Steroid Free Immunosuppression in Liver Transplantation: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Steroid Free Immunosuppression in Liver Transplantation (NCT00296244), a randomized phase 4 study. The primary outcome is Graft Survival Rate.

2. Clinical Question

The study’s stated purpose was to determine whether steroid-related complications can be avoided by using a steroid-free immunosuppressive drug regimen after liver transplantation. Its primary outcome, graft survival, addresses whether the graft is still working at the specified follow-up times. The listed secondary outcomes concern infection as an adverse effect of steroids, incidence and severity of HCV recurrence post-OLT, and new-onset diabetes mellitus.

The clinical question is therefore broader than whether the regimens differ on graft survival alone. It also concerns complications and other post-transplant outcomes. However, the registry record does not provide numerical results for the primary graft-survival comparison, nor does it provide comparative estimates for the listed secondary outcomes in the registry record for this analysis. The adverse-event counts can be described, but they do not by themselves answer whether either regimen changes graft survival or the risk of steroid-related complications.

3. Trial Design

The registry classifies this as a randomized, Phase 4 study with a factorial model and no masking. Enrollment is listed as 40. The study is marked completed. Its listed start is 2006-02 and its primary completion is 2008-05; these record dates do not supply details about each participant’s follow-up.

The two described regimens share Basiliximab, Tacrolimus, and EC-MPA. The study group is described as receiving those drugs without steroids, while the control group receives the same named drugs with steroids. The registry lists steroids, Basiliximab, Tacrolimus, and EC-MPA as interventions. Although the design classification says factorial, the meaning of the factorial structure, any factors beyond the described steroid contrast, and the allocation details are not reported in the registry record. The described arms alone do not establish how any factorial component was implemented.

Random allocation is relevant because, when implemented successfully, it can reduce systematic differences between groups at the start of a trial. The record does not state the randomization method, allocation concealment procedures, or whether any stratification was used. With no masking, participants and study personnel were not masked according to the registry’s classification; whether outcome assessors were masked is not reported in the registry record.

The sponsor is Thomas Jefferson University. The registry lists liver cirrhosis and liver transplant disorder as conditions. It identifies graft survival rate, expressed as a percentage of participants, as the primary outcome at 1 and 2 years. It also lists three secondary outcome topics related to infection, HCV recurrence, and new-onset diabetes mellitus. The registry record does not report a detailed protocol, full eligibility criteria, treatment duration, adherence information, or the statistical analysis plan.

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 recipient in the Steroid free group required re-transplantation and died within 1 month after the 2nd OLT, and was subsequently excluded from analysis.

Overall Study

Reasons for not completing this period:

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.

6. Primary Endpoint

The registry lists the primary outcome as Graft Survival Rate, measured over 1 and 2 years.

The primary endpoint is graft survival rate: the percentage of recipients whose liver grafts are still working at the end of 1 and 2 years. It is intended to describe graft status at specified follow-up times, rather than to report a measure of symptom change or a laboratory value. The registry does not define a more detailed operational rule for deciding whether a graft is still working.

Graft survival is used in transplant research because continued graft function is a direct outcome of the transplant. Reporting a percentage at stated follow-up times can make the outcome understandable as the proportion of recipients meeting the endpoint at each time. In general, such percentages are most informative when accompanied by the number assessed, a clear definition of the endpoint, and a measure of uncertainty. Those details are not all available in the registry record summarized for this analysis.

The record names 1 and 2 years as time points, but no percentages, group-specific denominators, confidence intervals, or statistical test results for graft survival are reported. The outcome is also not reduced to one comparison because it includes multiple time points. Consequently, the endpoint definition can be described, but the size and precision of any difference between the regimens cannot be assessed from the available primary-outcome information.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes the primary outcome as a percentage of participants whose grafts are still working at 1 and 2 years. That is a binary outcome at each stated time point: each assessed recipient is classified according to whether the graft meets the working-status definition at that time. The record does not provide the participant-level definition or the actual counts and percentages for this outcome. It also does not provide a statistical test or effect estimate for the primary comparison.

What a percentage can and cannot show

A percentage summarizes the share of a group meeting an outcome definition. Its interpretation depends on knowing the denominator: the participants included in that calculation. In general, a percentage alone does not show how much uncertainty surrounds the estimate. A confidence interval is a way to express uncertainty around an estimated quantity; it gives a range of values compatible with the data and the assumptions of the method. The registry record does not report confidence intervals for the primary endpoint, so the precision of the graft-survival estimates cannot be evaluated.

The endpoint is recorded at 1 and 2 years. In general, measurements at multiple time points can answer distinct questions about status at each time, but they also require a clear plan for reporting and interpreting each assessment. The registry does not state whether the time points were treated as separate primary comparisons, whether one was prioritized, or how any multiplicity was handled. Since no numerical graft-survival results are reported, neither time-specific estimates nor their relationship to one another can be evaluated.

