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 Evaluation of Satisfaction in Patients Receiving PegIntron Pen/Rebetol for Hepatitis C (Study P04067) (NCT00727259), a registered phase not stated study. The primary outcome is Evaluation of the Satisfaction of the PegPen (PegIntron Preparation and Injection Easiness) Using a Patient Questionnaire Answered at 1 Month and 3 Months.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00727259 |
| Phase | Phase not stated |
| Condition | Hepatitis C, Chronic |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 1995 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Merck Sharp & Dohme LLC |
| Results posted | Yes |
2. Clinical Question
Population
Adult patients with chronic hepatitis C receiving PegIntron pen and Rebetol treatment. The registry record reports that both questionnaires were returned by 940 subjects, while item-level missing data varied.
Intervention
Treatment with peginterferon alfa-2b, identified as PegIntron, administered using the PegIntron pen, alongside ribavirin, identified as Rebetol.
Comparator
A separate comparator group is not described. The registry record does not state an allocation method, and this is not reported as a randomized comparison.
Primary question
How satisfied were patients with aspects of PegPen preparation and injection, based on questionnaire ratings collected after 1 month and 3 months of treatment?
The study focuses on patients’ reported experience using the pen during combination treatment for chronic hepatitis C. The primary outcome is a satisfaction rating for questionnaire items, with responses on a scale from 0 (not satisfied) to 7 (very satisfied). The stated focus includes preparation and injection easiness.
This is a question about satisfaction, not a direct assessment of whether treatment cleared hepatitis C, how accurately the medication was administered, or whether the device changed clinical outcomes. The study description gives ease of use and administration accuracy as the rationale for developing and using the pen, but the listed primary outcome is patient satisfaction.
The questionnaires were intended to be completed and returned by mail after 1 month and 3 months of treatment. Because the registry record does not describe a separate control group or randomized assignment, the question is descriptive: what ratings did responding patients give? It does not establish how those ratings compare with ratings under another device or treatment approach. The registry record does not report the actual item ratings or a summary of satisfaction, so the direction and precision of the reported outcome cannot be evaluated from the record.
3. Trial Design
The registry identifies this as a completed study of adult patients with chronic hepatitis C treated with PegIntron pen and Rebetol. The registered enrollment is 1995. The sponsor is Merck Sharp & Dohme LLC. The recorded study start is 2004-10, and primary completion is recorded as 2008-04.
The treatment described combines peginterferon alfa-2b, identified as PegIntron, and ribavirin, identified as Rebetol. The arm description covers patients with chronic hepatitis C receiving this treatment. The record does not describe a separate control arm or state an allocation method. Random assignment, concealment, and blinding are not reported in the registry record. The study therefore should not be interpreted as a randomized, like-for-like comparison based on the available description.
The main measurement is a patient questionnaire about satisfaction with the PegPen, including preparation and injection easiness. Patients were instructed to answer and return the first self-questionnaire by mail after 1 month of treatment and the second after 3 months. This design collects patient-reported experience at two treatment time points; the record does not state whether the same items or scoring rules were applied identically at both times beyond its general description of satisfaction ratings.
The registry lists one outcome measure and zero analyses. It does not report a statistical analysis plan, prespecified contrasts between the two questionnaire time points, or a method for handling repeated responses from the same patient. Sample-size justification and details of any interim analyses are not reported in the registry record. The study status is completed, but completion status alone does not supply outcome estimates or explain how the available questionnaire responses were analyzed.
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: Enrolled: 1995 subjects; all questionnaires were returned for 940 subjects.
Overall Study
| Stage | Patients With Chronic Hepatitis C |
|---|---|
| STARTED | 1995 |
| COMPLETED | 940 |
| NOT COMPLETED | 1055 |
Reasons for not completing this period:
| Reason | Patients With Chronic Hepatitis C |
|---|---|
| Not all questionnaires completed | 1055 |
Analysis population for the primary outcome, as defined in the registry: Both patient questionnaires were returned by 940 subjects. However, some items were not rated on the returned questionnaires. The missing data for questionnaire items range from 24 subjects to 72 subjects.
