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 Study to Evaluate Safety of Vitamin D Receptor Activators in Patients Ages 0 to 16 With Chronic Kidney Disease Stage 5 Receiving Peritoneal Dialysis Within Current Clinical Practice (NCT01134315), a registered phase not stated study. The primary outcome is Percentage of Participants With at Least One Incidence of Hypercalcemia.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01134315 |
| Phase | Phase not stated |
| Condition | Secondary Hyperparathyroidism, End-Stage Renal Disease |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 61 |
| Arms in the primary outcome | n/a |
| Lead sponsor | AbbVie (prior sponsor, Abbott) |
| Results posted | Yes |
2. Clinical Question
Population
Pediatric participants ages 0 to 16 with stage 5 chronic kidney disease receiving peritoneal dialysis and treatment for secondary hyperparathyroidism. The study enrolled 61 participants; the primary outcome population was defined as participants who received at least one dose of either study drug.
Intervention
Paricalcitol capsules prescribed by each participant’s physician under that physician’s usual and customary practice. The study observed safety during clinical use rather than assigning treatment according to a stated standardized dosing protocol.
Comparator
Calcitriol prescribed under each physician’s usual and customary practice. The registry does not state how treatment allocation occurred. This was not a randomized comparison, so the arms should not be treated as like-for-like controls.
Primary question
What percentage of treated participants had at least one incidence of hypercalcemia during monitoring? Hypercalcemia was defined as calcium >10.2 mg/dL, and results were intended for the overall population and groups followed for less than 3 months or at least 3 months. Those outcome percentages are not reported in the registry record.
3. Trial Design
This was a prospective, multicenter observational safety study of paricalcitol capsules in pediatric participants with stage 5 chronic kidney disease receiving peritoneal dialysis. The stated objective was to observe paricalcitol use in participants being treated for secondary hyperparathyroidism. The registry also describes a calcitriol group. Physicians prescribed either drug under their usual and customary practice.
The study began in 2010-06, and its primary completion date was 2012-05. Its status is listed as terminated. The registry says participants were to be followed for a minimum of 3 months and up to approximately 36 months. The primary outcome monitoring timeframe is described separately as extending from informed consent through the end of the study plus 30 days, with a stated total of 745 days.
Allocation is not stated in the registry record, and the study was not a randomized comparison. The two treatment groups therefore cannot be assumed to have been comparable at baseline or during follow-up. Differences in who received each drug, clinical characteristics, prescribing decisions, and time observed could affect a descriptive comparison. The registry record does not report a protocol-level statistical analysis plan or explain why the study was terminated.
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 | Paricalcitol | Calcitriol |
|---|---|---|
| STARTED | 21 | 40 |
| COMPLETED | 12 | 21 |
| NOT COMPLETED | 9 | 19 |
Reasons for not completing this period:
| Reason | Paricalcitol | Calcitriol |
|---|---|---|
| Adverse Event | 1 | 2 |
| Other Reason | 8 | 17 |
Analysis population for the primary outcome, as defined in the registry: All Treated Population (all participants who received at least 1 dose of paricalcitol \[paricalcitol group\] or at least one dose of calcitriol \[calcitriol group\]).
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 | Paricalcitol | Calcitriol | Total |
|---|---|---|---|---|
| Participants analysed | 21 | 40 | 61 | |
| Age, Customized: <8 years | participants | 5 | 19 | 24 |
| Age, Customized: >=8 years | participants | 16 | 21 | 37 |
| Sex: Female, Male: Female | Participants | 7 | 12 | 19 |
| Sex: Female, Male: Male | Participants | 14 | 28 | 42 |
| Region of Enrollment: United States | participants | 21 | 40 | 61 |
6. Primary Endpoint
The registry lists the primary outcome as Percentage of Participants With at Least One Incidence of Hypercalcemia, measured over Monitored from time of informed consent through end of study + 30 days (total of 745 days)..
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | percentage of participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint was the percentage of participants with at least one incidence of hypercalcemia. The registry defines hypercalcemia as calcium >10.2 mg/dL and specifies the All Treated Population: participants who received at least one dose of paricalcitol or at least one dose of calcitriol. This endpoint expresses how common a recorded event was in the treated population over the monitoring period; it does not describe the severity or duration of an event.
The endpoint was monitored from informed consent through the end of the study plus 30 days, a stated total of 745 days. The registry planned to report the overall treated population and two follow-up-duration subgroups: participants in the study for less than 3 months and those in the study for at least 3 months. The subgroup definitions make duration of observation relevant to interpretation, since participants followed for different lengths of time have different opportunities for an event to be observed.
