Teriparatide (Forteo) in the Treatment of Patients With Postoperative Hypocalcemia: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Teriparatide (Forteo) in the Treatment of Patients With Postoperative Hypocalcemia (NCT00623974), a randomized phase 2 study. The primary outcome is Number of Patients With Success.

2. Clinical Question

The clinical question concerns short-term correction and maintenance of calcium levels after surgery. The study planned to compare three teriparatide doses, each added to calcium and calcitriol, against calcium and calcitriol alone. Its primary objective was to identify an optimal dose, rather than to establish a comparative result that can be interpreted from observed trial outcomes.

The planned setting included patients after total thyroidectomy and/or extensive neck dissections, including the surgical procedures listed in the registry summary. The condition recorded for the study is hypocalcemia. The record does not report eligibility details beyond the statement that none of the 7 participants met the criteria. It therefore does not establish which eligibility requirement prevented enrollment into the treatment arms.

The intended question and the available evidence must be kept distinct. The registry describes the therapeutic question and planned arms, but reports no treated participants, randomized participants, or primary outcome results. No conclusion about the comparative effect of the planned treatments can be drawn from this record.

3. Trial Design

The registry describes a Phase II, randomized, open-label, parallel-group study sponsored by M.D. Anderson Cancer Center. It lists four planned groups: calcium plus calcitriol, and three groups receiving teriparatide at 20 mcg, 40 mcg, or 60 mcg in addition to calcium and calcitriol. The listed calcium and calcitriol regimen was 1000 milligrams of calcium plus 0.25 micrograms of calcitriol orally every 12 hours.

The study was planned to examine a seven-day course of twice-daily teriparatide in patients with postoperative hypocalcemia. The record gives a total enrollment figure of 7, but also states that none of those participants met eligibility criteria and that none was treated or randomized to study arms. Thus, the design describes the intended comparison; it does not describe a completed randomized treatment comparison.

The registry lists the study as starting in 2008-05, with primary completion in 2010-06, and gives its status as terminated. The stated reason was low accrual. Further details about the timing or operational circumstances of termination are not reported in the registry record.

Masking is listed as none, so the planned study was open-label. The registry records a parallel model, meaning the intended design assigned participants to one treatment group rather than describing a crossover. However, because no eligible participant was randomized, these design features were not put into practice for a treatment comparison.

The record lists one primary outcome measure and no analyses. It does not report a statistical analysis plan, allocation procedure, or sample-size justification. The design should therefore be read as a description of what the investigators intended to study, with the termination and absence of eligible participants determining what evidence was ultimately available.

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: A total of 7 patients were consented and screened. None of the patients met study entry criteria and thus were not randomized to treatment. Due to slow accrual, the study was closed.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Terminated due low accrual, none of 7 participants met eligibility criteria therefore not treated nor randomized to study arms.

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 Number of Patients With Success, measured over 2 - 7 days post-treatment.

The primary outcome was the number of patients with success, assessed over the stated timeframe of 2 - 7 days post-treatment. Success was defined as a normal calcium level, with Ca at least 8 and no more than 10.5, within 48 hours after treatment initiation, followed by maintenance of a normal calcium level through day 7 after treatment initiation.

This endpoint combines an initial response with continued control over the treatment period. Requiring both conditions distinguishes a transient return to the target range from a response that is maintained through the specified follow-up. In general, a binary success endpoint can make a clinical target easier to interpret as a count or proportion of participants meeting a prespecified definition. It also depends on the exact threshold, timing, and measurement rules used to classify each participant.

The endpoint was intended to support the dose-selection objective: identifying a teriparatide dose associated with achieving and maintaining the target calcium range, compared with standard therapy. The record does not report how calcium measurements were scheduled, how corrected calcium was calculated, or how missing measurements would affect endpoint classification.

Most importantly, the registry says no eligible participant was treated or randomized. It therefore reports no participants who could be classified as successes or non-successes. The endpoint definition is available, but the endpoint result is not.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a randomized, open-label, parallel-group Phase II design. In general, random assignment is intended to reduce systematic differences between treatment groups, while an open-label design means treatment assignment is not masked. A parallel-group design assigns each participant to one group for the study rather than comparing treatments within the same participant. These are descriptions of the planned design: the record states that no eligible participant was randomized, so the planned randomization did not yield groups for analysis.

What would randomization contribute?

In general, randomization helps make the treatment groups comparable on average with respect to both measured and unmeasured participant characteristics. It does not guarantee balance in every realized trial, and its benefit depends on participants actually being assigned to groups and followed. In this study, no eligible participants were randomized. Accordingly, there are no randomized groups from which to estimate a treatment contrast, assess baseline balance, or make an intention-to-treat comparison.

