Growth Hormone and GnRH Agonist in Adolescents With Acquired Hypothyroidism: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Growth Hormone and GnRH Agonist in Adolescents With Acquired Hypothyroidism (NCT00206375), a randomized phase 4 study. The primary outcome is Final Height.

2. Clinical Question

The study record frames the question around growth during treatment for acquired hypothyroidism. It describes a rationale in which thyroid hormone treats hypothyroidism, growth hormone is intended to restore growth rate, and Lupron is used to delay puberty and prevent early closure of growing bones. These statements describe the study’s purpose and rationale; they are not results demonstrating an effect.

The question is difficult to interpret as a single treatment comparison because the record describes both long-term and short-term hypothyroidism groups. The contrast of greatest relevance to the stated treatment question appears to be the long-term group treated with Synthroid alone versus the long-term group treated with growth hormone, Synthroid, and Lupron. The short-term group is described separately as a control. The registry record does not clarify the intended analysis across these groups, and it reports no primary outcome data. The age range, disease duration definitions, and other eligibility details are not reported in the registry record.

3. Trial Design

The registry record identifies this as a Phase 4 study sponsored by Baylor College of Medicine. It lists randomized allocation and no masking, but also labels the model as single-group. Those design entries do not align straightforwardly with the three group descriptions in the record. The planned or implemented allocation process, and how the group structure was handled, are not reported in the registry record. The record therefore does not support a more definite account of the trial’s operational design.

The enrollment is listed as 16. Group descriptions refer to long-term hypothyroidism treated with thyroxine alone, long-term hypothyroidism treated with thyroxine, growth hormone, and a GnRH agonist, and short-term hypothyroidism treated with thyroxine as a control. The adverse-event record lists 6 participants at risk in the thyroxine-alone group, 3 in the combination-treatment group, and 7 in the short-term control group. These are safety-record counts and should not automatically be treated as the analysis population for the primary endpoint.

The study started in 2003-05 and had a primary completion date of 2011-09. Its status is terminated. The registry record says it was terminated because of insufficient funds; the principal investigator left the institution, efforts to locate the investigator were exhausted, and the data were no longer available and could not be reported.

The interventions list growth hormone and growth hormone treatment and puberty. The group descriptions also name Synthroid and Lupron, but the record does not explain the relationship between the intervention entries and the full group regimens. Details such as allocation procedures, treatment duration, adherence, follow-up schedule, and the intended statistical analysis are not reported in the registry record. No masking is listed.

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:

Analysis population for the primary outcome, as defined in the registry: n/a. The study was terminated due to insufficient funds.The study was terminated and the study PI has left the institution. All efforts to locate the study PI have been exhausted and the data is no longer available and cannot be reported

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 Final Height, measured over When bones are fused.

The primary endpoint is titled Final Height, with the timeframe specified as when bones are fused. Final height is intended to capture attained stature after skeletal growth has ended, rather than growth at an interim visit. In general, measuring an endpoint after growth is complete can address whether differences in growth during treatment persist to the end of skeletal development. That is the rationale implied by the endpoint and the study’s stated interest in final height.

The registry record does not give a unit, a statistical parameter, a measure of dispersion, or a numerical outcome. It also does not report how final height was measured, how the timing of fused bones was determined, or how participants without an available final-height measurement would have been handled. The record’s outcome description says the study was terminated and the data are no longer available and cannot be reported.

Consequently, the endpoint’s intended meaning can be described, but its observed distribution cannot. There is no reported group mean, median, difference, confidence interval, or statistical test for final height. Nor is there a reported estimate of the precision of any treatment contrast. The endpoint description alone does not establish whether final height differed between the treatment groups.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does random allocation mean in general?

In general, random allocation uses a chance-based process to assign participants to groups. When implemented as planned, it can help make groups comparable with respect to both measured and unmeasured characteristics at the point of assignment. It does not guarantee identical groups, especially when groups are small, and it does not address problems arising after assignment, such as missing outcome measurements or differences in treatment adherence. A clear account of allocation is needed to assess how well the method was implemented.

The registry record lists allocation as randomized, but it also lists a single-group model and describes three groups. The method used to assign participants, the allocation sequence, and the relationship between that assignment and the three descriptions are not reported in the registry record. Thus, the general benefits associated with random allocation cannot be assumed to resolve the design ambiguity in this particular record.

What does masking contribute?

In general, masking means keeping some people involved in a study unaware of treatment assignments. Depending on the design, this can reduce the influence of expectations on treatment delivery, outcome assessment, or reporting. Masking is not always possible, and its relevance depends on the intervention and endpoint. The record lists no masking. It does not describe who knew treatment assignments, how final height was assessed, or whether outcome assessment could have been influenced by knowledge of group membership.

