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 Long-Term Safety of Twice Daily Oxycodone Hydrochloride Controlled-release Tablets in Children Who Completed OTR3001 (NCT01369615), a na phase 3 study. The primary outcome is The Number of Participants With Adverse Events as a Measure of Safety..
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01369615 |
| Phase | Phase 3 |
| Condition | Pain |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 23 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Purdue Pharma LP |
| Results posted | Yes |
2. Clinical Question
Population
Children aged 6 to 17 years, inclusive, with moderate to severe malignant and/or nonmalignant pain requiring opioid therapy who completed the 4-week treatment period in OTR3001. The safety population comprised patients who received at least one dose during the extension study.
Intervention
Oxycodone hydrochloride controlled-release tablets, taken twice daily. The registry describes an open-label extension intended to characterize long-term safety.
Comparator
No separate comparator group is described. This is a single-group study, and the registry lists allocation as not applicable. The age groups in the adverse-event summaries are descriptive categories, not randomized treatment groups.
Primary question
What adverse events were reported among participants receiving the study drug during the extension, alongside other specified safety assessments? The primary outcome is the number of participants with adverse events. The registry describes assessments of vital signs, clinical laboratory results, and somnolence using the University of Michigan Sedation Scale. A comparative treatment-effect question is not addressed by this single-group design.
3. Trial Design
This completed study was a Phase 3, open-label extension of OTR3001. Its stated purpose was to characterize the long-term safety of twice-daily oxycodone hydrochloride controlled-release tablets in opioid-experienced pediatric patients who completed the 4-week treatment period in OTR3001. The eligible population was described as children aged 6 to 17 years, inclusive, with moderate to severe malignant and/or nonmalignant pain requiring opioid therapy.
The registry lists a single group receiving oxycodone hydrochloride controlled-release tablets, with no masking and no allocation. Accordingly, this was not a randomized comparison, and there was no concurrent control arm described. The two age categories in the adverse-event summaries provide descriptive groupings, not independent treatment arms or like-for-like controls.
Enrollment was 23. The registry lists the study start as 2011-10, primary completion as 2013-12, and status as completed. The primary safety timeframe was up to 6 months during the study, with a safety follow-up assessment 7-10 days poststudy. The extension safety population was defined as patients who received at least one dose of study drug during the extension.
The registry describes safety assessments that included adverse events, vital sign measurements, clinical laboratory test results, and somnolence measured using the University of Michigan Sedation Scale. It does not report a separate efficacy question or comparative hypothesis. The protocol details, including the rationale for the planned enrollment and any schedule for interim review, are not reported in the registry record.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Before assignment: Opioid-experienced pediatric patients with moderate to severe malignant and/or nonmalignant pain requiring around-the-clock opioid therapy were eligible for open-label Extension Study OTR3002 if they completed the 4-week treatment period Core Study OTR3001 and could benefit from continued treatment with oxycodone HCl CR 20 to 240 mg total daily.
Overall Study
| Stage | 6 to < 12 Years | ≥ 12 to ≤ 16 Years |
|---|---|---|
| STARTED | 9 | 14 |
| COMPLETED | 9 | 12 |
| NOT COMPLETED | 0 | 2 |
Reasons for not completing this period:
| Reason | 6 to < 12 Years | ≥ 12 to ≤ 16 Years |
|---|---|---|
| Withdrawal by Subject | 0 | 1 |
| Lost to Follow-up | 0 | 1 |
Analysis population for the primary outcome, as defined in the registry: The extension safety population was the group of patients who received at least 1 dose of study drug during the Extension Study.
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.
Population: The extension safety population was the group of patients who received at least 1 dose of study drug during the Extension Study.
| Characteristic | Unit | 6 to < 12 Years | ≥ 12 to ≤ 16 Years | Total |
|---|---|---|---|---|
| Participants analysed | 9 | 14 | 23 | |
| Age, Continuous | years | 9.9 (SD 1.76) | 14.3 (SD 1.49) | 12.6 (SD 2.69) |
| Sex: Female, Male: Female | Participants | 6 | 7 | 13 |
| Sex: Female, Male: Male | Participants | 3 | 7 | 10 |
| Race/Ethnicity, Customized: White | participants | 6 | 10 | 16 |
| Race/Ethnicity, Customized: Black or African American | participants | 3 | 4 | 7 |
6. Primary Endpoint
The registry lists the primary outcome as The Number of Participants With Adverse Events as a Measure of Safety., measured over Up to 6 months (during the study) and 7-10 days poststudy (safety follow-up assessment)..
