Surveillance of Humira Injection in Korean Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Surveillance of Humira Injection in Korean Patients (NCT01083121), a registered phase not stated study. The primary outcome is Number of Participants With Adverse Events (AEs).

2. Clinical Question

3. Trial Design

This completed record concerns post-marketing surveillance of Humira injection in Korean patients. The official title places it within the Korean new-drug re-examination framework. The registry lists AbbVie as sponsor, with Abbott identified as a prior sponsor. The study start is recorded as 2007-04 and primary completion as 2012-06.

Participants were prescribed adalimumab according to the approved Korean prescribing information and observed in normal medical practice. The brief description says patients would be observed for not less than 3 months after their first dose. It lists collection of demographic and diagnostic information, medical history, tuberculosis skin-test and chest X-ray results, treatment and concomitant medication information, physician global assessment, disease activity assessments for rheumatoid arthritis, Crohn’s disease and psoriasis, and adverse events.

The registry lists enrollment of 1779. The primary outcome is reported for a safety analysis population, and the adverse-event record gives 1698 as the number at risk. The record does not explain the relationship between these counts or report the details of any exclusions, withdrawals, or missing outcome data.

The design is observational: participants received the medicine as prescribed, rather than being randomized by the study. Allocation is not stated, and the registry explicitly cautions that the arms are not a like-for-like control comparison. The record identifies an adalimumab group but does not report a comparator group. The study status is COMPLETED. Its design is suited to describing what was recorded during surveillance, but the available information does not establish a controlled estimate of treatment effect.

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: Safety analysis population

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: Safety analysis population

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Adverse Events (AEs), measured over From Baseline until up to 70 days after the 3 month study period (total of 160 days)..

The primary endpoint is the number of participants with adverse events, measured in the safety analysis population. Its timeframe is from baseline until up to 70 days after the 3 month study period, described as a total of 160 days. The outcome is expressed as a participant count, not as a measure of event severity averaged across people or as a time-to-event estimate.

The registry defines an adverse event as an untoward medical occurrence that does not necessarily have a causal relationship with treatment. It distinguishes adverse drug reactions, which are described as noxious and undesired reactions related to an experimental drug or experiment. Serious adverse events are defined by specified outcomes, including death, life-threatening events, hospitalization, congenital anomaly, persistent or significant disability or incapacity, abortion, or intervention to prevent a serious outcome. The record also describes severity categories and investigator assessments of whether events were probably or possibly related to adalimumab.

Counting participants with events is useful for describing the safety experience recorded during surveillance. It is important to distinguish that descriptive purpose from causal attribution: an event recorded during treatment is not necessarily caused by treatment. The registry reports 47 participants with serious adverse events and 0 in the other adverse-event category. It does not report an inferential analysis for this primary endpoint, so the counts alone do not quantify comparative risk or statistical uncertainty.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a binary participant-level outcome in the sense that each participant is classified according to whether an adverse event is recorded. The registry presents the result as a number of participants, rather than as an event rate over person-time or a model-based treatment contrast. The posted entries are 47 participants with serious adverse events and 0 in the other adverse-event category, among 1698 participants at risk in the safety record.

What does a participant count describe?

A count describes the number of people in whom an outcome was recorded under the registry’s definitions and observation procedures. It does not, by itself, describe how many events each affected person experienced, how long each person was followed, or whether an event was caused by the treatment. Those questions require information beyond a participant count. The registry identifies its primary outcome as the number of participants with adverse events and supplies a timeframe, but does not report event-level detail or a time-to-event analysis.

In general, a proportion pairs an event count with a clearly defined denominator. Such a summary is interpretable only when the population and outcome definition are clear and the denominator corresponds to the people whose outcome status is being summarized. The record identifies the safety analysis population and lists participants at risk, but does not explain all population accounting or missing outcome handling. No independently calculated proportion is necessary to describe the reported counts, and no new proportion is stated.

Why does the observation design matter?

In a randomized trial, allocation can help make comparison groups similar in expectation with respect to factors that affect outcomes. This registry was not a randomized comparison, and allocation is not stated. Participants were prescribed adalimumab according to approved Korean prescribing information and observed in ordinary medical practice. A descriptive count from this setting cannot distinguish treatment effects from differences in clinical condition, concurrent care, or other factors that may influence both treatment and adverse events.

Adjustment methods can sometimes account for measured differences between groups, but they cannot automatically remove bias from unmeasured factors, poor measurement, or inadequate overlap. The registry reports no analyses, so no adjusted estimate is available to interpret. More fundamentally, the record does not identify a like-for-like comparator group. Statistical adjustment cannot create a direct randomized comparison where the design does not provide one.

How should uncertainty be understood?

