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 Effects of Ergocalciferol on Erythropoetin Stimulating Agent Dose (NCT01263028), a na na study. The primary outcome is Evaluate if Ergocalciferol Supplementation to Achieve 25-hydroxy Vitamin D Levels > 40ng/ml Will Decrease Erythropoietin Requirements.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01263028 |
| Phase | NA |
| Condition | Chronic Kidney Disease Stages 3-5 |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 6 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Kaiser Permanente |
| Results posted | Yes |
2. Clinical Question
Population
People with Chronic Kidney Disease Stages 3-5 who had vitamin D deficiency and required recombinant human erythropoietin for anemia related to kidney disease. The registry record lists an enrollment of 6. It does not report further eligibility details, participant characteristics, or the number who completed the study.
Intervention
Ergocalciferol supplementation, identified in the record as Vitamin D2. The stated primary objective was to assess supplementation intended to achieve 25-hydroxy Vitamin D levels > 40ng/ml. The dose, schedule, and adherence information are not reported in the registry record.
Comparator
No separate control group is listed. The study model is single group, and allocation is recorded as NA. The registry record therefore does not describe a randomized comparison or a like-for-like control group against which to estimate a treatment contrast.
Primary question
Over the stated timeframe of 24 Weeks, would erythropoietin requirements decrease with ergocalciferol supplementation intended to achieve the stated vitamin D level? This is the study's stated question, not a reported finding. The primary outcome's measurement unit, observed values, effect estimate, and analysis are not reported in the registry record, so the question cannot be answered from the posted results.
3. Trial Design
The registry record describes a single-group intervention study of ergocalciferol supplementation. It lists Chronic Kidney Disease Stages 3-5 as the condition, Kaiser Permanente as the sponsor, and an enrollment of 6. Allocation is recorded as NA, and masking is NONE. There is no separately listed comparison group; the record's own classification also cautions that the arms are not a like-for-like control comparison. The design therefore does not support a randomized between-group treatment contrast.
The study status is TERMINATED. The recorded start is 2010-08 and the primary completion is 2011-09. The phase is listed as NA. These record details describe the study's status and timeline, but do not establish why the study ended or whether all enrolled participants completed follow-up. The reason for termination and participant flow are not reported in the registry record.
The intervention is named Ergocalciferol supplementation and classified as a drug. The arm description is blank. Dose, administration schedule, adherence, and any co-interventions are not reported in the registry record. The primary outcome timeframe is 24 Weeks; the registry record does not clarify the timing or procedures for other assessments.
The registry record lists 5 outcome measures and 0 analyses. The listed secondary outcomes concern inflammatory markers; calcium, phosphorous, calcium x phosphorous product, and parathyroid hormone levels; iron supplementation; and erythropoietin adjusted for changes in inflammatory markers, vitamin D levels, and clinical and demographic confounders. No outcome results are posted in the record. A planned sample-size rationale, interim-analysis plan, and detailed statistical plan 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.
Before assignment: Participants were assessed for study inclusion based on chronic kidney disease (CKD) stage, age, current vitamin D levels \<30 ng/ml as well as history of vitamin D levels \< 30, and stable dose of erythropoietin and iron.
Overall Study
| Stage | Ergocalciferol Supplementation |
|---|---|
| STARTED | 6 |
| COMPLETED | 0 |
| NOT COMPLETED | 6 |
Reasons for not completing this period:
| Reason | Ergocalciferol Supplementation |
|---|---|
| Withdrawal by Subject | 1 |
| Adverse Event | 1 |
| Study terminated due to low enrollment. | 4 |
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 | Ergocalciferol Supplementation |
|---|---|---|
| Participants analysed | 6 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 1 |
| Age, Categorical: >=65 years | Participants | 5 |
| Sex: Female, Male: Female | Participants | 3 |
| Sex: Female, Male: Male | Participants | 3 |
| Region of Enrollment: United States | participants | 6 |
6. Primary Endpoint
The registry lists the primary outcome as Evaluate if Ergocalciferol Supplementation to Achieve 25-hydroxy Vitamin D Levels > 40ng/ml Will Decrease Erythropoietin Requirements, measured over 24 Weeks.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary outcome is framed as whether ergocalciferol supplementation to achieve 25-hydroxy Vitamin D levels > 40ng/ml will decrease erythropoietin requirements. Its stated timeframe is 24 Weeks. In clinical terms, the question focuses on the amount of erythropoietin needed to maintain a nonanemic state, as described in the study hypothesis, rather than on a comparison between separate treatment groups.