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with adverse events, expressed as a count of participants rather than as a change in a continuous measurement. The registry describes the assessment timeframe as up to 6 months during the study and 7-10 days poststudy for the safety follow-up assessment. It defines the extension safety population as patients who received at least one dose of study drug during the extension.
Counting participants with adverse events is a descriptive way to communicate how many people in the safety population experienced an event. It can help readers distinguish the number of affected participants from the number of event episodes: one participant may experience more than one event, and the count of participants does not itself describe event frequency, duration, severity, or causal relationship to treatment.
The registry also lists vital signs, clinical laboratory results, and somnolence assessed with the University of Michigan Sedation Scale as safety assessments. It does not give numerical results for those assessments in the record. Nor does it supply a numerical result for the primary endpoint as a single overall count. The posted adverse-event summaries give age-group counts for serious events and other events; those categories should not be mistaken for a complete account of every dimension of the primary safety assessment.
Safety endpoints are used to characterize events observed during exposure and follow-up. In a single-group extension, the counts describe what was recorded among participants in that group; they do not by themselves establish whether an event was caused by treatment or how the event rate compares with what would have occurred under another treatment.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry reports adverse-event counts by age group. Among participants aged 6 to under 12 years, 3 of 9 participants were recorded as having a serious adverse event, and 8 of 9 were recorded in the other adverse-event category. Among participants aged 12 to 16 years, inclusive, 2 of 14 were recorded as having a serious adverse event, and 8 of 14 were recorded in the other adverse-event category. These are descriptive counts within the listed age groups. They are not estimates from a randomized comparison.
The registry also lists serious adverse-event terms and percentages: sickle cell anaemia with crisis, 11.1%; constipation, 11.1%; pyrexia, 11.1%; vomiting, 7.1%; back pain, 7.1%; and headache, 7.1%. The record does not state in this listing whether participants could contribute to more than one term, nor does the listing explain the denominator or method used for each percentage. The percentages therefore should be read as registry-reported values, not reinterpreted as mutually exclusive categories or as a complete ranking of all events.
The enrollment was 23, while the age-group summaries list 9 participants and 14 participants at risk. Those group-specific denominators are the appropriate context for reading the corresponding counts. The age labels in the event summaries extend through 16 years, whereas the study description states eligibility from 6 to 17 years, inclusive. Whether any 17-year-olds participated, and how the age categories were applied to such participants, are not reported in the registry record.
The primary outcome title concerns the number of participants with adverse events, but a single overall count for that outcome is not reported in the registry record. The posted group summaries distinguish serious events and other events, which offer some safety information but do not provide event-level details for every participant. The registry also does not report numerical results for the vital-sign, laboratory, or somnolence assessments described as safety variables.
These results are descriptive. Because the study has one treatment group and no control arm, differences between age-group counts cannot be interpreted as treatment contrasts. The registry record does not establish causation, comparative risk, or an efficacy result. It also does not report confidence intervals or another measure of uncertainty for these counts. The figures can be read as the recorded experience in this study population, with the limits imposed by the small enrollment and the missing detail about event overlap and measurement results.
9. Statistical Methods Explained
The registry presents a single-group, open-label safety study. That design determines what the adverse-event counts can answer: they describe events recorded among participants who received the study drug, rather than comparing outcomes between independently assigned treatments. The age categories are useful for organizing the descriptive safety information, but they do not create a randomized comparison.
What does a participant count represent?
A count of participants with an event counts people, not event episodes. If one person experiences multiple events, that person may still contribute only once to a participant-level count for the relevant category. Event counts and participant counts answer different questions. The registry’s primary outcome is worded as the number of participants with adverse events, while its posted adverse-event summaries distinguish participants with serious events from those in an other-event category. The record does not provide enough detail to determine how all event categories were constructed or whether categories overlap.
