This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Prevention of Bone Loss After Acute SCI by Zoledronic Acid (NCT02325414), a randomized phase 2 study. The primary outcome is Percent Change in Bone Mass Density (BMD) in the Hip.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02325414 |
| Phase | Phase 2 |
| Condition | Spinal Cord Injury, Acute Spinal Cord Injury, Bone Loss |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 60 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Northwestern University |
| Results posted | Yes |
2. Clinical Question
Population
People studied in a trial concerning acute spinal cord injury and bone loss. The registry record lists spinal cord injury, acute spinal cord injury, bone loss, and osteoporosis as conditions. It does not report the detailed eligibility criteria or a more specific description of the outcome population.
Intervention
An intravenous infusion of zoledronic acid, 5 mg at baseline. The study objective was to evaluate an approach to preventing or mitigating loss of bone mass and bone strength after acute spinal cord injury.
Comparator
An intravenous infusion of placebo at baseline. The registry identifies the placebo group as the control arm.
Primary question
How did percent change in total-hip bone mineral density, measured by DXA over 0-12 months, compare between the zoledronic acid and placebo arms? The registry reports a median for each arm and a mixed-model analysis of the final values.
The primary endpoint focuses on a specific skeletal site and a defined follow-up interval. Its arm-level summaries describe the recorded distribution of percent change, while the sponsor-reported analysis gives a model-based comparison. Those are related but distinct summaries: the arm medians are not themselves the mixed-model estimate.
The study also listed percent change in femoral epiphyseal and metaphyseal integral bone mass content as secondary outcomes. The registry record names these outcomes but does not report values for them in the posted results. Details about the criteria used to select participants, baseline characteristics, and the clinical rationale for choosing the total hip as the primary site are not reported in the registry record.
3. Trial Design
This was a phase 2, randomized, quadruple-masked, parallel-group study sponsored by Northwestern University. The registry lists enrollment of 60 participants. The two posted outcome arms each have 30 participants: zoledronic acid and placebo. The registry status is completed, and the listed primary completion date is 2020-08-25; the study start is recorded as 2015-02.
The intervention descriptions specify an intravenous infusion of zoledronic acid, 5 mg at baseline, or an intravenous infusion of placebo at baseline. “Parallel” indicates that the arms are separate groups rather than a crossover comparison. Random allocation and quadruple masking are registry design labels; the record does not identify the people covered by masking or explain the procedures used to maintain it. Further information about allocation concealment, stratification, or implementation of randomization is not reported in the registry record.
The primary outcome is percent change in bone mineral density in the total hip, measured by DXA, over 0-12 months. Its reported summary is the median, with dispersion described as the inter-quartile range. Two secondary outcomes concern percent change in femoral epiphyseal and metaphyseal integral bone mass content. The record lists four outcome measures overall, but does not provide the other outcome names in the registry record recorded for this analysis.
Enrollment is a registry-level study figure, whereas the arm counts belong to the posted outcome data. The record does not explain participant flow from enrollment through follow-up, indicate whether every enrolled participant contributed data to the primary outcome, or define the analysis population. It also does not report the planned sample-size justification, the detailed statistical analysis plan, or whether interim analyses were planned or performed. Those omissions limit what can be inferred about how the trial was designed to address precision or analysis decisions.
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: After meeting eligibility, participants were randomized in a blinded fashion and received study drug at the baseline visit.
Overall Study
| Stage | Zoledronic Acid | Placebo |
|---|---|---|
| STARTED | 30 | 30 |
| COMPLETED | 22 | 24 |
| NOT COMPLETED | 8 | 6 |
Reasons for not completing this period:
| Reason | Zoledronic Acid | Placebo |
|---|---|---|
| Withdrawal by Subject | 3 | 1 |
| Lost to Follow-up | 5 | 5 |
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.
