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 A Canadian Open-Label Access Program to Evaluate Adalimumab When Added to Inadequate Therapy for the Treatment of Psoriasis (NCT00513370), a non-randomized phase 3 study. The primary outcome is Number of Subjects With Psoriasis Area and Severity Index (PASI) 75 Response at 16 Weeks.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00513370 |
| Phase | Phase 3 |
| Condition | Psoriasis |
| Allocation | Non-Randomized |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 203 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Abbott |
| Results posted | Yes |
2. Clinical Question
Population
People with active plaque psoriasis who had not adequately responded to prior psoriasis therapy. The registry record reports enrollment of 203 participants. The primary outcome population is described as observed cases: participants with nonmissing values at each time point. The record does not provide further eligibility details or the number with a nonmissing primary outcome at 16 weeks.
Intervention
Adalimumab, listed as Humira (adalimumab), was evaluated when added to inadequate therapy for psoriasis. The record describes the program as open-label. It also lists an adverse-event group titled “Adalimumab 40 mg Eow”; the intervention description does not otherwise give dosing instructions.
Comparator
No separate comparator group is described. The study is listed as non-randomized and single-group, so its design does not provide a like-for-like control arm. Changes over time within the treated group can be described, but they do not by themselves separate treatment effects from other explanations for change.
Primary question
The primary outcome is the number of participants achieving a PASI 75 response at 16 weeks. PASI 75 means a 75% or greater improvement on the Psoriasis Area and Severity Index. The registry record gives the outcome definition but does not report the observed number of responders or the number assessed at that time point.
In practical terms, the program set out to describe safety and effectiveness when adalimumab was used in a group with active plaque psoriasis and inadequate response to prior therapy. The brief summary also names economic impact as an evaluation aim, but the registry record does not report an economic outcome result. The listed secondary outcomes include PASI changes and responses, physician global assessments, and joint measures. These endpoints span skin disease and measures related to arthritic disease activity; their inclusion does not establish that all participants had a particular joint condition.
Because the study has no randomized comparator, the primary question is descriptive: how many observed participants met the response definition at the stated time point? It cannot, on its own, establish what would have happened to comparable participants without adalimumab or with another treatment. The missing outcome count also means the registry record cannot answer even the descriptive response question numerically.
3. Trial Design
The registry record describes a Phase 3, non-randomized, open-label, single-group study. It is titled as a Canadian open-label access program assessing adalimumab when added to inadequate therapy for psoriasis. The sponsor is Abbott. The listed intervention is Humira (adalimumab), and the condition is psoriasis. The program is marked completed, with enrollment of 203 participants.
The record gives a start date of 2007-09 and a primary completion date of 2008-09. These dates describe the registry timeline; they do not supply the timing of each participant’s treatment or follow-up beyond the outcome time points that are named. The primary outcome is assessed at 16 weeks. Secondary outcome titles refer to assessments at 16 and 24 weeks, along with response and assessment measures for which a specific time point is not stated in the title.
Open-label means the record does not describe masking, and it explicitly lists masking as none. Non-randomized allocation and a single-group model mean there is no randomized allocation to distinct treatment groups. The arm description is blank in the record, although the adverse-event information lists a group titled “Adalimumab 40 mg Eow.” Details of recruitment, eligibility criteria, treatment duration, adherence, concomitant therapies, and follow-up procedures are not reported in the registry record.
This design can provide a description of outcomes among participants treated in the program, subject to the completeness and definitions of the recorded data. It is not a randomized comparison. In particular, observed changes after treatment cannot be attributed uniquely to treatment because the design does not include a concurrent control group to account for the natural course of disease, other care, or other influences. Open-label assessment may also be relevant when outcomes involve judgments, although the record does not describe how such assessments were conducted.
The registry record lists 16 outcome measures and zero analysis entries. It does not report a statistical analysis plan, a sample-size justification, or interim analyses. The absence of those details should not be interpreted as evidence that a particular procedure was or was not used; the details are simply not reported in the registry record.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Adalimumab 40 mg Eow |
|---|---|
| STARTED | 203 |
| COMPLETED | 179 |
| NOT COMPLETED | 24 |
Analysis population for the primary outcome, as defined in the registry: Observed Cases - subjects with nonmissing values at each time point
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.
| Characteristic | Unit | Adalimumab 40 mg Eow |
|---|---|---|
| Participants analysed | 203 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 192 |
| Age, Categorical: >=65 years | Participants | 11 |
| Age Continuous | years | 45.5 (SD 12.34) |
| Sex: Female, Male: Female | Participants | 79 |
| Sex: Female, Male: Male | Participants | 124 |
| Region of Enrollment: Canada | participants | 203 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Subjects With Psoriasis Area and Severity Index (PASI) 75 Response at 16 Weeks, measured over 16 weeks.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with a PASI 75 response at 16 weeks. PASI is the Psoriasis Area and Severity Index, a measure of psoriasis severity and extent. The record describes its scale as running from 0-72, where 0 means no psoriasis and 72 means complete erythroderma of the severest possible degree. A PASI 75 response is defined as a 75% or greater improvement on that scale.