Why are denominators important?
A count is most interpretable alongside the number of participants at risk in that group. The posted summaries give age-specific denominators for serious and other adverse events. Those denominators provide context for the corresponding counts, but do not remove uncertainty: each group contains a limited number of participants, and the registry does not report confidence intervals for the event counts. A denominator also does not indicate how long each individual was observed or how much time each participant contributed.
What does an open-label design imply?
In an open-label study, treatment masking is not used. This can affect how events are noticed, reported, assessed, and coded, particularly for outcomes that depend on observation or participant report. This is a general design consideration, not evidence that any particular event in this study was misclassified. The registry does not report procedures for blinded event review or other safeguards against assessment bias.
Why does the lack of a control group matter?
A treatment comparison generally requires a suitable group exposed to a different condition, with design and analysis that support a fair contrast. No such control group is described in this record. The age groups are not substitutes for control groups because both are categories of participants in the same single-group extension. Therefore, the counts cannot show how event occurrence differed from a comparator or from the background experience of a similar population not receiving the study drug.
How should uncertainty be understood?
In general, a confidence interval communicates the range of values compatible with data under a specified statistical method and assumptions. It can show that an estimate is imprecise even when a point estimate is available. No confidence interval for the adverse-event counts is reported in the registry record. The counts should therefore be read as observed descriptive values, without treating them as exact estimates of event frequency in a broader population.
What can statistical testing add?
A statistical test can address a defined hypothesis under specified assumptions, but it cannot repair a design that lacks a comparator or make a descriptive count causal. The registry lists no analyses for this outcome. The statistical analysis plan, including any inferential tests, adjustment strategy, or handling of repeated events, is not reported in the registry record. No hypothesis-test result should be inferred from the reported counts alone.
What about planning calculations?
Any sample-size illustrations associated with the posted material are planning exercises based on an assumed effect and allocation, not observed power. The registry does not report that these calculations formed the study’s design or provide a sample-size justification. Since the trial is a single-group extension, calculations framed around two equal arms do not describe the actual allocation in this study. Such illustrations should not be treated as evidence that the study had a particular probability of detecting an effect.
How do other safety measures fit in?
Adverse events are one part of safety monitoring. The registry also describes vital signs, clinical laboratory results, and somnolence assessed using the University of Michigan Sedation Scale. These measures may capture different aspects of safety, but their numerical results and analysis methods are not reported in the registry record. A complete statistical interpretation would require the definitions, summaries, missing-data handling, and any prespecified analysis methods for each measure; those details are not reported.
10. Multiplicity, Missing Data and Analysis Populations
The registry describes one primary outcome concerning the number of participants with adverse events and also lists several safety assessments: vital signs, clinical laboratory results, and somnolence measured using the University of Michigan Sedation Scale. The statistical analysis plan, including whether any of these measures were primary or secondary for formal testing, is not reported in the registry record. A multiplicity strategy for handling several outcomes or event categories is also not reported. Consequently, the posted information does not support interpreting a collection of findings as if a prespecified family of statistical tests had been conducted.
The record lists no analyses for the outcome. It does not report a method for handling missing observations, incomplete follow-up, or participants who may have stopped treatment or left the study early. It also does not state whether adverse-event summaries included all participants with any available safety information or whether other analysis populations were used. The defined extension safety population includes patients who received at least one dose of study drug, but this definition alone does not explain how missing data were handled.
In general, missingness can affect interpretation when participants with incomplete observations differ from those with complete observations. The direction and size of any such effect depend on the reasons data are missing and the analysis approach; neither is reported. The registry gives a study timeframe of up to 6 months during the study and a 7-10 days poststudy safety follow-up assessment, but does not give participant-level follow-up duration or completeness. These omissions limit assessment of how fully the reported counts capture the planned safety observation period.
