RNF and Betaseron® Tolerability Study: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for RNF and Betaseron® Tolerability Study (NCT00428584), a randomized phase 3 study. The primary outcome is Visual Analog Scale (VAS) of Patient Reported Pain: Change in Mean VAS for the 21 Full-dose Injections at Pre-injection and 30 Minutes Post-injection Timepoints.

2. Clinical Question

The trial addressed tolerability, specifically pain at the injection site. The primary measure used a visual analog scale (VAS), on which participants marked their perceived pain intensity. The record defines the scale from 0, meaning no pain, to 100, meaning the worst possible pain, with scores measured in millimeters. It describes averaging each participant’s scores across the first 21 full-dose injections at pre-injection and 30 minutes post-injection.

The registry record does not report the group-level VAS results, the estimated difference between groups, or a confidence interval or p value for the primary outcome. It therefore does not show the size or precision of any observed between-group difference. The stated question can be described from the outcome definition, but its answer cannot be determined from the results recorded.

The record also lists secondary measures involving pain at other injection-related timepoints, pain-free status at 30 minutes, and injection-site redness. Those measures provide additional ways to describe tolerability, but their results and analysis details are not reported in the registry record.

3. Trial Design

This was a randomized, multicenter, parallel, two-arm, open-label Phase IIIb study, according to the official title. The registry lists the trial phase as Phase 3. The two groups received either the new formulation of Rebif or Betaseron. Because masking was listed as none, the study was open label: participants and study personnel were not described as blinded to treatment assignment.

The randomized comparison was planned for twelve weeks. The official title then describes a single-arm safety extension lasting a minimum of 82 weeks, with Rebif new formulation only. The record does not state how many participants entered or completed that extension, nor does it provide extension results. The extension should therefore be distinguished from the initial two-arm comparison: it does not provide a continuing randomized comparison with Betaseron.

The registry reports enrollment of 129. It does not report the allocation sequence, the method used to conceal assignment before enrollment, or whether allocation was balanced in practice. The adverse-event information gives group-specific numbers at risk, but those figures do not establish the analysis population for the primary outcome.

The primary outcome focused on mean pain scores over the first 21 full-dose injections, comparing pre-injection scores with scores 30 minutes after injection. The record also lists secondary outcomes at immediately after injection and 10 minutes after injection, pain-free status at 30 minutes, and injection-site redness. It reports 10 outcome measures and 5 analyses, but the registry record does not provide a complete analysis plan or explain how each outcome was analyzed.

One participant in the new-formulation Rebif group discontinued due to pregnancy, and the record says the full-dose 30-minute mean-change calculation was not made for that participant. It does not describe other discontinuations, the handling of missing measurements, or the populations used for each analysis.

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: Subjects had a pre-study evaluation period (screening) within 14 days of Study Day 1 which consisted of informed consent, medical/disease history, physical exam and laboratory assessments.

Comparative Phase

Extension Phase

Analysis population for the primary outcome, as defined in the registry: One subject from the new formulation of rebif group discontinued due to pregnancy therefore, data for the Full Dose Calculation 30min Mean Change was not calculated

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.

6. Primary Endpoint

The registry lists the primary outcome as Visual Analog Scale (VAS) of Patient Reported Pain: Change in Mean VAS for the 21 Full-dose Injections at Pre-injection and 30 Minutes Post-injection Timepoints, measured over From pre-injection to 30 minutes post injection of the VAS pain scores across the first 21 injections of full dose therapy of a new formulation of rebif and Betaseron.

The primary endpoint was a patient-reported measure of injection-site pain. Participants marked pain intensity on a visual analog scale measured in millimeters, with 0 defined as no pain and 100 as the worst possible pain. For each participant, the record describes calculating a mean across 21 full-dose injections at pre-injection and a corresponding mean at 30 minutes post-injection.

