assumptions about methods that may have been used elsewhere.
The safety summary has limited interpretability because the fish oil and placebo groups each list 0 participants at risk. The record does not provide a detailed explanation of the percentage attached to decreased hemoglobin or report death counts. It also does not describe the randomization sequence, allocation concealment, or which roles were masked. Taken together, these limitations mean that the record documents the study’s plan and early termination more fully than it documents comparative outcomes.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Fish Oil Versus Statins Versus Placebos in Reducing Atrial Fibrillation in Patients Undergoing Thoracic Surgery for Lung Cancer — NCT01259284.
- Registry record last updated 2012-08-07; status last verified 2012-07.
- Results first posted 2012-08-01.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
The registry record describes a randomized, triple-masked, parallel study listed as phase 2 and phase 3, comparing atorvastatin, fish oil supplement, and placebo before lung resection in patients with lung cancer. The primary outcome was new-onset sustained or clinically significant atrial fibrillation during the first 4 days after surgery.
The recorded enrollment was 2. The study is listed as terminated, with a start of 2011-01 and primary completion of 2011-09. The registry record states that inadequate enrollment resulted in early termination and that no primary outcome analysis was conducted. It therefore reports no comparative efficacy estimate or measure of its precision. Safety entries are descriptive and include groups with 0 participants at risk. The record supports a description of the intended design and endpoint, but not a conclusion about comparative treatment effects.