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 |
|---|---|---|---|
| 6 to < 12 Years | 3 | 9 | 33.3% |
| ≥ 12 to ≤ 16 Years | 2 | 14 | 14.3% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| 6 to < 12 Years | 8 of 9 |
| ≥ 12 to ≤ 16 Years | 8 of 14 |
Most frequent serious adverse event terms
| Event term | Organ system | 6 to < 12 Years | ≥ 12 to ≤ 16 Years |
|---|---|---|---|
| Sickle cell anaemia with crisis | Congenital, familial and genetic disorders | 1 of 9 | 1 of 14 |
| Constipation | Gastrointestinal disorders | 1 of 9 | 0 of 14 |
| Vomiting | Gastrointestinal disorders | 0 of 9 | 1 of 14 |
| Pyrexia | General disorders | 1 of 9 | 0 of 14 |
| Back pain | Musculoskeletal and connective tissue disorders | 0 of 9 | 1 of 14 |
| Headache | Nervous system disorders | 0 of 9 | 1 of 14 |
Most frequent non-serious adverse event terms
| Event term | Organ system | 6 to < 12 Years | ≥ 12 to ≤ 16 Years |
|---|---|---|---|
| Pyrexia | General disorders | 3 of 9 | 2 of 14 |
| Vomiting | Gastrointestinal disorders | 2 of 9 | 2 of 14 |
| Constipation | Gastrointestinal disorders | 1 of 9 | 1 of 14 |
| Nausea | Gastrointestinal disorders | 1 of 9 | 1 of 14 |
| Haemoglobin decreased | Investigations | 1 of 9 | 1 of 14 |
| Platelet count decreased | Investigations | 1 of 9 | 1 of 14 |
| Dyspnoea | Respiratory, thoracic and mediastinal disorders | 1 of 9 | 1 of 14 |
| Epistaxis | Respiratory, thoracic and mediastinal disorders | 2 of 9 | 0 of 14 |
| Anaemia | Blood and lymphatic system disorders | 1 of 9 | 0 of 14 |
| Lymphadenopathy | Blood and lymphatic system disorders | 1 of 9 | 0 of 14 |
Serious events with the highest arm-level rate: sickle cell anaemia with crisis (11.1%), constipation (11.1%), pyrexia (11.1%), vomiting (7.1%), back pain (7.1%).
The serious adverse-event summaries report 3 of 9 participants in the 6 to under 12 years group and 2 of 14 participants in the 12 to 16 years group, inclusive. The other adverse-event summaries report 8 of 9 and 8 of 14 participants, respectively. These values are participant counts within the age-group denominators, not counts of event episodes. The registry lists the age groups as descriptive categories; they are not treatment arms.
The record also names six serious adverse-event terms with registry-reported percentages: sickle cell anaemia with crisis and constipation and pyrexia at 11.1% each, and vomiting, back pain, and headache at 7.1% each. The listing does not report whether one participant could appear under multiple terms or explain the calculation denominator. It should not be interpreted as a mutually exclusive distribution.
The registry record does not report a numerical overall primary-endpoint count, confidence intervals, or the causal relationship of each event to treatment. Deaths are not numerically reported in the event summary. The counts describe recorded events in this study; they do not establish comparative risk or causation.
12. What the Result Does, and Does Not, Mean
The posted results provide descriptive information about adverse events recorded among participants in an open-label extension of oxycodone hydrochloride controlled-release tablets. They give age-group counts for serious adverse events and other adverse events, and a list of serious event terms with percentages. These observations contribute to a description of safety during the study timeframe and the poststudy safety follow-up assessment.
They do not provide a controlled estimate of the difference between oxycodone and another treatment, because no comparator group is described. They also do not establish that an event was caused by the study drug. Events observed during treatment may have multiple possible explanations, and the registry record does not report event-level causality assessments. The record likewise does not provide a basis for a treatment-efficacy conclusion.
The counts are not a complete account of the study’s stated safety assessments. Although the registry says that vital signs, clinical laboratory results, and somnolence were assessed, numerical results for those measures are not reported in the registry record. A single overall count for the primary adverse-event outcome, confidence intervals, and details about event overlap are also not reported. These omissions mean the posted counts cannot convey every aspect of event frequency, severity, duration, or uncertainty.
General statistical interpretation requires attention to design, denominator, follow-up, and precision. Here, the single-group design limits comparative inference, and the modest enrollment means the group-specific counts should be understood as observations in this study rather than definitive estimates for a broader population. The registry does not report participant-level follow-up completeness or methods for missing data, adding uncertainty about how fully the counts reflect the intended observation period.
