Strength Training as a Supplemental Therapy of Androgen Deficiency of the Aging Male: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Strength Training as a Supplemental Therapy of Androgen Deficiency of the Aging Male (NCT03282682), a non-randomized na study. The primary outcome is Change From Baseline in Lean Mass.

2. Clinical Question

The brief summary also describes interests in body composition, physical function, biochemical and molecular measures, and quality of life. Those broader aims do not replace the registered primary outcome, and the registry record does not provide numerical results for the primary outcome or the listed secondary outcomes.

3. Trial Design

This completed study is registered as NCT03282682 and is titled “Strength Training as a Supplemental Therapy of Androgen Deficiency of the Aging Male.” Comenius University is the listed sponsor. The record gives a start date of 2017-10-01 and a primary completion date of 2019-05-30. Enrollment is reported as 22. The phase is listed as NA.

The design is parallel and non-randomized, with no masking. Participants were listed in groups of hypogonadal males without TRT, hypogonadal males with TRT, and healthy eugonadal males. The registry record reports 6 participants at risk in the group without TRT and 8 at risk in each of the other listed groups for the adverse-event summaries. These are group-specific safety denominators; they should not be treated as evidence of randomized allocation or as interchangeable efficacy-analysis denominators.

Strength training was the intervention. The brief summary describes a 12-week training program performed 2 times per week. Participants in the TRT group also received regular prescribed testosterone therapy from their urologist. The record does not report whether TRT was initiated for the study, nor does it report further details about training supervision, adherence, or treatment exposure.

Because allocation was not randomized, differences between groups may reflect their pre-existing characteristics as well as any effects associated with their treatment or health status. The healthy eugonadal group is a descriptive comparison, not a randomized control. The registry record does not report a statistical plan that would establish how such differences were handled. It also does not report the rationale for enrollment, a sample-size justification, or interim analyses.

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 Change From Baseline in Lean Mass, measured over 7 days before intervention, 7 days after intervention.

The primary endpoint is change from baseline in lean mass. Lean mass is the amount of body mass attributed to non-fat tissue; it is a body-composition measure rather than a direct measure of muscle strength or physical function. The registry record specifies the mean and standard deviation as the planned summary and identifies grams as the unit.

Measurement was specified as total-body Dual-energy X-ray Absorptiometry using a Hologic fan-beam bone densitometer Discovery QDR series. The stated measurement windows were 7 days before intervention and 7 days after intervention. DXA provides a standardized way to assess body composition, which makes it relevant to a study investigating strength training and androgen deficiency. A change in lean mass can describe a body-composition outcome, but it does not by itself establish changes in strength, mobility, metabolic health, or quality of life.

The outcome definition and measurement method are reported, but the numerical lean-mass results are not reported in the registry record. Group means, standard deviations, changes, confidence intervals, and inferential test results are therefore not available from this record. Without those results, the size and precision of any observed change cannot be assessed.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record identifies the primary outcome as a continuous measure summarized by a mean and standard deviation. The outcome is change from baseline in lean mass, in grams. These choices describe how the measurement was intended to be represented; they do not provide the observed group values or specify the full inferential analysis.

What does a mean describe?

In general, a mean represents the arithmetic average of measured values in a group. For a change outcome, each participant’s post-intervention value is compared with that participant’s baseline value, and the group mean summarizes those changes. A mean can be useful for describing the average direction and size of change, but it can conceal variation among participants. The registry record does not report the mean changes or the individual data needed to examine their distribution.

What does a standard deviation describe?

In general, a standard deviation describes how dispersed measurements are around their mean. It is not the same as a confidence interval: the standard deviation describes variability among observations, whereas a confidence interval describes uncertainty around an estimated quantity. A standard deviation alone does not show whether a change is clinically important or whether a group difference is statistically distinguishable from chance. The registry record specifies standard deviation as the dispersion measure but does not report its values for the primary outcome.

What would a confidence interval add?

In general, a confidence interval gives a range of estimates compatible with the data and the method used to calculate it. A narrower interval indicates greater precision under that method; a wider interval indicates less precision. Intervals are especially useful alongside an effect estimate because they show which magnitudes remain plausible. No confidence interval for lean-mass change is reported in the registry record, so the precision of the primary outcome cannot be assessed from it.

Why does allocation matter?