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 | Patients With Chronic Hepatitis C |
|---|---|---|
| Participants analysed | 940 | |
| Age, Continuous | years | 47.50 (SD 12.34) |
| Sex/Gender, Customized: Female | Participants | 323 |
| Sex/Gender, Customized: Male | Participants | 616 |
| Sex/Gender, Customized: Missing data | Participants | 1 |
| Region of Enrollment: France | Participants | 940 |
6. Primary Endpoint
The registry lists the primary outcome as Evaluation of the Satisfaction of the PegPen (PegIntron Preparation and Injection Easiness) Using a Patient Questionnaire Answered at 1 Month and 3 Months, measured over The patient was instructed to answer and return by mail the first self-questionnaire after 1 month of treatment and the second one after 3 months of treatment..
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | satisfaction rating from 0-7 |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is patient satisfaction for items on the PegPen questionnaires. Each item is rated from 0 (not satisfied) to 7 (very satisfied). The endpoint is described as a mean, with standard deviation as the dispersion measure, and the questionnaires address PegPen preparation and injection easiness. The intended measurements occur after 1 month and 3 months of treatment.
A satisfaction rating captures patients’ reported experience rather than an objective measure of injection accuracy, treatment adherence, viral response, or safety. It is relevant to the study’s stated aim because ease of preparation and injection is the device experience the study set out to assess. A mean can describe the overall level of ratings, while a standard deviation describes how spread out individual ratings are around that mean.
Using a mean treats the ordered rating scale as if its steps can be averaged meaningfully. That can be a concise summary, but it does not show the full distribution: different patterns of individual responses can produce the same mean. The rating range also bounds possible values, so interpretations should remain tied to the scale’s endpoints and the actual response distribution.
The registry record says both questionnaires were returned by 940 subjects, but some items were not rated. Item-level missing data range from 24 subjects to 72 subjects. The actual item means, standard deviations, response distributions, and any comparisons between questionnaire time points are not reported in the registry record. Consequently, the endpoint’s observed level and uncertainty cannot be described from this record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record defines a patient-reported satisfaction outcome but does not include its numerical results. It gives the rating scale, the intended questionnaire time points, and a description of the responding population. It does not report means, standard deviations, confidence intervals, tests, or item-specific response distributions. No conclusion about the level of satisfaction can be drawn from the endpoint definition alone.
The mean would represent an average rating among the responses included in its calculation. The standard deviation would indicate how much ratings varied among those responses. Neither statistic is reported. Without them, it is not possible to tell whether ratings tended toward the satisfied or unsatisfied end of the scale, whether responses were tightly clustered or varied widely, or how precise an estimated average might be.
The two questionnaire time points could, in principle, describe satisfaction at different stages of treatment. A comparison would require clarity about the analyzed respondents, the item-level denominators, and whether the analysis accounted for paired responses from patients who completed both questionnaires. The registry record does not report such a comparison or its method. Even if ratings differed over time, a simple change would not by itself establish that treatment duration caused the difference. Response patterns, missing items, and changes in who returned questionnaires could affect the observed summaries.
The registry reports that both questionnaires were returned by 940 subjects, while individual items were missing for 24 to 72 subjects. These registry entries indicate that the available responses do not necessarily cover every enrolled patient or every questionnaire item. The record does not report why responses were missing or whether missingness was addressed through a specific method. The reported enrollment cannot be treated as the denominator for every item without further information.
The study is not described as a randomized comparison, and no separate comparator is identified. The results, if available elsewhere, would therefore need to be interpreted as patient-reported experience within the described treatment group, not as evidence that the pen produces greater satisfaction than another device or approach. The record also does not report clinical outcomes that would connect satisfaction ratings to treatment effectiveness.
In short, the registry record supports understanding what was intended to be measured and when. It does not provide enough outcome or analysis information to assess the observed satisfaction ratings, their statistical uncertainty, or any difference between the questionnaire time points.
9. Statistical Methods Explained
The registered outcome is continuous in the sense that the analysis describes a mean and standard deviation for a numerical rating. The original responses, however, are ratings on an ordered scale from 0 (not satisfied) to 7 (very satisfied). The mean compresses a set of ratings into a single average. The standard deviation describes how dispersed the ratings are around that average. These summaries answer different questions: the mean describes the central level, and the standard deviation describes variation among responses.
As a general statistical point, an average can be useful when ratings are treated as having roughly comparable steps. It does not preserve all information about the distribution. For example, the mean alone cannot show whether most patients selected similar ratings or whether responses were concentrated at contrasting ends of the scale. A distribution or category-level summary can provide that additional context. The registry record does not report those response details.
