Assessment of the Safety of Adalimumab in Rheumatoid Arthritis Patients Showing Rapid Progression of Structural Damage of the Joints, Who Have no Prior History of Treatment With Disease-modifying Anti-rheumatic Drugs or Biological Agents: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Assessment of the Safety of Adalimumab in Rheumatoid Arthritis Patients Showing Rapid Progression of Structural Damage of the Joints, Who Have no Prior History of Treatment With Disease-modifying Anti-rheumatic Drugs or Biological Agents (NCT01783730), a registered phase not stated study. The primary outcome is Number of Participants With Adverse Events.

2. Clinical Question

This is principally a safety question, not a randomized estimate of treatment effect. The study summary also says it examined effectiveness in daily clinical practice, and the listed secondary outcomes include disease activity measures. However, the registry record does not report numerical results for those secondary outcomes. The central posted evidence is therefore the safety count, which describes events observed among treated participants over the stated follow-up period. It cannot, on its own, establish how those counts compare with what would have occurred without treatment or under a different treatment.

3. Trial Design

The record identifies a completed special investigation of adalimumab in Japanese participants with rheumatoid arthritis who had no previous use of DMARDs or biological agents. The study focused on participants with high rheumatoid arthritis disease activity and rapid progression of structural joint damage. Its stated purpose was to examine safety and effectiveness in daily clinical practice.

The listed arm consists of participants with high rheumatoid arthritis disease activity who received adalimumab. A comparator arm is not reported, and allocation is not stated. The record therefore does not support a randomized between-group comparison or a like-for-like control comparison. The enrollment is 163 participants. The primary safety outcome lists 157 participants at risk; why these figures differ is not reported in the registry record.

The primary outcome was the number of participants with adverse events from baseline through week 26. The record defines adverse events broadly, including unfavorable or unintended signs, symptoms, diseases and abnormal laboratory findings, whether or not considered causally related to treatment. Events were collected from informed consent until study completion, up to 26 weeks.

The listed secondary outcomes include DAS28-4(ESR) at baseline and several follow-up visits, percentage achieving DAS28-4(ESR) remission, and CDAI scores at baseline and follow-up. Although the record lists 16 outcome measures, numerical results for these secondary measures are not reported in the registry record. The study start is 2013-02, primary completion is 2015-09, and status is COMPLETED. The sponsor is AbbVie.

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: Participants who received adalimumab treatment

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Participants who received adalimumab treatment

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: Participants who received adalimumab treatment

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants With Adverse Events, measured over From baseline through week 26.

The primary endpoint is the number of participants with adverse events from baseline through week 26. It is a participant count: it asks how many people had an event, rather than how many separate events occurred. The registry definition includes any untoward medical occurrence, including an abnormal laboratory finding, symptom or disease, whether or not it was considered causally related to the medicinal product.

Safety monitoring commonly uses this kind of endpoint because it can describe how often participants experienced events during a specified observation period. It is important to distinguish the presence of an event from a judgment about its cause. A temporal association means that an event occurred during the relevant period; it does not by itself establish that treatment caused it.

The posted safety data list 157 participants at risk, 4 participants with serious adverse events and 36 participants in the other adverse-event category. The record does not provide a comparative estimate against an untreated or differently treated group. It also does not report a numerical summary of event timing or duration. Thus, the endpoint supports a descriptive account of events recorded during follow-up, not a causal estimate of the treatment’s safety relative to an alternative.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a participant count represent?

A count of participants with an event records whether each person experienced an event during the observation period. This is different from a count of all event occurrences, since one participant might experience more than one occurrence. The primary endpoint is defined in terms of participants, and the posted results give counts of participants in the serious and other adverse-event categories. They do not provide a detailed event-by-event timeline.

Why does the endpoint definition matter?

An adverse event is a broad safety concept. It includes an untoward medical occurrence temporally associated with use of a medicinal product, regardless of whether a causal relationship is established. A clinical event may therefore qualify for recording without being judged caused by treatment. A count of adverse events is not automatically a count of adverse drug reactions, nor does it establish that treatment increased or decreased risk.

What can a denominator tell the reader?

The denominator identifies how many participants were considered at risk for the reported outcome. The safety record lists 157 participants at risk for each displayed category. The total enrollment is 163. The reason that the enrollment and the safety denominator differ is not reported in the registry record. A reader should not assume the missing participants had no events, nor infer why their data are not included. The record does not describe the flow of participants into the safety population or explain missing outcome information.

