Role of T-cells in Post-Menopausal Osteoporosis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Role of T-cells in Post-Menopausal Osteoporosis (NCT00787904), a registered phase not stated study. The primary outcome is Changes in T-cell Activation Measured by Flow Cytometry, Specifically the Percentage of CD3+CD69+ T-cells.

2. Clinical Question

3. Trial Design

This is an observational study listed as completed, sponsored by Atlanta VA Medical Center. Its title concerns the role of T-cells in post-menopausal osteoporosis; the official title specifies women undergoing surgical menopause. The registry record lists an enrollment of 19, a start date of 2006-12, and a primary completion date of 2011-06.

The study description says that women would be examined before and after surgery and followed over a two year period. The surgical menopause group is described as pre-menopausal women undergoing total hysterectomy with oophorectomy. The surgical control group consists of pre-menopausal women undergoing abdominal surgery without ovary removal. A healthy matched pre-menopausal control group is also listed. These group descriptions indicate that the study concerns differences in surgical and menopausal status, rather than assignment to a randomized treatment.

Allocation is not stated in the registry record, and the listed arms are not a like-for-like control comparison. The record does not explain how matching was performed, how measurements were timed within follow-up, or which between-group contrasts were planned. Those details matter because changes over time within a group and differences between groups answer distinct questions.

The primary outcome is a continuous measure of T-cell activation assessed by flow cytometry. Bone Mineral Density is listed as a secondary outcome. The record lists three outcome measures, but does not report statistical analyses for them. The completed status describes the registry record's study status; it does not by itself show that numerical results were posted.

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

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 Changes in T-cell Activation Measured by Flow Cytometry, Specifically the Percentage of CD3+CD69+ T-cells, measured over 2 years.

The primary endpoint concerns changes in T-cell activation measured by flow cytometry, specifically the percentage of CD3+CD69+ T-cells. The unit is the percentage of CD3 positive cells. CD3 positivity identifies a T-cell in the endpoint description, while CD69 positivity is part of the activation measure. The endpoint is reported as a mean with Standard Deviation and has a timeframe of 2 years.

As a general statistical point, a percentage can summarize how common a marker-positive subset is within a defined cell population. Measuring CD69 among CD3-positive cells therefore provides a way to describe activation within T-cells, rather than simply counting all cells together. The study's stated biological question makes this marker relevant to its investigation of T-cell activity in the setting of surgical menopause and post-menopausal osteoporosis.

A mean describes the average measurement in the analyzed group; the Standard Deviation describes the spread of individual measurements around that mean. Neither statistic alone describes the uncertainty in a comparison or establishes whether groups changed differently over time. That interpretation would require the relevant estimates and their uncertainty, as well as details of the analysis.

The registry record does not report numerical primary-endpoint results, a defined analysis population, or the detailed measurement schedule. Consequently, the recorded endpoint tells readers what was intended to be measured, but not what values were observed or how those values changed.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a mean and Standard Deviation describe?

The primary endpoint is continuous and is summarized as a mean with Standard Deviation. In general, the mean represents the average measurement among the observations included in an analysis. The Standard Deviation describes how dispersed those observations are around the mean. It is not the same as the uncertainty in the mean, and it is not a confidence interval for a group difference.

For a percentage based on flow cytometry, interpretation depends on the defined cell population and the way measurements were collected and processed. The endpoint specifies the percentage of CD3 positive cells that are CD69 positive. The registry record does not report the laboratory procedures, quality-control rules, or how repeated measurements were summarized for analysis. These details are not reported in the registry record.

How would change over time be interpreted?

As a general statistical point, a within-group change compares measurements from the same participants across time. A between-group contrast asks whether that change differs between groups. Those are not interchangeable estimands: a group can change over time without changing differently from a comparator. The study description says participants were examined before and after surgery and followed over a two year period, but the precise timing of endpoint measurements and the statistical approach to repeated observations are not reported in the registry record.

Repeated measurements from one participant are usually related rather than independent. General methods for longitudinal data account for that dependence when estimating changes and uncertainty. The registry record does not identify a longitudinal model, a covariance structure, an adjustment set, or any other statistical method for the primary endpoint. It would therefore be inappropriate to infer which method was used.

Why does the observational design matter?

In general, random allocation can help balance measured and unmeasured participant characteristics between comparison groups. This study is described as observational, and allocation is not stated in the registry record. Its groups are defined by surgery and menopausal status, and the record explicitly notes that the arms are not a like-for-like control comparison. As a result, an observed group difference would be an association in these groups, not by itself evidence that the surgery caused that difference.