Uncertainty is another part of interpretation. In general, a confidence interval gives a range of values compatible with the data under a specified statistical method and its assumptions. It can help distinguish a precise estimate from one that remains uncertain. No confidence interval or other uncertainty estimate for satisfaction is reported in the registry record. The sample-size illustrations associated with the posted results are planning calculations, not observed power and not evidence about the precision of this study’s satisfaction estimate.
Repeated questionnaire measurements raise a design and analysis issue. If the same patients provide ratings at both time points, their responses are related rather than independent. A method that compares time points should account for that relationship if it is estimating within-patient change. A comparison that ignores pairing may answer a different question and can misstate uncertainty. The registry record identifies the two intended time points but does not report whether a paired analysis was done, what contrast was targeted, or how repeated responses were handled.
Missing responses also affect interpretation. The registry reports that both questionnaires were returned by 940 subjects, but that some questionnaire items were left unrated, with missing counts ranging from 24 subjects to 72 subjects. An item’s mean should be based on responses to that item, so item-level denominators may differ. The record does not report the denominators for individual items or explain how the missing ratings were handled. In general, complete-response summaries describe the people with recorded answers; they may not represent people whose answers are missing if the reasons for missingness relate to satisfaction.
Over-dispersion is a general concern when counts vary more than a simple model assumes. It is not directly the central issue for this endpoint, which is a bounded satisfaction rating summarized by a mean and standard deviation. The more directly relevant questions are how the scale was summarized, how response distributions varied, whether repeated ratings were modeled as related, and how incomplete item responses were addressed. The registry does not give details on these analysis choices.
The study record lists zero analyses. It does not report hypothesis tests, a statistical model, covariate adjustment, a primary contrast, or a multiplicity procedure. These omissions matter because statistical conclusions depend not only on the outcome definition but also on the analysis population, estimand, model, and uncertainty calculation. None should be inferred from the fact that the study is marked completed.
The sample-size assumptions described for planning illustrations use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a fraction of the observed effect. Those are planning assumptions, not a description of this study’s design or analysis. The registry describes no randomized two-arm comparison, and no sample-size justification for the study itself is reported in the registry record. Such illustrations do not show that the study had a particular probability of detecting an effect, and they cannot substitute for reported outcome estimates and confidence intervals.
More generally, a p-value, when reported, summarizes how unusual data at least as extreme as those observed would be under a specified null model. It is not the probability that the null hypothesis is true, nor does it measure the size or practical importance of an effect. No p-value is reported for the satisfaction outcome. In the absence of an estimate and its uncertainty, the rating scale’s intended interpretation remains clear, but the actual statistical result does not.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists one outcome measure and zero analyses. It does not describe how many questionnaire items were evaluated as primary, whether the two time points were treated as separate endpoints, or whether any items were exploratory. The analysis plan and any procedure for controlling multiplicity are not reported in the registry record. If many items or time-point comparisons were examined, the chance of obtaining an apparently notable result by chance could increase; without the analysis details, that possibility cannot be assessed.
Both questionnaires were returned by 940 subjects, but some items were not rated. The reported range of missing item responses is 24 subjects to 72 subjects. Because missingness differs by item, the number of responses contributing to an item summary may also differ. The registry does not report item-specific denominators, whether incomplete questionnaires were included where possible, or whether any imputation was used.
In general, missingness can affect both the precision and representativeness of a summary. If people who omit an item differ in satisfaction from people who answer it, the mean among recorded responses may not describe the experience of all intended respondents. The reasons for missing ratings and the assumptions used to handle them are not reported in the registry record. The record also does not define an analysis population beyond its description of the questionnaire respondents, so the extent to which analyses used all eligible patients, questionnaire returners, or item-level responders is not reported.
11. What the Result Does, and Does Not, Mean
The registry record establishes the study’s measurement objective: describing patient satisfaction with the PegPen using ratings from 0 (not satisfied) to 7 (very satisfied), collected after 1 month and 3 months of treatment. It also documents that both questionnaires were returned by 940 subjects and that some item responses were missing. These details help define what the intended evidence concerns.
The record does not establish what the ratings actually were. It contains no satisfaction means, standard deviations, confidence intervals, item-level results, or analyses. Therefore, it cannot support a statement that patients were generally satisfied or dissatisfied, that ratings changed between time points, or that an observed pattern was statistically precise. The absence of results in the registry record is not evidence of a particular result.