| Characteristic | Unit | Zoledronic Acid | Placebo | Total |
|---|---|---|---|---|
| Participants analysed | 30 | 30 | 60 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 29 | 28 | 57 |
| Age, Categorical: >=65 years | Participants | 1 | 2 | 3 |
| Age, Continuous | years | 37.3 (SD 15.9) | 38.2 (SD 15.2) | 37.8 (SD 15.4) |
| Sex: Female, Male: Female | Participants | 9 | 3 | 12 |
| Sex: Female, Male: Male | Participants | 21 | 27 | 48 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 4 | 7 | 11 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 26 | 23 | 49 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 2 | 1 | 3 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 8 | 6 | 14 |
| Race (NIH/OMB): White | Participants | 20 | 21 | 41 |
| Race (NIH/OMB): More than one race | Participants | 0 | 2 | 2 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | participants | 30 | 30 | 60 |
| Time Since Injury (Days) | days | 68.7 (SD 28.5) | 62.7 (SD 23.2) | 65.7 (SD 25.9) |
6. Primary Endpoint
The registry lists the primary outcome as Percent Change in Bone Mass Density (BMD) in the Hip, measured over 0-12 months.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Inter-Quartile Range |
| Unit | percent change in bone mass density |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is percent change in bone mineral density in the total hip, measured by DXA over 0-12 months. Bone mineral density is a quantitative measure of bone at a specified skeletal site. Expressing change as a percentage relates the follow-up measurement to the participant’s starting measurement, though the registry record does not provide the individual-level calculation details.
The total hip is the anatomical site named for this primary outcome. Measuring change at a defined site gives the comparison a focused outcome rather than combining measurements from different parts of the skeleton. DXA is the measurement method specified by the registry. The outcome is recorded as a median and inter-quartile range, so the posted arm summaries describe the center and spread of the observed values using those statistics. The specific interpretation of the listed bounds is not further explained in the registry record.
In the context of acute spinal cord injury, the study’s stated overall objective was to define an approach to prevent or mitigate loss of bone mass and bone strength. The primary endpoint addresses bone mass at the total hip; it is not itself a direct measure of bone strength, fractures, mobility, or other clinical outcomes. The registry lists femoral integral bone mass content measures as secondary outcomes, but values for those outcomes are not reported in the registry record.
In general, choosing a primary endpoint before results are assessed helps distinguish the main trial question from additional outcomes. The registry identifies the primary measure and its timeframe, but the protocol’s rationale for choosing this specific measure, and details such as the timing of DXA assessments within the interval, are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted arm summaries report median percent change in total-hip bone mineral density of -2.21 for zoledronic acid and -12.82 for placebo over 0-12 months. The registry lists 30 participants in each arm. These are arm-level summaries; they do not describe every participant’s response or the full shape of the outcome distributions. The arm bounds recorded alongside the medians are not identified as confidence intervals. The registry describes the dispersion measure as the inter-quartile range, but does not give additional explanation of the bounds.
The sponsor-reported analysis is a mixed models analysis of final values. It gives a median difference of 10.61 and p = 0.05 for the comparison, classified as a superiority analysis. The registry does not report a confidence interval for this estimate. The reported difference is the model analysis result and should not be conflated with a subtraction of the two arm medians. In general, a model-based estimate may use information differently from separate arm summaries; the registry record does not provide enough model specification to explain the relationship in detail.
The p-value is reported as 0.05. In general, a p-value describes how compatible the observed data are with a specified statistical null model, under the assumptions of the analysis. It is not the probability that the null hypothesis is true, nor does it measure the size or clinical importance of an effect. The registry does not provide the full model specification, the exact inferential procedure, or a confidence interval for the model estimate, so the precision of that estimate cannot be fully assessed from the posted analysis.
The arm summaries and the sponsor’s comparison are consistent with a more negative reported median in the placebo arm, while the sponsor’s model analysis reports a median difference of 10.61. These statistics describe the recorded outcome; they do not establish what would happen in other populations or circumstances. The record does not report clinical outcome measures such as fractures alongside this primary result. The study’s stated objective includes bone mass and bone strength, but the primary endpoint is specifically a DXA measure of bone mass at the hip.
The registry lists two secondary bone-mass outcomes but does not report their values in the posted results. It also records four outcome measures overall. Without the full outcome results and a stated multiplicity procedure, the reported primary comparison should be understood in the context of incomplete information about the broader outcome set. Details about missing observations, analysis populations, and sensitivity analyses are not reported in the registry record. Accordingly, the displayed estimate and p-value are best read as the sponsor’s recorded analysis rather than as a complete account of all possible analyses or sources of uncertainty.