Matching is mentioned for healthy controls, but the matching variables, matching procedure, and analysis of matched observations are not reported in the registry record. The record also does not identify potential confounders or say whether estimates were adjusted. These omissions limit how precisely any hypothetical group contrast could be interpreted, even if numerical results were available.

What would uncertainty measures add?

As a general explanation, a confidence interval combines an estimate with information about its statistical uncertainty under an analysis model. It helps readers assess both the plausible range of effects and the precision of the estimate. A significance test addresses a specified null hypothesis, but a p-value alone does not communicate effect size or clinical importance. For this study, estimates, confidence intervals, and p-values are not reported in the registry record, so none can be evaluated.

Over-dispersion is a general concern when observed variation exceeds what a model assumes. If a model understates variability, its uncertainty estimates may be too optimistic. This concept can matter in biological measurements, but the registry record does not report a model or evidence of over-dispersion for this endpoint. It should not be assumed to have occurred.

How should planning illustrations be read?

General planning calculations are not observed power and are not a substitute for the trial's own design justification. The registry record describes planning illustrations based on the observed effect, a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect stated as a fraction of the observed effect. Such assumptions describe a calculation framework, not a reported analysis of the study's endpoint. The record does not report a sample-size justification or the study's own design assumptions. Any planning illustration should therefore be kept distinct from what participants actually experienced and from the unreported outcome results.

More broadly, a planning sample size is conditional on the assumed effect, variability, allocation, and analysis method. If those assumptions do not match the eventual study or the target question, the illustration may not describe the precision achieved. The registry record does not report enough detail to assess that alignment. No sample-size illustration can recover missing endpoint estimates or establish an observed treatment effect.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Surgical Menopause", "Surgical Control")
n   <- c(6, 13)
m   <- c(3.6, 1.8)
sp  <- c(0.5, 0.2)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Surgical Menopause  6  3.600  0.500  3.075  4.125
CARM  Surgical Control  13  1.800  0.200  1.679  1.921

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists three outcome measures and identifies T-cell activation as the primary outcome, with Bone Mineral Density listed as a secondary outcome. It reports zero analyses. The full outcome list and analysis results are not reported in the registry record, so it is not possible to determine which outcomes were analyzed or how multiple comparisons were handled.

As a general statistical point, examining multiple outcomes, time points, or group contrasts creates multiple opportunities to identify an apparently notable result. A prespecified hierarchy or multiplicity adjustment can help control the interpretation of those tests. The registry record does not report a multiplicity strategy, prespecified analysis hierarchy, or detailed statistical analysis plan. No adjustment should be assumed.

Methods for handling missing measurements are also not reported in the registry record. The record does not state how many endpoint observations were available at each time, whether participants missed follow-up, or how incomplete repeated measurements were handled. It therefore cannot establish whether the reported enrollment corresponds to the analysis population for the primary endpoint.

The analysis population is not reported in the registry record. There is no stated definition of which participants would be included in the primary analysis, nor a description of exclusions or protocol deviations. These omissions matter because the included observations determine the population to which an estimate applies. With no posted endpoint estimates or analyses, the effects of missing data, analysis-population choices, and multiplicity cannot be evaluated.

12. 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 safety entries list the Surgical Menopause group with 6 at risk and 0 affected by serious adverse events; the count affected by other adverse events is also 0 among 6 at risk. The Surgical Control group is listed with 13 at risk and 0 affected by serious adverse events; the count affected by other adverse events is also 0 among 13 at risk. These are the figures recorded for those two groups.

As a general statistical point, an entry of zero affected participants means that no affected participants are recorded in that particular registry count. It does not prove that an event is impossible, establish the absence of every type of harm, or provide a precise estimate of risk. The registry record does not provide an event-by-event description or safety analysis for these entries. Healthy controls are not included in the listed adverse-event groups, so their safety counts are not reported in the registry record.

Deaths are shown as null for both listed groups. Null is not a zero count; death counts are not reported in the registry record. These safety figures should be read as limited descriptive registry entries, not as a complete account of all safety outcomes across the study.

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

The study addresses a specific biological question: whether the percentage of CD3 positive cells that are CD69 positive changes in women undergoing surgical menopause. It is observational, includes surgical and healthy control groups in its descriptions, and follows the stated endpoint over 2 years. These features provide context for the question, but they do not supply evidence of an outcome by themselves.

