Immediate Response With Adalimumab and Its Impact on Quality of Life and Other Comorbidity Factors in Patients With Moderate to Severe Plaque Psoriasis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Immediate Response With Adalimumab and Its Impact on Quality of Life and Other Comorbidity Factors in Patients With Moderate to Severe Plaque Psoriasis (NCT01265823), a non-randomized phase 4 study. The primary outcome is Percentage of Participants With Psoriasis Area and Severity Index (PASI)-75 Response at Week 4.

2. Clinical Question

The study also records quality-of-life, psoriasis severity, and physician-assessment outcomes at Week 4 and Week 16. These outcomes can describe changes over time in the treated group, but a single-group design cannot separate change associated with treatment from change due to other factors, including the course of the condition, measurement variation, or expectations in an open-label study.

3. Trial Design

This completed phase 4 study is listed as non-randomized, unmasked, and single group. Its intervention is adalimumab, and no comparator arm is listed. The study summary describes a Mexican, open-label, multicenter investigation of safety and efficacy in people with active plaque psoriasis who had failed prior conventional systemic treatment or were candidates for systemic therapy. The registry lists enrollment of 150.

The record gives a start date of 2010-10 and a primary completion date of 2012-02. It does not report the details of the treatment schedule or the duration of treatment for individual participants. The listed primary endpoint is the percentage of participants achieving PASI-75 at Week 4. Secondary outcomes include Dermatology Life Quality Index scores and categories at baseline, Week 4, and Week 16; PASI-50, PASI-90, and PASI-100 response percentages at Week 4 and Week 16; and Physician's Global Assessment at Week 4 and Week 16.

Enrollment is not the same as the number contributing data to a particular endpoint. The registry record does not state the primary endpoint numerator or denominator, nor does it give a participant flow account or endpoint-specific numbers assessed. The record lists 22 outcome measures, but does not report outcome analysis entries. It also does not report random assignment, masking, a control group, or a statistical analysis plan. These features limit interpretation of any change over time as a treatment effect: without a concurrent comparison, the results would describe the observed experience in the study group rather than establish what would have happened under another treatment or no treatment.

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: A total of 187 participants were screened and 37 were considered screening failures.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intention-to-treat (ITT) population. Participants with missing scores were considered nonresponders.

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.

6. Primary Endpoint

The registry lists the primary outcome as Percentage of Participants With Psoriasis Area and Severity Index (PASI)-75 Response at Week 4, measured over Week 4.

The primary endpoint is the percentage of participants who achieved a PASI-75 response at Week 4. PASI is a composite measure incorporating the affected body surface area and the degree of erythema (reddening), induration (plaque thickness), and desquamation (scaling) observed at examination. Its score ranges from 0, indicating no psoriasis, to 72, indicating very severe psoriasis.

A PASI-75 response means that a participant's score at Week 4 was at least 75% lower than that participant's baseline score. Expressing the endpoint as a percentage describes how common this threshold response was in the endpoint population; it does not describe the size of each participant's change or the average change in PASI. The registry states that PASI improvement was used as a measure of efficacy.

A threshold endpoint is useful for communicating the proportion meeting a defined response criterion, but it discards information about the amount of improvement above or below that threshold. It also depends on baseline and follow-up measurements and on how missing observations are handled. For this endpoint, the registry specifies an intention-to-treat population and classifies participants with missing scores as nonresponders. The actual response percentage, its uncertainty, and the endpoint denominator are not reported in the registry record, so the primary result cannot be quantified from that record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Interpreting a clinical study involves separating the outcome definition, the population included in an analysis, the statistical summary, and the design that produced the data. The registry record gives some of these elements for this study but not a complete analysis description. The concepts below are general explanations, with the study-specific details identified separately.

What does a percentage response measure?

For a binary response endpoint, each participant is classified as either meeting the stated response criterion or not meeting it. The response percentage summarizes the share of the endpoint population classified as responders. In this study, response means achieving at least a 75% reduction from baseline in PASI at Week 4. Such a summary is easy to interpret, but it treats responses just above and just below the threshold as different categories, even if the underlying score changes are similar. It also does not show how much participants improved beyond the threshold.

The numerator is the number classified as responders, and the denominator is the number included in the endpoint calculation under the analysis rules. Neither primary endpoint count is reported in the registry record. The enrollment of 150 should therefore not be assumed to be the endpoint denominator. Participant withdrawal, unavailable assessments, or other analysis rules can affect the denominator, but endpoint-specific accounting is not reported.

What does intention-to-treat mean in this record?

The primary endpoint population is identified as intention-to-treat (ITT). Generally, an ITT approach aims to analyze participants according to their original study assignment or group, rather than excluding them based on later adherence or events. Because this study is listed as single group, the usual comparison of randomized assignments does not apply in the same way as it would in a randomized trial. The registry does not further define the population or state how all possible post-enrollment events were handled. It does specify that participants with missing scores were considered nonresponders. That rule makes missing observations count against meeting the endpoint rather than removing them from the response calculation, but its effect on the estimate cannot be assessed without the missing-data counts and observed response result.