The endpoint is relevant to the stated study question because erythropoietin requirement is the outcome the investigators proposed would change following supplementation. The registry record does not specify the outcome's unit, the method used to summarize or compare erythropoietin requirements, or the exact assessment schedule. Those details are not reported in the registry record. Nor does the record provide baseline and follow-up values, a change estimate, a measure of variability, or an analysis of the primary endpoint.
Consequently, the endpoint's clinical rationale can be described, but its observed behavior cannot be evaluated from the posted results. Without a reported estimate and its uncertainty, there is no basis in the registry record to determine the direction or precision of any change. The single-group design also means that even a reported before-and-after change would not by itself provide a randomized comparison with a control group.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a clinically specific hypothesis: ergocalciferol supplementation in people with chronic kidney disease and vitamin D deficiency might be associated with lower erythropoietin requirements. It states that the goal was to achieve 25-hydroxy Vitamin D levels > 40ng/ml and gives a primary outcome timeframe of 24 Weeks. These details describe the question and intended observation period. They are not evidence that the target was achieved or that erythropoietin requirements changed.
The posted record lists an enrollment of 6 and a single-group model. It does not list a separate control group, and allocation is NA. There is therefore no randomized comparison in the registry record. The record lists 0 analyses, and it contains no primary outcome estimate, participant-level outcome summary, confidence interval, p-value, or measure of dispersion. The primary outcome's unit is also not reported in the registry record. As a result, neither the magnitude nor the precision of any change can be assessed from the posted results.
Several secondary outcome topics are named, including inflammatory markers, mineral and parathyroid hormone measures, iron supplementation, and adjusted erythropoietin. Their names indicate what was of interest, but the registry record does not give numerical results for them. It also does not report which participants contributed data to any outcome or how missing observations were handled. The absence of posted estimates is not evidence that an outcome did not change; it means that the registry record does not permit an estimate of change.
The study is marked TERMINATED. That status does not, by itself, explain why enrollment or follow-up ended, whether the planned assessments were completed, or whether termination was connected to the results. The reason is not reported in the registry record. The record also does not describe the study's sample-size justification or a planned interim analysis, so those features cannot be reconstructed.
Any sample-size figures displayed with the analysis are planning illustrations, not results from participants and not observed power. Their stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. Those assumptions do not turn this single-group study into a two-arm comparison, nor do they establish the study's actual design or analysis plan. The registry record supplies no primary outcome estimate to interpret alongside such planning illustrations.
The sound reading is therefore limited: the registry describes a small, terminated, single-group study and states its intended clinical question, but posts no outcome analyses with which to answer it. No conclusion about the size, direction, or precision of a treatment-associated change can be drawn from this record alone.
9. Statistical Methods Explained
The methods can be understood by separating the study design, the outcome being targeted, and the statistical evidence needed to interpret a result. The registry record identifies a single-group model, an enrollment of 6, and no separate control group. It lists 0 analyses. Thus, the record gives a study question and design description but does not report an analyzed estimate for the primary outcome.
What a single-group study can estimate
In general, a single-group study can describe outcomes among participants receiving the intervention. If outcomes are collected at more than one time, an analysis may describe within-participant change, provided the relevant measurements and analysis are reported. Such a change is not automatically an effect caused by the intervention. Without a concurrent comparison group, changes over time may also reflect other influences, measurement variation, changes in care, or participant characteristics. These are general design considerations, not findings about this study.
The registry record names no control arm and gives allocation as NA. A comparison between treated participants and a control group is therefore not available in the registered design. The record also leaves the arm description blank, so it does not clarify how participants were handled beyond naming the supplementation intervention. The dose, timing, and adherence details are not reported in the registry record.
What an endpoint estimate would contribute
An outcome estimate would describe the observed value or change in erythropoietin requirements, according to a defined measurement and analysis. A measure of variability would indicate how dispersed individual observations were around a summary. A confidence interval, in general, describes the range of values compatible with the data and the method's assumptions; it is not a guarantee that the true value lies within that range. A p-value, in general, measures how unusual the data would be under a specified null model. Neither a confidence interval nor a p-value can substitute for the size and clinical meaning of an estimate.
For this primary outcome, the registry record gives the objective and timeframe, but does not report the outcome unit, numerical values, variability, confidence interval, or p-value. Those quantities cannot be interpreted when they are absent. The registry record does not report an analysis method for the primary outcome, so it is not possible to assess which summary or model was intended.
Why dispersion and model assumptions matter
In general, outcome distributions may be more variable or less symmetric than a simple statistical model assumes. Over-dispersion means that variability is greater than a model expects; if ignored, uncertainty can be understated. A model's assumptions should therefore be matched to the outcome's scale and distribution. This is general statistical guidance. The registry record does not describe the primary endpoint's scale, its distribution, or a model used to analyze it, so no assessment of over-dispersion or other assumptions is possible for this study.