9. Statistical Methods Explained
The registry identifies the primary outcome summary as a median with inter-quartile range. A median is the middle of an ordered set of observations, and the inter-quartile range describes the span of the central portion of that distribution. In general, these summaries can be useful when outcome values are not well represented by a mean and standard deviation, or when extreme observations affect the mean. The registry does not explain why this summary was selected or provide the participant-level distribution.
The arm medians are -2.21 for zoledronic acid and -12.82 for placebo. These summarize each arm separately; they are not the same statistic as the sponsor-reported mixed-model comparison. The registered dispersion description is inter-quartile range, but the posted arm records include lower and upper bounds without stating separately what those bounds mean. They should not be interpreted as confidence limits on the arm medians without clarification from the registry record.
The sponsor reports a mixed models analysis, with the parameter described as a median difference in final values. The reported estimate is 10.61, with p = 0.05. Mixed models are a general family of methods that can represent relationships among repeated or otherwise grouped observations, depending on the model specification. That general description does not establish which structure or covariates were used in this trial. The model formula, covariance structure, assumptions, handling of baseline measurements, and estimation procedure are not reported in the registry record. The posted description therefore does not support a detailed assessment of model fit or a reconstruction of the analysis.
The outcome timeframe is 0-12 months, but the registry does not state the schedule of measurements within that interval or clarify how the final value was selected. It also does not report whether the mixed model used repeated measurements, only final measurements, or other data. The wording “final values” appears in the reported analysis description; more detailed timing and model use are not reported in the registry record.
General interpretation of a p-value depends on the null hypothesis and analysis assumptions. The reported p-value of 0.05 is a tail probability calculated under a statistical model when its null hypothesis holds; it is not a probability that the result is due to chance, nor a measure of effect size. Because the registry does not report the full analysis plan or model details, the precise test underlying this p-value is not available. A confidence interval for the mixed-model estimate is also not reported in the registry record. In general, a confidence interval would communicate the range of estimates compatible with the data and method at a stated confidence level; without one, the precision of the reported comparison is less directly conveyed.
General statistical context: over-dispersion means that observed variability is greater than a model’s assumptions allow. When relevant, it can make standard errors too small if not addressed, which in turn can affect uncertainty estimates and tests. The registry does not report a count model or an over-dispersion assessment for this continuous bone-density outcome, so over-dispersion should not be assumed to be an issue in this trial.
Planning illustrations based on an observed effect are not observed power. General sample-size planning uses assumptions about the target effect, variability, significance level, allocation, and statistical method. The stated planning assumptions specify a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the target effect expressed as a fraction of the observed effect. For time-to-event outcomes, the stated convention is a total event count; for other outcomes, it is participants per arm. Such planning calculations illustrate sample sizes under assumptions; they do not describe the trial’s actual power, prove that the original design was adequate, or replace the trial’s own design justification. The sample-size justification used for the trial is not reported in the registry record.
For the observed comparison, the registry lists 30 participants per arm. The record does not state whether these are all randomized participants, all participants with outcome data, or a particular analysis population. Details of missing-data methods, assumptions about missingness, imputation, sensitivity analyses, and protocol deviations are not reported in the registry record. General methodological interpretation must therefore remain limited to the posted summaries and the named analysis.
The registry records a single reported analysis and lists four outcome measures, including two named secondary outcomes. It does not report a multiplicity adjustment or describe whether the primary endpoint was designated before data analysis. In general, testing multiple outcomes can increase the chance of at least one nominally small p-value if no adjustment or interpretive strategy is used. That general concern does not establish that the reported primary analysis is invalid; it identifies information needed to understand the wider set of analyses.
10. Analyses Reported by the Sponsor
| Method | Estimate | 95% CI | P-value |
|---|---|---|---|
| Mixed Models Analysis | Median Difference (Final Values) 10.61 | not reported | 0.050 |
The sponsor’s reported analysis is a mixed models analysis of final values. It gives a median difference of 10.61 and p = 0.05, and is identified as a superiority analysis. No confidence interval for this estimate is reported in the registry record. The analysis description does not provide the model specification or details of the inferential procedure.