A binary percentage is useful for presenting whether an event occurred, but its interpretation depends on a clear denominator, complete outcome ascertainment, and the observation period. The registry record does not report the actual group-specific primary endpoint percentages or their uncertainty.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central limitation for interpreting the primary safety question is that the registry record gives the endpoint definition and monitoring period but does not report the actual hypercalcemia percentages. It therefore does not establish from the posted primary outcome data how often hypercalcemia occurred in either treatment group, nor how precisely those event proportions were estimated. No primary endpoint confidence intervals or p-values are reported in the registry record.
The design also limits comparisons between paricalcitol and calcitriol. Treatment was prescribed in usual clinical practice, allocation is not stated, and the registry identifies the study as not randomized. Consequently, the groups may differ in ways that influence both treatment choice and observed safety outcomes. A difference between descriptive group results, if available, would not by itself isolate a treatment effect. The registry record does not report an adjusted comparative analysis.
The planned follow-up varied: participants were to be followed for a minimum of 3 months and up to approximately 36 months, while the primary outcome description gives a monitoring window through the end of the study plus 30 days. The record also defines subgroups by whether participants were in the study for less than 3 months or at least 3 months. Event percentages across groups with different observation durations need to be read with care, because a longer period of observation can provide more opportunity to record an event. The actual subgroup results and details of handling incomplete follow-up are not reported.
The adverse-event summaries provide some descriptive safety counts: the serious adverse-event figures list 8 of 21 for paricalcitol and 26 of 40 for calcitriol. Other adverse-event figures list 15 of 21 and 29 of 40, respectively. These are descriptive summaries, not evidence of a causal difference between treatments. The record does not report deaths, and the listed serious-event terms do not substitute for the missing primary hypercalcemia results.
Overall, the registry record documents the study’s clinical question, outcome definition, and selected safety summaries, but it does not provide the primary event percentages or an inferential analysis of the treatment groups. Conclusions about comparative risk, precision, or treatment effect cannot be drawn from the reported primary outcome information.
9. Statistical Methods Explained
The registry describes a binary primary endpoint: whether a participant had at least one incidence of hypercalcemia during the specified monitoring period. A participant meeting that definition contributes to the event category; a participant without a recorded qualifying event contributes to the non-event category, subject to the outcome and follow-up information available. The endpoint is expressed as a percentage of participants, so the denominator and the completeness of follow-up are important to understanding any reported percentage. The registry record does not report the actual endpoint percentages.
What does a percentage measure?
As a general statistical explanation, an event percentage is a proportion of a defined group in which the outcome was recorded. It is a descriptive quantity, not a measure of how precisely the underlying event frequency is known. Precision is commonly conveyed with a confidence interval. A confidence interval describes the range of values compatible with the observed data under a statistical model; a wider interval indicates less precision. No confidence interval for the primary outcome is reported in the registry record, so its precision cannot be assessed from the primary results described there.
The registry defines the primary outcome as hypercalcemia, with a threshold of calcium >10.2 mg/dL, and specifies monitoring from informed consent through the end of the study plus 30 days. It also specifies an overall result and follow-up-duration subgroups. Those details identify what was to be counted and the intended observation window, but they do not reveal the actual count of events or the percentage in each group. The subgroup distinction matters because a proportion observed after a shorter period may not have the same opportunity to capture events as one observed over longer follow-up.
What can the treatment groups establish?
As a general statistical point, a randomized comparison uses allocation by chance to help balance measured and unmeasured characteristics between groups. Here, the registry states that the comparison was not randomized and does not state how participants were allocated. Treatment was prescribed by physicians within their usual practice. Clinical characteristics or prescribing choices could therefore differ between the groups. Descriptive outcomes can characterize what was recorded among participants receiving each drug, but they do not, on their own, establish that a difference was caused by the drug.
An adjusted analysis can sometimes account for recorded differences between groups, but it cannot automatically eliminate confounding, particularly from factors not measured or not included. The registry record does not report an adjusted comparative analysis, its covariates, or a statistical analysis plan. It also lists zero analyses in the registry analysis record. That absence should not be read as proof that no analysis was conducted outside the registry; it means the registry record does not provide analysis entries to evaluate.
How should planning calculations be read?
As a general explanation, sample-size calculations describe the number of participants that a future study might need under stated assumptions. They are planning illustrations, not observed power and not evidence that a study was adequately powered after the fact. The stated planning approach uses a two-sided significance level of 0.05, equal allocation between the arms, a normal approximation, and effects set as a stated fraction of the observed effect. The registry record does not report the trial’s own sample-size justification or design assumptions. Planning estimates based on an observed effect are particularly dependent on how that effect was estimated; they do not repair the limitations of a nonrandomized comparison.
For a binary endpoint, the event frequency used in planning can influence the estimated sample size, and uncertain or missing event results limit the ability to assess such calculations. No sample-size estimate or observed primary effect is reported in the registry record. Any planning illustration should therefore be read only as a hypothetical design scenario, not as a result of this study.
Why can over-dispersion matter?
