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 Effect of Alendronate on Bone in People With Chronic Spinal Cord Injury (SCI) Previously Treated With Teriparatide (NCT02195895), a na phase 2 study. The primary outcome is BMD of Total Hip by DXA.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02195895 |
| Phase | Phase 2 |
| Condition | Spinal Cord Injury, Bone Loss, Osteoporosis |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 17 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Northwestern University |
| Results posted | Yes |
2. Clinical Question
Population
People with chronic spinal cord injury who had previously been treated with teriparatide. The registry record lists spinal cord injury, bone loss, and osteoporosis as conditions. It does not report additional eligibility details such as age range or injury characteristics.
Intervention
Weekly oral alendronate 70 mg for 12 months, with 1000 mg calcium and 1000 IU vitamin D daily for 12 months.
Comparator
There was no separate comparator group. The study used a single-group design, and its stated purpose was to compare bone density after treatment with baseline values.
Primary question
What was the mean percent change in total-hip bone mineral density, measured by DXA, after 12 months of treatment? The numerical estimate and its 95% confidence interval are not reported in the registry record.
The study also set out to investigate bone strength, adverse events, and serum markers of bone metabolism. The listed secondary outcomes include CTX, lumbar-spine BMD by DXA, P1NP, and BSAP. These are distinct measurements and should not be treated as substitutes for the primary total-hip BMD endpoint.
Because there was no control group, the clinical question is about change during treatment in this group, not a randomized comparison of treatment against another therapy or no treatment. A baseline comparison can describe how measured BMD changed over time among participants with available measurements. It cannot, on its own, isolate the effect of alendronate from other influences on change. The record does not provide a numerical primary result or enough information to assess the size or precision of the observed change.
3. Trial Design
This was a Phase 2, single-group, open-label study sponsored by Northwestern University. The registry record lists enrollment of 17 participants and describes the study as completed. The official title identifies it as a 12-month open-label extension study in people with chronic spinal cord injury previously treated with teriparatide. The start is listed as 2014-04 and primary completion as 2016-08-05.
Participants in the single listed group received weekly oral alendronate 70 mg for 12 months, alongside daily calcium 1000 mg and vitamin D 1000 IU for 12 months. The primary endpoint was assessed at 12 months. The study description frames the main question as whether treatment would maintain or increase BMD relative to baseline, and also names bone strength, adverse events, and serum bone-metabolism markers as areas of interest.
The allocation entry is NA, the masking entry is none, and the model is single group. Thus, the design does not include a randomized parallel control group or blinded treatment assignment. The participants' measurements over time may be compared with their own baseline values, but that is not a like-for-like comparison with a concurrent control group. The registry record does not report a protocol rationale for the design, nor does it describe any further study procedures or the schedule of assessments beyond the stated 12-month primary endpoint.
Enrollment does not establish how many participants completed follow-up or contributed data to each endpoint. Completion status describes the study's registry status; it does not itself indicate that every enrolled participant had an observed 12-month measurement. The number analyzed for the primary endpoint and any reasons for missing measurements are not reported in the registry record.
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
| Stage | Alendronate, Calcium, Vitamin D |
|---|---|
| STARTED | 17 |
| COMPLETED | 17 |
| NOT COMPLETED | 0 |
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 | Alendronate, Calcium, Vitamin D |
|---|---|---|
| Participants analysed | 17 | |
| Age, Continuous | years | 43.89 (23.13 to 68.05) |
| Sex: Female, Male: Female | Participants | 4 |
| Sex: Female, Male: Male | Participants | 13 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 3 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 14 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 1 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 7 |
| Race (NIH/OMB): White | Participants | 9 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| American Spinal Injury Association (ASIA) Impairment Scale: ASIA A (Complete Injury) | Participants | 12 |
| American Spinal Injury Association (ASIA) Impairment Scale: ASIA B (Sensory Incomplete Injury) | Participants | 1 |
| American Spinal Injury Association (ASIA) Impairment Scale: ASIA C (Motor Incomplete Injury) | Participants | 4 |
| American Spinal Injury Association (ASIA) Impairment Scale: ASIA D (Motor Incomplete Injury) | Participants | 0 |
6. Primary Endpoint
The registry lists the primary outcome as BMD of Total Hip by DXA, measured over 12 months.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | Percent change |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the mean percent change in bone mineral density of the total hip after 12 months of treatment. BMD was evaluated using dual-energy X-ray absorptiometry, or DXA. DXA uses low-dose X-ray beams to measure bone density at different areas of the body. The endpoint focuses on the total hip rather than on a whole-body measure or a different skeletal site.