Random allocation can, on average, reduce systematic differences between groups at the start of a study. This study is recorded as non-randomized, so group membership may be associated with participant characteristics or clinical decisions. For example, TRT was prescribed by participants’ urologists in the TRT group. A simple contrast between that group and the group without TRT would therefore not isolate the effect of TRT unless relevant differences were addressed. The registry record does not report an adjustment strategy or an analysis plan for these comparisons. The record itself cautions that the arms are not a like-for-like control comparison.

What can planning illustrations tell readers?

In general, sample-size planning asks how many participants per arm might be needed to detect a specified effect under stated statistical assumptions. Such a calculation depends on the effect size chosen, the variability expected, the significance level, the desired power, and the design. The registry record describes any planning illustration as based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It states that the effect to detect is a stated fraction of the observed effect. It also distinguishes participants per arm from total events for time-to-event calculations.

Those assumptions describe a planning illustration, not the study’s original design or an observed-power result. The record does not report a sample-size justification for the trial, and the observed primary effect is not reported in the registry record. Without that effect and the calculation inputs, the assumptions alone cannot establish whether the enrollment was adequate for a specific target.

What analysis is documented?

The registry record lists 20 outcome measures and reports 0 analyses. It does not report a model, covariate adjustment, handling of repeated measurements, missing-data method, or inferential test for the primary outcome. Those details are important because different analysis choices can produce different estimates and uncertainty. In their absence, readers should not infer a particular statistical procedure from the outcome’s mean-and-standard-deviation description.

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("Hypogonadal Males Without TRT", "Hypogonadal Males With TRT", "Healthy Eugonadal Males")
n   <- c(6, 8, 8)
m   <- c(2734, 499, 2268)
sp  <- c(1967, 1566, 2609)
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  Hypogonadal Males Without TRT  6  2734.000  1967.000  669.760  4798.240
CARM  Hypogonadal Males With TRT  8  499.000  1566.000  -810.209  1808.209
CARM  Healthy Eugonadal Males  8  2268.000  2609.000  86.821  4449.179

11. Multiplicity, Missing Data and Analysis Populations

The record lists 20 outcome measures, including the primary lean-mass endpoint and secondary measures of body composition, walking performance, strength, and treadmill performance. Assessing many outcomes can increase the chance of finding at least one apparently unusual result by chance when multiple statistical tests are conducted. In general, a multiplicity strategy may control that risk by adjusting tests or by distinguishing confirmatory from exploratory outcomes.

The registry record reports 0 analyses and does not report a multiplicity plan, hierarchy of secondary outcomes, or adjustment method. Since numerical outcome results and inferential tests are not reported in the registry record, it is not possible to determine how multiplicity was handled in practice or how it would affect interpretation.

The record does not report a missing-data method, the number of participants with endpoint measurements, or an analysis population for the primary outcome. Enrollment and the group-specific safety denominators do not establish the number included in an efficacy analysis. In general, missing measurements can affect an estimate if the participants without measurements differ systematically from those measured. Methods such as complete-case analysis or imputation rely on assumptions that should be stated and assessed; the registry record does not say which, if any, were used.

It also does not report whether the primary analysis followed an intention-to-treat principle, a per-protocol approach, or another definition of the analysis population. These omissions do not prove that no analyses occurred outside the registry record. They mean that the registry record does not provide enough detail to evaluate analysis populations, missingness, or multiplicity.

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 0% reporting threshold.

The adverse-event record lists serious adverse events, other adverse events, and deaths separately for the listed groups. For hypogonadal males without TRT, 0 serious adverse events were reported among 6 at risk, 0 other adverse events among 6 at risk, and 0 deaths. For hypogonadal males with TRT, the corresponding figures are 0 among 8 at risk for serious adverse events, 0 among 8 at risk for other adverse events, and 0 deaths. For healthy eugonadal males, the record reports 0 among 8 at risk for serious adverse events, 0 among 8 at risk for other adverse events, and 0 deaths.

These are the registry’s reported counts, not estimates of risk beyond the observed study record. A zero count does not establish that an event is impossible or that a treatment is free of risk. The number of participants and the period and method of safety monitoring affect how much can be learned from event counts. The registry record does not report further details about safety-event definitions, ascertainment procedures, or follow-up for these summaries. It also lists no top serious adverse-event terms.

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

The record documents a completed, non-randomized investigation of strength training in hypogonadal males, with and without TRT, alongside a healthy eugonadal group. It defines lean-mass change as the primary outcome and specifies DXA measurement. These design and measurement details identify the question the study set out to address.