Why does a comparator matter?

Descriptive counts show what was observed in the treated group. To estimate a difference attributable to treatment, a study generally needs a suitable comparison and an analysis that accounts for how groups were formed and followed. This record does not report a comparator, and allocation is not stated. Its safety counts cannot isolate treatment effects from background events, participant characteristics, clinical care or other influences. The counts should be understood as observations in the treated cohort rather than as comparative evidence.

What is the role of uncertainty?

In general, statistical uncertainty describes how much an estimate may vary because the observed participants are only a sample of a broader population or because events are relatively uncommon. A confidence interval is one way to express uncertainty around an estimate, under the assumptions of the method used. The registry record does not report confidence intervals or an inferential analysis for the primary endpoint. The counts alone therefore do not convey a formal range of uncertainty or establish the precision of a treatment comparison.

What does the record say about analyses?

The registry record lists no statistical analyses. It names secondary outcomes involving DAS28-4(ESR), remission and CDAI, but numerical results for those outcomes are not reported in the registry record. Without posted analysis details, readers cannot assess the analysis population for each secondary outcome, the handling of incomplete observations, or whether any adjusted models were used. Those methods are not reported in the registry record.

How should planning calculations be understood?

In general, a sample-size calculation estimates the amount of information a study might need to detect a specified effect under stated assumptions. A planning illustration is not the same as the sample size chosen for the trial, and it is not observed power. The planning assumptions associated with this record describe 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 an observed effect. The record does not report that these assumptions were the trial’s own design or sample-size justification. In particular, the absence of a like-for-like comparator means the posted safety counts do not provide a randomized treatment contrast. Any such illustration should be read as hypothetical planning, not as a retrospective demonstration that the study could or could not establish an effect.

Statistical methods clarify what an estimate can support, but they cannot supply information that the record does not report. Here, the available primary result is a set of descriptive counts within a stated period. No adjusted estimate, comparative effect, confidence interval or analysis of secondary outcomes is reported in the registry record.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Participants With High Rheumatoid Arthritis Diseas")
n      <- c(157)
events <- c(40)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Participants With High Rheumatoid Arthritis Diseas  157  40  25.5  18.9  33.0  19.3  32.8  19.3  32.8

11. Multiplicity, Missing Data and Analysis Populations

The record lists multiple outcome measures, including repeated DAS28-4(ESR) measurements, remission and CDAI scores, in addition to the primary adverse-event outcome. When a study assesses multiple outcomes or time points, the chance of finding an apparently notable result by chance can be affected by how many analyses are conducted and how results are interpreted. In general, multiplicity methods can control or describe that issue. A multiplicity plan or adjustment is not reported in the registry record.

The registry lists no statistical analyses, and numerical results for the listed secondary outcomes are not reported in the registry record. It is therefore not possible to determine whether comparisons across visits were prespecified, whether any multiplicity adjustment was used, or how the secondary outcomes were analyzed.

The primary safety outcome identifies participants who received adalimumab, but a more detailed analysis-population definition is not reported. The record does not explain how participants with incomplete follow-up or missing safety information were handled. It also does not report whether participants were included according to treatment received, enrollment status or another analysis rule. The difference between enrollment of 163 and 157 participants at risk is recorded, but its explanation is not reported in the registry record. Missing-data methods, exclusions and reasons for any unavailable outcomes are likewise not reported.

These gaps limit assessment of the completeness and robustness of the posted results. They do not establish that data were missing or that a particular analysis method was used; they mean those details are not reported in the registry record.

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: pyelonephritis (0.6%), pneumocystis jiroveci pneumonia (0.6%), pericarditis (0.6%), interstitial lung disease (0.6%), pleurisy (0.6%).

The safety results list 4 participants with serious adverse events and 36 participants in the other adverse-event category, with 157 participants at risk. These are participant counts, not necessarily counts of separate event episodes. The registry definition of an adverse event does not require a causal connection to adalimumab.

The listed serious adverse-event terms are Pyelonephritis, Pneumocystis jiroveci pneumonia, Pericarditis, Interstitial lung disease and Pleurisy, each reported at 0.6%. The record does not provide further detail about the timing, course, treatment attribution or outcome for these terms. Deaths are not reported in the registry record; that is different from a report that no deaths occurred.