Adjustment can be useful when prespecified covariates are measured and a suitable model is chosen. The listed secondary outcome includes erythropoietin adjusted for changes in inflammatory markers, vitamin D levels, and clinical and demographic confounders. The record does not specify which variables were measured, how they were defined, which adjustment model was used, or whether this outcome was analyzed. The outcome's listing is not evidence that an adjusted estimate was produced.
How to read the planning illustrations
Planning calculations answer a different question from an outcome analysis. They illustrate the number of participants that would be needed under stated assumptions to detect a chosen effect at a specified significance level and power. They do not show that the study actually had that power, and they are not a measure of the probability that a reported finding is true. The stated sample-size illustration uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It is explicitly not the trial's own design.
Because this study is listed as single group with no control arm, assumptions about equal allocation between two arms describe a hypothetical planning scenario, not the registered trial structure. The illustration is described as based on the observed effect, with the effect to detect set as a stated fraction of that observed effect. The registry record does not report the primary outcome estimate or analysis from which to assess such an effect. Any displayed planning values should therefore be read only as conditional illustrations, not as trial findings or observed power.
What the record permits
Statistical interpretation depends on reporting the analysis population, endpoint definition, estimate, and uncertainty, along with enough detail to assess the assumptions. Here, the record lists 5 outcome measures and 0 analyses, but no numerical outcome findings. It is not possible to reconstruct missing analyses from the study title, hypothesis, enrollment, or adverse-event counts. General statistical principles can explain what evidence would be needed, but they cannot supply the absent result.
10. Multiplicity, Missing Data and Analysis Populations
The record lists 5 outcome measures, including the primary question and secondary topics covering inflammatory markers, mineral and parathyroid hormone measures, iron supplementation, and adjusted erythropoietin. When a study examines multiple outcomes, multiplicity is a general statistical concern: the chance of at least one apparently notable result can increase as more analyses are conducted. Common approaches include defining a primary outcome in advance, ordering hypotheses, or adjusting inference across selected comparisons. The registry record does not report a multiplicity strategy, so it is not possible to assess whether or how it was addressed.
The record lists 0 analyses and does not provide outcome estimates. Thus there are no posted outcome tests to interpret, and no reported adjustment method to evaluate. The presence of several named outcomes does not establish that every outcome was measured or analyzed.
Missing-data methods and analysis populations are also not reported in the registry record. It does not state whether all enrolled participants contributed primary outcome data, how incomplete follow-up was handled, or whether any participants were excluded from an analysis. The reason for termination is not reported either. These omissions limit assessment of potential bias: when data are unavailable, the result can depend on which observations are missing and why. No conclusion about missingness or participant completion can be drawn from enrollment alone.
In general, an analysis population should be described so readers can understand who contributed to each estimate. A missing-data approach should also make clear what assumptions were used and whether sensitivity analyses were performed. Those details are not reported in the registry record, so neither the analysis population nor the robustness of any result can be assessed.
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 |
|---|---|---|---|
| Ergocalciferol Supplementation | 0 | 6 | 0.0% |
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 |
|---|---|
| Ergocalciferol Supplementation | 1 of 6 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Ergocalciferol Supplementation |
|---|---|---|
| Low Hemoglobin | Blood and lymphatic system disorders | 1 of 6 |
The registry record lists safety counts for the Ergocalciferol Supplementation group. For serious adverse events, it records 6 at risk and 0 affected. For other adverse events, it records 6 at risk and 1 affected. These are counts in the posted safety record; they do not describe the event types, timing, severity details, or relationship to the intervention.
No serious adverse-event terms are listed. This should be read as an absence of listed terms in the registry record, not as a detailed account of event surveillance. The death count is not reported in the registry record. It should not be interpreted as a reported count of no deaths.
Safety counts alone do not establish whether an intervention caused an event. In a single-group study, there is no separate comparison group in this record to contextualize the observed counts. The enrollment is 6, so the safety figures describe a limited group of participants and do not provide a precise estimate of event frequency in a broader population. The record does not report additional information needed to judge event definitions, ascertainment, follow-up completeness, or attribution. These counts should therefore be read descriptively and not as a comparative safety analysis.
12. What the Result Does, and Does Not, Mean
The record establishes that a study was registered to examine whether ergocalciferol supplementation intended to achieve 25-hydroxy Vitamin D levels > 40ng/ml would decrease erythropoietin requirements over 24 Weeks. It also establishes that the study was single group, had an enrollment of 6, and is marked TERMINATED. These are details about the study design and registry status, not a statement of efficacy.
