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 Study Evaluating the Safety and Efficacy of Etanercept in Patients With Psoriatic Arthritis Treated by Rheumatologists (NCT00293722), a registered phase not stated study. The primary outcome is Percentage of Participants With Treatment-Emergent Adverse Events (AEs) or Serious Adverse Events (SAEs).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00293722 |
| Phase | Phase not stated |
| Condition | Arthritis, Psoriatic, Psoriasis, Skin Diseases, Papulosquamous |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 1308 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Pfizer |
| Results posted | Yes |
2. Clinical Question
Population
People with psoriatic arthritis treated by rheumatologists. The safety analysis set included participants enrolled in the study who had safety data available.
Intervention
Etanercept under usual-care settings.
Comparator
No comparator is described. The registry record does not state an allocation method, and the study is not a randomized comparison.
Primary question
What percentage of participants experienced treatment-emergent adverse events or serious adverse events from baseline up to Week 52?
The study is identified as prospective post-marketing surveillance, with a stated purpose of evaluating the safety and effectiveness of etanercept in usual care. Its primary endpoint is safety-focused: it concerns events arising after treatment starts or events that worsen relative to the pretreatment state. The registry defines serious events by outcomes such as death, hospitalization, a life-threatening experience, persistent or significant disability, or congenital anomaly, as well as events judged significant for another reason.
The record also lists clinical and patient-reported outcomes, including psoriasis involvement, joint-related measures, physician assessment, inflammatory markers, itching, and pain. These measures do not create a comparator group. Without a stated control condition or randomized allocation, the central question supported by the record is descriptive: what adverse events were reported among participants observed while receiving etanercept in this setting? The registry record does not report an estimate of treatment effect against an alternative treatment or no treatment.
3. Trial Design
This was a prospective post-marketing surveillance study of etanercept in people with psoriatic arthritis treated by rheumatologists. The registry describes the setting as usual care and gives an enrollment of 1308. Its status is completed. The listed study dates are a start in 2006-01 and primary completion in 2013-02.
The intervention is etanercept, and the listed participant group is patients with psoriatic arthritis. No separate comparator group is described. Allocation is not stated, and the registry identifies the study as not being a randomized comparison. Its available description therefore does not support interpreting the participant group as a treatment arm compared with a like-for-like control arm.
The primary outcome concerns treatment-emergent adverse events and serious adverse events from baseline up to Week 52. The safety analysis set is defined as participants enrolled in the study who had safety data available. The adverse-event record lists 1285 participants at risk for each of the serious and other adverse-event groupings. It reports 77 participants affected in the serious-event grouping and 453 in the other-event grouping. Those counts describe events recorded in the safety group; they do not, by themselves, establish whether treatment caused an event.
Secondary outcomes include changes in psoriasis body surface area, joint and physician assessments, C-reactive protein, itching, and pain, as well as nail involvement. The registry lists 11 outcome measures, but analyses of those outcomes are not reported in the registry record. Details such as eligibility criteria, treatment schedules, follow-up procedures beyond the stated primary timeframe, and the statistical analysis plan are 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 | Participants With Psoriatic Arthritis |
|---|---|
| STARTED | 1291 |
| COMPLETED | 864 |
| NOT COMPLETED | 427 |
Reasons for not completing this period:
| Reason | Participants With Psoriatic Arthritis |
|---|---|
| Other | 427 |
Analysis population for the primary outcome, as defined in the registry: Safety analysis set included all participants who were enrolled in this study and had safety data available.
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 set included all participants who were enrolled in this study and had safety data available. Out of a total of 1285 participants included in the safety analysis set, data for baseline measure (age) was available only for 1274 participants.
| Characteristic | Unit | Participants With Psoriatic Arthritis |
|---|---|---|
| Participants analysed | 1285 | |
| Age, Continuous | years | 50.9 (SD 11.4) |
| Sex/Gender, Customized: Female | participants | 708 |
| Sex/Gender, Customized: Male | participants | 571 |
| Sex/Gender, Customized: Missing | participants | 6 |
6. Primary Endpoint
The registry lists the primary outcome as Percentage of Participants With Treatment-Emergent Adverse Events (AEs) or Serious Adverse Events (SAEs), measured over Baseline up to Week 52.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | percentage of participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the percentage of participants with treatment-emergent adverse events or serious adverse events, assessed from baseline up to Week 52. An adverse event is defined as an untoward medical occurrence in a participant who received study drug, without requiring a possible causal relationship to the drug. Serious adverse events are events with specified serious outcomes or events judged significant for another reason. Treatment-emergent events are those arising between the first dose and Week 52 that were absent before treatment or worsened relative to the pretreatment state.