The arm summaries report medians of -2.21 for zoledronic acid and -12.82 for placebo. These descriptive summaries are not interchangeable with the sponsor’s model-based estimate. A simple unadjusted recalculation from arm-level summaries, if available, would answer a different statistical question from a mixed-model analysis. No separate recalculated result is reported in the registry record, so there is no additional estimate to compare against the sponsor’s result.
The registry does not identify a discrepancy between the posted summaries and the sponsor’s analysis. The reported sponsor analysis should therefore be read as the registry’s inferential result, while the arm medians remain descriptive. Missing model details and the absence of an estimate’s confidence interval limit independent evaluation of the analysis and its precision. The registry record also does not report the analysis plan needed to determine how the model was specified in advance.
11. Multiplicity, Missing Data and Analysis Populations
The registry names the primary outcome as percent change in total-hip bone mineral density and lists two secondary outcomes: percent change in femoral epiphyseal integral bone mass content and percent change in femoral metaphyseal integral bone mass content. It records four outcome measures overall. Values for the two named secondary outcomes are not reported in the registry record, and the remaining outcome measures are not identified in the registry record for this analysis.
Multiplicity concerns arise in general when multiple outcomes, time points, subgroups, or statistical tests are considered. Without a stated strategy, a reader cannot determine whether the reported p-value was interpreted as one test among several, or whether an adjustment or hierarchy was planned. The registry does not report a multiplicity procedure, an outcome hierarchy beyond naming the primary outcome, or a detailed statistical analysis plan. The number and nature of all analyses planned are therefore not fully described by the posted record.
The registry records a single reported analysis for the primary comparison. This does not establish that only one analysis was planned or performed; further information is not reported in the registry record. The record also does not describe interim analyses, stopping rules, or any adjustments associated with such analyses. Their existence or absence should not be inferred.
The outcome arm counts are 30 in each group, but the record does not define the analysis population or clarify whether these counts represent participants with complete outcome measurements. Missing-data methods, reasons for missingness, numbers with measurements at each time, and sensitivity analyses are not reported in the registry record. In general, missing outcomes can affect both estimates and uncertainty, depending on how much information is missing and why. Without those details, the impact of missing data cannot be assessed.
Likewise, the registry does not describe whether the analysis followed an intention-to-treat principle, how participants who did not receive the assigned infusion were handled, or how protocol deviations were addressed. These are matters of analysis population and implementation, not details that can be reconstructed from the arm summaries alone. The reported results can be described as posted, but a fuller assessment of multiplicity and missing-data handling would require information not reported in the registry record.
12. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Zoledronic Acid | 8 | 30 | 26.7% |
| Placebo | 9 | 30 | 30.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Zoledronic Acid | 0 of 30 |
| Placebo | 0 of 30 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Zoledronic Acid | 28 of 30 |
| Placebo | 22 of 30 |
Most frequent serious adverse event terms
| Event term | Organ system | Zoledronic Acid | Placebo |
|---|---|---|---|
| Urinary Tract Infection | Renal and urinary disorders | 3 of 30 | 5 of 30 |
| Acute Phase Response | General disorders | 2 of 30 | 0 of 30 |
| Autonomic Dysreflexia | Nervous system disorders | 0 of 30 | 2 of 30 |
| Septic Shock | Infections and infestations | 1 of 30 | 1 of 30 |
| Altered Mental Status | Psychiatric disorders | 1 of 30 | 0 of 30 |
| C. difficile Infection | Infections and infestations | 1 of 30 | 0 of 30 |
| Dehydration | Metabolism and nutrition disorders | 0 of 30 | 1 of 30 |
| Thrombus | Vascular disorders | 0 of 30 | 1 of 30 |
| Epilepsy | Nervous system disorders | 1 of 30 | 0 of 30 |
| Exophoria with Intermittent Exotropia | Eye disorders | 1 of 30 | 0 of 30 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Zoledronic Acid | Placebo |
|---|---|---|---|
| Urinary Tract Infection | Renal and urinary disorders | 15 of 30 | 10 of 30 |
| Acute Phase Response | General disorders | 20 of 30 | 3 of 30 |
| Upper Respiratory Infection | Respiratory, thoracic and mediastinal disorders | 2 of 30 | 8 of 30 |
| Pressure Ulcer | Skin and subcutaneous tissue disorders | 3 of 30 | 4 of 30 |
| Joint Pain | Musculoskeletal and connective tissue disorders | 2 of 30 | 4 of 30 |
| Fever | General disorders | 2 of 30 | 3 of 30 |
| Heterotopic Ossification, new or worsened | Musculoskeletal and connective tissue disorders | 3 of 30 | 2 of 30 |
| Hypertension | Vascular disorders | 3 of 30 | 2 of 30 |
| Autonomic Dysreflexia | Nervous system disorders | 3 of 30 | 1 of 30 |
| Flu | Respiratory, thoracic and mediastinal disorders | 2 of 30 | 2 of 30 |
Serious events with the highest arm-level rate: urinary tract infection (16.7%), acute phase response (6.7%), autonomic dysreflexia (6.7%), altered mental status (3.3%), c. difficile infection (3.3%).
