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 Comparison of NovaFerrum® vs Ferrous Sulfate Treatment in Young Children With Nutritional Iron Deficiency Anemia (NCT01904864), a randomized phase 4 study. The primary outcome is Hemoglobin Concentration Over Time.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01904864 |
| Phase | Phase 4 |
| Condition | Iron Deficiency Anemia |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 80 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Texas Southwestern Medical Center |
| Results posted | Yes |
2. Clinical Question
Population
Infants and young children with nutritional iron deficiency anemia were the intended population. The registry describes a single-center study and lists iron deficiency anemia as the condition. It does not report further eligibility details or a demographic description of enrolled participants, so the age range, baseline clinical characteristics, and other features of the population cannot be characterized from this record.
Intervention
The intervention was a once-daily dose of elemental iron as NovaFerrum®, described as a 15 mg/ml preparation given at 3mg/kg for 12 weeks. The trial aimed to assess this regimen in children with nutritional iron deficiency anemia. The registry does not report adherence results or enough information to assess how closely participants followed the dosing schedule.
Comparator
The comparator was a once-daily dose of elemental iron as ferrous sulfate, also described as a 15 mg/ml preparation given at 3mg/kg for 12 weeks. Both arms therefore had the same stated dose and treatment duration, while the iron preparations differed. The record does not provide further information about treatment administration or concomitant care.
Primary question
The primary question was whether the change in peripheral blood hemoglobin concentration over 12 weeks differed between the two treatment groups. Hemoglobin was to be measured at 0, 4, 8, and 12 weeks after treatment began. The stated hypothesis favored greater hemoglobin increase with NovaFerrum®, but the registry record does not report the observed changes, an estimated between-group contrast, or an inferential result. The hypothesis is therefore a statement of the question, not evidence of the answer.
3. Trial Design
The registry describes a randomized, quadruple-masked, parallel-group, phase 4 study sponsored by the University of Texas Southwestern Medical Center. It was single-center and had an enrollment of 80. The study status is completed. The recorded start was 2013-07 and primary completion was 2015-11. The record describes treatment for infants and young children with nutritional iron deficiency anemia.
Participants were assigned to NovaFerrum® or ferrous sulfate. Each arm description specifies a single daily dose of 3mg/kg from a 15 mg/ml elemental iron preparation for 12 weeks. The arms thus share a stated dosing schedule and duration; the comparison concerns the preparations. The record does not report details of sequence generation, concealment of allocation, how masking was maintained, or which individuals were masked. The label quadruple-masked should not be taken to establish those operational details.
The planned primary outcome was hemoglobin concentration over time, expressed in g/dL, with a 12-week timeframe. The registry describes serial measurements at 0, 4, 8, and 12 weeks after treatment initiation. Its stated primary analysis was a linear mixed regression model, with treatment and time as covariates and patient random effects to account for correlation among repeated measurements within a participant.
The record also lists secondary aims concerning adverse effects, laboratory measures of iron stores, adherence, and once-daily dosing. It does not give reported results for those aims in the outcome information summarized in the registry record. The participant flow, numbers completing follow-up, protocol deviations, and analysis-population definitions are not reported in the registry record. Consequently, the design can be described, but the conduct and completeness of the analysis cannot be fully evaluated.