This endpoint is used to describe the safety experience during the observation period. Counting participants affected gives a clinically interpretable account of how many people in the safety group had events, while the percentage expresses that count relative to the group assessed. The registry record reports the endpoint definition and participant counts, but does not report a primary endpoint percentage or an uncertainty interval. The distinction matters: event counts describe what was recorded, while a percentage and its uncertainty would help characterize the frequency and precision of the estimate.
Because the study has no stated comparator and is not a randomized comparison, the endpoint is descriptive rather than a controlled estimate of harm attributable to etanercept. Events occurring during treatment may have other explanations, and the registry’s definition explicitly does not require causal attribution. The endpoint therefore characterizes reported safety events in this study population and timeframe, not the difference in risk between treatment strategies.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record reports 77 participants with serious adverse events among 1285 at risk, and 453 participants with other adverse events among 1285 at risk. These are participant counts for the safety record. They should be read as separate event groupings, not added together: the record does not state whether participants could appear in both groupings, and an adverse event can be serious or non-serious. The primary endpoint describes participants with treatment-emergent adverse events or serious adverse events, but a combined primary endpoint percentage is not reported in the registry record.
The record also lists serious-event terms with percentages: intervertebral disc protrusion, 0.4%; condition aggravated, 0.3%; coronary artery disease, 0.2%; atrial fibrillation, 0.2%; chest pain, 0.2%; and cholecystitis, 0.2%. These entries identify reported terms and their displayed percentages. They do not establish that etanercept caused those conditions, and the registry record does not report term-specific causal assessments or uncertainty intervals.
Precision cannot be judged fully from the counts alone. In general, an estimate has sampling uncertainty because the observed participants represent a particular study group rather than every person who might receive care in similar circumstances. A confidence interval communicates a range of values compatible with the observed data under the method used. The registry record does not report confidence intervals for the primary safety endpoint, so the precision of its percentage cannot be assessed from the record.
The study’s prospective, usual-care setting is relevant to understanding the source of the observations: the aim was surveillance in clinical practice, rather than a randomized comparison. That setting can describe events recorded during routine treatment, but without a comparator it cannot separate treatment-related effects from background illness, other care, or differences in who was observed. The record does not report adjustment methods that might address such differences.
The registry lists secondary outcomes spanning skin, joint, physician-assessed, laboratory, and patient-reported measures, but analyses are not reported in the registry record. Consequently, the listed outcomes should not be interpreted as evidence of changes or improvement. The record’s completion status and study dates describe the study’s administrative timeline; they do not fill in missing outcome estimates or analyses. Overall, the posted safety counts are descriptive observations from the recorded safety group, with important limits on causal and precision claims.
9. Statistical Methods Explained
For this study, the primary outcome is defined as a percentage of participants with treatment-emergent adverse events or serious adverse events during baseline up to Week 52. The safety analysis set consists of enrolled participants with safety data available. The adverse-event record gives the same at-risk count, 1285, for serious and other adverse-event groupings, with 77 affected in the serious grouping and 453 affected in the other grouping. The registry record does not report a calculated primary endpoint percentage, confidence interval, or inferential test.
What does a percentage measure?
In general, a participant percentage is a proportion: the number of participants meeting a specified event definition relative to the number assessed for that outcome. It is useful because it puts an event count in the context of the population observed. For a safety endpoint, interpretation depends on who was included, how the event was defined, and the period in which events were counted. Here, the registry specifies the safety population and the Week 52 timeframe, but does not report the primary percentage itself. The listed counts should therefore remain counts; deriving a percentage would be a new calculation and would not replace a registry-reported estimate.