A continuous endpoint such as percent change retains information about the magnitude and direction of measured change. Reporting a group mean describes the average change among the participants included in the analysis, while the confidence interval conveys uncertainty around that estimate. It does not show how much individual participants varied unless individual-level distribution information is also reported.
BMD is used in this study as a measurable indicator of bone mass. The registry description also identifies bone strength as an area of investigation, but the primary endpoint is BMD, not a direct clinical outcome such as fracture. The registry record does not provide the numerical mean percent change, the bounds of its 95% confidence interval, or the number of participants contributing to that calculation. Consequently, the direction, magnitude, and precision of the primary result cannot be assessed from the posted results described in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The design and endpoint define what the results could establish: a description of mean change in total-hip BMD during 12 months in a single group of people with chronic spinal cord injury previously treated with teriparatide. The registry record describes 17 enrolled participants and identifies a 12-month primary endpoint, but it does not report the numerical estimate or 95% confidence interval for that endpoint. Therefore, the posted results do not allow a reader to determine the observed direction or magnitude of mean BMD change, or how precisely it was estimated.
A mean is a summary of the measurements used in its calculation. It does not indicate whether all participants changed in the same direction, and it may not describe the experience of every participant. A confidence interval is a statistical expression of uncertainty around an estimate under the assumptions of the analysis. A narrower interval generally indicates greater precision than a wider interval, but precision is not the same as absence of bias. Since the confidence interval itself is not reported in the registry record, its precision cannot be evaluated.
The study has no separate control group. A change from baseline may reflect treatment exposure, but a single-group before-and-after comparison cannot distinguish treatment-related change from other explanations, including natural change over time, concurrent care, measurement variability, or selective availability of follow-up measurements. These are general considerations for interpreting uncontrolled longitudinal results, not findings about what occurred in this study.
The record lists four secondary outcomes: CTX, lumbar-spine BMD by DXA, P1NP, and BSAP. It also describes an interest in bone strength and adverse events. Numerical results for the primary and secondary outcomes are not reported in the registry record. The absence of numerical results prevents assessment of whether outcomes moved together, whether findings were consistent across skeletal sites or markers, or how large any changes were.
The safety record lists 17 participants at risk for serious adverse events and 4 with serious adverse events. It lists 17 at risk for other adverse events and 13 with other adverse events, and reports 0 deaths. The listed serious-event terms and percentages give some descriptive context, but do not provide a full account of event timing, severity, relatedness, recurrence, or exposure-adjusted rates. The registry record does not support a comparison of safety between treatment groups because there is only one listed group.
Any sample-size figures based on the observed effect are planning illustrations rather than evidence that the study had a particular probability of detecting an effect. They are not observed power. In addition, the registry record does not provide the underlying primary estimate needed to judge the effect used in such an illustration. Overall, the record supports an account of the study question, design, and reported adverse-event counts, but not a numerical conclusion about the primary BMD endpoint.
9. Statistical Methods Explained
The registry record identifies a continuous primary outcome summarized by a mean: percent change in total-hip BMD at 12 months. Statistical interpretation depends on both the estimate and the method used to quantify its uncertainty. The record names a 95% confidence interval as the dispersion measure, but gives no numerical estimate or interval bounds. It also lists no analysis entries. As a result, the reader cannot verify the calculation or determine which participants' measurements contributed to the estimate.
What a mean describes
General statistical explanation: For a continuous measure, the mean is the arithmetic average of the values included in an analysis. It provides a concise summary of the group but does not show the spread of individual observations or the shape of their distribution. Two groups can have the same mean while their participants' values vary in different ways. A mean percent change is also not the same as a count of participants who increased or decreased.