As a general statistical explanation, over-dispersion occurs when observed variability exceeds what a chosen model assumes. If a model underestimates variability, uncertainty intervals can be too narrow and tests can appear more decisive than warranted. The registry record does not describe an over-dispersion assessment or identify a model for the primary binary outcome. It is therefore not possible to determine whether such a model issue was considered. The basic interpretive priorities remain the missing primary results, variable follow-up, and nonrandomized treatment assignment.
More generally, the registry’s endpoint definition and population description help readers understand what the intended safety measure represents. They are not a substitute for event counts, denominators by outcome group, uncertainty estimates, and a transparent account of analysis choices. Those primary outcome details are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists eight outcome measures overall, including the primary hypercalcemia measure and secondary safety and laboratory outcomes. Secondary measures include treatment-emergent adverse events, serious adverse events, deaths and discontinuations due to adverse events, as well as baseline values and changes in laboratory measures at the final visit. The registry record does not report a multiplicity strategy, such as whether particular outcomes were designated as confirmatory or how multiple statistical tests would be interpreted. No registry analysis entries are listed.
As a general statistical point, evaluating many outcomes can increase the chance that at least one result appears notable by chance when each is tested separately. A prespecified approach to multiplicity can help readers distinguish confirmatory findings from exploratory ones. Without a reported strategy or analysis plan, the strength of any inference across multiple outcomes cannot be assessed. This does not establish that an unreported strategy was or was not used outside the registry.
The primary population is defined as all treated participants who received at least one dose of either study drug. The registry record does not report how missing outcome observations, early discontinuations, or different follow-up lengths were handled in the primary analysis. It also does not describe imputation, censoring, or sensitivity analyses. These omissions matter because the endpoint is observed over time and follow-up was planned to vary. The actual amount and pattern of missing outcome data are not reported in the registry record.
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 |
|---|---|---|---|
| Paricalcitol | 8 | 21 | 38.1% |
| Calcitriol | 26 | 40 | 65.0% |
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 |
|---|---|
| Paricalcitol | 15 of 21 |
| Calcitriol | 29 of 40 |
Most frequent serious adverse event terms
| Event term | Organ system | Paricalcitol | Calcitriol |
|---|---|---|---|
| Peritonitis | Infections and infestations | 4 of 21 | 8 of 40 |
| Pyrexia | General disorders | 1 of 21 | 3 of 40 |
| Dehydration | Metabolism and nutrition disorders | 1 of 21 | 2 of 40 |
| Hypertension | Vascular disorders | 1 of 21 | 2 of 40 |
| Anaemia | Blood and lymphatic system disorders | 0 of 21 | 2 of 40 |
| Vomiting | Gastrointestinal disorders | 0 of 21 | 2 of 40 |
| Catheter Site Erosion | General disorders | 1 of 21 | 1 of 40 |
| Medical Device Complication | General disorders | 0 of 21 | 2 of 40 |
| Otitis Media | Infections and infestations | 0 of 21 | 2 of 40 |
| Pneumonia | Infections and infestations | 0 of 21 | 2 of 40 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Paricalcitol | Calcitriol |
|---|---|---|---|
| Upper Respiratory Tract Infection | Infections and infestations | 3 of 21 | 5 of 40 |
| Nausea | Gastrointestinal disorders | 2 of 21 | 5 of 40 |
| Diarrhoea | Gastrointestinal disorders | 1 of 21 | 5 of 40 |
| Abdominal Pain | Gastrointestinal disorders | 1 of 21 | 4 of 40 |
| Vomiting | Gastrointestinal disorders | 1 of 21 | 4 of 40 |
| Pyrexia | General disorders | 1 of 21 | 4 of 40 |
| Catheter Site Infection | Infections and infestations | 2 of 21 | 3 of 40 |
| Peritonitis | Infections and infestations | 2 of 21 | 3 of 40 |
| Pharyngitis Streptococcal | Infections and infestations | 3 of 21 | 2 of 40 |
| Cough | Respiratory, thoracic and mediastinal disorders | 3 of 21 | 2 of 40 |
Serious events with the highest arm-level rate: peritonitis (20.0%), convulsion (9.5%), pyrexia (7.5%), anaemia (5.0%), vomiting (5.0%).
The serious adverse-event summaries report 8 of 21 for the paricalcitol group and 26 of 40 for the calcitriol group. The other adverse-event summaries report 15 of 21 and 29 of 40, respectively. These are descriptive counts in the registry record; they should not be read as randomized treatment comparisons or as estimates adjusted for differences between the groups. The registry states that treatment was prescribed in usual clinical practice and that allocation was not stated.
The registry also lists serious-event terms with percentages: Peritonitis, 20.0%; Convulsion, 9.5%; Pyrexia, 7.5%; Anaemia, 5.0%; Vomiting, 5.0%; and Medical Device Complication, 5.0%. The denominators for these term percentages are not described in the record, so they should not be interpreted as percentages of all participants without further information. Deaths are not reported in the registry record. These safety summaries do not provide the missing primary hypercalcemia results.