The adverse-event record lists 30 participants at risk in each arm. Serious adverse events affected 8 participants in the zoledronic acid group and 9 in the placebo group. The registry lists zero deaths in each group. These are participant counts, not event counts, and the record does not provide a time-to-event comparison or an adjusted analysis of serious adverse events.
The most frequently listed serious-event term is urinary tract infection, at 16.7%. Acute phase response and autonomic dysreflexia are each listed at 6.7%. Altered mental status, C. difficile infection, and dehydration are each listed at 3.3%. These percentages are registry entries for serious-event terms; the record does not provide further detail about severity, duration, timing, recurrence, or attribution for each term.
Other adverse events affected 28 participants in the zoledronic acid arm and 22 in the placebo arm. The registry’s aggregate figures do not establish that the events were caused by the assigned infusion, nor do they show the clinical course of individual participants. In general, adverse-event counts are descriptive safety information and need context about exposure, follow-up, definitions, and ascertainment. Those details are not reported in the registry record. These figures alone do not establish comparative safety or support medical advice.
13. What the Result Does, and Does Not, Mean
The primary result describes percent change in DXA-measured total-hip bone mineral density over 0-12 months among the posted outcome groups. The recorded medians are -2.21 for zoledronic acid and -12.82 for placebo. The sponsor’s mixed-model analysis reports a median difference of 10.61 and p = 0.05. Together, these statistics convey the direction and magnitude of the recorded summaries and the sponsor’s statistical comparison, but they do not provide a complete account of uncertainty or of all trial outcomes.
The result does not by itself establish the size of a clinically meaningful change. The registry does not report a clinical threshold for interpreting the endpoint, a confidence interval for the model estimate, or values for the named secondary outcomes. Nor does the primary outcome directly measure bone strength, fractures, or other consequences of bone loss. Those distinctions matter because a measured change in bone mass is not identical to a change in every outcome that may matter to participants.
The comparison also does not establish what would occur outside the study population or under different treatment conditions. Detailed eligibility criteria, participant characteristics, adherence, and missing-data handling are not reported in the registry record. The recorded enrollment and arm counts do not substitute for those details. The study was a phase 2 randomized, quadruple-masked, parallel-group trial, but the registry record does not provide enough information to assess every aspect of implementation or analysis.
The p-value is not the probability that the intervention is effective, and it does not measure the probability that the observed result would be repeated. In general, statistical evidence must be considered with effect size, precision, design, endpoint relevance, and completeness of reporting. Here, precision is difficult to evaluate because the model estimate’s confidence interval is not reported. Multiplicity procedures and the analysis population are also not described.
Accordingly, the registry supports a description of the posted primary endpoint summaries and sponsor analysis, alongside explicit limits in the available reporting. It does not justify claims beyond those measured and reported. The broader objective included bone mass and bone strength, but the reported primary outcome is a site-specific bone-mass measure, and other relevant outcomes and their results are not reported in the registry record.
