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 Safety of Twice Daily Oxycodone Hydrochloride Controlled-release Tablets in Children With Moderate to Severe Malignant and/ or Nonmalignant Pain Requiring Opioids (NCT01192295), 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 | NCT01192295 |
| Phase | Phase 3 |
| Condition | Pain |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 155 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Purdue Pharma LP |
| Results posted | Yes |
2. Clinical Question
Population
Opioid-experienced children aged 6 to 16 years, inclusive, with moderate to severe malignant and/or nonmalignant pain requiring opioid analgesics. The safety population consisted of patients who received at least one dose of study drug. The record gives age-specific safety groups for children aged 6 to under 12 years and those aged 12 through 16 years.
Intervention
Oxycodone hydrochloride controlled-release tablets, taken twice daily. The study aimed to characterize safety during treatment and follow-up; the record does not describe a separate intervention arm.
Comparator
There was no randomized comparator. The record describes an open-label, single-group study, with safety information summarized by age group. Those age groups are descriptive subgroups, not like-for-like treatment and control groups.
Primary question
The primary safety question was how many participants experienced adverse events during the study and safety follow-up. The stated assessment window was up to 4 weeks during the study and 7-10 days after the study. Safety assessments also included physical examinations, clinical laboratory tests, vital signs, pulse oximetry, and somnolence assessments.
This is a descriptive safety question rather than a test of whether the treatment is better than another treatment. The registry record identifies adverse events as the primary measure, but the posted figures in the adverse-event record distinguish serious adverse events from other adverse events. They do not give a single overall count for all participants with any adverse event as the primary endpoint. Consequently, the available counts can describe reported event categories, but they do not fully answer the primary question as worded.
3. Trial Design
The registry record describes a Phase 3, open-label, multicenter study of twice-daily oxycodone hydrochloride controlled-release tablets. The official title identifies opioid-experienced children aged 6 to 16 years, inclusive, with moderate to severe malignant and/or nonmalignant pain requiring opioid analgesics. The study was completed. Enrollment was 155. The recorded start was 2010-11, and primary completion was 2014-07.
The design is single-group, with no masking and no randomized allocation. All participants received the study drug; the registry record does not describe a separate placebo or active-control arm. Safety results are summarized descriptively within two age groups: 6 to under 12 years and 12 through 16 years. These age groups allow readers to see reported counts separately by age, but they are not randomized groups and should not be treated as a controlled comparison.
The safety population was defined as patients who received at least one dose of study drug. The adverse-event record lists 27 participants at risk in the younger age group and 128 in the older age group. These are the denominators attached to the age-specific adverse-event counts; the record does not establish that every enrolled participant received a dose.
The primary outcome was the number of participants with adverse events. The timeframe was up to 4 weeks during the study and 7-10 days for the poststudy safety follow-up assessment. The record lists additional outcomes addressing pain ratings, supplemental pain medication, caregiver assessments of change and functional disability, and pharmacokinetic data. It does not report a statistical analysis plan, sample-size justification, interim analyses, or a protocol-level explanation of how the age-specific summaries were chosen.
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 | 6 to < 12 Years | ≥ 12 to ≤ 16 Years |
|---|---|---|
| STARTED | 27 | 128 |
| COMPLETED | 17 | 105 |
| NOT COMPLETED | 10 | 23 |
Reasons for not completing this period:
| Reason | 6 to < 12 Years | ≥ 12 to ≤ 16 Years |
|---|---|---|
| Adverse Event | 3 | 7 |
| Withdrawal by Subject | 3 | 4 |
| Lost to Follow-up | 0 | 1 |
| Lack of Efficacy | 0 | 5 |
| Administrative | 4 | 6 |
Analysis population for the primary outcome, as defined in the registry: The safety population was the group of patients who received at least 1 dose of study drug during the 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 safety population was the group of patients who received at least 1 dose of study drug during the study.
