Low Dose Thymoglobin in Renal Transplant Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Low Dose Thymoglobin in Renal Transplant Patients (NCT01280617), a randomized na study. The primary outcome is Rates of Acute Cellular Rejection Between Study Group.

2. Clinical Question

The clinical question concerns two dose regimens within a renal transplant setting, rather than a comparison between Thymoglobulin and no induction treatment. The study description says patients would also receive a standard immunosuppression regimen of prograf/cellcept and a fast steroid taper. The official title describes prednisone-free regimens, but the posted results do not establish what steroid treatment each participant actually received or whether the intended regimen was followed.

The primary outcome is titled as rates of acute cellular rejection between study groups. Its description specifies incidence of biopsy-proven acute rejection at 1 year post transplant, while the unit is listed as number of rejection. The result is therefore presented as event counts: 4 in the 1.25mg/kg group and 2 in the 0.75mg/kg group. The registry does not report participant-level details that would clarify whether these counts represent participants with rejection, multiple rejection events in some participants, or another counting convention.

3. Trial Design

The registry describes a planned, prospective, randomized, single-center study sponsored by Lahey Clinic. The record is marked completed. The recorded study start is 2010-10, and primary completion is 2013-11. The phase is recorded as NA. Enrollment is listed as 44, while the primary-outcome groups have recorded counts of 23 and 20. The registry record does not explain the difference between the enrollment figure and the group counts used for the posted outcome.

The study used a parallel-group design with no masking. Participants were randomly assigned to one of two Thymoglobulin induction regimens: 1.25mg/kg x 3 doses or 0.75mg/kg x 3 doses. The description says randomization was to use sealed envelopes, with investigators selecting envelopes sequentially at the time of randomization. It does not report further details about sequence generation, whether envelopes were opaque or otherwise protected, or procedures for allocation concealment. Those details are not reported in the registry record.

The study description says data would be obtained for up to one year post-transplant. The primary outcome timeframe is 1 year from date of transplant. No additional details are reported about visit schedules, outcome adjudication, biopsy criteria, or how rejection events were counted. The primary endpoint is presented as a number of rejection events in each group, rather than as a time-to-event estimate. The registry does not report whether participants were analyzed according to their assigned group, how deviations from assigned treatment were handled, or how loss to follow-up was addressed.

The registry lists adverse-event counts for both groups, as well as serious infections as a leading serious-event term. These figures describe recorded safety events, but the posted record does not specify a full safety-analysis method or the observation period for those counts. No further information about the conduct of the trial or its statistical plan is reported in the registry record.

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

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 Rates of Acute Cellular Rejection Between Study Group, measured over 1 year from date of transplant.

The primary endpoint is described as incidence of biopsy-proven acute rejection at 1 year post transplant. Acute rejection is an outcome of interest after renal transplantation because it records an event involving the transplanted organ; requiring biopsy means the event definition relies on biopsy evidence. The registry’s description does not give the specific biopsy criteria, the process for confirming events, or details about whether an independent reviewer assessed them.

The endpoint title uses the word rates, but the recorded unit is number of rejection, and the posted group values are 4 and 2. The record does not provide a rate definition, a participant-level risk, or a time-to-event estimate. Counts can describe the total recorded events, but without additional information they do not establish how many distinct participants experienced rejection or whether some participants had more than one event. The registry record does not clarify this counting convention.

The 1 year timeframe sets the period of interest relative to transplant, but the posted summary does not show participant-level follow-up or explain how incomplete observation was handled. That matters because a count can depend on the duration and completeness of follow-up. The registry does not report an analysis population or missing-data approach for this endpoint. The endpoint is therefore interpretable as the posted event counts and the registry’s stated comparison, with important details about its construction and analysis unavailable.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

General statistical context: randomized allocation is intended to make treatment groups comparable, on average, with respect to factors that might affect outcomes. Randomization does not guarantee identical groups in a particular trial, especially when group sizes are limited. It also cannot correct problems arising after allocation, such as incomplete follow-up or differences in outcome ascertainment. The registry describes sealed-envelope assignment and a parallel design, but does not report enough operational detail to evaluate how the allocation sequence was generated or protected.