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 | NovaFerrum® (Iron Polysaccharide Complex) | Ferrous Sulfate |
|---|---|---|
| STARTED | 40 | 40 |
| COMPLETED | 31 | 28 |
| NOT COMPLETED | 9 | 12 |
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 | NovaFerrum® (Iron Polysaccharide Complex) | Ferrous Sulfate | Total |
|---|---|---|---|---|
| Participants analysed | 40 | 40 | 80 | |
| Age, Continuous | Months | 23 (11 to 34) | 22 (10 to 37) | 23 (10 to 37) |
| Sex: Female, Male: Female | Participants | 18 | 18 | 36 |
| Sex: Female, Male: Male | Participants | 22 | 22 | 44 |
| Race/Ethnicity, Customized: Hispanic white | Participants | 26 | 23 | 49 |
| Race/Ethnicity, Customized: Non-Hispanic white | Participants | 3 | 4 | 7 |
| Race/Ethnicity, Customized: Black | Participants | 4 | 5 | 9 |
| Race/Ethnicity, Customized: Asian | Participants | 2 | 2 | 4 |
| Race/Ethnicity, Customized: Native Hawaiian/Pacific Islander | Participants | 1 | 0 | 1 |
| Race/Ethnicity, Customized: >1 Race/ethnicity | Participants | 4 | 6 | 10 |
| Region of Enrollment: United States | Participants | 40 | 40 | 80 |
6. Primary Endpoint
The registry lists the primary outcome as Hemoglobin Concentration Over Time, measured over 12 weeks.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | g/dL |
| Endpoint classification | Continuous Endpoint |
The primary endpoint concerns change in peripheral blood hemoglobin concentration during treatment. Hemoglobin is a continuous laboratory measure, recorded in g/dL. In this trial it was planned to be measured at baseline, identified as 0 weeks, and again at 4, 8, and 12 weeks after treatment began. The outcome description calls for serial measurements rather than a single measurement at the end of treatment.
Using a continuous measure can retain information about the amount of change across participants, rather than reducing the result to a category such as improved or not improved. Repeated measurements can also describe the pattern of change over time. These are general statistical reasons for using a longitudinal continuous outcome; they do not establish that a particular treatment caused a change.
The registry states that the primary analysis would use a linear mixed regression model with treatment and time as covariates and patient random effects. In general, a mixed model can account for the fact that repeated measurements from the same participant are related, rather than treating each measurement as independent. The record does not report the model’s estimated treatment contrast, its uncertainty, or the observed hemoglobin measurements. It therefore does not allow readers to quantify the primary endpoint result or judge its precision.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry sets out a comparative question and an analysis plan, but it does not report the primary outcome result. It identifies hemoglobin concentration over time as the primary outcome and describes measurements at 0, 4, 8, and 12 weeks. However, no group summaries for hemoglobin, estimated change, treatment contrast, confidence interval, or p-value are reported in the registry record. The planned comparison therefore cannot be interpreted as an observed treatment difference from this record alone.
The stated hypothesis was that NovaFerrum® would have greater efficacy than ferrous sulfate in increasing hemoglobin concentration during a 12-week treatment course. That is the direction the investigators proposed to examine. It is not a result. Without the estimated between-group difference and its uncertainty, the registry cannot establish whether the observed data favored either group, how large any difference was, or how compatible the data were with no difference.
The endpoint uses repeated measurements, and the planned mixed model includes treatment and time as covariates with patient random effects. As a general interpretation, a treatment coefficient or other prespecified contrast from such a model would need to be read alongside its confidence interval and the model specification. A confidence interval describes the range of effect estimates reasonably compatible with the data under the model and assumptions. Neither a confidence interval nor a treatment-effect estimate is reported, so precision cannot be assessed.
The record lists adverse-event counts separately, including serious events and other events, but those counts do not replace the missing primary outcome analysis. They answer a different descriptive question. Similarly, the registry lists secondary aims about iron-store laboratory measures and medication adherence, but does not provide the corresponding results in the outcome information available in this record. No inference about those secondary aims follows from the stated primary hypothesis or the adverse-event counts.
The completed status means the registry lists the study as completed; it does not itself show that every planned measurement was collected or analyzed. Enrollment is recorded as 80, but the record does not describe the number included in the primary analysis, whether all participants contributed measurements at each visit, or how missing observations were handled. Those omissions matter because a longitudinal estimate depends on the data included and on assumptions about incomplete follow-up.
Overall, this registry record supports a description of the design, endpoint, and planned model, but not a conclusion about comparative hemoglobin outcomes. The statistical result and its precision are not reported in the registry record. Any interpretation of efficacy based on this record would go beyond the information it contains.
9. Statistical Methods Explained
The planned primary analysis is described as a linear mixed regression model. This is a model for a continuous outcome that can incorporate repeated measurements while representing the fact that observations from the same participant may be correlated. In general, measurements taken from one person over time tend to share characteristics; treating them as unrelated observations can misstate the uncertainty of a treatment comparison. A participant-level random effect is one way to represent stable differences between participants and account for within-participant correlation.