| Characteristic | Unit | 6 to < 12 Years | ≥ 12 to ≤ 16 Years | Total |
|---|---|---|---|---|
| Participants analysed | 27 | 128 | 155 | |
| Age, Continuous | years | 9.6 (SD 1.65) | 14.5 (SD 1.34) | 13.7 (SD 2.33) |
| Sex: Female, Male: Female | Participants | 14 | 75 | 89 |
| Sex: Female, Male: Male | Participants | 13 | 53 | 66 |
| Race/Ethnicity, Customized: White | participants | 20 | 88 | 108 |
| Race/Ethnicity, Customized: Black or African American | participants | 7 | 31 | 38 |
| Race/Ethnicity, Customized: Asian | participants | 0 | 1 | 1 |
| Race/Ethnicity, Customized: Other | participants | 0 | 8 | 8 |
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 4 weeks (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 stated as the number of participants with adverse events, a safety measure intended to describe how many people experienced an adverse event during the specified observation period. The stated window extends up to 4 weeks during the study and includes a 7-10 day poststudy safety follow-up assessment. The listed safety assessments also cover physical examinations, clinical laboratory tests, vital signs, pulse oximetry, and somnolence.
In general, counting participants with an event is useful because it distinguishes the number of affected people from the number of individual event episodes. A participant can experience more than one event, so a count of events and a count of participants with events answer different questions. A participant-level endpoint can give a clear overview of how many people had at least one recorded event, while details about event type, severity, timing, and recurrence provide additional context.
The record’s posted adverse-event figures separate serious events and other events by age group. It does not report one overall primary-endpoint count for participants with any adverse event, nor does it provide a fuller account of the endpoint’s event definitions or handling of events spanning multiple categories. The available categories should therefore be read as safety descriptions, not as a complete substitute for the stated primary endpoint. No comparison against another treatment is built into this single-group outcome.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record reports serious adverse events for each age group: 5 of 27 participants aged 6 to under 12 years, and 22 of 128 participants aged 12 through 16 years. It also lists other adverse events for those groups: 13 of 27 and 60 of 128, respectively. These are descriptive counts within the stated safety groups. The record does not provide a randomized control group against which to interpret them.
The serious-event terms listed most often are neutropenia and pyrexia, each recorded as 7.4%, followed by febrile neutropenia, cardio-respiratory arrest, stomatitis, and back pain, each recorded as 3.7%. These percentages are reproduced as reported. The registry record does not clarify in this summary how the percentages were calculated or how the terms relate to the age-specific counts, so they should not be used to infer a subgroup-specific rate or a treatment effect.
The primary endpoint is phrased as the number of participants with adverse events, but the posted adverse-event figures distinguish serious adverse events and other adverse events rather than giving one overall count of participants with any adverse event. The record therefore offers some safety information but does not report the primary endpoint as a single complete participant count. It also does not report uncertainty intervals or inferential comparisons for these figures.
Age-group counts alone do not establish that risks differ by age. The groups are descriptive, their sizes differ, and no adjusted analysis or statistical comparison is reported in the registry record. In general, when group sizes differ, raw counts are not sufficient for comparing how frequently an event occurs. Even when denominators are available, a direct comparison would require an appropriate design and analysis, with attention to uncertainty and relevant differences between groups.
The study was open-label and single-group, so the adverse-event counts describe events recorded among participants who received the study drug; they cannot isolate the contribution of the drug from the underlying illness, other treatments, or other influences. The registry record also does not provide a detailed account of event severity beyond the serious-event category, exposure time for each participant, or event timing. The figures are best read as descriptive safety observations within this study, not as evidence from a controlled comparison.
9. Statistical Methods Explained
The registry record describes the primary safety endpoint as a number of participants with adverse events and says that safety variables were summarized descriptively within age group for the safety population. That population included patients who received at least one dose of study drug. No statistical analyses are listed in the registry record. In particular, it does not report an inferential model, a formal test comparing age groups, or an adjusted analysis.
What does a participant count represent?
In general, a participant count for an adverse-event endpoint records how many people experienced the event definition at least once during the observation window. It is not the same as a count of every episode. If a person has repeated episodes, a participant-level summary may still count that person once, whereas an episode-level summary can count each occurrence. The endpoint wording is participant-based, but the registry record’s adverse-event figures are split into serious events and other events. It does not give one overall count for participants with any adverse event, or explain in detail how participants with events in multiple categories were represented.