Why do uncertainty measures matter?

A point estimate, such as a response percentage, is an estimate of the outcome in the study population. It does not by itself show how much uncertainty surrounds that estimate. In general, a confidence interval expresses a range of values compatible with the data and the chosen statistical method. A narrower interval indicates greater precision than a wider interval, but interpretation also depends on the design and assumptions. The registry record does not report a primary response estimate, confidence interval, or other uncertainty measure. Consequently, neither the estimated response level nor its precision can be assessed.

What does a one-group design allow?

In a single-group study, participants receive the listed intervention and outcomes are observed over time. The observed follow-up outcome can describe what happened in that group. Without a concurrent control group, it cannot show the counterfactual outcome that would have occurred for comparable participants under another strategy. Non-random allocation also means treatment groups are not formed by chance, though there is no second group to compare. This is a limitation of causal interpretation, not a claim that the study's observations are uninformative.

Open-label status means masking is listed as none. General sources of potential influence in an unmasked study include expectations, participant reporting, and assessment practices. The extent to which any such influence affected this study is not reported. PASI includes clinical assessment components, while DLQI is a quality-of-life measure; different outcomes can therefore have different sensitivities to how information is collected. The registry record does not provide further measurement procedures.

What can be inferred from the planning assumptions?

The record describes a planning illustration based on the observed effect, using 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. It explicitly distinguishes this planning illustration from the trial's own design. Those assumptions are not evidence that the actual study was randomized, had two arms, or used that analysis. The record does not report the sample-size justification for the trial or its statistical plan. Planning sample sizes, when presented, are illustrations of assumptions rather than observed power or evidence about the study's outcome.

For binary outcomes, general statistical methods may use a model or an interval procedure to estimate a response proportion or compare groups. The specific method depends on the design, sample information, and analysis plan. No such primary endpoint method, test, or estimate is reported in the registry record. Therefore, no recalculation or comparison of the primary result is possible, and no claim about statistical significance can be made.

Why is multiplicity relevant?

When investigators examine many endpoints, categories, or follow-up times, the chance of at least one apparently notable result can increase. A statistical plan may address this through a prespecified hierarchy, adjustment, or other strategy, but such methods are not automatic and can affect how results are interpreted. The record lists 22 outcome measures, including several outcome types and visits. It does not report whether multiplicity was considered or adjusted for. The number of listed outcomes alone does not reveal which outcomes were analyzed or how any results should be weighted.

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("Adalimumab")
n      <- c(150)
events <- c(46)
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  Adalimumab  150  46  30.7  23.4  38.7  23.8  38.5  23.8  38.5

11. Multiplicity, Missing Data and Analysis Populations

The primary endpoint population is identified as intention-to-treat, with participants who had missing scores counted as nonresponders. This is the only specific missing-data rule stated for the primary endpoint. The registry record does not report how many scores were missing, why they were missing, or whether missingness differed across visits. It also does not describe sensitivity analyses or rules for missing secondary outcomes. Without those details, the influence of missing data on the observed result cannot be evaluated; in this case, the primary result itself is not reported.

The record lists 22 outcome measures, including several types of assessment and more than one follow-up visit. When many endpoints, categories, or time points are tested, multiplicity can increase the chance of a result that appears notable by chance. This is a general statistical issue, not evidence that any particular finding in this study is false. Whether outcomes were prespecified in a hierarchy, whether adjustments were made, and how secondary outcomes were analyzed are not reported in the registry record.

The record identifies the primary population but does not describe the statistical analysis plan, the primary endpoint estimation method, or a formal approach to multiplicity. It lists no outcome analysis entries. Therefore, the stated endpoint and missing-as-nonresponse rule can be described, but the analysis details needed to assess robustness and the interpretation of multiple outcomes are not available.

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: cholelithiasis (0.7%).

The safety record lists 150 participants at risk for serious adverse events and 1 participant affected. It also lists 150 participants at risk for other adverse events and 86 affected. These are registry counts, not comparative estimates: the study has one listed group and no concurrent control group. The record lists cholelithiasis at 0.7% among the top serious-event terms.

These figures should be read as counts recorded in the registry, not as proof that an event was or was not caused by the intervention. The record does not provide a comparator, details of event severity beyond the serious-event classification, or information needed to compare rates across treatment strategies. A count also does not describe the timing, duration, or clinical course of events. Deaths are not reported in the registry record.

The serious and other adverse-event summaries represent different categories, and they should not be added together. The registry information does not provide enough detail to infer comparative safety or to characterize all possible harms. These data describe the adverse events recorded for this study group; they do not establish a general risk level for people outside the study.