This responder endpoint turns change on a continuous severity scale into a clinically interpretable category: whether a participant crossed the stated improvement threshold. Counting participants who meet the definition can make the outcome easier to communicate than a mean score change alone. It also discards detail: participants just short of the threshold and those with little change are both counted as nonresponders, while different amounts of improvement among responders are not distinguished by the binary outcome.
The registry specifies an observed-cases population, meaning participants with nonmissing values at each time point. It does not report the number of participants with available 16-week values, the number meeting the PASI 75 definition, or an uncertainty interval for the result. Therefore the endpoint’s definition is available, but its observed value and precision cannot be assessed from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central interpretive point is that the registry record defines the primary outcome but does not report the primary outcome result. It states that the number of participants with PASI 75 response at 16 weeks was an outcome of interest and defines the response threshold. It does not give the number of responders, the number evaluated, a proportion, or an uncertainty interval. No conclusion about the observed response frequency can be drawn from this record alone.
The registry lists secondary outcome measures including mean change and mean percent change in PASI at 16 and 24 weeks; physician global assessment outcomes; PASI 50, 75, 90, and 100 response counts; and changes in joint counts and physician global assessment of arthritic disease activity. The outcome titles describe what was intended to be assessed, not the results. Numerical findings for these outcomes are not reported in the registry record, so their direction, size, and precision cannot be evaluated.
The design also limits what any within-group result could establish. In a single-group program, a change from baseline can be described among participants with measurements, but without a concurrent randomized comparator it does not isolate the effect of treatment. General statistical interpretation: a before-and-after change can reflect several influences, including the underlying course of the condition, changes in other care, measurement variability, and selective availability of follow-up data. The record does not quantify these influences.
The primary endpoint uses observed cases, defined as participants with nonmissing values at each time point. This definition makes the available-data population relevant to interpretation. If availability of measurements is related to outcomes, a result among observed participants may not represent all enrolled participants. The registry record does not report how many participants had missing values, why data might be missing, or whether any method was used to address missingness.
Safety information is also incomplete for estimating rates. The listed group has 9 participants affected by serious events and 145 affected by other events, while the counts at risk are not reported. The record lists myocardial infarction at 1.0%, and tongue oedema, pericarditis, death, appendicitis, and pneumonia each at 0.5% among the top serious terms. The denominator and details behind these percentages are not reported in the registry record. The death count field is also not reported, so the listed death term should not be treated as a complete account of deaths or as evidence about causation.
In general, a confidence interval describes the statistical uncertainty around an estimate and helps distinguish a relatively precise estimate from one compatible with a broad range of values. No primary estimate or interval is reported, so precision cannot be judged. The registry record’s status as completed does not substitute for outcome results. The posted information supports a description of the design and prespecified outcome definitions, but not a numerical conclusion about efficacy, safety rates, or economic impact.
9. Statistical Methods Explained
What does the registry record report about analysis?
The record identifies a binary primary outcome: a participant either meets the PASI 75 response definition at 16 weeks or does not. It describes the primary population as observed cases, meaning participants with nonmissing values at each time point. It does not report an analysis method, a statistical analysis plan, an estimate, a confidence interval, or a p-value. The record lists zero analysis entries. These omissions mean the method used to produce a primary numerical result cannot be reconstructed from the registry record.
How should a binary endpoint be understood?
General explanation: for a binary endpoint, each participant is classified into one of two categories according to a specified rule. A count of responders describes how many meet that rule in the analyzed group. A proportion would relate that count to the number assessed, but neither count nor denominator for the primary outcome is reported. Without both, a response frequency cannot be evaluated. The binary classification is also a simplification of the original scale: it captures whether the threshold was met but not the full amount of change.
What does a confidence interval add?
General explanation: a confidence interval expresses sampling uncertainty around an estimate. A narrower interval indicates greater statistical precision under the assumptions of the method; a wider interval indicates more uncertainty. An interval does not repair limitations in study design, such as the lack of a randomized comparison, and it does not account automatically for all sources of bias. Since the registry record does not report a primary estimate or interval, its precision cannot be described.