The record gives age-specific denominators alongside the serious and other adverse-event counts. This makes it possible to read each count in the context of its stated safety group. The counts should not be treated as a direct comparison between age groups: the study was not randomized by age, and no formal age-group comparison is reported. In general, descriptive stratification can help show whether the observed pattern differs across groups, but it does not by itself demonstrate that age explains a difference or that the groups are otherwise comparable.
Why does the observation window matter?
An adverse-event count depends on the time during which events are observed. The stated timeframe was up to 4 weeks during the study and 7-10 days after the study for safety follow-up. In general, people followed for different lengths of time have different opportunities for an event to be recorded. A simple count does not adjust for unequal exposure or follow-up. The registry record does not provide participant-level follow-up durations or an exposure-adjusted analysis, so the counts should be understood within the stated observation window rather than as event rates per unit of time.
Safety summaries can also differ according to how an adverse event is defined, whether it is judged serious, and how events are coded. The record lists serious-event terms and a separate category of other adverse events, but a fuller account of coding rules, adjudication, or event attribution is not reported in the registry record. In general, a serious-event classification describes a regulatory or clinical category; it does not by itself establish that the study drug caused the event. The record does not report a causal comparison that would separate treatment-related events from events occurring for other reasons.
What can a confidence interval add?
In general, a confidence interval expresses the uncertainty around an estimate under the assumptions of the analysis. For an event proportion, it can show how much uncertainty remains about the underlying frequency, rather than presenting only the observed count. No confidence intervals for the adverse-event counts are reported in the registry record. Without an interval or a specified model, the posted counts should not be read as precise estimates of the frequency that would occur in other patients or settings.
In general, over-dispersion matters when a model assumes less variability than the data contain. It can make model-based uncertainty too small if ignored. The registry record does not report a count model or any assessment of over-dispersion, and the available participant counts do not justify claiming that such a model was used. For this participant-level binary endpoint, a model would also need to respect the distinction between whether a participant experienced an event and how many event episodes occurred.
How should planning illustrations be read?
Any sample-size planning illustrations associated with the results are not the study’s original design calculation. Their stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. The illustration is not a description of this single-group, nonrandomized study and cannot create a control comparison that the trial did not have. Such calculations are planning illustrations, not observed power. The registry record does not report the original sample-size justification or the assumptions used to plan enrollment.
For a randomized comparison, a two-arm planning calculation can be relevant to a future study if its assumptions match that future design and question. In general, a normal approximation is a mathematical shortcut whose suitability depends on the outcome and data structure. Neither the calculation assumptions nor a planning result would alter what this study observed. The posted safety figures remain descriptive, and no inferential conclusion about a comparative effect follows from the planning assumptions alone.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists multiple secondary outcomes, including pain assessments in the two age groups, supplemental pain medication, caregiver assessments, functional disability assessments, and pharmacokinetic measures. It does not report a multiplicity procedure, such as a prespecified strategy for controlling the chance of false-positive findings across multiple tests. No statistical analyses are listed in the registry record, so there are no reported test results on which to assess multiplicity adjustments. The absence of a reported procedure should not be interpreted as proof that none was used outside the registry record.
Missing-data methods are not reported in the registry record. The record does not explain how missing outcome assessments, incomplete follow-up, or withdrawal from the study were handled in the safety summaries. It also does not give the extent or pattern of missing data for the outcomes. In general, missingness can affect interpretation when the chance that a value is unobserved is related to a participant’s health, treatment, or experience of an adverse event. Without details, the impact of missing observations cannot be evaluated from the registry record.
The primary safety population is defined as patients who received at least one dose of study drug. The adverse-event information is presented by age group, with the corresponding group counts at risk. The record does not report whether every enrolled participant entered this population or provide a flow account of enrollment, dosing, and follow-up. The counts therefore apply to the safety groups as recorded, not automatically to everyone enrolled.