Why does the event definition matter?
The registry defines an adverse event broadly as an untoward medical occurrence in someone who received study drug, without regard to whether a causal relationship is possible. Seriousness is based on specified consequences or another reason an event is deemed significant. Treatment emergence is based on timing and change from the pretreatment state: an event must be absent before treatment or worsen after treatment begins. These definitions determine which observations contribute to the endpoint. They do not, on their own, show that treatment caused an event.
How should uncertainty be understood?
In general, a confidence interval describes uncertainty around an estimated quantity. A narrower interval indicates greater precision under the assumptions of the statistical method; a wider interval indicates less precision. An interval does not correct for biases in how participants entered the study or how outcomes were recorded. No confidence interval for the primary endpoint is reported in the registry record. Thus, the registry counts indicate what was observed in the recorded group, but do not quantify the statistical uncertainty around an endpoint percentage.
In general, a significance test evaluates how compatible observed data are with a specified statistical hypothesis under a model. Its interpretation depends on the hypothesis, test, assumptions, and analysis population. The registry record does not report a test for the primary safety endpoint. It also lists no analyses for the secondary outcomes. No test result or statistical evidence of a difference should be inferred from the outcome list or event counts.
What can a usual-care surveillance design establish?
In general, prospective observation records outcomes as participants are followed forward, but a nonrandomized study may not make treatment groups comparable. In this record, no comparator is described and allocation is not stated. The data can describe event experience among the participants observed, but do not provide a randomized contrast. Factors such as underlying health, concurrent care, and clinical decisions can influence both treatment and outcomes; the registry record does not report methods to account for such factors. This limits causal interpretation even if an event occurs after treatment begins.
Over-dispersion is a general issue for count outcomes when variation exceeds what a simple statistical model expects. It can make model-based uncertainty too small if the model fails to allow for the extra variation. This endpoint is described as a participant percentage, and the registry record does not report a count-model analysis or a method for assessing over-dispersion. It would therefore be inappropriate to claim that a particular model or adjustment was used.
What do the planning assumptions represent?
In general, a sample-size calculation illustrates how many participants might be needed to detect a specified effect under chosen assumptions. The planning illustrations associated with this study are described as based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. They are illustrations, not a description of the trial’s own design or evidence of observed power. The study itself is not a randomized comparison, and the registry record does not report its sample-size justification or a two-arm allocation. The effect fractions used for planning are not described as observed treatment effects that establish causation.
Statistical methods such as adjustment, subgroup analysis, interim monitoring, and missing-data imputation are often relevant to clinical trials. Whether they were used in this study is not reported in the registry record. The record also does not report the statistical analysis plan. These absences prevent attributing particular methods, assumptions, or decision rules to the study.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 11 outcome measures, including the primary safety outcome and secondary measures involving psoriasis, joint activity, physician assessment, nail involvement, C-reactive protein, itching, and pain. When many outcomes are examined, the chance of finding an apparently unusual result by chance can increase. In general, multiplicity methods may adjust testing or designate outcomes in advance to control how results are interpreted. The registry record does not report a multiplicity plan, and analyses of the outcomes are not reported in the registry record.
Missing-data methods matter because participants without outcome observations may differ from those with observations. In general, excluding participants with missing data can affect an estimate if missingness is related to health status or the outcome. The safety analysis set includes enrolled participants with safety data available, but the registry record does not report how much safety data were missing, why data were missing, or how missing observations were handled. It also does not report whether the number assessed varied by endpoint.
The stated safety population is not necessarily the same as all enrolled participants: it is defined by availability of safety data. The record gives enrollment of 1308 and an at-risk count of 1285 for both adverse-event groupings, but does not explain the difference between those figures. No explanation for exclusions from the safety set is reported in the registry record.