Using repeated observations can describe a participant’s typical reported pain across injections rather than relying on a single injection. Comparing the pre-injection and post-injection values is intended to capture change over the injection period. In general, a patient-reported pain scale can represent an experience that is not directly measured by an observer or laboratory test. It is meaningful as a measure of reported symptoms, while remaining dependent on how participants interpret and use the scale.

The registry record identifies the timepoints and measurement scale but does not report the observed means, the calculated change, or the between-group estimate. It also does not explain whether the primary analysis compared changes directly or used another statistical model. The result and its precision are therefore not reported in the registry record.

The outcome definition notes that one participant in the new-formulation Rebif group discontinued due to pregnancy, so the full-dose 30-minute mean-change calculation was not made for that participant. The record does not specify how other incomplete injection records, if any, were handled.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a randomized, parallel-group comparison with no masking. Randomization is intended, in general, to make treatment groups comparable on average with respect to factors that could affect the outcome. It does not guarantee identical groups, and the record does not report the specific randomization procedure or allocation concealment method. In an open-label study, knowledge of treatment assignment may influence expectations or reporting, which is relevant when the main measure is self-reported pain.

What does the pain score represent?

The VAS is a continuous scale: participants indicate perceived pain along a line anchored by no pain and the worst possible pain. The registry describes scores in millimeters, from 0 to 100. Treating the score as a numerical outcome allows summaries such as a mean, but a mean alone would not show how responses vary among participants. A dispersion measure, such as a standard deviation or range, can help describe variability. Although the primary outcome description says dispersion was the full range, the registry record does not provide the numerical range or the group-level endpoint summaries.

The primary measure averages observations across the first 21 full-dose injections for each participant. Repeated measurements can give a broader account of pain during treatment than a single measurement. They also create a statistical issue: measurements from the same participant are generally not independent in the way measurements from different participants may be. In general, analysis of repeated observations should account for within-participant correlation, or use a participant-level summary that appropriately reduces the repeated measurements. The registry record describes participant-level means but does not specify the statistical method used to compare groups.

Why distinguish within-participant change from a group contrast?

A change from pre-injection to 30 minutes post-injection describes a within-participant contrast between two timepoints. A treatment comparison then asks how that change differs between groups. These are related but distinct quantities. A change in one group by itself does not establish a difference between treatments; the between-group estimate is needed to address the randomized comparison. The record defines the timepoints and mean-change measure but does not report a group contrast or state precisely how it was estimated.

In general, an estimate is most informative when accompanied by a measure of uncertainty, commonly a confidence interval. The interval helps show which values are compatible with the data under the analysis assumptions. A p value can address a null hypothesis, but it does not communicate effect size or precision on its own. Neither a primary confidence interval nor a primary p value is reported in the registry record, so these inferential aspects cannot be evaluated.

What does over-dispersion mean in general?

Over-dispersion occurs when count data vary more than a statistical model assumes. It can make standard errors too small if the extra variability is ignored. This issue is generally relevant to outcomes expressed as counts or proportions, rather than automatically to a continuous VAS mean. The record does not report an over-dispersion assessment or a count-model analysis for the primary pain outcome. No such method should be inferred from the outcome definition alone.

How should planning illustrations be read?

The record describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation. The stated effect to detect is a fraction of the observed effect. These are planning assumptions, not evidence that the original trial was designed using them. A sample-size illustration estimates how many participants per arm might be needed under chosen assumptions; it is not observed power. The registry record does not report the trial’s own sample-size justification, or provide enough primary-outcome results in this record to assess the observed effect itself.

In general, planning calculations depend on the assumed effect, outcome variability, significance level, desired power, allocation, and analysis method. If those assumptions differ from the study’s actual conditions, the illustration may not describe the study’s operating characteristics. No planning result should be treated as a clinical outcome or as confirmation that the trial could detect a particular difference.

What can be inferred from the registry methods?