What does the reported test address?

The registry records a two-sided t-test for the primary comparison. In general, a t-test evaluates evidence about a difference in group means under its model assumptions. A two-sided version allows evidence in either direction rather than testing only a prespecified direction. The record does not state whether the test was applied to participant-level counts, another summary, or a transformed measure. It gives no test statistic or degrees of freedom. Consequently, the method label alone does not reveal the analysis in enough detail to reproduce or fully assess it.

The primary outcome is described as a number of rejection events. Count data can be distributed differently from the continuous measurements for which a conventional t-test is commonly introduced. General statistical context: the suitability of a test depends on the data structure and its assumptions, including the distribution of observations and the independence of those observations. The record does not report diagnostics or a justification for the selected test. This lack of detail does not prove the test was inappropriate; it means the reader cannot evaluate the choice from the registry entry.

Why do event definitions and follow-up matter?

Counts are interpretable only alongside a clear definition of what is counted and how completely it was observed. Here, the endpoint description refers to biopsy-proven acute rejection at 1 year, while the unit says number of rejection. The record does not clarify whether each event is counted once per participant, whether repeat events can contribute more than once, or how a participant with incomplete observation is handled. It also does not report the number of participants with complete follow-up for the endpoint. These omissions limit interpretation of the group counts and prevent a reliable reconstruction of a participant-level comparison.

General statistical context: a confidence interval gives a range of values compatible with the data and the method used, while also reflecting statistical uncertainty. An effect estimate paired with an interval would help describe the direction, size, and precision of a comparison. No such estimate or interval is reported for the primary result. The reported p-value threshold therefore cannot substitute for an estimate of the difference or its precision.

What does a reported p-value mean?

In general, a p-value measures how unusual data at least as inconsistent with a null model would be if that model and the test assumptions were correct. It is not the probability that a treatment has no effect, and it is not a measure of the likelihood that a result will repeat. The registry reports p <0.05, rather than an exact value. The record does not state the trial’s prespecified significance threshold or whether the reported test was specified before the data were examined. The planning assumptions mention a two-sided significance level of 0.05 for a sample-size illustration, but this does not establish the analysis plan for the completed trial.

The same two-sided test and p-value threshold appear twice in the analysis records. No explanation identifies separate hypotheses, populations, or analytic versions associated with these entries. It would be inappropriate to treat them as independent replications or to infer that they test different outcomes. The registry record does not report the reason for the repeated entry.

How should planning calculations be read?

General statistical context: power calculations describe the chance that a planned study would detect an effect of a specified size under stated assumptions. A planning illustration based on an observed effect is retrospective and should not be called observed power. The record’s sample-size assumptions describe a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. Such calculations are illustrative, not evidence about what the original investigators planned or justified. The trial’s own sample-size justification is not reported in the registry record.

For a count endpoint, the choice of statistical model can affect estimates, uncertainty, and tests, particularly if event counts vary more across observations than a simple model expects. General statistical context: over-dispersion means that variation is greater than a model assumes; if it is present and ignored, uncertainty can be understated. The registry does not report a dispersion assessment or a count-specific model, so no conclusion about over-dispersion can be drawn. The posted summary statistics are also insufficient for a dependable unadjusted recalculation, as the count-other endpoint is not estimable as a two-arm comparison from the available summaries.

10. Analyses Reported by the Sponsor

The registry’s own reported analysis is a two-sided t-test with p <0.05. It does not include an effect estimate, confidence interval, test statistic, or exact p-value. The record contains two identical analysis entries and does not explain their relationship. These limitations mean that the sponsor’s reported inferential result can be described, but its magnitude and precision cannot be read from the posted analysis details.

A simple unadjusted recalculation from the posted group summaries is not estimable for this count-other endpoint. No recalculated comparison should therefore be treated as a substitute for the registry’s analysis. The registry does not indicate a discrepancy between a sponsor analysis and a recalculation, but the missing estimate and uncertainty information still prevent a fuller comparison of the statistical results.