What would an endpoint comparison require?

In general, comparing a continuous outcome such as height requires outcome values for the relevant participants and a defined approach to summarizing or modeling those values. A treatment contrast might be expressed as a difference in group averages, or through another prespecified measure appropriate to the data and design. A confidence interval communicates the uncertainty around an estimate; it is not a guarantee that the true effect lies within the interval. The choice of analysis also depends on the endpoint distribution, the group structure, missing observations, and any repeated measurements.

For this study, the registry record does not report final-height values, an analysis population, an outcome summary, a treatment contrast, or a confidence interval. The outcome’s unit and statistical parameter are also absent. No primary-outcome analysis is listed. Consequently, there is no study-specific estimate to explain and no way to evaluate the assumptions or precision of a primary analysis.

How should the planning illustrations be understood?

In general, sample-size calculations are planning tools: they describe how much information a proposed study might need under stated assumptions. They are not observed results and do not establish whether a study detected an effect. The registry record’s planning assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with planning tied to a stated fraction of an observed effect. For time-to-event settings, the record specifies total events; for other settings, it specifies participants per arm.

These assumptions do not establish that the study itself used those design choices. The record does not report the trial’s own sample-size justification, and it does not report an analysis of final height from which readers could assess an observed effect. Any planning illustration should therefore be read as conditional on its assumptions, not as a description of the trial’s actual statistical power or evidence about the treatment contrast. Planning illustrations are never observed power.

Why do missing data and over-dispersion matter in general?

Missing outcomes can affect both the amount of information available and the validity of a comparison. If participants with measured outcomes differ systematically from those without them, an analysis limited to observed values may not represent the enrolled groups. Statistical approaches to missing data require assumptions about why measurements are absent; those assumptions and any missing-data methods are not reported in the registry record. The record specifically says the primary data are no longer available, so the limitation is broader than an unreported analysis choice.

Over-dispersion is a general concern when observed variability is greater than a statistical model expects. If ignored, uncertainty estimates can be too small and tests can be misleading. It can matter for outcomes such as counts, where the variance may exceed what a simple model assumes. Final height is described as the primary outcome here, but no outcome data or analysis model are reported, so there is no basis to assess over-dispersion or claim that it was relevant to the analysis actually used.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists Final Height as the primary outcome and Bone Age and Growth Factors as secondary outcomes. It reports 3 outcome measures and no analyses. The outcome descriptions do not give numerical results. The record does not identify a primary statistical contrast, a hierarchy among secondary outcomes, or a plan for handling multiple comparisons. Multiplicity procedures are therefore not reported in the registry record.

In general, testing several outcomes or several group contrasts can increase the chance of at least one apparently unusual result if each is assessed separately. A prespecified hierarchy or adjustment can help address that issue, but the choice depends on the intended claims and analysis plan. Since there are no posted analyses, there is no reported procedure to evaluate and no basis for deciding whether multiplicity affected any result.

Missingness is especially consequential because the registry record says the study data are no longer available and cannot be reported. The number of participants with final-height measurements, the amount and pattern of missing outcome data, and the reasons for any participant-level missingness are not reported in the registry record. The termination explanation identifies insufficient funds and the principal investigator’s departure; it does not describe participant-level follow-up or measurement completeness.

The analysis populations are also not reported. The record does not state whether analyses were intended to include all randomized participants, only participants who received assigned treatment, or another defined group. It does not say how protocol deviations, withdrawals, or incomplete follow-up were to be handled. Although the safety record lists participants at risk in each described group, those safety denominators do not define the population used for the primary endpoint. With no endpoint data or analysis description, neither the extent nor the statistical consequences of missingness can be assessed.

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 0% reporting threshold.

The adverse-event record lists 0 serious adverse events among 6 participants at risk in the long-term hypothyroidism group treated with thyroxine alone; 0 among 3 in the long-term group treated with thyroxine, growth hormone, and a GnRH agonist; and 0 among 7 in the short-term hypothyroidism control group. It also lists 0 other adverse events in each of those groups. These figures describe the safety entries in the registry record.

The record does not list serious adverse-event terms. Death counts are not reported in the registry record. The time period over which participants were monitored for adverse events, the event-collection procedures, and whether any participants had incomplete safety follow-up are not reported. Therefore, the zero counts should be read as the posted event counts, not as proof that no events occurred outside the recorded observation or that the regimens have no safety risks.

These safety figures do not answer the primary question about final height. They also do not provide a statistical comparison of safety between groups. With the small group counts listed and no information on monitoring duration or event ascertainment, the record offers a limited account of observed adverse events rather than a complete estimate of safety.

