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 Study to Evaluate Efficacy and Safety of Anakinra in the Treatment of Acute Gouty Arthritis (NCT03002974), a randomized phase 2 study. The primary outcome is Change in Patient-assessed Pain Intensity in the Index Joint From Baseline to 24-72 Hours for the First Gout Flare Treated in the Study as Measured by VAS.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03002974 |
| Phase | Phase 2 |
| Condition | Acute Gouty Arthritis |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 165 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Swedish Orphan Biovitrum |
| Results posted | Yes |
2. Clinical Question
Population
The condition recorded is acute gouty arthritis. The study summary describes patients with acute gout who cannot take non-steroidal anti-inflammatory drugs (NSAIDs) and colchicine. The full eligibility criteria and the characteristics of enrolled participants are not reported in the registry record, so the population should not be defined more broadly or narrowly than those descriptions allow.
Intervention
The trial evaluated subcutaneous anakinra at 100 mg or 200 mg. The 100 mg group received one injection daily for 5 days. The 200 mg group received two 100 mg injections daily for 5 days. Both groups also received an intramuscular placebo corresponding to triamcinolone.
Comparator
The active-control group received a single intramuscular injection of triamcinolone 40 mg and subcutaneous placebo corresponding to anakinra once daily for 5 days. These placebo injections were part of the group descriptions; the detailed procedures used to maintain masking are not reported in the registry record.
Primary question
The primary endpoint was the change in patient-assessed pain intensity in the index joint from baseline, averaged across assessments at 24, 48 and 72 hours. The scale was a visual analogue scale from 0, no pain, to 100, unbearable pain. The registry record does not report the group-level changes, between-group estimates, confidence intervals, or p-values. It therefore does not establish from the posted results how the groups compared on this endpoint.
3. Trial Design
This was a randomized, parallel-group, phase 2 study. The official title describes it as double-blind, active-control and multicenter; the registry’s masking entry is quadruple. The record does not explain which people or roles were included in that masking designation, or provide further details of how masking was maintained. The study status is completed, with enrollment recorded as 165.
Three treatment groups are described: anakinra 100 mg, anakinra 200 mg, and triamcinolone 40 mg. The 100 mg anakinra group received one subcutaneous injection daily for 5 days, plus placebo injections corresponding to anakinra and triamcinolone. The 200 mg group received two subcutaneous 100 mg injections daily for 5 days, plus intramuscular placebo. The triamcinolone group received placebo injections corresponding to anakinra and one intramuscular injection of triamcinolone 40 mg. Allocation ratios and the number enrolled in each treatment group are not reported in the registry record.
The official title includes an extension period of up to 2 years. The primary endpoint timeframe, however, concerns the first gout flare treated in the study and pain assessments from baseline through 72 hours. The start is recorded as 2016-12 and primary completion as 2018-06. The record identifies Swedish Orphan Biovitrum as sponsor. Further details about conduct, recruitment, protocol deviations and the extension period’s analyses 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 | Triamcinolone 40 mg | Anakinra 100 mg | Anakinra 200 mg |
|---|---|---|---|
| STARTED | 55 | 56 | 54 |
| Intention To Treat Populatio | 55 | 56 | 54 |
| Safety Population | 54 | 55 | 52 |
| COMPLETED | 35 | 40 | 36 |
| NOT COMPLETED | 20 | 16 | 18 |
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 | Triamcinolone 40 mg | Anakinra 100 mg | Anakinra 200 mg | Total |
|---|---|---|---|---|---|
| Participants analysed | 55 | 56 | 54 | 165 | |
| Age, Continuous | years | 56.8 (SD 10.3) | 53.7 (SD 11.9) | 54.0 (SD 13.1) | 54.8 (SD 11.8) |
| Sex: Female, Male: Female | Participants | 7 | 8 | 7 | 22 |
| Sex: Female, Male: Male | Participants | 48 | 48 | 47 | 143 |
| Race/Ethnicity, Customized: Race – White | Participants | 39 | 38 | 42 | 119 |
| Race/Ethnicity, Customized: Race – Black or African American | Participants | 15 | 15 | 12 | 42 |
| Race/Ethnicity, Customized: Race – Asian | Participants | 1 | 3 | 0 | 4 |
| Region of Enrollment: United States | participants | 55 | 56 | 54 | 165 |
6. Primary Endpoint
The registry lists the primary outcome as Change in Patient-assessed Pain Intensity in the Index Joint From Baseline to 24-72 Hours for the First Gout Flare Treated in the Study as Measured by VAS, measured over At baseline (pre-dose) and at 24, 48 and 72 hours for the first gout flare treated in the study.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | Units on a scale |
| Endpoint classification | Continuous Endpoint |
The primary endpoint measures change in pain intensity in the joint identified as most affected at baseline, termed the index joint. Patients rated pain using a visual analogue scale from 0, meaning no pain, to 100, meaning unbearable pain. The endpoint is the average of patient assessments at 24, 48 and 72 hours, compared with the baseline assessment. The registry describes the outcome as a mean and gives a 95% confidence interval as its dispersion measure.