What does the endpoint measure?

The primary endpoint was a binary success classification based on two conditions: calcium reaching the specified range within 48 hours after treatment initiation and remaining in that range through day 7. In general, converting a clinical criterion into a binary endpoint can support a clear comparison of the proportion meeting the criterion. That simplification also discards detail about the exact calcium values and their course over time. Whether that tradeoff is appropriate depends on the scientific question and the prespecified endpoint definition.

The registry does not report individual measurements, group-level success counts, or an estimated treatment effect. Without those data, no success proportions or between-group differences can be interpreted. No new estimates should be inferred from the endpoint definition alone.

How should uncertainty be understood?

In general, a confidence interval describes a range of effect values compatible with the observed data under the assumptions of the statistical method. Its width reflects the amount and variability of information available, as well as the method used. An interval for a treatment contrast would require outcome information from participants in the relevant groups. Since the registry reports no treated or randomized participants, it provides no primary-outcome estimate or confidence interval to interpret.

A p-value, in general, measures how incompatible observed data are with a specified null model, under the assumptions of the test. It is not a measure of the probability that a treatment works, nor does it describe the size or clinical importance of an effect. The registry does not report a primary-outcome test or p-value. No statistical significance conclusion is available.

What can the planning information tell readers?

The registry contains a general sample-size planning assumption describing an illustration based on an observed effect, equal allocation between two arms, a two-sided significance level of 0.05, and a normal approximation. Such planning illustrations are not observed trial results and are not evidence that a study had a particular probability of detecting an effect. In general, sample-size calculations depend on assumptions about the effect to detect, outcome variability or event frequency, allocation, and analysis method. The trial's own sample-size justification is not reported in the registry record.

No sample-size illustration can compensate for the absence of eligible, treated participants. Nor can an assumed effect for planning be treated as an effect estimated by this trial. The record does not support an observed-power calculation or a recalculated comparison. Any planning values should be understood only as assumptions for hypothetical future studies, not as results from the terminated trial.

What is not described?

The registry does not report the statistical analysis plan, any interim analyses, covariate adjustment, handling of repeated calcium measurements, or a missing-data strategy. It also does not provide an analysis population beyond noting that none of the participants met eligibility criteria and none was treated or randomized. These omissions matter because analysis choices can influence how endpoint results are estimated and interpreted. In this instance, however, the most fundamental limitation precedes those choices: no treatment outcome data were available for analysis.

For a future study of this question, general methodological considerations could include defining the eligible population and endpoint measurement schedule in advance, specifying the comparison and analysis population, and describing how incomplete measurements would be handled. These are general considerations, not features reported for this trial. The registry record does not establish what methods the investigators would have used had recruitment progressed.

10. Multiplicity, Missing Data and Analysis Populations

The planned design included three teriparatide dose groups and a calcium-plus-calcitriol group, which could have led to several treatment comparisons. In general, when multiple hypotheses are tested, the chance of at least one false-positive finding can increase unless the analysis plan accounts for multiplicity. The registry record does not report a multiple-comparison strategy, hierarchy of comparisons, or allocation of statistical error across comparisons. No treatment comparisons were performed because no eligible participant was randomized.

The registry lists one primary outcome measure and zero analyses. It does not report whether there were planned secondary outcomes, prespecified subgroup analyses, or interim analyses. These matters are not reported in the registry record and should not be inferred from the Phase II designation or the dose-selection objective.

Missing-data methods are also not reported. In general, missing endpoint data can affect estimates when outcomes are unavailable for some participants, and the consequences depend on why data are missing and on the method used. Here, the record's stated issue is not missing outcome observations following treatment: no eligible participant was treated or randomized. There is therefore no primary outcome dataset from which to evaluate missingness or apply an analysis method.

The record does not describe an intention-to-treat, per-protocol, or safety analysis population. It states that none of the 7 participants met eligibility criteria and none was treated or randomized. An analysis-population definition cannot create a treatment comparison when no one entered the planned arms. Conclusions about multiplicity, missing-data effects, or analysis-population sensitivity are consequently unavailable.

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

The record establishes that the investigators planned a Phase II randomized comparison of calcium and calcitriol alone against the same regimen combined with one of three teriparatide doses. It also records a primary endpoint focused on achieving and maintaining a defined calcium range after treatment initiation. These details clarify the scientific question the study was designed to address.

The record does not establish whether teriparatide changed calcium outcomes, whether one dose was better than another, or whether any regimen met the endpoint. No eligible participant was treated or randomized, and the trial was terminated due to low accrual. Thus, the absence of reported treatment outcomes is not evidence of no effect; it reflects the lack of an evaluable treatment comparison.