In general, an estimate based on observed participants has sampling uncertainty: another sample from a similar setting might yield a different estimate. A confidence interval communicates a range of values compatible with the data and the assumptions of the method used. Its width reflects statistical precision, while its validity depends on the design, measurement, and analysis assumptions. The registry record reports no confidence interval or other inferential result for the primary endpoint. Consequently, precision cannot be evaluated from a reported interval, and the counts should not be treated as exact estimates of event frequency in every patient or setting.

A p-value, in general, evaluates how compatible data are with a specified statistical model or null hypothesis. It is not a measure of the probability that a treatment caused an event, and it does not express the size or clinical importance of an effect. No p-value or hypothesis test is reported in the registry record. There is therefore no basis for describing the primary outcome as statistically significant or not statistically significant.

What do the serious-event terms add?

The listed terms offer descriptive detail about types of serious events and the percentages recorded beside them. The registry gives pyelonephritis and abdominal pain as 0.2% each, and pneumonia, pulmonary tuberculosis, herpes zoster, and peritoneal tuberculosis as 0.1% each. The record does not supply term-specific participant counts or explain whether one participant could contribute to more than one term. These percentages should be treated as reported descriptors, not as comparative estimates or proof of treatment causation.

The registry distinguishes an event being serious from an event being related to adalimumab. Seriousness is defined by the outcome or intervention associated with the event. Relatedness is an investigator assessment, with probably or possibly related categories described in the record. The results of those relatedness assessments are not reported in the registry record. Similarly, severity is classified as mild, moderate, or severe, but the record does not give the distribution of events across those severity categories.

Can a planning calculation establish power?

In general, a sample-size calculation is a planning exercise based on an assumed effect, variability, significance level, allocation, and analysis method. It is not evidence that a study had a particular probability of detecting an effect after results are observed. The registry describes a planning illustration based on a fraction of an observed effect, with two-sided significance level 0.05, equal allocation, and a normal approximation. It also distinguishes participant-based calculations from total-event calculations for time-to-event settings. These are stated as planning assumptions, not as the study’s own design. A sample-size justification, statistical plan, or observed-power analysis is not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 2 outcome measures and 0 analyses. The primary measure concerns participants with adverse events; the secondary outcome listed is physician’s global assessment for effectiveness. The existence of multiple outcomes raises a general interpretive issue: when many outcomes or comparisons are tested, the chance of at least one apparently unusual result can increase. Methods for addressing multiplicity depend on the prespecified questions and analysis plan. That plan, including any multiplicity strategy, is not reported in the registry record. Since no analyses are reported, there are no posted test results from which to assess multiplicity adjustment.

Missing data can affect descriptive counts and inferential estimates. For example, if outcome status is unavailable for some participants, the interpretation depends on how those records are handled and whether missingness is related to health status or other factors. This is a general concern, not a claim about why any information is absent in this surveillance record. The registry does not report a missing-data method, completeness details, or reasons for any unavailable outcomes.

The primary outcome is identified as using the safety analysis population. The adverse-event record lists 1698 participants at risk, while enrollment is listed as 1779. The registry does not explain the population accounting in enough detail to infer why the counts differ; no reason should be assumed. The record also does not describe exclusions, withdrawals, or a participant-flow analysis.

These gaps limit assessment of how robust the descriptive findings are to missing outcomes or analysis choices. They do not alter the fact that the posted record reports its stated counts, but they constrain interpretation of who contributed to those counts and how uncertainty was handled.

11. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent serious adverse event terms

Serious events with the highest arm-level rate: pyelonephritis (0.2%), abdominal pain (0.2%), pneumonia (0.1%), pulmonary tuberculosis (0.1%), herpes zoster (0.1%).

The adverse-event record gives 1698 participants at risk, 47 participants with serious adverse events, and 0 in the other adverse-event category. The primary outcome timeframe is from baseline until up to 70 days after the 3 month study period, described as a total of 160 days. The record defines serious adverse events by outcomes such as death, life-threatening events, hospitalization, congenital anomaly, persistent or significant disability or incapacity, abortion, or an intervention to prevent a serious outcome.

Seriousness should not be confused with severity or causal relationship. The registry separately describes severity categories and investigator assessments of whether adverse events were probably or possibly related to adalimumab. It does not report the results of those relatedness assessments or the distribution across severity categories. Thus the serious-event count is not a count of events established as treatment-caused.

The serious-event listing includes pyelonephritis and abdominal pain at 0.2% each, and pneumonia, pulmonary tuberculosis, herpes zoster, and peritoneal tuberculosis at 0.1% each. These are the registry’s reported percentages; term-specific counts and overlap among terms are not reported in the registry record. The figures are descriptive and do not establish comparative risk. Because no control comparison or inferential analysis is reported, they cannot show whether these events occurred more often or less often than they would have under another care approach.

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

The registry documents a completed post-marketing surveillance study of adalimumab prescribed under approved Korean prescribing information. It reports 47 participants with serious adverse events and 0 in the other adverse-event category among 1698 participants at risk in the safety record. It also lists several serious-event terms with accompanying percentages. These entries describe what the registry records for this surveillance population and its stated observation window.