Patient ratings capture the symptom directly from the person experiencing it. Using the index joint focuses the assessment on the joint most affected at baseline, while repeated ratings over the first 72 hours describe pain over several post-dose time points rather than at a single instant. Averaging those follow-up assessments produces one summary measure for the stated period. These are general reasons such an endpoint can be useful; they do not establish that the measure captures every aspect of a gout flare or that the chosen timing is optimal.
The registry record does not report the observed mean change for any group, the difference between groups, or the confidence intervals around those estimates. It also does not report how baseline and follow-up observations were handled when a rating was missing. Without those results and details, the endpoint definition can be described, but the magnitude and precision of any treatment-group contrast cannot be assessed.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a clinically focused primary endpoint: change in patient-assessed pain in the index joint, using the average of assessments at 24, 48 and 72 hours. It also identifies the treatment groups and records enrollment as 165. These details describe what the study set out to compare, but they are not themselves evidence of a difference in pain outcomes.
The posted results do not include group means for the primary endpoint, treatment contrasts, confidence intervals or p-values. Consequently, the direction and size of the primary comparison are not reported in the registry record. The record also does not state whether either anakinra dose differed from triamcinolone on the primary endpoint, or whether the two anakinra dose groups differed from one another. No conclusion about the endpoint’s statistical precision can be drawn without estimates and their uncertainty.
In general, an estimate describes the observed size and direction of a contrast, while a confidence interval conveys uncertainty around that estimate under the analysis assumptions. A p-value addresses compatibility of the data with a specified null hypothesis under a statistical model; it is not a measure of clinical importance. Those general interpretations cannot be applied to this trial’s primary comparison in the absence of its estimates and analysis results.
The record lists secondary outcomes concerning pain over additional time points, time to onset, response, pain resolution and rescue medication, as well as physician assessments. Their presence indicates a broader set of outcomes was registered, but their numerical results are not included in the registry record described for the registry record. The record lists zero analyses. Details such as the analysis model, adjustment variables, handling of repeated measurements, and whether any planned analyses were completed are not reported in the registry record.
Safety information is reported as numbers of participants at risk and affected for serious and other adverse events. These counts can be described as recorded, but they do not replace the missing efficacy estimates, and they do not establish a causal relationship between a treatment and an event. Overall, the registry record allows the study question, endpoint, design and selected safety counts to be characterized. It does not provide the numerical primary efficacy results needed to interpret the observed treatment contrasts.
9. Statistical Methods Explained
The registry record gives some information about the outcome measure and trial structure, but little about the statistical analysis. The endpoint is a mean of a continuous pain measure, and its dispersion is described as a 95% confidence interval. The record does not provide a statistical analysis plan or report the fitted model, analysis populations, missing-data method, or multiplicity procedure. The explanations below are general statistical context, not claims about methods used in this study.
What does a mean change represent?