Interim analyses, stopping rules, prespecified analysis populations beyond the safety-set definition, and sensitivity analyses are not reported in the registry record. Without those details, readers cannot assess whether results were examined repeatedly, how decisions about analysis populations were made, or whether conclusions are robust to alternative assumptions about missing observations. These are uncertainties about reporting; they are not evidence that any particular procedure was or was not carried out.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Participants With Psoriatic Arthritis | 77 | 1285 | 6.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Participants With Psoriatic Arthritis | 453 of 1285 |
Most frequent serious adverse event terms
| Event term | Organ system | Participants With Psoriatic Arthritis |
|---|---|---|
| Intervertebral disc protrusion | Musculoskeletal and connective tissue disorders | 5 of 1285 |
| Condition aggravated | General disorders | 4 of 1285 |
| Coronary artery disease | Cardiac disorders | 3 of 1285 |
| Atrial fibrillation | Cardiac disorders | 2 of 1285 |
| Chest pain | General disorders | 2 of 1285 |
| Cholecystitis | Hepatobiliary disorders | 2 of 1285 |
| Cholelithiasis | Hepatobiliary disorders | 2 of 1285 |
| Pyelonephritis | Infections and infestations | 2 of 1285 |
| Osteonecrosis | Musculoskeletal and connective tissue disorders | 2 of 1285 |
| Rotator cuff syndrome | Musculoskeletal and connective tissue disorders | 2 of 1285 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Participants With Psoriatic Arthritis |
|---|---|---|
| Injection site erythema | General disorders | 66 of 1285 |
| Nasopharyngitis | Infections and infestations | 50 of 1285 |
| Condition aggravated | General disorders | 41 of 1285 |
| Injection site pruritus | General disorders | 32 of 1285 |
| Psoriasis | Skin and subcutaneous tissue disorders | 23 of 1285 |
| Upper respiratory tract infection | Infections and infestations | 22 of 1285 |
| Fatigue | General disorders | 20 of 1285 |
| Injection site reaction | General disorders | 19 of 1285 |
| Bronchitis | Infections and infestations | 19 of 1285 |
| Diarrhoea | Gastrointestinal disorders | 18 of 1285 |
Serious events with the highest arm-level rate: intervertebral disc protrusion (0.4%), condition aggravated (0.3%), coronary artery disease (0.2%), atrial fibrillation (0.2%), chest pain (0.2%).
The adverse-event record lists 1285 participants at risk for serious events and 77 participants affected. For other adverse events, it lists 1285 at risk and 453 affected. These figures describe participants in the recorded safety group. They are not percentages, and no calculation should be substituted for a registry-reported rate. The registry defines adverse events broadly and does not require a possible causal relationship to study drug.
Serious adverse events are distinguished by their consequences or by being judged significant for another reason. The listed serious-event terms and percentages are intervertebral disc protrusion, 0.4%; condition aggravated, 0.3%; coronary artery disease, 0.2%; atrial fibrillation, 0.2%; chest pain, 0.2%; and cholecystitis, 0.2%. The record does not report term-specific uncertainty intervals or causal assessments.
In general, safety counts are most informative when the event definitions, observation period, population, and completeness of follow-up are clear. Here, the timeframe is baseline up to Week 52, and the safety population is defined as enrolled participants with safety data available. The record does not explain the difference between total enrollment and the at-risk count, or report missing safety data. As the study has no stated comparator, the counts describe reported events during observation and cannot establish how event frequency would compare under another treatment or without treatment.
12. What the Result Does, and Does Not, Mean
The posted results establish that the registry records adverse-event counts among participants in the safety analysis set. It lists 77 participants affected by serious adverse events and 453 affected by other adverse events, each among 1285 at risk. It also lists selected serious-event terms with percentages. These are descriptive safety observations from a prospective post-marketing surveillance study in usual-care settings.
They do not establish that etanercept caused any particular event. The adverse-event definition does not require a causal relationship, and the study is not a randomized comparison. Without a comparator, the record does not show how the observed event experience differs from that under another treatment or in the absence of etanercept. The counts also do not establish the percentage for the combined primary endpoint, because that percentage is not reported in the registry record.
The results do not show the size or precision of a treatment effect. The registry record does not report a confidence interval or inferential test for the primary safety endpoint. It lists secondary outcomes, but does not report analyses for them. No conclusion about changes in skin disease, joint activity, laboratory measures, itching, or pain can be drawn from outcome titles alone.