In this trial, the specified mean concerns percent change in total-hip BMD, rather than the absolute BMD value or the mean at a different skeletal site. The registry record does not give the actual mean, its calculation details, or the analyzed sample size. It therefore cannot show whether the reported endpoint was calculated for all enrolled participants or for a subset with observed measurements.
What a confidence interval contributes
General statistical explanation: A confidence interval expresses uncertainty around an estimated quantity under the statistical model and assumptions used. The interval is not a range containing every individual participant's outcome. It also does not account automatically for systematic problems such as selection bias, measurement error, or confounding. Its width can help readers judge precision when the estimate and interval are available, but an interval alone does not establish that a finding is clinically important.
The primary endpoint is assigned a 95% confidence interval in the registry description. The numerical limits are not reported in the registry record. Accordingly, it is not possible to assess whether the interval is narrow or wide, whether it includes no change, or which values are compatible with the analysis. No alternative dispersion statistic is reported for the primary endpoint.
Why the design matters for analysis
General statistical explanation: In a single-group longitudinal study, a change from baseline is a within-group comparison. Each participant may contribute measurements at more than one time point, so the analysis needs to handle the relationship between repeated measurements appropriately. A concurrent control group would help address how the observed change compares with change under another condition. Without such a group, baseline change alone does not identify what would have happened to the same population without the treatment regimen.
This study is recorded as single group, with no masking and allocation listed as NA. The stated comparison is with baseline, not with a randomized control arm. The registry record does not describe the statistical method used for repeated measurements, any covariate adjustment, assumptions about missing observations, or checks of model assumptions. Those details are not reported in the registry record.
How to read planning illustrations
General statistical explanation: A sample-size calculation asks how many participants a future or planned study would need under specified assumptions to reach a chosen design target. The registry record describes planning illustrations computed from the observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It says the target effect is a stated fraction of the observed effect. These are planning assumptions, not a description of this trial's single-group design.
The record distinguishes illustrations reporting participants per arm from time-to-event illustrations reporting a total number of events. It identifies the latter as using the Schoenfeld method. The primary outcome in this trial is continuous, and the registry record does not give numerical sample-size illustration results or the observed primary effect needed to interpret them. Such planning calculations should not be called observed power. They do not show the probability that the completed study detected an effect, and their relevance depends on the assumptions used.
Over-dispersion and model fit
General statistical explanation: Over-dispersion occurs when observed variability is greater than a model assumes. If a model understates variability, uncertainty estimates can be too small and intervals can be too narrow. This is especially relevant to some count-data models; it is not automatically a feature of a continuous BMD endpoint. The registry record does not report an over-dispersion assessment or a model-fit procedure, so no such issue can be attributed to this study.
More broadly, statistical methods need to match the outcome scale, study design, and data structure. The record identifies the endpoint type and the confidence-interval summary but does not report the estimator, software, model, or diagnostic checks. The analysis method beyond the information in the registry record is therefore not reported.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists five outcome measures: the primary total-hip BMD endpoint and four secondary measures—CTX, lumbar-spine BMD by DXA, P1NP, and BSAP. Considering several outcomes can raise a multiplicity issue: as more statistical questions are tested, the chance of at least one apparently notable result can increase. This is a general statistical concern, not evidence that a particular error occurred in this study.
The registry record does not report a multiplicity adjustment, a hierarchy for testing outcomes, or an analysis plan specifying which outcomes would be treated as confirmatory. The number of analysis entries is zero in the registry record. That means no analysis entries are listed there; it does not establish that no analyses were conducted. Numerical outcome results and analysis details are not reported in the registry record, so there is no basis for reconstructing how multiple outcomes were handled.
Missing-data handling is also not reported. The registry record lists enrollment of 17, but does not state how many participants contributed to the 12-month primary endpoint, whether any measurements were missing, why they might be missing, or how missing values were treated. These details matter because an estimate based only on participants with observed follow-up may differ from one based on all enrolled participants if availability of measurements is related to outcomes.