Randomization and comparisons

Randomized allocation is intended to make treatment groups comparable, on average, with respect to factors measured and unmeasured at baseline. This is a design principle, not a guarantee that groups will be identical in a particular trial. The registry says allocation was randomized but does not report the sequence-generation method, allocation concealment, stratification, or details of analysis by assigned group. The lack of masking is recorded; further details about masking of outcome assessors are not reported in the registry record.

A comparative analysis would ordinarily communicate the outcome in each group and an effect estimate, such as a difference between group percentages, with an uncertainty interval. No such graft-survival comparison is available in the record used for this analysis. No comparison should therefore be reconstructed from the adverse-event counts, since those are different outcomes and do not provide the missing graft-survival information.

Planning illustrations and observed results

The registry information describes planning illustrations based on an observed effect, using a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. The effect to detect is stated as a fraction of the observed effect. For time-to-event outcomes, the planning convention gives the total number of events using the Schoenfeld method; other outcomes use participants per arm. These are hypothetical planning quantities, not observed trial results and not observed power.

A planning calculation based on an observed effect answers a conditional question: how large a future study might need to be under the chosen assumptions to detect an effect of the specified size. It does not show that the current trial was adequately powered, and it does not turn an imprecise or unreported effect into evidence of a treatment difference. The registry does not report the trial’s own sample-size justification or the assumptions used when it was designed. In addition, the primary endpoint has multiple time points and is not reduced to one comparison in the record. Any planning illustration should therefore be kept distinct from the primary results and interpreted only in light of its stated assumptions.

Over-dispersion and binary outcomes

For a binary outcome, the observed proportion can vary from one sample to another. General statistical models may account for additional variability beyond what a simple model expects; this is often called over-dispersion. Accounting for such variability can affect uncertainty estimates and tests. The registry does not state that an over-dispersion adjustment, a particular model, or any model-based analysis was used. It would be inappropriate to attribute such a method to this study.

Likewise, the registry’s factorial classification does not by itself reveal which statistical model was used or whether an interaction was assessed. A factorial design may include more than one treatment factor, and interpretation depends on how factors and their combinations are defined and analyzed. The registry provides two arm descriptions centered on the presence or absence of steroids, but does not detail the factorial structure or analysis. No specific factorial effect or interaction can be inferred from the classification alone.

The registry lists 0 analyses. This is a description of the analyses recorded in the registry information, not proof that investigators conducted no analyses. In the absence of posted analysis results, the statistical interpretation is limited to the design labels, endpoint definition, and descriptive adverse-event summaries that are recorded.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 6 outcome measures, including the primary graft-survival outcome at 1 and 2 years and secondary topics of infection, HCV recurrence, and new-onset diabetes mellitus. Considering multiple outcomes or time points can raise multiplicity: when several statistical questions are tested, the chance of at least one apparently notable result can increase. General approaches include prioritizing outcomes in advance or adjusting interpretation for multiple tests. The registry record does not report a multiplicity strategy, a hierarchy among secondary outcomes, or which comparisons were designated for formal testing.

The registry lists 0 analyses. No analysis-level results, confidence intervals, or p-values are reported in the available record. The statistical methods for the primary endpoint and secondary outcomes are not reported in the registry record. It is therefore not possible to determine how the investigators handled multiple outcome measures or whether any reported analysis was prespecified.

Missing-data handling and analysis populations are also not reported in the registry record. There is no description of participant flow, withdrawals, exclusions, or the number assessed for graft survival at either time point. The adverse-event summaries use denominators of 20 for the control group and 19 for the study group, while enrollment is listed as 40. These figures alone do not identify why the denominators differ or whether participants were missing from any other outcome assessment. They should not be treated as evidence of a particular exclusion or missing-data mechanism.

In general, missing outcomes can affect estimates if the people without recorded outcomes differ systematically from those with data. Assessing that possibility requires information about follow-up and reasons for missingness, which is not reported. The record also does not state whether analyses followed randomized assignment, included only participants who received treatment, or used another analysis population.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: death (15.8%).

The registry reports serious adverse events affecting 2 of 20 participants in the control group and 3 of 19 in the study group. It also reports other adverse events affecting 16 of 20 in the control group and 17 of 19 in the study group. These are participant counts and denominators as recorded for the two groups. The figures are descriptive; the registry record does not provide an adjusted comparison, uncertainty interval, or statistical test for these adverse-event summaries.

The record lists Death as a top serious term at 15.8%. The denominator and group attribution for this percentage are not reported in the registry information available for this analysis. It therefore should not be interpreted as a group-specific percentage or converted into a number of participants. A term listing also does not establish the cause of the event or whether it was judged related to a treatment.

Serious and other adverse-event summaries should be kept distinct from the primary graft-survival outcome. The record does not specify event definitions, severity grading procedures, timing, overlap between participants with events, or attribution rules. Without those details, the counts describe the registry’s reported categories but do not establish comparative safety or causation.

12. What the Result Does, and Does Not, Mean

The registry record establishes the clinical question, the described treatment groups, and the primary endpoint: graft survival at 1 and 2 years. It also reports adverse-event counts for the two groups. These details describe what the trial was intended to examine and provide limited descriptive safety information.