Because the registry does not report a comparator, the safety figures cannot show whether events were more or less frequent than under another treatment or without treatment. They describe the events recorded in this treated cohort during the stated follow-up period.

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

The posted results provide a descriptive account of adverse events recorded among participants who received adalimumab. The primary outcome covers baseline through week 26, and the registry lists 157 participants at risk, 4 participants with serious adverse events and 36 participants in the other adverse-event category. The record also names serious-event terms and reports each listed term at 0.6%.

These findings do not establish that adalimumab caused the reported events. The event definition includes occurrences that may not be considered causally related to treatment. Nor do the counts establish whether the observed safety experience differs from that under another treatment or in the absence of treatment: no comparator is reported and allocation is not stated.

The record’s stated purpose included examining effectiveness in daily clinical practice, and it lists disease-activity outcomes. However, numerical results for those measures are not reported in the registry record. The available results therefore do not permit an interpretation of changes in disease activity or an estimate of effectiveness from those outcomes.

The enrollment and safety denominator also require care: the record gives enrollment of 163 and lists 157 participants at risk for the safety outcome. The reason for this difference is not reported. No statistical analysis, confidence interval or explanation of missing outcome information is reported, so the precision and completeness of the safety counts cannot be fully assessed from the registry record.

In short, the results describe events recorded during the stated observation period in a treated group. They do not establish causation, comparative safety, or a treatment effect on disease activity.

14. Why This Trial Matters Statistically

This record is statistically informative because it illustrates the difference between describing observed events and estimating a comparative treatment effect. A safety count can document what was recorded in a treated cohort, while a causal comparison requires an appropriate reference group and a design or analysis that supports that comparison. No comparator is reported, and allocation is not stated.

The endpoint also makes the distinction between event occurrence and causation explicit. The registry definition includes medical occurrences that are temporally associated with treatment whether or not they are considered causally related. This is important when interpreting safety counts: counting events is not equivalent to attributing them to a drug.

The record shows why denominators and analysis populations matter. Enrollment is 163, while the safety outcome lists 157 participants at risk. Since the reason for that difference is not reported, readers cannot determine from the registry record how the safety population was formed or how unavailable information was handled. This uncertainty about the analysis population is distinct from uncertainty about the event counts themselves.

Finally, the record lists disease-activity outcomes but does not report their numerical results or statistical analyses. That limits assessment of both effectiveness outcomes and the methods used to analyze them. These features make careful separation of reported details, unreported methods and unsupported conclusions especially important.

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 interpretation is the absence of a reported comparator. The listed participants received adalimumab, but the record does not describe a like-for-like control group, and allocation is not stated. As a result, the safety counts are descriptive and cannot estimate a comparative effect.

The enrollment is 163, whereas the safety outcome lists 157 participants at risk. The reason for this difference, the participant flow and the handling of unavailable safety information are not reported in the registry record. No detailed analysis-population definition is reported beyond the description of participants who received adalimumab.

The registry does not report statistical analyses, confidence intervals, or methods for handling missing data. It lists secondary disease-activity outcomes, but their numerical results are not reported in the registry record. The methods for those outcomes and any multiplicity considerations are also not reported.

The safety outcome has a defined observation period through week 26, but detailed event timing, duration, attribution and outcomes are not reported for the listed serious-event terms. Deaths are not reported in the registry record. These omissions do not indicate what unreported events or methods might have been; they limit what can be concluded from the posted record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Assessment of the Safety of Adalimumab in Rheumatoid Arthritis Patients Showing Rapid Progression of Structural Damage of the Joints, Who Have no Prior History of Treatment With Disease-modifying Anti-rheumatic Drugs or Biological Agents — NCT01783730.
• Registry record last updated 2016-10-26; status last verified 2016-09.
• Results first posted 2016-10-26.
• 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

NCT01783730 is a completed Japanese investigation sponsored by AbbVie. It enrolled 163 participants with rheumatoid arthritis and focused on participants with high disease activity, rapid structural progression and no prior DMARD or biological-agent treatment. The listed treatment was adalimumab in daily clinical practice.

The primary outcome was the number of participants with adverse events from baseline through week 26. The safety results list 157 participants at risk, 4 with serious adverse events and 36 in the other adverse-event category. Several serious-event terms are listed at 0.6% each. The record reports no comparator or allocation method, lists no statistical analyses, and does not report numerical results for the listed secondary disease-activity outcomes. The reason for the difference between enrollment and the safety denominator is not reported in the registry record.