12. What the Result Does, and Does Not, Mean
The study record is relevant as a description of safety monitoring for paricalcitol capsules and calcitriol in pediatric participants with stage 5 chronic kidney disease receiving peritoneal dialysis. It identifies hypercalcemia as the primary safety endpoint, defines the calcium threshold, specifies the treated population, and describes the intended monitoring period. It also reports selected adverse-event counts and serious-event terms.
However, the primary endpoint percentages are not reported in the registry record. Without those results, readers cannot assess the observed frequency of hypercalcemia in either treatment group or the precision of an estimate. The record also does not provide a comparative statistical analysis, confidence intervals, or p-values for the primary endpoint. The listed serious adverse-event counts describe recorded events but do not answer the primary hypercalcemia question.
The study was not randomized, and allocation is not stated. The two groups may therefore differ in participant characteristics, clinical circumstances, or prescribing patterns. Even if outcome percentages were available, a simple difference between these groups would not establish that one drug caused a different event frequency. The record does not report an adjusted analysis that might address measured group differences.
The findings should not be interpreted as proving that either treatment is safe or unsafe, or as establishing comparative effectiveness. The registry describes a safety study and its intended measures, but the missing primary results and limited analysis information prevent strong conclusions about comparative risk. The adverse-event summaries are descriptive and require the same caution about nonrandomized treatment selection.
13. Why This Trial Matters Statistically
This trial is statistically notable because its question concerns a defined safety event in a pediatric population with stage 5 chronic kidney disease receiving peritoneal dialysis, while treatment was used in usual clinical practice. A pragmatic, nonrandomized record can describe what was observed in clinical use, but its treatment groups do not have the protection against confounding that random allocation is intended to provide. The registry does not state how participants entered each group.
The endpoint also highlights the importance of aligning an event definition with its observation period. Hypercalcemia was defined using a stated calcium threshold and monitored over a period that could differ among participants. The registry planned duration-based subgroups, making length of observation part of the interpretation rather than a minor detail. The primary results needed to evaluate those groups are not reported.
For biostatistical readers, this record illustrates why a clear endpoint definition is only one part of interpretable evidence. Denominators, event counts, follow-up completeness, uncertainty estimates, analysis choices, and a transparent treatment comparison are also needed. The record provides some safety counts but no reported primary endpoint percentages or registry analysis entries. Those limitations set a boundary on what the study can contribute to comparative inference.
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.
Important trial-specific limitations include the absence of reported primary hypercalcemia results and the lack of a reported inferential analysis. The registry defines the event and monitoring window but does not provide the outcome percentages by treatment group or follow-up-duration subgroup. It also does not report confidence intervals, p-values, or an adjusted comparison. The registry lists zero analysis entries, while the statistical plan and rationale for the study’s termination are not reported in the registry record.
The design is observational, treatment was prescribed under usual clinical practice, and allocation is not stated. Differences between treatment groups could reflect clinical choices or participant characteristics as well as treatment. The record does not report baseline comparability or an approach for addressing confounding. Planned follow-up ranged from a minimum of 3 months to approximately 36 months, while the primary outcome description specifies monitoring through the end of the study plus 30 days. The handling of variable follow-up and missing outcome data is not reported.
The registry lists secondary safety and laboratory outcomes but does not report a multiplicity strategy or details of missing-data methods. Deaths are not reported. The serious-event term percentages have no stated denominators in the record. These limitations mean that the available descriptive safety summaries cannot resolve the primary outcome question or support a causal comparison.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study to Evaluate Safety of Vitamin D Receptor Activators in Patients Ages 0 to 16 With Chronic Kidney Disease Stage 5 Receiving Peritoneal Dialysis Within Current Clinical Practice — NCT01134315.
- Registry record last updated 2013-08-13; status last verified 2013-05.
- Results first posted 2013-08-13.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
NCT01134315 was a prospective, multicenter safety study of paricalcitol capsules and calcitriol in pediatric participants ages 0 to 16 with stage 5 chronic kidney disease receiving peritoneal dialysis and treatment for secondary hyperparathyroidism. The registry lists enrollment of 61, a start date of 2010-06, a primary completion date of 2012-05, and status as terminated. Treatment was prescribed according to usual clinical practice; allocation is not stated, and the study was not randomized.
The primary endpoint was the percentage with at least one incidence of hypercalcemia, defined as calcium >10.2 mg/dL. The registry record does not report the primary outcome percentages or a comparative analysis. It reports selected adverse-event counts and serious-event terms, but deaths are not reported. Missing primary results, nonrandomized treatment assignment, variable follow-up, and unreported analysis and missing-data methods limit comparative interpretation.