A mean summarizes values across participants by their arithmetic average. For a change endpoint, each participant’s follow-up measurement is compared with their baseline measurement, and those changes can then be summarized within a group. Here, the registered endpoint is the average of pain assessments at 24, 48 and 72 hours for the first treated flare, relative to baseline. The registry record identifies the outcome as a mean, but does not report the actual group means or explain how the average across time points was calculated when assessments were unavailable.
Means are useful summaries, but they do not describe every participant’s experience or the full shape of the data. A mean can be influenced by unusually large or small values. Additional measures, such as a standard deviation or a distributional summary, can help show variability, but those measures are not reported for the primary endpoint in the registry record.
What does the confidence interval convey?
In general, a confidence interval expresses uncertainty around an estimated quantity under the statistical assumptions used to calculate it. A narrower interval indicates greater precision in that estimate; a wider interval indicates less precision. A 95% confidence interval is the dispersion measure specified for the primary outcome, but no interval endpoints are reported. It is therefore not possible to assess the precision of the trial’s primary result from the registry record. A confidence interval should also be interpreted for the particular estimate it accompanies: an interval around a group mean is not the same as an interval around a between-group difference.
How does randomization relate to the comparison?
Randomized allocation is recorded, and the study is described as parallel-group. In general, randomization is intended to make treatment assignment independent of participant characteristics, helping support a fair comparison. It does not guarantee that groups will be identical, particularly in a finite trial. A clear account of the allocation procedure, concealment, baseline characteristics and group sizes would help readers assess how the design was implemented. Those details are not reported in the registry record, beyond the total enrollment and treatment-group descriptions.
The official title calls the study double-blind, while the registry masking entry says quadruple. Masking can reduce the influence of expectations on treatment delivery, outcome assessment and reporting. The meaning of the registry’s masking category and the roles masked are not explained in the record. The placebo injections are described in the arms, but detailed masking procedures are not reported.
Why do repeated measurements matter?
Pain was assessed at multiple times, and the primary endpoint combines assessments at 24, 48 and 72 hours. Repeated observations on the same person are generally correlated rather than independent. Statistical methods for repeated measures can account for that dependence and may use information from more than one time point. Alternatively, a protocol may define a summary such as an average over time. The registry specifies the average endpoint but does not report the statistical model or how within-person correlation was handled.
The secondary outcomes include pain at time points from 6 hours to 8 days, and several time-to-event outcomes. In general, time-to-event analyses account for both the timing of an event and the possibility that an event has not occurred by the end of observation. Their interpretation depends on definitions of the event, follow-up and censoring. Those analysis details are not reported in the registry record.
What statistical details are unavailable?
The record lists no analyses. It does not report a primary treatment-effect estimate, standard error, confidence interval endpoints or p-value. Nor does it state whether the primary comparison was adjusted, how treatment groups were contrasted, what assumptions were checked, or how missing outcomes were handled. These omissions prevent a detailed appraisal of the actual statistical analysis.
The record also does not report a sample-size justification or a planned power calculation. Enrollment alone does not show whether a study was adequately sized for a particular contrast. In general, the precision of an estimate depends on the amount and variability of outcome information, as well as the analysis. No sample-size illustration or calculation should be treated as an observed result or as evidence that the trial had a particular probability of detecting an effect. The registry record does not report the information needed to assess those design considerations.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one primary endpoint and multiple secondary outcomes. These include pain ratings at time points from 6 hours to 8 days, median time to onset of effect, response and pain resolution, time to first rescue medication, and physician assessments of global response, tenderness and swelling. Considering multiple outcomes or multiple treatment contrasts raises a general statistical issue: the more hypotheses examined, the greater the chance that at least one result may appear notable by chance alone. This is why analysis plans often specify which comparisons are primary and how secondary comparisons will be interpreted or adjusted.
Multiplicity procedures, any ordering of hypotheses, and any distinction between confirmatory and exploratory analyses are not reported in the registry record. The record lists zero analyses, so it does not provide outcome-level results from which to assess how multiple comparisons were handled. It would be inappropriate to assume that a correction was or was not used.