Even with reported ratings, satisfaction would remain a patient-reported experience outcome, not a direct measure of clinical benefit, administration accuracy, adherence, or treatment safety. The study rationale mentions ease of use and accuracy, but the listed primary outcome is satisfaction. A high or low satisfaction score alone would not establish a change in hepatitis C outcomes.
The lack of a described comparator also limits interpretation. This record does not support a comparative claim about the PegIntron pen versus another delivery method. Nor does it establish that the device itself caused any satisfaction rating, since a randomized comparison and its results are not described. The narrowest defensible interpretation is that the study was designed to collect patient satisfaction ratings during the described treatment, while the registry record does not report the outcome findings needed to characterize those ratings.
12. Why This Trial Matters Statistically
This study illustrates why an outcome definition and an outcome result are not interchangeable. The registry carefully identifies a patient-reported rating scale, its endpoints, and the intended times of measurement. Those details tell readers what the investigators sought to describe. Without numerical summaries and uncertainty estimates, however, the record cannot show what the observed responses imply.
It also illustrates the importance of matching the statistical summary to the measurement. A mean and standard deviation are compact descriptions, but ratings on a bounded scale can have distributions that the mean alone obscures. Item-level missing responses and repeated measurements further affect which patients contribute to each summary and how comparisons should be analyzed. Reporting denominators, distributions, and analysis choices would make those issues assessable.
Finally, the study’s stated rationale and its primary endpoint address related but distinct topics. Ease of using a device may matter to patients, while clinical effectiveness is a separate outcome. Statistical interpretation should remain tied to the measured endpoint and the design that generated it. Here, the registry supports description of the question and its measurement approach, but not a conclusion about the size, direction, or precision of patient satisfaction.
13. 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 interpreting this trial from the registry record is that the satisfaction results are not reported. Although the outcome measure is described, the record provides no mean ratings, standard deviations, confidence intervals, item-level distributions, or analyses. The study’s completed status does not fill this gap.
The record identifies two questionnaire time points but does not explain how their relationship was analyzed. It does not state whether the same respondents’ ratings were compared, whether the analysis accounted for repeated measurements, or whether a particular time-point contrast was prespecified. Consequently, any change over time cannot be assessed from the registry information.
Questionnaire return and item completeness are additional constraints. Both questionnaires were returned by 940 subjects, but 24 to 72 subjects did not rate particular items. The registry does not report why items were left blank, the denominator for each item, or the method used to address missing responses. It also does not provide enough detail to identify the analysis population for each outcome summary.
The design description does not identify a separate comparator or an allocation method. The record therefore does not support a randomized comparative interpretation. It also does not report a statistical analysis plan, sample-size justification, interim analyses, or multiplicity handling. The absence of these details prevents evaluation of how the analysis may have shaped the reported conclusions.
Finally, the endpoint measures satisfaction, not clinical effectiveness or safety. Those distinctions limit the claims the endpoint could support even if its numerical results were available. The registry record does not provide a basis for relating satisfaction ratings to treatment outcomes.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: Evaluation of Satisfaction in Patients Receiving PegIntron Pen/Rebetol for Hepatitis C (Study P04067) — NCT00727259.
- Registry record last updated 2015-04-29; status last verified 2015-04.
- Results first posted 2009-08-06.
- 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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17. Record Summary
NCT00727259 is a completed study titled “Evaluation of Satisfaction in Patients Receiving PegIntron Pen/Rebetol for Hepatitis C (Study P04067).” It concerns adult patients with chronic hepatitis C treated with PegIntron pen and Rebetol. The sponsor is Merck Sharp & Dohme LLC. The registry records the study start as 2004-10 and primary completion as 2008-04, with enrollment of 1995.
The primary outcome is patient satisfaction with PegPen preparation and injection easiness, rated from 0 (not satisfied) to 7 (very satisfied). Questionnaires were intended after 1 month and 3 months of treatment. Both questionnaires were returned by 940 subjects, and item-level missing responses ranged from 24 subjects to 72 subjects.
The registry lists one outcome measure and zero analyses. It does not report the satisfaction results, an analysis plan, or a comparator group. The record describes a measurement objective and study population, but does not provide the numerical evidence needed to characterize the observed satisfaction ratings.