The posted record does not report a primary outcome estimate, its variability, or an analysis. It therefore does not show the direction or size of any change in erythropoietin requirements, nor how precisely such a change was measured. It also does not report whether the vitamin D target was attained. The listed secondary outcomes have no numerical results in the record. The clinical hypothesis cannot be confirmed or rejected using the posted results.
Even if a within-participant change were available, the single-group design would not provide a randomized control comparison. A change over time could be associated with the intervention, but the design alone would not separate that association from other possible influences. This is a general limitation of uncontrolled before-and-after evidence, not a claim about what happened in these participants.
The record's safety counts provide limited descriptive information: 0 serious adverse events among 6 at risk and 1 affected participant among 6 at risk for other adverse events. Event details and the death count are not reported in the registry record. These figures do not establish causation or characterize risk with precision.
Planning calculations, if displayed, are hypothetical sample-size illustrations under their stated assumptions. They are not observed findings, do not demonstrate that the study had a particular power, and cannot replace missing outcome estimates. Overall, the registry record describes a research question and a small terminated study but does not post the outcome evidence needed to quantify or interpret the primary result.
13. Why This Trial Matters Statistically
This study is statistically informative as an example of the distinction between a research hypothesis and a reported result. The hypothesis specifies a possible relationship between ergocalciferol supplementation and erythropoietin requirements, while the registry record supplies no analyzed primary outcome estimate. A clear endpoint question is important, but it does not tell readers what the data showed.
The single-group design also matters. A treated group can be described, and repeated measurements could describe change if reported, but the registry record has no control group for a randomized contrast. This affects the kind of conclusion the design could support even if outcome data were available. It also explains why hypothetical planning calculations based on two-arm assumptions should not be mistaken for the study's design.
The record includes named secondary outcomes and safety counts, yet no analyses. That distinction matters because a list of outcomes is not a list of findings. Without estimates and uncertainty, readers cannot assess the magnitude, precision, or consistency of results across outcomes. Missing information on analysis populations, missing data, multiplicity, and the reason for termination further limits evaluation of how the study was conducted and interpreted.
For clinical researchers, the record illustrates why outcome reporting should include clear definitions, measurement units, estimates, uncertainty, analysis methods, and participant accounting. For biostatisticians, it underscores the need to distinguish descriptive safety counts, outcome analyses, and planning scenarios. Each answers a different question. The registry record supports description of the design and stated aims, but not a statistical conclusion about whether the primary outcome changed.
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 principal trial-specific limitation is the absence of posted outcome analyses. The registry record lists 0 analyses, does not provide primary or secondary outcome estimates, and does not report a measure of variability or uncertainty for the primary outcome. The primary outcome's unit is not reported in the registry record. As a result, the central question about erythropoietin requirements cannot be evaluated quantitatively.
The study is single group, with allocation recorded as NA and no separate control group listed. This precludes a randomized between-group comparison in the registered design. Enrollment is 6, and the record does not report a sample-size justification, participant flow, or number completing follow-up. The status is TERMINATED, but the reason for termination is not reported in the registry record.
Details needed to assess outcome measurement and implementation are also absent. The arm description is blank, and the dose, schedule, adherence, and endpoint measurement procedures are not reported in the registry record. The record does not specify the analysis population, missing-data method, statistical model, multiplicity approach, or interim-analysis plan. It also does not report whether the stated vitamin D target was achieved.
Safety reporting is limited to aggregate affected and at-risk counts, without listed serious adverse-event terms or event details; the death count is not reported in the registry record. These constraints make the safety information descriptive rather than comparative. Collectively, the omissions prevent assessment of the primary outcome's magnitude, precision, robustness, and relationship to the intervention.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Effects of Ergocalciferol on Erythropoetin Stimulating Agent Dose — NCT01263028.
- Registry record last updated 2015-03-30; status last verified 2015-03.
- Results first posted 2012-09-20.
- 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.
18. Record Summary
The registry record describes a terminated, single-group study of ergocalciferol supplementation in Chronic Kidney Disease Stages 3-5. Kaiser Permanente is listed as sponsor, enrollment is 6, masking is NONE, and allocation is NA. The recorded start is 2010-08 and primary completion is 2011-09.
The primary question concerns whether supplementation intended to achieve 25-hydroxy Vitamin D levels > 40ng/ml will decrease erythropoietin requirements over 24 Weeks. The record lists 5 outcome measures and 0 analyses. It does not report primary or secondary outcome estimates, the primary outcome unit, or a detailed statistical plan. Safety counts list 0 serious adverse events among 6 at risk and 1 affected among 6 at risk for other adverse events; the death count is not reported in the registry record.
The posted record therefore supports a description of the study's aim, design, status, and limited safety counts, but does not provide analyzed results with which to answer the primary question.