An Interventional Study to Assess the Efficacy and Safety of Oxycodone/Naloxone in Korean Patients With Spinal Disorders: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for An Interventional Study to Assess the Efficacy and Safety of Oxycodone/Naloxone in Korean Patients With Spinal Disorders (NCT01811238), a na phase 4 study. The primary outcome is Change From Baseline in Pain Intensity of Patient With Spinal Disorder as Measured by NRS..

2. Clinical Question

3. Trial Design

This was a completed, multicenter, phase IV interventional study sponsored by Mundipharma Korea Ltd. The official title describes an assessment of efficacy and safety of oxycodone/naloxone in Korean patients with spinal disorders. The registry lists the study start as 2012-09 and primary completion as 2013-04. Its enrollment is 240.

The design is described as a single-group study of oxycodone/naloxone. Allocation is listed as NA, and masking is listed as NONE. There is no parallel control arm in the registry record. This matters for interpretation: changes observed from baseline describe the participants' course during the study, but do not by themselves isolate the treatment's effect from other influences that could alter pain over time.

The primary objective was to assess pain reduction after 8 weeks of treatment from baseline. Secondary objectives included pain change after 4 weeks, EQ-5D, physician and participant overall satisfaction, and safety. The registry also names outcomes for quality of life at Week 8, Clinical Global Impression of Change, pain change at Week 4, EQ-5D VAS, and Patient Global Impression of Change.

The registry lists six outcome measures and two analyses. It does not report the protocol's full statistical analysis plan, sample-size justification, planned interim analyses, or a numerical primary endpoint result. Those details should not be inferred from the study's phase, enrollment, or outcome descriptions.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: The 209 is IIT set population. ITT set included all subjects who participated in the study and had at least one dose of the study drug and had at least one primary efficacy endpoint data available. Missing values were imputed by LOCF.

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: Total 240 patients were enrolled. However, 20 patients were excluded due to no administeration of investigational drug during the study. The 220 is Safety set population included all subjects who had at least one dose of the study drug.

6. Primary Endpoint

The registry lists the primary outcome as Change From Baseline in Pain Intensity of Patient With Spinal Disorder as Measured by NRS., measured over Baseline, 8 week.

The primary endpoint is change from baseline in pain intensity, measured with the NRS. The registry describes the measure as the mean pain over the past 24 hours before the visit. The scale ranges from 0 (No pain) to 10 (Worst possible pain). The endpoint timeframe is baseline and 8 weeks, and the record defines change as the mean score at Week 8/ET minus the mean score at baseline.

A change score expresses how the measured outcome differs from its starting value. The mean summarizes the average change across the participants included in the relevant analysis population. Its direction must be interpreted using the stated subtraction: a lower follow-up score than baseline produces a negative change, while a higher follow-up score produces a positive change. This explains the sign convention; it does not establish the magnitude or statistical certainty of the study result.

Pain intensity is the primary measure because the stated primary objective is to assess pain reduction. A measure covering the preceding 24 hours captures a defined recent period rather than an unspecified general impression. The endpoint alone does not show whether any observed change is attributable to treatment, particularly in a single-group study without a concurrent control.

The numerical mean change, standard deviation, confidence interval, and test result are not reported in the registry record. The endpoint definition is available, but the result's size and precision cannot be assessed from the registry information.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous: it is a score summarized as a mean, with standard deviation specified as the measure of dispersion. In general, a mean describes the average observed value, while a standard deviation describes how spread out individual observations are around that average. The endpoint is a change score, defined as the Week 8/ET mean NRS score minus the baseline mean. The registry does not report the numerical estimate or standard deviation for that endpoint.

What does the change score represent?

Change scores compare measurements taken at different times for the study population. Here, the stated comparison is between baseline and Week 8 or early termination. The subtraction order determines the sign: later minus baseline. A lower later mean would produce a negative change, and a higher later mean would produce a positive change. This general interpretation does not tell us what change occurred in the study, because its numerical value is not reported in the registry record.

A mean change is a summary of the population's average, not a description of every participant's experience. Participants can have different individual changes even when the average is close to zero, and the mean alone cannot show that distribution. Dispersion measures and interval estimates can help describe variability and uncertainty, but the relevant numerical primary results are not reported in the registry record.

How should uncertainty be understood?

In general, a confidence interval gives a range of values compatible with the observed data under a statistical procedure and its assumptions. A narrow interval indicates greater precision than a wide interval, all else equal. The interval does not show the range of individual participant outcomes, nor does it resolve design limitations such as the absence of a control group. No primary confidence interval is reported in the registry record.

A p-value is a measure tied to a particular statistical test and null hypothesis. It is not the probability that the study hypothesis is true, and it does not communicate the size or clinical importance of a change. Interpretation of a p-value depends on the test, analysis population, and assumptions. The registry record does not report a primary endpoint p-value or enough detail to identify the complete inferential procedure.