The analysis population is not reported in the registry record. There is no stated intention-to-treat, per-protocol, or other analysis population definition, and no participant flow information in the record to connect enrollment with endpoint-specific analysis. Thus, the population represented by any numerical estimate cannot be independently assessed from the registry information.
11. 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 |
|---|---|---|---|
| Alendronate, Calcium, Vitamin D | 4 | 17 | 23.5% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Alendronate, Calcium, Vitamin D | 0 of 17 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Alendronate, Calcium, Vitamin D | 13 of 17 |
Most frequent serious adverse event terms
| Event term | Organ system | Alendronate, Calcium, Vitamin D |
|---|---|---|
| Urinary Tract Infection (UTI) | Renal and urinary disorders | 1 of 17 |
| Kidney stone | Renal and urinary disorders | 1 of 17 |
| Sepsis | Renal and urinary disorders | 1 of 17 |
| Inferior Vena Cava (IVC) filter shifted | Injury, poisoning and procedural complications | 1 of 17 |
| Spinal cord cysts | Nervous system disorders | 1 of 17 |
| Pressure sore | Skin and subcutaneous tissue disorders | 1 of 17 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Alendronate, Calcium, Vitamin D |
|---|---|---|
| Cold | Infections and infestations | 3 of 17 |
| Musculoskeletal Pain | Musculoskeletal and connective tissue disorders | 3 of 17 |
| Urinary Tract Infection (UTI) | Renal and urinary disorders | 3 of 17 |
| Cyst | Skin and subcutaneous tissue disorders | 2 of 17 |
| Pressure sore | Skin and subcutaneous tissue disorders | 2 of 17 |
| Soreness | Musculoskeletal and connective tissue disorders | 2 of 17 |
| Abdominal pain | Gastrointestinal disorders | 1 of 17 |
| Abscess (perineal) | Skin and subcutaneous tissue disorders | 1 of 17 |
| Bacteremia | Blood and lymphatic system disorders | 1 of 17 |
| Blister | Skin and subcutaneous tissue disorders | 1 of 17 |
Serious events with the highest arm-level rate: urinary tract infection (uti) (5.9%), kidney stone (5.9%), sepsis (5.9%), inferior vena cava (ivc) filter shifted (5.9%), spinal cord cysts (5.9%).
The registry record lists one treatment group and reports 17 participants at risk for serious adverse events, of whom 4 had serious adverse events. For other adverse events, it lists 17 participants at risk and 13 affected. It reports 0 deaths. These are descriptive counts within the listed group; the record does not present a comparison against a separate control group.
The registry lists six serious adverse-event terms, each with a reported frequency of 5.9%: urinary tract infection (UTI), kidney stone, sepsis, inferior vena cava (IVC) filter shifted, spinal cord cysts, and pressure sore. The percentages belong to the individual listed terms. They should not be added together to estimate the number of people with any serious event: one participant may have experienced more than one event, and the registry record does not provide participant-level overlap.
Counts of participants with events do not describe event duration, recurrence, timing, severity beyond the serious-event classification, or whether investigators considered an event related to treatment. The registry record does not report those details. Nor does the single-group design establish whether the listed events occurred more often or less often than they would have under another treatment or no study treatment. The figures are a record of reported events in this group, not a comparative safety estimate.
12. What the Result Does, and Does Not, Mean
The study was designed to describe whether mean total-hip BMD changed over 12 months in people with chronic spinal cord injury previously treated with teriparatide who received alendronate, calcium, and vitamin D. The registry record specifies the primary outcome and its intended summary, but the numerical primary result and its 95% confidence interval are not reported. The available record therefore does not establish the direction, magnitude, or precision of the primary endpoint result.
Even if a within-group change were reported, a single-group before-and-after comparison would not, by itself, demonstrate that the treatment regimen caused that change. General influences such as time, concurrent care, measurement variation, and which participants have follow-up data can affect observed change. A control group would address a different comparison question, but this study does not list one.