14. Why This Trial Matters Statistically
This trial is statistically informative because it connects a clearly named quantitative endpoint with a randomized, masked, parallel-group comparison. The endpoint is specific: percent change in total-hip bone mineral density measured by DXA over 0-12 months. The record also identifies the arm-level summary as a median and inter-quartile range, making clear that the posted descriptive result is not a mean-based summary.
The trial illustrates why separate arm summaries and an inferential model result should be read as different quantities. The registry reports arm medians and a mixed-model comparison of final values, but gives limited detail about how the model was constructed. Readers can identify the reported estimate and p-value while also recognizing that model specification and a confidence interval are not reported. That distinction supports a careful rather than automatic interpretation of a nominal statistical result.
It also highlights the importance of outcome completeness. Two secondary bone-mass outcomes are named, and four outcome measures are listed overall, yet the secondary values are not reported in the registry record. The record does not describe multiplicity handling, missing-data methods, or the analysis population. These omissions do not erase the posted primary findings, but they constrain broader conclusions about the outcome set and the robustness of the comparison.
Finally, the safety record shows why descriptive counts need context. Serious adverse events and other adverse events are reported by arm, along with selected serious-event terms, but detail about attribution, timing, and exposure is not reported. In general, transparent reporting of estimands, uncertainty, participant flow, analysis decisions, and outcomes helps researchers assess both statistical evidence and its limits. This record offers some of that information while leaving important methodological details unspecified.
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 registry record does not report detailed eligibility criteria, baseline participant characteristics, or the composition of the outcome population. As a result, it is not possible to assess how closely the posted participants represent particular groups of people with acute spinal cord injury, or how comparable the arms were on characteristics relevant to the primary endpoint.
Although the design is identified as randomized and quadruple-masked, the record does not describe sequence generation, allocation concealment, the roles of the masked parties, or how masking was maintained. It does not report adherence to the assigned infusion, protocol deviations, or participant flow through follow-up. The 30 participants listed in each outcome arm should not be assumed to resolve those questions.
The primary endpoint is reported with arm medians and an inter-quartile range description, but the meaning of the listed lower and upper bounds is not further clarified. The sponsor-reported model estimate has no confidence interval in the registry record, and the model specification is not described. This limits assessment of precision, assumptions, adjustment choices, and whether the model matches the repeated-measure structure, if any.
The record does not report the sample-size justification used for the trial, a detailed statistical analysis plan, multiplicity procedures, interim analyses, or the handling of missing data. It also does not define the analysis population or identify the number with data at each measurement time. These details can influence interpretation of estimates and tests, but cannot be inferred from the posted summary statistics.
Two named secondary outcomes have no reported values, and the other outcome measures are not identified in the record details used for this analysis. Adverse-event information is aggregate and does not include detailed timing, attribution, or severity descriptions. These reporting limitations restrict interpretation to the outcomes and summaries actually recorded; they do not establish that unreported procedures or results were absent.
16. Related Tutorials
17. Related Statistical Calculators
18. Sources
- ClinicalTrials.gov: Prevention of Bone Loss After Acute SCI by Zoledronic Acid — NCT02325414.
- Registry record last updated 2025-12-02; status last verified 2025-11.
- Results first posted 2021-06-02.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
19. Record Summary
NCT02325414 is a completed phase 2 randomized, quadruple-masked, parallel-group study sponsored by Northwestern University. The registry lists enrollment of 60 and an outcome sample of 30 participants in each arm. Participants received an intravenous baseline infusion of zoledronic acid, 5 mg, or placebo.
The primary outcome was percent change in total-hip bone mineral density measured by DXA over 0-12 months. The arm medians were -2.21 for zoledronic acid and -12.82 for placebo. The sponsor reported a mixed-model median difference of 10.61, with p = 0.05; a confidence interval for that estimate is not reported in the registry record.
The record names two secondary femoral integral bone mass outcomes but does not report their values. It also lists serious and other adverse-event counts and zero deaths in each arm. Important details concerning model specification, missing data, analysis populations, multiplicity, participant flow, and the trial’s sample-size justification are not reported in the registry record.