What does the model description say?
The registry says that the model includes treatment and time as covariates and patient random effects. Treatment represents the comparison between the NovaFerrum® and ferrous sulfate groups. Time represents the sequence of hemoglobin assessments. The record does not specify whether time was modeled as a categorical or continuous variable, whether a treatment-by-time interaction was included, what covariance structure was used, or what exact contrast was designated as the primary comparison. Those details are not reported in the registry record.
In general, including time can help distinguish changes associated with the measurement schedule from differences between treatment groups. If the scientific question concerns whether the groups changed differently over follow-up, an interaction or a clearly defined contrast across time may be important. The registry’s brief model description does not say whether or how such a term was used. It would therefore be inappropriate to infer a more detailed model specification than the record states.
Why account for repeated measurements?
Repeated observations from one participant are not usually statistically independent. A mixed model allows the analysis to use multiple observations per participant while recognizing this dependence. This can be useful when the outcome is measured at several scheduled visits, as in this trial. The model’s validity still depends on its assumptions, including how the outcome relates to time and how within-participant variation is represented. The registry record does not report diagnostic checks or sensitivity analyses, so those aspects cannot be assessed.
General explanations of confidence intervals and p-values apply only if those results are reported. A confidence interval communicates uncertainty around an estimated contrast; a p-value summarizes how unusual the data would be under a specified null hypothesis and model. Neither quantity alone describes clinical importance, and neither can be interpreted without the corresponding estimate and analysis context. The registry record does not report a primary treatment estimate, confidence interval, or p-value.
What does the endpoint definition contribute?
The outcome is a continuous measure, with the mean listed as its measure type and standard deviation as its dispersion. These summaries can describe the distribution of hemoglobin measurements, but the registry’s outcome description focuses on change over serial assessments and a mixed regression model. A group mean at a particular visit would not by itself answer whether the longitudinal treatment comparison differed, especially without baseline information and a defined contrast. No hemoglobin summary values are reported in the registry record.
In general, the standard deviation describes variation among observations, whereas a confidence interval describes uncertainty in an estimated quantity. They are not interchangeable. The record’s mention of standard deviation as a dispersion measure does not provide actual standard deviations for the primary outcome. No additional numerical summaries should be inferred from the endpoint description.
How should planning estimates be understood?
Planning calculations are hypothetical illustrations, not observed results and not evidence that a study had a particular probability of detecting an effect after it was completed. The planning assumptions associated with this record describe a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation; the effect to detect is expressed as a fraction of an observed effect. Those assumptions describe a planning framework, not the trial’s own documented design justification. A sample-size justification is not reported in the registry record.
When planning calculations use an observed effect, the result is sensitive to that effect estimate. A smaller target effect generally requires more information to detect with a given design, while a larger target effect requires less; this is a general relationship, not a calculation for this study. Planning values should be labeled as participants per arm for 80% power when that is what they represent, and should not be called observed power. The registry record does not report the primary outcome effect needed to independently assess such an illustration.
What can be concluded from the methods description?
The record establishes that a longitudinal continuous outcome and a mixed-model approach were planned. It does not establish which model terms were ultimately fitted, whether the planned analysis was completed as described, or what result it produced. The distinction between a planned method and an observed estimate is essential: a stated analysis plan explains how investigators intended to compare the groups, while the estimate and its uncertainty are needed to interpret the comparison. Those primary statistical results are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary hemoglobin outcome and secondary aims concerning adverse effects, laboratory measures of iron status, adherence, and once-daily dosing. It does not report how the investigators addressed multiplicity across these outcomes or comparisons. Multiplicity arises when several hypotheses are examined: even if each test is considered separately, the chance of at least one apparently notable finding can increase across a set of tests. This is a general statistical concern, not evidence that any particular adjustment was or was not performed.
The primary outcome description contains serial measurement times at 0, 4, 8, and 12 weeks. The registry says the intended primary analysis would incorporate subsequent time points into a linear mixed regression model, but does not explain how the primary contrast across time was defined. It also does not report whether any additional time-specific comparisons were planned or how they would be interpreted. A multiplicity strategy is not reported in the registry record.