The record describes descriptive summaries within age group rather than a randomized comparison. It does not report adjustment for baseline characteristics, exposure duration, or other potential differences between age groups. Those omissions limit what can be inferred about comparative risk, even though the group-specific counts are useful descriptions of events recorded during the stated 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 | 5 | 27 | 18.5% |
| ≥ 12 to ≤ 16 Years | 22 | 128 | 17.2% |
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 | 13 of 27 |
| ≥ 12 to ≤ 16 Years | 60 of 128 |
Most frequent serious adverse event terms
| Event term | Organ system | 6 to < 12 Years | ≥ 12 to ≤ 16 Years |
|---|---|---|---|
| Pyrexia | General disorders | 2 of 27 | 5 of 128 |
| Febrile neutropenia | Blood and lymphatic system disorders | 1 of 27 | 4 of 128 |
| Neutropenia | Blood and lymphatic system disorders | 2 of 27 | 1 of 128 |
| Vomiting | Gastrointestinal disorders | 0 of 27 | 2 of 128 |
| Pain | General disorders | 0 of 27 | 2 of 128 |
| Seroma | Injury, poisoning and procedural complications | 0 of 27 | 2 of 128 |
| Coma | Nervous system disorders | 1 of 27 | 1 of 128 |
| Headache | Nervous system disorders | 0 of 27 | 2 of 128 |
| Cardio-respiratory arrest | Cardiac disorders | 1 of 27 | 0 of 128 |
| Sickle cell anaemia with crisis | Congenital, familial and genetic disorders | 0 of 27 | 1 of 128 |
Most frequent non-serious adverse event terms
| Event term | Organ system | 6 to < 12 Years | ≥ 12 to ≤ 16 Years |
|---|---|---|---|
| Vomiting | Gastrointestinal disorders | 6 of 27 | 26 of 128 |
| Nausea | Gastrointestinal disorders | 3 of 27 | 20 of 128 |
| Headache | Nervous system disorders | 3 of 27 | 17 of 128 |
| Constipation | Gastrointestinal disorders | 4 of 27 | 12 of 128 |
| Pyrexia | General disorders | 5 of 27 | 8 of 128 |
| Dizziness | Nervous system disorders | 0 of 27 | 11 of 128 |
| Pruritus | Skin and subcutaneous tissue disorders | 3 of 27 | 7 of 128 |
Serious events with the highest arm-level rate: neutropenia (7.4%), pyrexia (7.4%), febrile neutropenia (3.7%), cardio-respiratory arrest (3.7%), stomatitis (3.7%).
The registry record lists serious adverse events for the two age groups as 5 of 27 participants aged 6 to under 12 years and 22 of 128 participants aged 12 through 16 years. It lists other adverse events as 13 of 27 and 60 of 128, respectively. Read each numerator with its corresponding age-group denominator; the counts describe the safety population, not a comparison with an untreated or alternative-treatment group.
The serious-event terms recorded as 7.4% are neutropenia and pyrexia. Febrile neutropenia, cardio-respiratory arrest, stomatitis, and back pain are each recorded as 3.7%. The record does not provide further detail about the calculation basis or age-group assignment for these term percentages. They should be quoted as registry entries rather than interpreted as age-specific risks or treatment-attributable rates.
In general, serious adverse events and other adverse events are different categories, and they should not be combined unless the reporting definition and overlap are clear. The record does not explain in detail whether a participant could appear in both categories or how repeated events were counted. It also does not report a control group, exposure-adjusted event rates, or an analysis attributing events to treatment. The counts describe what was recorded in this study and do not establish what caused an event.
12. What the Result Does, and Does Not, Mean
The findings describe safety observations among opioid-experienced children who received oxycodone hydrochloride controlled-release tablets in an open-label, single-group study. The registry record reports serious and other adverse-event counts by age group, and lists several serious-event terms with their recorded percentages. These observations can help characterize what events were recorded during the study and follow-up period.
They do not establish how the event counts would compare with no study drug or with another treatment. Without a randomized control group, differences from an external population could reflect differences in illness, other treatments, participant characteristics, event observation, or other factors. The age-specific summaries also do not demonstrate an age-related difference: the groups were descriptive, and a formal comparison is not reported.
The posted figures do not give a complete overall count for the stated primary endpoint of participants with adverse events. Instead, the adverse-event information distinguishes serious events and other events. The record does not report uncertainty intervals, exposure-adjusted estimates, or details sufficient to assess the precision of the counts as estimates for other populations. Nor does the list of event terms establish that the study drug caused those events.