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

The registry record defines a focused primary question: the percentage of participants meeting a PASI-75 response threshold at Week 4. It also describes an open-label, single-group study of adalimumab in people with active plaque psoriasis who had failed prior conventional systemic treatment or were candidates for systemic therapy. This provides context for understanding the intended study population and endpoint.

The record does not report the primary response percentage, numerator, denominator, confidence interval, or test result. Consequently, it is not possible to say from this record how often participants met the response criterion, how precise an estimate was, or whether a result was statistically distinguishable from a specified benchmark. No outcome value should be inferred from enrollment or from the presence of an endpoint definition.

Even if a response result were available, the design would constrain what it means. A single treated group has no concurrent comparator, and participants were not randomized between treatment groups. An observed response would describe the study group, but could not on its own establish how outcomes would differ under another treatment or no treatment. The open-label design is also relevant when considering subjective or assessor-influenced measures, although the extent of any influence is not reported.

The study lists quality-of-life, PASI response, and physician-assessment outcomes at Week 4 and Week 16, but their results are not reported in the registry record. The missing-data rule for the primary endpoint is stated, but missing counts and details for other outcomes are not. The record also does not describe multiplicity handling or the statistical analysis plan.

Thus, the available information supports a description of the study question, structure, and selected safety counts. It does not support a conclusion about the magnitude or precision of the primary result, a causal treatment effect, or comparative safety. Those distinctions separate what the registry documents from what cannot be established from its reported information.

14. Why This Trial Matters Statistically

This study is statistically informative as an example of how endpoint definitions and study design shape interpretation. PASI-75 at Week 4 is defined as a threshold reduction from an individual baseline score, and the registry specifies how missing primary scores were classified. Those choices determine what the planned percentage response would represent. Yet the endpoint definition alone is not a result: without its numerator, denominator, and estimate, the study's observed response cannot be characterized.

The single-group, open-label design highlights an important distinction between describing outcomes and estimating comparative effects. A one-group study can record outcomes over time, but does not directly provide a contemporaneous counterfactual. This matters for clinical researchers interpreting response percentages, as well as for biostatisticians assessing what estimand and analysis are appropriate to a design.

The record's many listed outcomes also make multiplicity a relevant issue to consider. Multiple outcome types and visits can generate a broad descriptive profile, but they require careful distinction between primary and secondary questions and transparent reporting of analysis choices. The registry does not state whether any multiplicity strategy was used, so no conclusion about adjustment or outcome prioritization can be drawn.

Finally, the record illustrates why an enrollment count, safety counts, and a response endpoint should not be treated as interchangeable evidence. Enrollment does not establish endpoint completeness; safety counts do not make a controlled comparison; and a planned endpoint does not reveal its observed value. These are general lessons in reading registry records, particularly when key estimates and analysis details are not reported.

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.

Several limitations specific to this record affect interpretation. First, the primary endpoint result is not reported. There is no response percentage, participant count meeting the PASI-75 criterion, endpoint denominator, or uncertainty measure. The enrollment figure of 150 therefore cannot be treated as the number analyzed for the primary endpoint.

Second, this is a non-randomized, single-group, unmasked study with no listed comparator. It can describe outcomes in the study group but cannot provide a like-for-like control comparison. The open-label design may also matter for assessment and reported outcomes, but the registry record does not describe procedures intended to mitigate that concern.

Third, missing scores were counted as nonresponses for the primary endpoint, but the number and reasons for missing observations are not reported. No corresponding missing-data approach is stated for the listed secondary outcomes. The record also does not report the statistical analysis plan, endpoint analysis method, confidence intervals, or multiplicity strategy. Although 22 outcome measures are listed, their reported results and analysis entries are absent.

Finally, the safety information is limited to event counts and a listed serious-event term. The record does not provide a comparator or the additional detail needed to assess event timing and comparative risk. Deaths are not reported in the registry record. These reporting gaps limit conclusions about efficacy, precision, and safety beyond the study's described design and recorded counts.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Immediate Response With Adalimumab and Its Impact on Quality of Life and Other Comorbidity Factors in Patients With Moderate to Severe Plaque Psoriasis — NCT01265823.
• Registry record last updated 2013-03-11; status last verified 2013-02.
• Results first posted 2013-03-11.
• 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

The registry describes a completed phase 4, open-label, non-randomized, single-group study of adalimumab in people with active plaque psoriasis. The summary specifies a Mexican multicenter study population that had failed prior conventional systemic psoriasis treatment or was considered a candidate for systemic therapy. Enrollment is listed as 150, with a start date of 2010-10 and primary completion date of 2012-02.

The primary endpoint is the percentage achieving PASI-75 at Week 4, with missing scores classified as nonresponses in the intention-to-treat population. The primary result is not reported in the registry record. The record lists 22 outcome measures, but does not report outcome analysis entries or a statistical analysis plan. It lists 1 participant affected by a serious adverse event and 86 affected by other adverse events; comparative safety cannot be assessed from this single-group record.