What the record does not establish is the comparative result for graft survival. No group-specific graft-survival percentages or statistical analysis of that endpoint are reported. The direction and size of any difference, and how precisely it was estimated, cannot be determined. The secondary outcomes are named, but their comparative results are not reported in the registry record. The adverse-event counts do not fill those gaps and cannot be used to infer an effect on graft survival, infection, HCV recurrence, or new-onset diabetes mellitus.

Randomization is an important design feature, but a randomized label alone does not give the result or its precision. Interpretation requires outcome data, an analysis that matches the design, and details on follow-up and missing data. These are not fully reported in the record. Similarly, a completed status does not itself show whether the study met its aims or what the results were.

The record’s enrollment of 40 is a study-level count, while the adverse-event summaries use group denominators of 20 and 19. Those quantities should not be conflated: the adverse-event denominators describe the reported summaries, and the reason for the difference from enrollment is not reported. No conclusions about participant losses or analysis populations follow from those counts alone.

In short, the posted information supports a description of the trial and of the recorded adverse-event counts, but not a conclusion about whether the regimens differed on graft survival or other clinical outcomes. The absence of a reported estimate is not evidence that the groups were the same; it means the comparative result and its uncertainty are unavailable in the registry record.

13. Why This Trial Matters Statistically

This trial illustrates why a clearly named endpoint and a reported treatment comparison are both necessary for statistical interpretation. The registry defines graft survival as the percentage of recipients with a working graft at 1 and 2 years. That definition identifies what the primary outcome is intended to measure, but the absence of group-specific estimates prevents evaluation of the effect and its precision.

The design also highlights the distinction between a study’s design label and its analyzable details. Randomized allocation is reported, and the model is classified as factorial, yet the factorial structure and analysis are not described. Those distinctions matter because the meaning of a treatment contrast depends on which groups were assigned and how the factors were incorporated into the analysis. The arm descriptions identify a steroid-free and a steroid-containing regimen, but do not establish all details of the design.

Multiple outcome topics and time points make prespecification and transparent reporting important. The registry lists 6 outcome measures, including multiple primary time points and several secondary topics, but does not report the multiplicity plan or analysis-level results. Readers therefore cannot distinguish prespecified tests from other analyses or assess the uncertainty associated with any outcome comparison.

Finally, the record demonstrates why adverse-event counts need denominators, definitions, attribution, and context. The counts are useful descriptive information, but they do not by themselves quantify comparative risk or establish causality. Together, these features show how statistical conclusions depend not only on a randomized design, but also on complete reporting of endpoints, analyses, uncertainty, and participant accounting.

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 interpreting this specific trial is that the primary graft-survival results are not reported in the registry record. The endpoint is described at 1 and 2 years, but no percentages, group denominators, effect estimates, confidence intervals, or tests are available. The primary outcome also includes multiple time points and is not reduced to one comparison in the record.

The registry reports enrollment of 40, while the adverse-event denominators are 20 and 19. Participant disposition and the reasons for these denominators are not reported. There is no information on the number assessed at each graft-survival time point, losses to follow-up, or missing-data handling. Consequently, the completeness of outcome ascertainment cannot be evaluated.

Further details needed to assess the design are also absent: the eligibility criteria, randomization procedure, allocation concealment, the implementation of the factorial model, treatment duration, adherence, and assessor masking are not reported in the registry record. The record classifies the study as having no masking, but does not specify whether outcome assessors were masked.

The statistical analysis plan, sample-size justification, analysis populations, model specifications, and multiplicity approach are not reported. The registry lists 0 analyses, so the recorded information does not allow assessment of how outcomes were analyzed or whether analyses followed a prespecified plan. The adverse-event information lacks details on event definitions, timing, seriousness criteria, overlap, and attribution. In particular, the group and denominator for the Death term at 15.8% are not reported. These limitations restrict interpretation of both the comparative outcome and the adverse-event summaries.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Steroid Free Immunosuppression in Liver Transplantation — NCT00296244.
• Registry record last updated 2012-11-19; status last verified 2012-10.
• Results first posted 2012-11-19.
• 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.

18. Record Summary

NCT00296244 is a completed randomized Phase 4 study sponsored by Thomas Jefferson University. The registry lists enrollment of 40, no masking, and a factorial model. The study compares a steroid-free regimen of Basiliximab, Tacrolimus, and EC-MPA with a steroid-containing regimen that adds steroids. The listed start is 2006-02 and primary completion is 2008-05.

The primary outcome is graft survival rate, defined as the percentage of recipients whose liver grafts are still working at 1 and 2 years. The registry’s stated purpose concerns whether steroid-related complications can be avoided with a steroid-free immunosuppressive regimen. Secondary outcome topics include infection, HCV recurrence, and new-onset diabetes mellitus.

The registry reports serious adverse events for 2 of 20 control participants and 3 of 19 study participants, and other adverse events for 16 of 20 and 17 of 19, respectively. It lists Death at 15.8% as a top serious term, without a group-specific denominator in the record. The primary graft-survival results, comparative analyses, and key statistical and missing-data methods are not reported in the registry record.