Why is the design important to statistical interpretation?
General explanation: random allocation to a treatment and a comparator can help balance known and unknown factors between groups, on average. This study is listed as non-randomized and single-group, so that type of between-group comparison is not available. A within-group change may be calculated in a study of this kind, but it does not by itself distinguish an intervention-associated change from changes that could have occurred for other reasons. The registry record does not report an adjusted or comparative analysis.
The program is also open-label, with no masking listed. General explanation: when participants and assessors know the treatment being given, expectations or knowledge of treatment can influence some measurements or reporting. The extent to which this could affect a specific outcome depends on how it is measured and collected. The registry record does not describe assessment procedures, so the possible influence cannot be quantified.
What is over-dispersion, and is it relevant?
General explanation: over-dispersion occurs when observed variability in data is greater than a statistical model assumes. It can make standard errors too small and uncertainty appear understated if the model does not account for the extra variability. Whether over-dispersion matters depends on the outcome and analysis model. The registry record does not identify a model or report an analysis for the primary endpoint, so it is not possible to determine whether over-dispersion was assessed or relevant to any analysis.
What can be said about planning calculations?
The sample-size section is described as a planning illustration based on an observed effect, not the trial’s own design. Its stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. For time-to-event tables, the stated quantity is the total number of events; for other tables, it is participants per arm. These are planning assumptions, not a report of the study’s actual enrollment plan or a measure of observed power.
General explanation: planning calculations ask how much information might be needed to detect a specified effect under chosen assumptions. Their output depends on the assumed effect and the analysis framework. A planning illustration using two arms does not turn this single-group study into a two-arm comparison, and it should not be interpreted as an observed property of the enrolled participants. The registry record does not report its own sample-size justification, and no numerical planning outputs are stated in the registry record.
How should safety counts be read?
The adverse-event record lists affected-participant counts of 9 for serious events and 145 for other events in the named adalimumab group. The corresponding numbers at risk are not reported. General explanation: a count alone does not provide a rate unless its denominator and the relevant observation period are known. Counts also do not establish that an event was caused by treatment. The listed serious-event terms and percentages offer some descriptive information, but the registry record does not give their denominators or enough detail to estimate risk or compare it with another group.
Overall, the statistical methods that were actually applied are not reported in the registry record. General statistical concepts can clarify what information would ordinarily support interpretation, but they cannot replace the missing outcome estimates, denominators, uncertainty measures, or analysis details.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists multiple outcomes: 16 outcome measures in total, including the primary PASI 75 response and secondary measures spanning PASI, physician assessments, and joint counts. When many outcomes or time points are examined, the chance of obtaining at least one apparently notable finding by chance can increase. General statistical practice may address this through a prespecified hierarchy, adjustment, or clear emphasis on a primary endpoint, but the appropriate approach depends on the analysis plan.
The registry record does not report a multiplicity strategy, a hierarchy among secondary outcomes, or whether any adjustment was used. It also lists zero analysis entries, so no outcome-specific analysis results are available to assess. The absence of reported multiplicity procedures does not establish that none were used; the procedures are not reported in the registry record.
For missing data, the primary outcome population is described as observed cases, meaning participants with nonmissing values at each time point. The number with missing 16-week values, reasons for missingness, and any sensitivity analyses are not reported in the registry record. General explanation: an observed-cases analysis uses the measurements that are available, but its interpretation can be affected if the likelihood of having a measurement is related to a participant’s outcome. The record does not allow that possibility to be evaluated.
The number enrolled is 203, but the primary outcome denominator is not reported. Enrollment should therefore not be treated as the number analyzed at 16 weeks. The registry record also does not report an intention-to-treat population, a per-protocol population, rules for handling intercurrent events, or an imputation method. These details are important for understanding which participants contributed to each outcome and how incomplete measurements were handled.
11. What the Result Does, and Does Not, Mean
The registry record establishes what the program set out to evaluate: adalimumab added to inadequate psoriasis therapy, with a primary outcome defined as the number of participants attaining PASI 75 at 16 weeks. It also describes a completed, open-label, non-randomized, single-group program and lists multiple secondary outcomes. These registry entries clarify the study question and the limits imposed by its design.
What the record does not establish is the observed primary response count or its precision. It does not report the number assessed at 16 weeks, the primary estimate, a confidence interval, or a p-value. Secondary outcome results and economic results are also not reported. Thus the registry record cannot show how many participants met the response definition, how their scores changed, or how outcomes compared with an alternative.