The adverse-event entries likewise should not be read as evidence of safety. The registry lists zero events in the planned treatment groups, but no participant was treated or randomized. The record therefore supplies no meaningful information about the frequency of harms during exposure to the study interventions.

In general, an inconclusive study may leave a clinical question unresolved without favoring either treatment. That is the appropriate interpretation. The planned endpoint and regimen remain descriptions of the research question, not estimates of benefit or harm.

The enrollment figure of 7 does not represent a treated or randomized study population: the record explicitly says none of those participants met eligibility criteria. The trial therefore offers information about feasibility in the sense that recruitment did not yield eligible participants, but it does not quantify treatment efficacy or comparative safety. The reason for ineligibility and other recruitment details are not reported in the registry record.

12. Why This Trial Matters Statistically

This trial matters statistically because it illustrates the difference between a randomized design on paper and an analyzable randomized comparison. The registry describes randomization and four parallel groups, but reports that no eligible participant was treated or assigned to a study arm. A design label alone does not generate comparative evidence; the outcome data and group assignments needed for estimation must exist.

The record also shows why endpoint definitions should be separated from endpoint results. The success criterion is specific about the target calcium range and when it must be reached and maintained. That definition can help readers understand the intended clinical outcome, but without observations it cannot answer whether the endpoint occurred or whether treatments differed.

For statistical interpretation, an empty treatment comparison is different from an imprecise estimate. An imprecise estimate would still be calculated from observed data, though uncertainty could be substantial. Here, no effect estimate is reported because no eligible participant entered the study arms. Thus, there is no interval or test result that can be interpreted as evidence for or against a treatment effect.

The terminated study also underscores that eligibility and accrual determine whether a planned analysis can be carried out. The record attributes termination to low accrual and states that none of the 7 participants met eligibility criteria. Why eligibility was not met is not reported in the registry record, so the reasons cannot be generalized to other settings or populations.

Statistically, the clearest contribution is a transparent account of a research question that could not be evaluated. Recognizing this distinction prevents a non-result from being mislabeled as evidence of no effect, while keeping the limits of the available record explicit.

13. 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 primary limitation is that the trial generated no treated or randomized comparison. The registry states that none of the 7 participants met eligibility criteria, and that the study was terminated due to low accrual. As a result, there are no primary outcome results, treatment-effect estimates, or uncertainty intervals to interpret.

The record gives the intended eligibility context but not the specific reasons that participants failed to qualify. It does not report recruitment details sufficient to explain why accrual was low, or whether changes to eligibility criteria or recruitment procedures were considered. These details are not reported in the registry record.

The primary endpoint is defined, but measurement procedures are not described in detail. The registry does not report the timing or frequency of calcium assessments, the method used to calculate corrected calcium, or the handling of values that were unavailable or outside the expected measurement schedule. Since no participants were treated, these omissions do not conceal an analyzable outcome dataset; they limit understanding of how the planned endpoint would have been operationalized.

The statistical analysis plan, sample-size justification, multiplicity approach, and analysis populations are not reported in the registry record. No assumptions about those plans can be made from the listed design or treatment arms. The planned dose groups also cannot be compared because there were no randomized participants.

Finally, the zero adverse-event entries do not provide an interpretable estimate of safety in the absence of treatment exposure. The record's limitations are therefore both substantive and statistical: it documents the intended study question, but cannot supply evidence about comparative effectiveness or harms.

14. Related Tutorials

15. Related Statistical Calculators

16. Sources

• ClinicalTrials.gov: Teriparatide (Forteo) in the Treatment of Patients With Postoperative Hypocalcemia — NCT00623974.
• Registry record last updated 2012-12-06; status last verified 2012-12.
• Results first posted 2010-09-13.
• 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.

17. Record Summary

The registry describes a Phase II randomized, open-label, parallel-group study of teriparatide for postoperative hypocalcemia. It planned to compare calcium plus calcitriol alone with that regimen combined with teriparatide at 20 mcg, 40 mcg, or 60 mcg. The primary outcome was success in reaching and maintaining the stated normal calcium range over the specified post-treatment period.

The study is listed as terminated due to low accrual. Although enrollment is recorded as 7, the primary outcome description states that none of the participants met eligibility criteria and that none was treated or randomized. The registry lists one outcome measure and zero analyses, with no primary treatment results reported.

The record therefore identifies the intended clinical question and endpoint, but cannot estimate a treatment effect or provide interpretable safety comparisons. The trial did not evaluate its planned objective.