What does the single-group design permit?

Because the registry describes one treatment group and no concurrent comparator, the primary endpoint is a within-study before-and-after assessment. Such an assessment can describe change over time among included participants. In general, it cannot distinguish treatment effects from natural variation, changes in other care, expectations, or other time-related influences. A comparison with an appropriate control group would address a different question by estimating the difference between groups under the trial design.

Allocation is listed as NA and masking as NONE. The registry does not describe random assignment or blinding. These design features should not be inferred from the phase or from the study's multicenter label. The absence of a concurrent control is the central limitation for estimating a treatment-specific effect from the primary change score.

How should the missing-data approach be read?

The registry states that missing values were imputed by LOCF, or last observation carried forward. In general, this method substitutes a participant's most recent available value for a later missing value. It can make an analysis possible when follow-up values are absent, but the substituted value may not represent the value that would have been observed at the planned assessment. Its validity depends on assumptions about why values are missing and how outcomes evolve over time.

The record does not report how many endpoint values were missing, the reasons for missingness, or sensitivity analyses assessing alternative assumptions. It describes the ITT set as participants who received at least one dose and had at least one primary endpoint value, and identifies 209 as the IIT set population. The numerical size of the described ITT set is not reported in the registry record. These details affect how broadly the result would apply and how robust it is to incomplete follow-up.

What do the planning illustrations mean?

The registry's planning assumptions describe an illustration based on the observed effect, not the trial's own design. They specify a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect to detect expressed as a stated fraction of the observed effect. For non-time-to-event outcomes, such illustrations are expressed as participants per arm for 80% power or another stated power level, when such values are displayed. They are planning illustrations, not observed power and not evidence that the completed single-group study was designed using those assumptions.

In general, a power calculation asks how often a specified analysis would detect an assumed effect under stated conditions. It is not a measure of how likely the observed result is true. Assumptions about effect size, variability, allocation, and statistical model determine the illustration. The registry does not report a trial-specific sample-size justification or statistical plan, and the numerical primary outcome needed to assess the observed effect is not reported in the registry record.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Oxycodone/Naloxone")
n   <- c(209)
m   <- c(-1.69)
sp  <- c(2.18)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Oxycodone/Naloxone  209  -1.690  2.180  -1.987  -1.393

11. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary pain endpoint and several secondary outcomes, including pain change at Week 4, EQ-5D measures, physician and participant global impressions of change, and safety. It reports six outcome measures and two analyses. Testing or interpreting multiple outcomes can raise multiplicity concerns: when many hypotheses are examined, the chance of at least one apparently notable result can increase. Whether and how this concern was addressed depends on the prespecified analysis plan. The multiplicity strategy is not reported in the registry record.

The primary population description says the ITT set included participants who received at least one dose and had at least one primary efficacy endpoint value. It also identifies 209 as the IIT set population. The numerical size of the ITT set is not reported in the registry record. These labels should not be treated as interchangeable without further explanation from the record.

Missing values were imputed using LOCF. In general, carrying forward the last observed value requires assumptions about what an unobserved later value would have been. The registry does not report the number of missing primary measurements, reasons for missingness, the timing or distribution of missingness, or sensitivity analyses. Consequently, the impact of imputation on the primary estimate cannot be assessed.

The registry does not report the full statistical analysis plan, including any prespecified multiplicity adjustment, model details, or interim analyses. The numerical primary estimate and its uncertainty are also not reported in the registry record. These omissions limit assessment of both the analysis choices and the robustness of any efficacy interpretation.

12. 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: femur fracture (0.5%), osteoarthritis (0.5%), renal cancer (0.5%).

The registry lists 220 participants at risk for serious adverse events and 3 affected by serious adverse events. It separately lists 220 at risk for other adverse events and 77 affected. These are counts reported by the registry; they do not provide a comparison with an untreated or alternative-treatment group.

The serious adverse event terms listed include Femur fracture, osteoarthritis, and Renal cancer, each shown with 0.5%. These term-level figures should be read as registry listings, not as evidence that the events were caused by the study drug. The record does not provide a causal assessment in the details.

The death value is not reported in the registry record. The listed counts do not describe event timing, duration, severity beyond the serious-event classification, recurrence, or the clinical circumstances. Nor do they provide the information needed to compare safety between treatments. Since this was a single-group study, the safety figures are descriptive observations among those at risk, not estimates of a difference against a concurrent control.

In general, adverse-event counts need context, including how events were defined and collected, follow-up duration, and whether participants could experience more than one event. Those details are not reported in the registry record. The counts should therefore be interpreted as registry-reported safety summaries rather than as a complete account of risk or causation.