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

The record establishes that investigators set out to study growth hormone and a GnRH agonist alongside thyroid hormone in children and adolescents with acquired hypothyroidism. It identifies final height, assessed when bones were fused, as the primary endpoint and describes long-term and short-term hypothyroidism groups. It also records that the study was terminated because of insufficient funds and that the data are no longer available and cannot be reported.

It does not establish whether final height differed between the described groups. There is no reported endpoint value, group comparison, confidence interval, or primary-outcome analysis. Without those results, the direction, size, and precision of any possible difference are unknown. The registry record cannot support a conclusion that the combination regimen increased final height, decreased it, or had no effect.

That distinction matters: a missing result is not a finding of no difference. It also is not evidence that a treatment effect exists. The stated rationale for using growth hormone and Lupron describes why the question was posed, not what the study found. Similarly, the adverse-event counts cannot fill the gap in the primary outcome or establish the overall safety profile.

The design information should also be interpreted cautiously. Randomized allocation is listed, but the model is described as single-group and the study summary describes three groups. The registry record does not explain this inconsistency or report the allocation process. As a result, even the intended group contrasts cannot be reconstructed confidently from the record alone.

In general, a clinical trial result is informative when readers can assess the outcome measurement, analysis population, treatment contrast, uncertainty, and missing data. Those details are unavailable for final height in this case. The appropriate statistical interpretation is therefore limited to describing the question, design entries, termination, and missing results, without inferring an effect from the study.

13. Why This Trial Matters Statistically

This study matters statistically because it illustrates the difference between a research question and an analyzable result. The registry record describes an endpoint and treatment groups, but the primary data are unavailable. Without observed final-height measurements, readers cannot estimate a treatment contrast or assess its uncertainty. A well-defined endpoint cannot answer a question in the absence of reportable outcome data.

It also illustrates why consistent design reporting matters. Randomized allocation, a single-group model, and three group descriptions appear together in the record. These labels do not by themselves explain how participants were assigned or what comparisons were intended. Clear reporting of the assignment process and analysis population is needed to understand what a result would represent.

The case also separates safety counts from evidence about effectiveness. The listed adverse-event figures give a limited description of recorded events, but they do not measure final height and do not resolve the primary research question. Each outcome needs its own definition, data, and analysis.

Finally, a terminated study with unavailable data creates a reporting limitation that statistical methods cannot repair. General approaches to confidence intervals, missing data, or multiplicity are useful only when the underlying observations and analysis details can be examined. The record documents the reason the endpoint results are absent, but it does not allow a statistical assessment of the intended treatment comparison. This makes transparent registry reporting important even when a study cannot produce a final analysis.

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 limitation is that the primary endpoint data cannot be reported. The registry record states that the study ended because of insufficient funds, the principal investigator left the institution, efforts to locate the investigator were exhausted, and the data are no longer available. This prevents evaluation of the primary question rather than merely limiting the precision of an otherwise reported estimate.

Several details needed to interpret the design are not reported in the registry record. Although allocation is listed as randomized, the model is labeled single-group and three groups are described. The allocation process, the relation between the intervention entries and the group regimens, and the intended comparisons are not explained. Masking is listed as none, but procedures for outcome assessment are not described.

The registry record does not report a sample-size justification, the primary analysis plan, endpoint values, analysis populations, participant-level missingness, or methods for handling missing data. It does not specify the unit or statistical parameter for final height, or give a measure of dispersion. Follow-up duration and the method for determining when bones were fused are also not reported in the registry record.

The adverse-event entries have limited interpretability because monitoring duration, collection methods, and completeness of follow-up are not described. Death counts are not reported. The safety counts do not establish who contributed primary endpoint data. Taken together, these limitations mean that neither the magnitude nor the precision of a final-height comparison can be assessed from the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Growth Hormone and GnRH Agonist in Adolescents With Acquired Hypothyroidism — NCT00206375.
• Registry record last updated 2020-10-30; status last verified 2020-10.
• Results first posted 2020-10-30.
• 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

NCT00206375 is a Phase 4 study sponsored by Baylor College of Medicine, with enrollment listed as 16. It concerns growth hormone and a GnRH agonist alongside thyroid hormone in children and adolescents with acquired hypothyroidism. The described groups include long-term hypothyroidism treated with thyroxine alone, long-term hypothyroidism treated with thyroxine, growth hormone, and a GnRH agonist, and short-term hypothyroidism treated with thyroxine as a control.

The registry record lists randomized allocation, no masking, and a single-group model. It identifies final height, assessed when bones were fused, as the primary outcome. The study started in 2003-05, had a primary completion date of 2011-09, and is listed as terminated. The record attributes termination to insufficient funds and says the principal investigator left the institution and the data are no longer available and cannot be reported.

No primary outcome analyses are listed. Bone Age and Growth Factors are listed as secondary outcomes. The available record does not establish a final-height treatment effect or its precision.