The sponsor analysis is the only inferential result reported for the primary endpoint. Its p-value threshold does not reveal whether the observed difference is large, precise, or clinically important. The record also does not provide enough information to assess the chosen test, the analysis population, or whether the method was prespecified. The reported test should therefore be read as the registry’s stated analysis, with these uncertainties kept in view rather than filled in by assumptions.

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome and one secondary outcome, described as total adverse events, including infections, leucopenia, and malignancy. It also contains two analysis entries for the primary comparison, both described as a two-sided t-test with p <0.05. The record does not explain whether those entries represent different hypotheses or duplicate records. It does not report a multiplicity adjustment, a hierarchy of outcomes, or a prespecified plan for interpreting multiple tests.

General statistical context: when several outcomes or comparisons are tested, the chance of at least one apparently unusual result can increase if each test is interpreted separately. Methods for addressing multiplicity can be prespecified, but the registry record does not report whether any such method was planned or used. It also does not identify whether the listed secondary outcome had a formal statistical comparison or what results were obtained for it. The absence of that information does not establish that no analysis occurred; it means the registry record does not report it.

The analysis population is not stated for the primary endpoint. The record does not say whether all randomized participants were analyzed in their assigned groups, whether any participants were excluded, or how treatment deviations were handled. Missing-data methods and endpoint-specific follow-up completeness are also not reported in the registry record. Because the recorded enrollment and the primary-outcome group counts do not match, the relationship between enrollment and the analyzed outcome population is unclear. The record does not explain whether this reflects missing outcomes, exclusions, or another reason.

These gaps matter to interpretation. Different analysis populations or missing-data assumptions can affect an estimated group comparison, while unreported multiplicity procedures make it difficult to know how the p-value was intended to fit into the broader set of outcomes. The available record supports description of the posted counts and test, but not reconstruction of a complete statistical analysis plan.

12. Safety Results

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

Deaths

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: serious infections (13.0%).

The posted safety figures list 3 participants with serious events among 23 at risk in the 1.25mg/kg group and 2 among 20 at risk in the 0.75mg/kg group. For other adverse events, the figures are 3 among 23 at risk and 8 among 20 at risk, respectively. The recorded death counts are 0 and 3, respectively. These are descriptive registry counts; no comparative safety estimate or confidence interval is reported.

Serious infections are listed as the leading serious-event term, with 13.0% recorded. The record does not specify the denominator or group attribution for that percentage in the term listing, so it should not be assigned to either treatment group from the available information. The registry also does not provide a detailed event-by-event breakdown or the observation period used for the safety counts.

General statistical context: safety counts can be difficult to compare when the groups differ in size, follow-up, or completeness of event reporting. The posted figures do not establish that every participant had the same period of observation, and the registry does not describe event collection or adjudication procedures. They should be read as recorded counts, not as proof of a causal relationship or as a complete characterization of comparative safety.

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

The registry record documents a randomized comparison of Thymoglobulin 1.25mg/kg x 3 doses and 0.75mg/kg x 3 doses in renal transplant recipients. The primary outcome is described as biopsy-proven acute rejection at 1 year from transplant. The posted counts are 4 and 2, respectively, and the registry reports a two-sided t-test with p <0.05. This is the core statistical information available for the primary comparison.

The result does not provide a numerical estimate of the difference between groups or its uncertainty. It does not show whether the counts represent distinct participants or repeated events, and it does not explain the relationship between recorded enrollment of 44 and the outcome group counts of 23 and 20. The registry also does not report the analysis population, missing-data handling, a detailed statistical plan, or whether the reported test was prespecified. Those omissions limit how far the result can be interpreted.

General statistical context: evidence from a test and evidence about the size and practical importance of an effect are different questions. A p-value threshold alone does not answer how large a group difference is or how precisely it has been estimated. Nor does a randomized design eliminate uncertainty from limited information, incomplete follow-up, or measurement choices. The record does not allow those considerations to be resolved.