The endpoint is a measure of BMD, not a direct report of fractures or another clinical event. The registry description says the study also investigated bone strength and bone-metabolism markers, but numerical results for those outcomes are not reported in the registry record. The listed adverse-event counts provide descriptive information for the one group, not a comparative estimate of risk.
Enrollment of 17 describes the registered study enrollment, not necessarily the number with complete measurements or the number included in each analysis. The registry record does not report those analysis populations, missing-data methods, or numerical endpoint results. The appropriate interpretation is therefore limited to what is explicitly documented: the question, the single-group treatment regimen, the planned endpoint, and the adverse-event counts. No conclusion about treatment benefit or lack of benefit follows from the absence of numerical results in the registry record.
13. Why This Trial Matters Statistically
This study raises an important statistical distinction between measuring change and attributing change. Its primary endpoint is a continuous measure of total-hip BMD assessed at baseline and after 12 months. A single-group study can describe change among participants with available measurements, but it does not supply a concurrent counterfactual comparison. That distinction is central when interpreting results from open-label studies.
The trial also illustrates why a point estimate should be read together with its uncertainty and analysis population. The registry record names a mean percent change and a 95% confidence interval, but reports neither the numerical estimate nor the interval bounds. It also does not state how many participants contributed to the endpoint. Without these items, neither the size of the observed change nor its precision can be evaluated.
Multiple outcomes add another statistical consideration. Alongside the primary hip BMD measure, the record lists lumbar-spine BMD and three serum markers. These measures may address related but distinct aspects of bone, and their presence makes it important to know how outcomes were prioritized and how multiple analyses were handled. The registry record does not report a testing hierarchy or multiplicity approach.
Finally, the safety counts are interpretable as descriptive counts in one treatment group, not as relative risks. Overall, the record is useful for understanding the study design and the questions it set out to address. Its missing numerical outcome and analysis details also demonstrate why registration details and posted numerical results are both needed for a full statistical appraisal.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The most direct limitation for interpreting this trial is that the registry record does not report the numerical primary outcome. Although the endpoint is defined as mean percent change in total-hip BMD at 12 months with a 95% confidence interval, neither estimate nor interval is available. Numerical results for the secondary outcomes are also not reported. This prevents assessment of effect size, precision, consistency across measures, or the relation between the endpoint findings and the stated study aims.
The single-group, open-label design has no separate comparator. A baseline comparison cannot distinguish treatment-associated change from other changes over time, and the absence of masking may affect participant or investigator behavior and outcome assessment. DXA is the specified measurement method, but the record does not describe assessor masking, measurement quality procedures, or any approach to reduce measurement variability.
The registry record lists enrollment of 17 but does not provide endpoint-specific sample sizes, participant flow, completion counts, or reasons for missing data. It does not report the analysis population or methods for handling missing measurements. These omissions limit appraisal of whether the analyzed participants represent the enrolled group.
Further details are not reported in the registry record, including the statistical model, covariate adjustments, analysis assumptions, multiplicity strategy, and protocol-based sample-size justification. The listed adverse-event counts lack detail on timing, recurrence, attribution, and participant-level overlap among serious-event terms. These limitations do not establish that a particular bias or problem occurred; they identify uncertainties that the registry record does not resolve.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Effect of Alendronate on Bone in People With Chronic Spinal Cord Injury (SCI) Previously Treated With Teriparatide — NCT02195895.
- Registry record last updated 2023-03-30; status last verified 2023-03.
- Results first posted 2018-09-26.
- 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.
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18. Record Summary
This completed Phase 2 study was a single-group, open-label 12-month study in people with chronic spinal cord injury previously treated with teriparatide. The registry record lists 17 enrolled participants. The regimen was weekly oral alendronate 70 mg, daily calcium 1000 mg, and daily vitamin D 1000 IU.
The primary endpoint was mean percent change in total-hip BMD by DXA at 12 months, with a 95% confidence interval specified as the dispersion measure. The numerical primary result, secondary outcome results, analysis population, and missing-data methods are not reported in the registry record. The record lists 4 participants with serious adverse events among 17 at risk, 13 with other adverse events among 17 at risk, and 0 deaths.