The primary endpoint results are not reported in the registry record. Without group measurements or change estimates, the posted record cannot show whether T-cell activation increased, decreased, or remained similar. It also cannot establish the size or precision of any difference between the groups. The listed Bone Mineral Density outcome has no reported numerical result in the registry record either.

Even if numerical differences were available, the design would call for cautious interpretation. As a general point, an observational comparison can identify patterns among the groups studied, but group differences do not alone prove that surgical menopause caused those patterns. The record does not state allocation, matching details, confounder adjustment, or the analysis population in sufficient detail to assess those issues.

The safety counts provide a limited description for the two listed surgical groups: zero affected participants are recorded for serious and other adverse events, with the listed at-risk counts. Deaths are not reported in the registry record. These entries do not establish comprehensive safety or resolve the primary biological question.

Accordingly, the most defensible reading is that the record documents a completed observational study and its intended primary measure, while leaving the central numerical result unavailable. It does not support a claim that T-cell activation did or did not change, nor a conclusion about treatment benefit or harm.

14. Why This Trial Matters Statistically

This study is statistically interesting because it frames a biological question around a continuous cellular measure collected in relation to a major change in menopausal status. The endpoint is specific: the percentage of CD3 positive cells that are CD69 positive, measured by flow cytometry. The study description also distinguishes surgical menopause from abdominal surgery without ovary removal and from healthy matched pre-menopausal controls.

That structure highlights common challenges in clinical research. Measurements before and after surgery are repeated observations, and repeated measurements on the same participant are generally related. Comparisons across groups also require care because observational groups may differ in ways beyond the exposure of interest. The record's note that the arms are not a like-for-like control comparison makes this issue explicit.

The endpoint is reported as a mean with Standard Deviation, which separates a summary of average values from a description of their spread. In general, interpreting change also requires estimates of uncertainty and a clear definition of the comparison being made. The registry record does not report those analyses, making it a useful example of the distinction between a stated research question and posted statistical evidence.

The record also illustrates why study status and enrollment are not enough to assess a result. Although the study is listed as completed and reports an enrollment of 19, primary outcome estimates and analyses are not reported. The absence of those results limits assessment of effect size, precision, missingness, and the role of secondary outcomes. The statistical significance of the record is therefore methodological: it shows what information is necessary to move from a biological rationale to an interpretable estimate.

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 specific to this record constrain interpretation. First, the primary endpoint's numerical results are not reported in the registry record. There are no posted group means, Standard Deviations, change estimates, or uncertainty measures with which to assess the stated question. The record lists zero analyses.

Second, the enrollment is 19, while the adverse-event entries show at-risk counts only for the Surgical Menopause and Surgical Control groups. The record does not explain the relationship between those safety counts and the full enrolled population, and the healthy control group's safety counts are not reported in the registry record. The primary outcome analysis population and group distribution are also not reported.

Third, this is an observational comparison. Allocation is not stated, and the record notes that the arms are not a like-for-like control comparison. Matching is described for healthy controls, but matching details and any adjustment for group differences are not reported in the registry record. These features restrict causal interpretation.

Finally, the record does not report the timing of measurements within follow-up, missing-data procedures, analysis methods, or multiplicity handling. Those details are important for repeated measures and for interpreting multiple outcomes. The primary outcome population is not specified. The listed completed status cannot resolve these reporting gaps or substitute for the absent numerical results.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Role of T-cells in Post-Menopausal Osteoporosis — NCT00787904.
• Registry record last updated 2016-12-13; status last verified 2016-10.
• Results first posted 2016-12-13.
• 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.

19. Record Summary

NCT00787904 is an observational study titled “Role of T-cells in Post-Menopausal Osteoporosis”; its official title concerns women undergoing surgical menopause. Atlanta VA Medical Center is listed as sponsor. The record reports enrollment of 19, a start date of 2006-12, a primary completion date of 2011-06, and completed status.

The study describes women undergoing total hysterectomy with oophorectomy, surgical controls undergoing abdominal surgery without ovary removal, and healthy matched pre-menopausal controls. Its primary endpoint is changes over 2 years in the percentage of CD3 positive cells that are CD69 positive, summarized as a mean with Standard Deviation. Bone Mineral Density is listed as a secondary outcome.

Numerical primary-endpoint results and statistical analyses are not reported in the registry record. The adverse-event entries list zero serious and other affected participants in the two surgical groups, while death counts are not reported.