The record does not describe missing-data rates, reasons for missingness, imputation, or sensitivity analyses. In general, incomplete repeated measurements can affect a longitudinal analysis, and the consequences depend on why observations are missing and on the model’s assumptions. The record also does not define analysis populations, such as whether the primary analysis was based on all randomized participants or another group. Participant disposition and exclusions from analysis are not reported in the registry record.
These omissions prevent assessment of whether the planned analysis population and handling of incomplete data were appropriate or whether they differed from the completed analysis. They also limit interpretation of any result beyond the central fact that the registry does not report the primary outcome estimate.
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 |
|---|---|---|---|
| NovaFerrum® (Iron Polysaccharide Complex) | 0 | 40 | 0.0% |
| Ferrous Sulfate | 1 | 40 | 2.5% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| NovaFerrum® (Iron Polysaccharide Complex) | 0 of 40 |
| Ferrous Sulfate | 0 of 40 |
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 |
|---|---|
| NovaFerrum® (Iron Polysaccharide Complex) | 32 of 40 |
| Ferrous Sulfate | 29 of 40 |
Most frequent serious adverse event terms
| Event term | Organ system | NovaFerrum® (Iron Polysaccharide Complex) | Ferrous Sulfate |
|---|---|---|---|
| Methemoglobinemia | Blood and lymphatic system disorders | 0 of 40 | 1 of 40 |
Most frequent non-serious adverse event terms
| Event term | Organ system | NovaFerrum® (Iron Polysaccharide Complex) | Ferrous Sulfate |
|---|---|---|---|
| Gastrointestinal | Gastrointestinal disorders | 32 of 40 | 29 of 40 |
Serious events with the highest arm-level rate: methemoglobinemia (2.5%).
The registry reports serious adverse events for both treatment groups. For NovaFerrum®, the serious-event figures are 0 affected among 40 at risk; for ferrous sulfate, they are 1 affected among 40 at risk. The record lists 0 deaths in each group. These are descriptive counts from the registry, not a statistical comparison, and they do not establish whether any event was caused by treatment.
The registry lists methemoglobinemia at 2.5% as the top serious term. It does not provide enough detail in the recorded term listing to connect that term to a particular arm or to describe its clinical course. The serious-event count is small, and the absence of a reported serious event in one group should not be read as proof that serious events cannot occur. Conversely, the one affected participant listed in the other group does not, by itself, establish a difference in risk.
In general, adverse-event counts are best interpreted with attention to the definitions used, the observation period, completeness of reporting, and the number of participants observed. The registry does not report additional detail about event ascertainment or exposure time. Its serious-event counts should therefore be read as the recorded safety summary, not as a complete comparative safety analysis. The record also lists other adverse events, but those are distinct from serious adverse events and should not be combined with them when reading the serious-event figures.
12. What the Result Does, and Does Not, Mean
The record describes a randomized comparison of two iron preparations, with the same stated dose and duration in each arm, and identifies change in hemoglobin concentration over time as the primary question. It also states the investigators’ hypothesis about which group they expected to have greater hemoglobin increase. These details explain the purpose and planned structure of the study; they do not tell readers what the primary analysis found.
The primary hemoglobin results are not reported in the registry record. There is no group-specific outcome summary, between-group estimate, confidence interval, or p-value in the registry outcome information. Thus, the record cannot establish the direction or size of an observed difference, nor how precise any estimate was. It is not possible to conclude from this registry record that one preparation produced a greater hemoglobin increase, that the treatments were equivalent, or that there was no difference.
The listed serious adverse-event counts are descriptive and do not demonstrate that an event was caused by treatment or that one group had a reliably different safety profile. The secondary aims are also not accompanied by reported results in the outcome information. No conclusion about iron-store normalization, adherence, or other secondary outcomes should be drawn from their mention as aims.
In general, a randomized design can help reduce systematic differences between groups at assignment, but interpretation still depends on the analysis performed, completeness of outcome data, uncertainty around estimates, and how the study was conducted. The registry record does not supply those details for the primary result. The study’s completed status is not a substitute for outcome reporting.