The findings do not establish that adalimumab caused the recorded events. The registry’s definition of an adverse event explicitly allows that an event may have no causal relationship with treatment. Although investigator assessments of relatedness are described, their results are not reported in the registry record. The seriousness classification identifies consequential events; it does not itself establish causation.

Nor do the posted counts establish a comparative treatment effect. This was not a randomized comparison, allocation is not stated, and the registry cautions that the arms are not a like-for-like control comparison. The record does not report a comparator group for the adalimumab outcome. Without a suitable comparison and an analysis that addresses relevant differences, observed counts cannot answer what would have happened to similar patients under another treatment or without treatment.

The record also does not report confidence intervals, p-values, adjusted estimates, or a statistical analysis plan. Thus it does not quantify statistical precision or support a claim about statistical significance. The counts remain useful as descriptive surveillance information, but their interpretation is bounded by the population definition, observation period, outcome recording, and missing analysis details.

These limitations do not make the recorded information meaningless. They specify what kind of evidence it is: a description of adverse events captured during post-marketing observation, rather than a randomized test of efficacy or a causal safety comparison. Interpretation should remain within that scope.

13. Why This Trial Matters Statistically

This record illustrates a central distinction in biostatistics: describing events observed during treatment is not the same as estimating events caused by treatment. The registry’s adverse-event definition explicitly says that an event need not have a causal relationship with treatment. In ordinary medical practice, patients have underlying conditions, receive concomitant medication, and experience clinical events for multiple reasons. The surveillance count is informative about what was recorded, but causal interpretation requires a credible comparison and assumptions that the design can support.

The record also highlights why outcome definitions matter. It distinguishes an adverse event, an adverse drug reaction, a serious adverse event, event severity, and investigator-assessed relatedness. These categories answer different questions. A serious event is defined by its consequences; relatedness concerns the investigator’s judgment about a connection to treatment. Treating these categories as interchangeable would overstate what the data establish.

Population accounting is another important statistical issue. Enrollment is listed as 1779, while 1698 participants are at risk in the safety record. Because the registry does not explain this accounting, the difference should not be assigned a cause or treated as a documented exclusion pattern. Clear participant flow and missing-data reporting help readers understand which observations contribute to an endpoint and how complete the evidence is.

Finally, the registry reports no analyses. Without reported uncertainty estimates or a comparator analysis, readers should not infer statistical significance, precision, or comparative safety from the event counts. The value of the record lies in its descriptive surveillance context, accompanied by careful attention to the limits of observational data.

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 registry does not report a control group for the adverse-event outcome, and it identifies the study as not being a randomized comparison. Allocation is not stated. Consequently, the record cannot support a like-for-like contrast between adalimumab and another treatment or no treatment. Clinical differences between patients and treatment decisions may influence which events are observed, but the registry does not report analyses addressing such differences.

Although the brief description lists demographic, diagnostic, medical-history, tuberculosis-screening, treatment, concomitant-medication, physician-assessment, disease-activity, and adverse-event information for collection, the posted record does not provide results for those measures beyond the reported adverse-event entries and the secondary outcome name. The results of investigator assessments of relatedness and the distribution of event severity are not reported in the registry record.

The record does not provide a participant-flow account explaining enrollment of 1779 alongside 1698 participants at risk in the safety analysis population. It also does not report missing-data procedures, completeness of follow-up, or reasons for unavailable outcome information. The planned observation is described as not less than 3 months after first dose, while the primary outcome timeframe extends until up to 70 days after the 3 month study period; the record does not provide individual follow-up durations.

No statistical analysis results, confidence intervals, p-values, adjusted estimates, or statistical plan are reported. A sample-size justification and interim-analysis details are not reported in the registry record. The serious-event percentages are listed without term-specific counts or an explanation of possible overlap. Together, these omissions limit assessment of precision, analysis choices, and the breadth of conclusions that can be drawn from the surveillance counts.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Surveillance of Humira Injection in Korean Patients — NCT01083121.
• Registry record last updated 2013-08-21; status last verified 2013-08.
• Results first posted 2013-08-20.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

NCT01083121 is a completed post-marketing surveillance record titled Surveillance of Humira Injection in Korean Patients. It concerns adalimumab prescribed according to approved Korean prescribing information and observed in normal medical practice. Enrollment is listed as 1779; the safety record lists 1698 participants at risk. The study start is 2007-04 and primary completion is 2012-06.

The primary outcome is the number of participants with adverse events during the stated observation period. The registry reports 47 participants with serious adverse events and 0 in the other adverse-event category. It lists serious-event terms with percentages, but does not report inferential analyses. The record identifies physician’s global assessment for effectiveness as a secondary outcome.

Because the surveillance was not randomized and no like-for-like comparator is reported, the findings are descriptive rather than a controlled estimate of treatment effect. Details of missing-data handling, outcome analyses, and participant accounting are not reported in the registry record.