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

The registry describes a phase IV, multicenter, single-group study of oxycodone/naloxone in Korean patients with spinal disorders. Its primary question concerned change in NRS pain intensity from baseline to Week 8 or early termination. The record explains the score scale, endpoint timing, and subtraction order. These details clarify what the study intended to measure.

The numerical primary result is not reported in the registry record. There is no reported mean change, standard deviation, confidence interval, or primary p-value in the available description. Thus, the size, direction, and precision of the observed primary change cannot be stated. The registry's endpoint description is not itself evidence of a particular result.

Even if a before-and-after change estimate were available, the single-group design would not establish how much of that change was due to the study drug. Without a concurrent comparator, differences over time cannot be separated from other possible influences on pain. The design does not answer the same causal question as a randomized comparison.

The registry also lists secondary outcomes and safety counts. Their inclusion shows that quality of life, global impressions, and adverse events were assessed, but their outcome descriptions do not establish their results. The safety figures are descriptive and do not quantify a comparative risk. The death value is not reported in the registry record.

These limitations do not mean that no change occurred or that the treatment had no effect. They mean that the registry information is insufficient to quantify an efficacy effect or its uncertainty, and the design does not support a controlled causal contrast. Interpretation should remain bounded by the reported study structure and the numerical results that are actually recorded.

14. Why This Trial Matters Statistically

This trial is statistically notable as a single-group assessment of change from baseline rather than a controlled comparison. That distinction determines what the primary endpoint can answer. A before-and-after mean change can describe the observed course among participants, but it cannot by itself separate treatment-associated change from other changes over the same period.

The endpoint is clearly defined as mean NRS pain at Week 8/ET minus mean baseline pain. Stating the scale, time points, and subtraction order is important for interpreting the direction and meaning of a change estimate. However, those definitions do not replace the estimate itself. The numerical primary result and its precision are not reported in the registry record.

The record also illustrates why an analysis population and missing-data method matter. It describes an ITT set using dose and endpoint availability criteria, identifies 209 as the IIT set population, and reports LOCF imputation. Without the numerical analysis population, missingness information, and sensitivity analyses, readers cannot judge how strongly the reported approach may influence an estimate.

Finally, the study lists multiple secondary outcomes alongside the primary endpoint. A prespecified plan for interpreting multiple outcomes helps distinguish a primary test from exploratory findings, but that plan is not reported in the registry record. The record contains useful design and measurement details, while leaving the numerical efficacy result and key statistical context unavailable. This makes it important to distinguish a description of what was assessed from evidence about the size or reliability of an effect.

15. 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 efficacy is the absence of a concurrent control group. A single-group change from baseline cannot distinguish the effect of treatment from natural changes, other care, expectations, or other influences over time. Allocation is listed as NA and masking as NONE, so the registry does not describe randomized assignment or blinding.

The numerical primary endpoint result is not reported in the registry record. Neither the mean change nor its standard deviation, confidence interval, or p-value is available in the described information. The absence of these values prevents assessment of magnitude, variability, precision, and statistical evidence. The full statistical analysis plan and trial-specific sample-size justification are also not reported.

The record describes missing-value imputation using LOCF but does not report the number of missing measurements, reasons for missingness, or sensitivity analyses. It identifies 209 as the IIT set population and provides an ITT-set definition, but the numerical size of that ITT set is not reported in the registry record. These gaps limit evaluation of analysis-population choice and missing-data effects.

The study lists several secondary outcomes, but the multiplicity strategy is not reported. The registry also lists safety counts without a concurrent comparison, and the death value is not reported in the registry record. The described information does not provide event-level context or establish causation. Together, these limits mean the registry record supports a description of design and measurement, but not a firm estimate of treatment-specific efficacy or comparative safety.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: An Interventional Study to Assess the Efficacy and Safety of Oxycodone/Naloxone in Korean Patients With Spinal Disorders — NCT01811238.
• Registry record last updated 2016-05-12; status last verified 2016-04.
• Results first posted 2016-05-12.
• 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.

19. Record Summary

NCT01811238 is a completed, multicenter, phase IV, single-group study of oxycodone/naloxone in Korean patients with spinal disorders. The registry lists enrollment of 240, a start of 2012-09, and primary completion in 2013-04. Allocation is NA and masking is NONE.

The primary endpoint is mean NRS pain change from baseline to Week 8/ET, defined as later mean minus baseline mean. The record describes LOCF imputation and identifies 209 as the IIT set population. Numerical primary efficacy results and their precision are not reported in the registry record.

Safety listings include 3 affected by serious adverse events among 220 at risk and 77 affected by other adverse events among 220 at risk. The registry lists Femur fracture, osteoarthritis, and Renal cancer as serious-event terms, each with 0.5%. The study has no concurrent control group, limiting causal and comparative interpretation.