In general, observational safety information can help characterize events recorded in clinical practice, while causal comparisons require stronger design or analysis assumptions. The study’s usual-care context is part of what the record describes, but it also means that participant characteristics and clinical decisions may shape who receives treatment and what outcomes are observed. The registry record does not report adjustment methods that would address those issues.
The completion status indicates that the study is recorded as completed; it does not resolve gaps in outcome reporting. The appropriate reading is limited to the event counts and terms documented for the stated population and period. Broader claims about comparative safety, causation, or effectiveness are not supported by the registry record.
13. Why This Trial Matters Statistically
This study is statistically relevant because it illustrates the difference between surveillance and a controlled treatment comparison. A prospective usual-care design can record safety experience in a clinical setting, and the record specifies an observation period and a safety population. Those details help define what the event counts represent. At the same time, the absence of a stated comparator and randomized allocation constrains what those counts can establish.
The distinction between event counts and event rates is also important. The registry reports the number affected and the number at risk for serious and other events, but does not report a primary endpoint percentage or its uncertainty. Counts are useful descriptive information, yet they do not by themselves show precision or support comparisons across treatment strategies. Clear definitions and denominators are essential when readers interpret safety outcomes.
The record also shows why outcome listings are not equivalent to outcome evidence. It names a range of secondary measures, but analyses are not reported in the registry record. Without estimates, uncertainty measures, and analysis details, those outcomes cannot be used to assess changes or treatment effects. The absence of reported multiplicity and missing-data methods further limits appraisal of the statistical evidence.
Finally, planning illustrations must be kept separate from study design and observed power. The stated planning assumptions describe an illustrative two-arm calculation, while the registry characterizes this study as not a randomized comparison. Such illustrations do not convert a surveillance study into a controlled trial or establish that its design was powered for a particular causal question. Keeping these distinctions clear helps prevent descriptive safety records from being overinterpreted.
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 main trial-specific limitation is the absence of a stated comparator and randomized allocation. The record therefore supports description of the safety experience in the observed group, not a like-for-like estimate of how outcomes differ under alternative care. Because the study concerns usual-care treatment, the record does not establish that observed events resulted from etanercept rather than underlying illness, other care, or other influences.
Reporting is incomplete for statistical interpretation. The primary endpoint is defined as a percentage, but the registry record does not report that percentage, a confidence interval, or a statistical test. It reports participant counts for serious and other adverse events, but does not explain the relationship between those groupings or whether affected participants overlap. The selected serious-event terms are accompanied by percentages, but term-specific denominators and uncertainty estimates are not reported in the registry record.
The record gives enrollment of 1308 and an at-risk count of 1285, but does not explain the difference. The safety population includes enrolled participants with safety data available; the amount and handling of missing safety data are not reported. Analyses for the listed secondary outcomes are also not reported in the registry record.
Further details relevant to evaluation—including the statistical analysis plan, sample-size justification, interim analyses, adjustment methods, sensitivity analyses, and multiplicity procedures—are not reported in the registry record. The planning assumptions described for illustrative sample-size calculations should not be mistaken for the study’s own design or for observed power. These limitations restrict precision, reproducibility, and causal interpretation of the posted information.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study Evaluating the Safety and Efficacy of Etanercept in Patients With Psoriatic Arthritis Treated by Rheumatologists — NCT00293722.
- Registry record last updated 2014-02-26; status last verified 2014-01.
- Results first posted 2014-02-26.
- 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.
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18. Record Summary
The registry identifies NCT00293722 as a completed prospective post-marketing surveillance study of etanercept for people with psoriatic arthritis treated by rheumatologists under usual-care settings. Enrollment was 1308; the recorded start was 2006-01 and primary completion was 2013-02. The primary endpoint was the percentage of participants with treatment-emergent adverse events or serious adverse events from baseline up to Week 52.
The safety analysis set included enrolled participants with safety data available. The adverse-event record lists 1285 at risk and 77 affected for serious events, and 1285 at risk and 453 affected for other events. The registry also lists secondary outcomes across skin, joint, physician-assessed, laboratory, and patient-reported measures. Analyses of those outcomes are not reported in the registry record. No comparator is described, and allocation is not stated; the record identifies the study as not a randomized comparison.