The record establishes the broad design and the pain measurement schedule, but not the full statistical plan. It does not report the primary model, covariate adjustment, assumptions checks, handling of repeated measurements beyond the participant-level means, or a prespecified approach to missing data. It also does not report analysis-population definitions. Without those details and the outcome estimates, readers cannot reproduce the primary analysis or assess its sensitivity to alternative reasonable methods.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 10 outcome measures and 5 analyses. The outcomes include the primary VAS change from pre-injection to 30 minutes post-injection, measures at other pain-assessment timepoints, pain-free status at 30 minutes, and injection-site redness. Testing multiple outcomes or timepoints can increase the chance of at least one apparently unusual result when many statistical tests are considered. In general, multiplicity procedures can control error rates or distinguish a primary confirmatory test from exploratory analyses.

The registry record does not report whether a multiplicity adjustment was planned or used, how the five analyses relate to the 10 outcome measures, or which results were treated as confirmatory. It also does not provide numerical results for the primary or secondary outcomes, so the consequences of any multiplicity approach cannot be evaluated.

For missing data, the record specifically states that one participant in the new-formulation Rebif group discontinued due to pregnancy and that the full-dose 30-minute mean-change calculation was not made for that participant. It does not describe the missing-data method, whether any other measurements were incomplete, or whether the participant was included in other analyses. The registry record does not report whether the primary analysis used all randomized participants, participants with available outcome data, or another analysis population.

In general, missing-data methods rely on assumptions about why observations are unavailable. Different assumptions can lead to different estimates, especially when missingness is related to treatment experience or outcome. The record does not provide enough information to assess those assumptions or conduct a sensitivity interpretation.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: accidental overdose (1.6%), cholelithiasis / gallstones (1.6%), diverticulitis (1.6%), hip fracture (1.6%), intestinal obstruction (1.6%).

The registry reports serious adverse events by group, alongside the number at risk. For new-formulation Rebif, it lists 4 participants affected among 65 at risk; for Betaseron, it lists 5 affected among 64 at risk. It also lists other adverse-event counts of 62 among 65 at risk for new-formulation Rebif and 57 among 64 at risk for Betaseron. These are the recorded counts and denominators; no further calculation is needed to read them.

The registry lists serious-event terms that include accidental overdose, cholelithiasis or gallstones, diverticulitis, hip fracture, intestinal obstruction, and cholecystitis. The listed percentages are 1.6% for accidental overdose, 1.6% for cholelithiasis or gallstones, 1.6% for diverticulitis, 1.6% for hip fracture, 1.6% for intestinal obstruction, and 1.5% for cholecystitis. The record does not identify these terms as group-specific in the information.

Death counts are not reported in the registry record. These adverse-event figures describe events recorded during the study; they do not establish that an event was caused by treatment. The registry information does not provide event timing, duration, severity beyond the serious-event classification, or a detailed account of how events were attributed.

12. What the Result Does, and Does Not, Mean

The study was designed to compare injection-site pain with new-formulation Rebif and Betaseron during a randomized, open-label, twelve-week period. Its primary measure was based on participant-reported VAS scores before injection and 30 minutes afterward, averaged across the first 21 full-dose injections. Those details explain what the comparison was intended to address.

The registry record does not report the numerical primary outcome results. It therefore does not establish which group had a higher or lower mean change, how large any difference was, or how uncertain the estimate may be. No conclusion about the primary comparison can be drawn from the endpoint definition alone. This absence is not evidence that the groups had the same outcome; it means the relevant results are not reported in the registry record.

In general, a statistical result should be interpreted using its estimated magnitude and precision, not only whether a test crosses a significance threshold. For this trial, the registry record does not report the estimate, confidence interval, or p value needed for that interpretation. It also does not provide the numerical secondary-outcome results that could show whether findings across pain timepoints and other tolerability measures were consistent.

The record reports serious and other adverse-event counts, but those counts do not answer the primary pain question. They are descriptive safety information and should not be treated as proof of cause or as a substitute for the missing efficacy or tolerability estimates. The safety extension is described as a single-arm Rebif-only extension, so it does not preserve the randomized two-arm comparison.