Even if within-group outcome values were available, general statistical interpretation would distinguish an observed change from a causal treatment effect. A single-group, non-randomized design has no concurrent control group to represent what might have happened without the intervention. Changes could have multiple explanations, and the record does not report analyses that address them. The open-label design is another feature to consider for outcomes involving judgments or participant reports.
The safety entries describe affected-participant counts and selected serious-event terms, but the at-risk denominators are not reported. These counts do not by themselves establish event rates or causation. The listed percentage for a term should be read as the registry’s descriptive entry, not as a comparative risk estimate. The death count is not reported, despite “Death” appearing among the listed serious terms.
Accordingly, the available record supports a careful account of the study design, outcome definitions, enrollment, and selected safety entries. It does not support a conclusion about the magnitude or precision of an efficacy result, comparative benefit or harm, or the economic impact of treatment. Those questions require results and analysis details that are not reported in the registry record.
12. Why This Trial Matters Statistically
This trial is statistically instructive because its primary question is clear while its numerical answer is absent from the registry record. The primary outcome is specified as a responder count at a named time point, with a defined PASI threshold. Yet without the number responding and the number assessed, the endpoint cannot be summarized as an observed frequency or judged for precision. A well-defined outcome and a reported outcome result are different kinds of information.
The single-group, non-randomized design also makes the distinction between description and causal inference especially important. An outcome measured after treatment can describe participants’ observed status, but it cannot on its own supply the counterfactual comparison needed to attribute change uniquely to treatment. This is a design limitation, not a statistical defect that can be removed simply by calculating a more elaborate estimate.
The record further illustrates why analysis populations and missingness matter. The primary endpoint is based on observed cases, but the number with available measurements is not reported. Enrollment of 203 does not identify how many participants contributed to the 16-week endpoint. Without that denominator and information about missing values, the scope of the observed-case result cannot be assessed.
Finally, the study lists many outcomes and several time points, while its analysis plan and multiplicity approach are not reported. This makes it difficult to evaluate how results would have been selected and interpreted if numerical findings were available. The safety entries similarly show why counts need denominators and context. Together, these features make the registry record useful for understanding the study’s stated question and design, while underscoring the limits of outcome interpretation when results and analytic details are unavailable.
13. 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 trial-specific limitation is the lack of a reported primary outcome result. Although the PASI 75 definition and 16-week time point are stated, the registry record does not give the responder count, number assessed, estimate, or precision. As a result, the primary endpoint cannot be evaluated numerically.
The single-group, non-randomized design has no like-for-like control comparison. It therefore cannot establish a treatment contrast against another intervention or against no added treatment. The open-label design also leaves masking absent; the registry record does not describe how outcome assessments were conducted or whether assessment procedures could reduce the influence of expectations.
The primary population is restricted to observed cases, but missing-data counts, reasons, and handling methods are not reported. The number enrolled cannot be assumed to equal the number analyzed at the primary time point. The record also does not report detailed eligibility criteria, recruitment methods, adherence, treatment duration, concomitant care, or follow-up procedures, limiting assessment of who contributed data and how representative the observed participants may be.
For safety, the record gives affected counts but no numbers at risk. The listed serious-event terms and percentages lack reported denominators, and the death count is not reported. These entries therefore do not support a complete rate assessment or attribution of events to treatment. Finally, the statistical analysis plan, sample-size justification, interim analyses, and multiplicity procedures are not reported in the registry record. These omissions constrain evaluation of the intended and applied analyses.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: A Canadian Open-Label Access Program to Evaluate Adalimumab When Added to Inadequate Therapy for the Treatment of Psoriasis — NCT00513370.
- Registry record last updated 2011-04-11; status last verified 2011-04.
- Results first posted 2009-11-20.
- 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.
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17. Record Summary
The registry record describes a completed Phase 3, open-label, non-randomized, single-group access program evaluating adalimumab when added to inadequate therapy for psoriasis. It reports enrollment of 203 participants, identifies Abbott as the sponsor, and gives a start date of 2007-09 and primary completion date of 2008-09.
The primary outcome is the number of participants with PASI 75 response at 16 weeks, defined as a 75% or greater improvement on the PASI scale. The primary population is observed cases. The record lists 16 outcome measures and zero analysis entries, but does not report numerical efficacy results or the primary endpoint denominator.
Safety entries list 9 participants affected by serious events and 145 affected by other events; numbers at risk are not reported. Selected serious-event terms and percentages are listed, but their denominators are not reported. The record does not report an analysis plan, missing-data methods, multiplicity strategy, or sample-size justification.