The safety entries are also descriptive. They list serious events, other adverse events, deaths, and a leading serious-event term, but do not provide comparative estimates or sufficient detail to attribute the serious-infection percentage to a group. These figures should not be used alone to infer a treatment effect or a complete safety profile.

Thus, the posted information supports a narrow account of the recorded endpoint counts, the reported test threshold, and the listed safety counts. It does not establish that either dose is more effective or safer, and it does not provide enough precision or methodological detail for broader conclusions. No medical advice follows from these registry results.

14. Why This Trial Matters Statistically

This trial raises several statistical issues common to small randomized studies with event-count outcomes. The registry reports random assignment between two active dosing regimens, but the primary outcome appears as a count rather than a clearly defined participant-level risk or time-to-event measure. Clear specification of what constitutes an event, how repeated events are counted, and how follow-up is handled is important for interpreting such results.

The reported test is a two-sided t-test, while the outcome is described as a number of rejection events. The record does not explain how the data were represented for that test or why the method was selected. This does not establish that the analysis was invalid, but it illustrates why a test label without an estimate, uncertainty interval, or analytic detail may not support an independent assessment. Count-specific methods and their assumptions can matter; the registry does not report whether these were considered.

The record also illustrates the distinction between a p-value and a treatment-effect estimate. The reported threshold conveys limited information without the exact p-value, effect size, interval, or prespecified analysis plan. The two repeated analysis entries add uncertainty about how many hypotheses were actually assessed. Missing information about the analysis population and incomplete follow-up further constrains interpretation.

Finally, the gap between recorded enrollment and primary-outcome group counts highlights the importance of accounting for participants from randomization through endpoint analysis. The registry does not explain this difference, so readers cannot determine whether it reflects missing data, exclusions, or another process. These features make the trial statistically informative as an example of what registry summaries can and cannot establish, while leaving key questions unresolved.

15. 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.

Several limitations are specific to the posted record. The primary outcome is titled as a rate, but its unit is number of rejection, and the actual values are event counts. The registry does not explain whether the counts represent unique participants, episodes, or another definition. It gives no event adjudication details or biopsy criteria beyond describing the outcome as biopsy-proven acute rejection.

The reported analysis is incomplete for independent evaluation. The record names a two-sided t-test and reports p <0.05 twice, but provides no exact p-value, effect estimate, confidence interval, test statistic, or explanation for the repeated entry. The statistical plan, including any prespecified significance threshold for the trial’s primary analysis, is not reported in the registry record. The sample-size assumptions describe a planning illustration, not the trial’s original design justification.

The registry records enrollment of 44 and primary-outcome group counts of 23 and 20, without explaining how those numbers relate. It does not report the primary analysis population, participant flow, outcome completeness, reasons for exclusions, or missing-data handling. Details of allocation sequence generation, concealment, adherence, and treatment deviations are also not reported. Although the description refers to a single center and no masking, it does not provide enough information to assess outcome-assessment procedures.

The safety summary has further limits: the serious-infection percentage has no stated denominator or group attribution, and safety follow-up and event-collection procedures are not described. No comparative safety estimates are reported. These omissions restrict interpretation of both benefit-related and safety-related outcomes to the descriptive information in the registry.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Low Dose Thymoglobin in Renal Transplant Patients — NCT01280617.
• Registry record last updated 2021-03-16; status last verified 2021-02.
• Results first posted 2021-03-16.
• 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.

19. Record Summary

The record describes a completed, prospective, randomized, parallel-group, single-center study sponsored by Lahey Clinic. It compares Thymoglobulin induction at 1.25mg/kg x 3 doses with 0.75mg/kg x 3 doses in renal transplant recipients. The recorded enrollment is 44, and the primary outcome is biopsy-proven acute rejection at 1 year from transplant.

The primary-outcome counts are 4 in the 1.25mg/kg group and 2 in the 0.75mg/kg group. The registry reports a two-sided t-test with p <0.05 twice, without an effect estimate or confidence interval. It also lists adverse-event counts and serious infections as a leading serious-event term. The record does not explain the outcome-group counts relative to enrollment or provide important details about the analysis population, missing data, and statistical plan.