The appropriate reading is therefore bounded: the registry documents the trial’s design, treatment groups, endpoint definition, one stated missing primary calculation, and some adverse-event counts. It does not provide enough primary outcome information to quantify or assess the between-group pain comparison. No treatment recommendation or claim of benefit follows from these posted data alone.

13. Why This Trial Matters Statistically

This trial illustrates the difference between a clear research question and a complete statistical result. The registry describes a randomized comparison and specifies the pain scale, the pre-injection and 30-minute post-injection timepoints, and the averaging of measurements across the first 21 full-dose injections. Those details help define what the intended outcome represents. But without the estimated group results and their uncertainty, readers cannot evaluate the magnitude or precision of the comparison.

The endpoint also highlights a recurring issue in clinical research: a patient-reported measure can capture a directly experienced symptom, while remaining vulnerable to expectations and reporting context. That consideration is especially relevant in an open-label study. Randomization supports a comparative design, but it does not remove every possible influence on reporting or resolve questions about missing measurements and analysis choices.

Repeated observations within a participant can improve the description of experience over time, but they require an analysis that respects the data structure. The registry describes participant-level averages, yet does not give the statistical method used for the group comparison. This makes the record a useful example of why endpoint definitions and analysis methods should be reported alongside estimates and uncertainty.

The safety information provides another statistical distinction: event counts and denominators can be described without making a causal claim or replacing the primary-outcome analysis. The record also separates the initial randomized comparison from a single-arm safety extension. Keeping those designs distinct is essential when interpreting what a study can establish.

Overall, the record shows why transparent reporting needs more than trial design and outcome descriptions. Numerical results, analysis populations, missing-data handling, and uncertainty measures are necessary to support an interpretable comparison. Their absence limits the conclusions that can be drawn, regardless of the study’s stated question.

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 main limitation for interpreting this trial from the registry record is the absence of numerical results for the primary VAS comparison. Group means, mean changes, a between-group estimate, confidence interval, and p value are not reported. Without them, neither the direction nor the precision of the primary contrast can be assessed.

The record gives limited information about analysis methods. It does not specify the primary statistical model, any adjustment variables, the analysis population, or how repeated measurements were incorporated beyond describing participant-level means. The registry record also does not state whether multiplicity was addressed across the listed outcome measures and analyses.

Missing-data reporting is limited. One participant in the new-formulation Rebif group discontinued due to pregnancy, and the record states that the full-dose 30-minute mean-change calculation was not made for that participant. The method for handling this missing endpoint value, and any other incomplete observations, is not reported in the registry record.

The design was open label, which is relevant because the primary outcome was self-reported pain. The record does not describe procedures intended to reduce possible reporting effects. It also does not provide numerical results for the secondary outcomes, the number entering or completing the safety extension, or detailed safety-event timing and attribution.

Finally, the registry record does not report the trial’s sample-size justification or complete statistical plan. The information available is sufficient to describe the study’s broad design and intended endpoint, but not to reproduce the analysis or assess the primary result.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: RNF and Betaseron® Tolerability Study — NCT00428584.
• Registry record last updated 2013-08-07; status last verified 2013-08.
• Results first posted 2010-03-04.
• 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.

18. Record Summary

The record describes NCT00428584, a randomized, multicenter, open-label, parallel, two-arm Phase IIIb study of new-formulation Rebif and Betaseron in interferon-naive participants with relapsing-remitting multiple sclerosis. Enrollment was 129. The initial comparison lasted twelve weeks, followed in the official title by a single-arm Rebif safety extension lasting a minimum of 82 weeks.

The primary outcome was change in mean VAS pain scores from pre-injection to 30 minutes post-injection across the first 21 full-dose injections. The scale ranged from 0, no pain, to 100, the worst possible pain. One participant in the new-formulation Rebif group discontinued due to pregnancy, and the record says the full-dose 30-minute mean-change calculation was not made for that participant.

The registry record does not report numerical primary or secondary outcome results, the primary analysis method, or full missing-data and multiplicity procedures. It reports group-level adverse-event counts and serious-event terms, but those data do not provide the missing primary comparison.