In general, safety findings are interpreted alongside the definitions of events, follow-up duration, missing-data handling, and the design’s capacity to distinguish treatment effects from background events. Several of those details are not reported in the registry record. The study’s listed safety assessments are broader than the event counts alone, but the record does not provide enough detail to assess all those measures. The appropriate statistical reading is therefore descriptive: the counts characterize reported events in the study population during the stated observation period, while comparative and causal conclusions remain unsupported by the design and reporting available.
13. Why This Trial Matters Statistically
This study raises statistical issues common to pediatric safety research: how to describe adverse events in a population without a control group, how to distinguish serious events from other events, and how to make age-stratified summaries informative without overinterpreting them. The registry record provides counts by age group, which preserves an important descriptive distinction rather than presenting only a single combined summary.
The single-group design makes the limits of the evidence especially important. In general, adverse events occur in the context of underlying disease and other care, so an observed event count cannot by itself identify the cause. A randomized comparison can help separate treatment effects from background risks, while a descriptive study can document events in the treated population. This record supports the latter kind of description, not a controlled estimate of comparative effect.
The distinction between participants with events and event episodes also matters. A participant-level count answers how many people experienced an event at least once, while an episode count can reflect recurrence. The stated primary endpoint is participant-based, but the posted figures do not provide one overall count for participants with any adverse event. That gap illustrates why an endpoint definition and a clear presentation of its corresponding result are both important.
Finally, the registry record identifies a safety population and a defined follow-up window, but does not report methods for missing data, uncertainty estimates, or a detailed statistical plan. These omissions constrain precision and reproducibility. A careful reading keeps the observed counts in view while distinguishing them from causal claims, generalization, or an age-group comparison that the design and reported analyses do not establish.
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 is the absence of a randomized control group. The study is open-label and single-group, so the reported adverse-event counts cannot show how outcomes would have differed under another treatment or no study drug. The age groups are descriptive, not randomized comparison arms. Their observed counts should not be treated as evidence that one age group has a higher or lower risk.
The primary endpoint is described as the number of participants with adverse events, but the registry record does not report one overall count for participants with any adverse event. Instead, the available adverse-event figures distinguish serious events from other events. Details about category overlap, event coding, causality assessment, and repeated events are not reported in the registry record. The serious-event term percentages are listed, but their calculation basis and age-group breakdown are not clarified.
The registry record does not report confidence intervals or other uncertainty estimates for the counts. It also does not provide participant-level exposure duration, exposure-adjusted event rates, or a statistical comparison between age groups. The observation window is stated, but the record does not describe how varying follow-up or incomplete observations were handled.
Missing-data methods, multiplicity procedures, an interim-analysis plan, and the original sample-size justification are not reported in the registry record. The record also does not provide a detailed participant flow account connecting enrollment, receipt of study drug, and follow-up. These reporting limitations make it difficult to assess precision, completeness, or the extent to which the safety summaries represent all enrolled participants. The findings should therefore be interpreted as descriptive registry information for the recorded safety groups, with no controlled estimate of treatment effect.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety of Twice Daily Oxycodone Hydrochloride Controlled-release Tablets in Children With Moderate to Severe Malignant and/ or Nonmalignant Pain Requiring Opioids — NCT01192295.
- Registry record last updated 2020-03-23; status last verified 2020-03.
- Results first posted 2015-02-06.
- 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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18. Record Summary
The registry record describes a completed Phase 3, open-label, multicenter, single-group study of twice-daily oxycodone hydrochloride controlled-release tablets in opioid-experienced children aged 6 to 16 years with moderate to severe malignant and/or nonmalignant pain requiring opioid analgesics. Enrollment was 155. The recorded study start was 2010-11, and primary completion was 2014-07.
The primary safety outcome was the number of participants with adverse events during up to 4 weeks of study and 7-10 days of safety follow-up. The record defines the safety population as patients who received at least one dose and reports serious and other adverse-event counts within two age groups. It also lists serious-event terms and several secondary outcomes. No statistical analyses are listed in the registry record. Because there is no randomized comparator and no overall count for participants with any adverse event, the available figures are descriptive rather than a controlled estimate of comparative safety.