The appropriate reading is therefore limited: the registry documents a planned randomized comparison and a longitudinal statistical approach, along with a brief safety summary, but does not report the principal efficacy estimate. Any stronger claim about comparative benefit, equivalence, or lack of effect would require results and analysis details not reported in the registry record.
13. Why This Trial Matters Statistically
This study raises a useful statistical question because the primary outcome is continuous and measured repeatedly during treatment. A single end-of-treatment measurement and a pattern of measurements over time do not necessarily answer the same question. A longitudinal model can use observations from several scheduled visits while accounting for their correlation within participants. The registry’s choice to describe a mixed regression model is therefore relevant to the structure of the outcome.
The comparison also illustrates why an analysis plan and an analysis result must be distinguished. Knowing that treatment and time were intended as covariates, and that participant random effects were intended to account for repeated measures, helps explain the planned approach. It does not reveal the estimated contrast, the uncertainty, or whether the fitted model followed the stated plan. Statistical interpretation requires the result as well as the method.
The registry further distinguishes a primary question from several secondary aims. That distinction matters because multiple outcomes can create multiple opportunities to observe apparently notable results. A clear hierarchy and a documented approach to multiplicity help readers understand how much weight to place on each finding. Such an approach is not reported in the registry record, and no secondary results are included in the outcome information.
Finally, the record demonstrates the importance of reporting the data needed to interpret a trial: group summaries, effect estimates, uncertainty, participant flow, missing-data handling, and the population analyzed. Without these, a completed randomized study can be described but its central comparative result cannot be evaluated. The statistical importance lies not in a reported treatment effect, but in the gap between a specified longitudinal question and the absence of its outcome estimate in the registry record.
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 important limitation for interpretation is that the registry record does not report the primary hemoglobin results. Without observed summaries, a treatment contrast, and a measure of uncertainty, the comparative outcome cannot be quantified. The analysis plan alone cannot establish the direction, magnitude, or precision of an effect.
The record gives only a brief description of the proposed mixed model. It does not state the exact treatment contrast, the form used for time, whether a treatment-by-time interaction was included, or the covariance structure. It also does not report model diagnostics or sensitivity analyses. These omissions limit assessment of the model’s implementation and assumptions.
Participant flow, completion of scheduled assessments, and the analysis population are not reported in the registry record. Missing-data amounts, reasons, and handling are also not described. As a result, readers cannot determine how much of the planned longitudinal information contributed to the analysis or how incomplete follow-up may have affected it.
The registry does not report detailed baseline characteristics or eligibility criteria beyond the intended population description. It also does not provide operational details about randomization and masking. The single-center setting is recorded, but the record does not contain enough information to assess how the enrolled participants compare with other populations of infants and young children with nutritional iron deficiency anemia.
Secondary aims are listed, but their results and any approach to multiplicity are not reported in the registry record. Safety information is limited to event counts and a serious-event term listing, without detailed descriptions or a causal assessment. These limits do not show that the study was conducted improperly; they describe what cannot be evaluated from the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Comparison of NovaFerrum® vs Ferrous Sulfate Treatment in Young Children With Nutritional Iron Deficiency Anemia — NCT01904864.
- Registry record last updated 2017-12-14; status last verified 2017-11.
- Results first posted 2017-09-13.
- 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
The registry describes a completed, randomized, quadruple-masked, parallel-group phase 4 study sponsored by the University of Texas Southwestern Medical Center. Enrollment is recorded as 80, and the study is described as a single-center comparison in infants and young children with nutritional iron deficiency anemia.
Participants were assigned to once-daily NovaFerrum® or ferrous sulfate, each described at 3mg/kg for 12 weeks. The primary outcome was hemoglobin concentration measured over time, with assessments scheduled at 0, 4, 8, and 12 weeks. The planned analysis was a linear mixed regression model with treatment and time as covariates and patient random effects.
The registry record does not report the primary hemoglobin estimate or its uncertainty. It lists serious-event counts of 0 among 40 at risk with NovaFerrum® and 1 among 40 at risk with ferrous sulfate, with 0 deaths in each group. Participant flow, missing-data handling, analysis populations, and results for the secondary aims are not reported in the registry record.