The appropriate reading is therefore narrow: these are the event counts and terms recorded for participants in this extension, as categorized in the registry. They can inform a descriptive account of what was observed, but they do not establish comparative safety, causality, or efficacy.
13. Why This Trial Matters Statistically
This study is statistically notable because it illustrates the distinction between safety description and treatment comparison. An extension can collect information about events over continued exposure, but a single-group design answers a different question from a randomized controlled comparison. The posted counts describe what was recorded among participants in the extension; they do not estimate how the same participants would have fared under a different treatment.
The age-group summaries also show why counts should always be read with their denominators. The registry reports serious and other adverse-event counts within the listed age categories. Those figures make the scale of the observed groups visible, while also underscoring that the summaries represent a limited number of participants. They are not precise population-level estimates, and the record does not report confidence intervals to quantify their uncertainty.
Another statistical lesson is that an endpoint label does not supply every result needed for interpretation. The primary outcome is described as the number of participants with adverse events, but a single overall numerical result is not reported in the registry record. The registry does list event categories and terms, yet the definitions, overlap rules, and denominator details are not fully described in the posted summary. This limits how far readers can compare or combine the listed values.
Finally, the stated safety assessments extend beyond adverse-event counts to vital signs, laboratory results, and somnolence. Their numerical results are not reported in the registry record. That gap highlights the need to distinguish measures that were assessed from measures for which results are available. Statistically, a clear description of the analysis population, follow-up, missingness, and uncertainty is necessary to move from a list of observations toward a well-supported interpretation.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The principal limitation is the absence of a comparator group. The registry describes a single-group, open-label extension with no allocation, so its adverse-event counts cannot support a randomized treatment contrast. The age categories do not function as control groups. Any differences between their counts are descriptive and may reflect differences in group composition or observation that the registry does not detail.
The enrollment was 23, and the adverse-event summaries contain relatively small age-group denominators. Such counts can be sensitive to the experience of individual participants. The registry does not report confidence intervals or another measure of precision for these outcomes. It also does not report a single overall numerical result for the stated primary endpoint.
The study description states eligibility for ages 6 to 17 years, inclusive, while the event summaries use categories ending at 16 years. Whether participants aged 17 were enrolled or how such participants were represented is not reported in the registry record. The record also does not give participant-level follow-up time or completeness, despite describing a study period of up to 6 months and a 7-10 days poststudy safety follow-up assessment.
Further limitations include unreported details about adverse-event coding, overlap among event terms, causal assessment, missing-data handling, and the statistical analysis plan. Numerical results for the listed vital-sign, laboratory, and somnolence assessments are not reported. The registry does not report a sample-size justification or a multiplicity strategy. These gaps constrain interpretation of both the observed event counts and the broader safety profile; they do not, by themselves, indicate what unreported results would have shown.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Long-Term Safety of Twice Daily Oxycodone Hydrochloride Controlled-release Tablets in Children Who Completed OTR3001 — NCT01369615.
- Registry record last updated 2015-09-09; status last verified 2015-08.
- Results first posted 2015-01-15.
- 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
NCT01369615 is a completed Phase 3, open-label, single-group extension study sponsored by Purdue Pharma LP. It evaluated long-term safety of twice-daily oxycodone hydrochloride controlled-release tablets in opioid-experienced children who completed the 4-week treatment period in OTR3001. The study description identifies eligible patients aged 6 to 17 years, inclusive, with moderate to severe malignant and/or nonmalignant pain requiring opioid therapy.
The registry lists enrollment of 23, a study start of 2011-10, and primary completion of 2013-12. The primary outcome concerns the number of participants with adverse events, with a timeframe of up to 6 months during the study and a 7-10 days poststudy safety follow-up assessment. The registry reports age-group adverse-event counts and selected serious adverse-event terms, but not a single overall primary-endpoint result or numerical results for the other described safety measures.
Because no comparator group is described, the findings are descriptive rather than comparative. Analysis-plan details, missing-data methods, and precision estimates are not reported in the registry record.