They do not establish the outcome. Numerical results for lean mass and the listed secondary outcomes are not reported in the registry record. Therefore, the direction, size, and precision of observed changes cannot be described from this record. The investigators’ expectations in the brief summary should not be read as findings.

Even if group results were available, non-randomized allocation would limit causal interpretation. Participants receiving TRT may differ from those not receiving TRT, and the healthy eugonadal group is not a randomized control for the hypogonadal groups. Without a reported analysis addressing relevant differences, a contrast between groups could not be attributed solely to training or TRT.

The safety summaries report zero serious adverse events, zero other adverse events, and zero deaths in each listed group. Those observations describe the registry’s recorded counts; they do not rule out uncommon events or establish general safety. The record does not provide the additional monitoring details needed to interpret the breadth of safety ascertainment.

Overall, the registry record supports a description of the study’s design, endpoint, and reported safety counts. It does not support a quantitative estimate of the primary outcome or a conclusion about treatment effect. Missing numerical results should be treated as unavailable information, not as evidence of no change.

14. Why This Trial Matters Statistically

This study raises a statistical question that is common in clinical research: how to interpret outcomes when groups are defined by clinical status or treatment rather than randomized allocation. The record includes hypogonadal participants with and without TRT and a healthy eugonadal comparison group. Because those groups are not like-for-like randomized arms, differences in outcomes could reflect baseline differences as well as treatment or training.

The primary endpoint also illustrates the distinction between a clearly specified measurement and a reportable result. The registry record identifies lean-mass change, its unit, its summary statistics, and a DXA measurement method. Those details help define what should be analyzed. But without group estimates and uncertainty, readers cannot judge the magnitude or precision of the outcome.

The many listed outcomes make multiplicity relevant in principle. A prespecified analysis hierarchy or adjustment strategy can help readers distinguish primary evidence from exploratory findings. The registry record does not report such a plan, and it reports 0 analyses. That absence limits assessment of how the outcome set was handled.

The study also makes clear why planning calculations must be kept separate from observed evidence. A sample-size illustration based on an observed effect is a hypothetical planning tool, not observed power and not proof that a study was adequately designed. The registry record does not provide the primary outcome results or a trial sample-size justification.

For biostatistical interpretation, the record is therefore informative about design and measurement but limited as an account of efficacy. It shows why allocation, transparent analysis plans, missing-data reporting, and complete outcome results are essential to assessing precision and the strength of conclusions.

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.

The principal limitation for interpreting outcomes is that numerical results are not reported in the registry record. The primary endpoint is defined, but there are no reported group means, standard deviations, effect estimates, confidence intervals, or test results for lean-mass change. The listed secondary outcomes also lack numerical findings in the record.

The non-randomized allocation limits causal comparisons. Hypogonadal males receiving TRT and those not receiving TRT may differ for reasons related to clinical care or participant characteristics. Healthy eugonadal males differ by health status, so their group cannot be treated as a randomized control. The registry record itself cautions that the arms are not a like-for-like control comparison.

The record does not report eligibility criteria beyond the group descriptions, baseline characteristics, adherence to strength training, or details of TRT exposure. It does not state how group differences were handled statistically. It also does not report a sample-size justification, a statistical analysis plan, an approach to missing data, or analysis-population definitions. These omissions make it difficult to assess selection, comparability, precision, and robustness.

The registry record specifies the primary measurement method and timing, but does not report endpoint completion or whether measurements were available for all participants. Safety counts are reported, but further information on event definitions and ascertainment is not reported in the registry record. These limitations concern what can be evaluated from the record; they do not establish that unreported procedures or analyses did not occur.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Strength Training as a Supplemental Therapy of Androgen Deficiency of the Aging Male — NCT03282682.
• Registry record last updated 2021-07-30; status last verified 2021-07.
• Results first posted 2020-05-05.
• 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

NCT03282682 is a completed, non-randomized, parallel study sponsored by Comenius University. The registry record reports enrollment of 22 and describes strength training for hypogonadal males with or without TRT and healthy eugonadal males. The brief summary describes a 12-week program performed 2 times per week.

The primary outcome was change from baseline in lean mass, measured in grams by total-body DXA, with mean and standard deviation specified. Numerical primary and secondary outcome results are not reported in the registry record, which lists 0 analyses. The record reports zero serious adverse events, zero other adverse events, and zero deaths in each listed group. Non-randomized group comparisons, absent outcome estimates, and unreported analysis details limit interpretation of treatment effects and precision.