Missing-data methods are also not reported. The primary endpoint requires baseline and follow-up pain assessments, but the registry record does not state how incomplete assessments were treated, whether participants who discontinued remained in an analysis, or what assumptions were used for missing values. Analysis populations—such as whether all randomized participants were included—are not reported in the registry record. The total enrollment does not establish how many participants contributed to a particular endpoint. These omissions matter because the choice of analysis population and missing-data assumptions can affect estimates and their uncertainty.
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 |
|---|---|---|---|
| Triamcinolone 40 mg | 0 | 54 | 0.0% |
| Anakinra 100 mg | 4 | 55 | 7.3% |
| Anakinra 200 mg | 1 | 52 | 1.9% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Triamcinolone 40 mg | 0 of 54 |
| Anakinra 100 mg | 0 of 55 |
| Anakinra 200 mg | 0 of 52 |
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 |
|---|---|
| Triamcinolone 40 mg | 22 of 54 |
| Anakinra 100 mg | 19 of 55 |
| Anakinra 200 mg | 29 of 52 |
Most frequent serious adverse event terms
| Event term | Organ system | Triamcinolone 40 mg | Anakinra 100 mg | Anakinra 200 mg |
|---|---|---|---|---|
| Coronary artery disease | Cardiac disorders | 0 of 54 | 1 of 55 | 1 of 52 |
| Anaemia | Blood and lymphatic system disorders | 0 of 54 | 1 of 55 | 0 of 52 |
| Seizure | Nervous system disorders | 0 of 54 | 1 of 55 | 0 of 52 |
| Gastric ulcer | Gastrointestinal disorders | 0 of 54 | 1 of 55 | 0 of 52 |
| Sickel cell anaemia | Congenital, familial and genetic disorders | 0 of 54 | 1 of 55 | 0 of 52 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Triamcinolone 40 mg | Anakinra 100 mg | Anakinra 200 mg |
|---|---|---|---|---|
| Influenza | Infections and infestations | 0 of 54 | 3 of 55 | 5 of 52 |
| Blood triglycerides increased | Investigations | 1 of 54 | 0 of 55 | 5 of 52 |
| Hypertriglyceridaemia | Metabolism and nutrition disorders | 0 of 54 | 3 of 55 | 2 of 52 |
| Arthralgia | Musculoskeletal and connective tissue disorders | 1 of 54 | 2 of 55 | 2 of 52 |
| Neutropenia | Blood and lymphatic system disorders | 0 of 54 | 1 of 55 | 3 of 52 |
| Headache | Nervous system disorders | 2 of 54 | 0 of 55 | 2 of 52 |
| Nausea | Gastrointestinal disorders | 1 of 54 | 2 of 55 | 1 of 52 |
| Oedema peripheral | General disorders | 0 of 54 | 1 of 55 | 2 of 52 |
| Ligament sprain | Injury, poisoning and procedural complications | 1 of 54 | 0 of 55 | 2 of 52 |
| Nasopharyngitis | Infections and infestations | 0 of 54 | 1 of 55 | 1 of 52 |
Serious events with the highest arm-level rate: coronary artery disease (1.9%), anaemia (1.8%), seizure (1.8%), gastric ulcer (1.8%), sickel cell anaemia (1.8%).
Safety counts are reported for three groups. For triamcinolone 40 mg, 54 participants were at risk for serious adverse events and 0 were affected; 54 were at risk for other adverse events and 22 were affected. For anakinra 100 mg, the corresponding counts were 55 at risk and 4 affected for serious adverse events, and 55 at risk and 19 affected for other adverse events. For anakinra 200 mg, they were 52 at risk and 1 affected for serious adverse events, and 52 at risk and 29 affected for other adverse events. Deaths are recorded as 0 in each group.
These are participant counts, not adjusted comparisons. The registry record does not provide statistical comparisons, exposure-adjusted rates, event duration, severity grading, or an assessment of whether events were caused by study treatment. It also does not explain the detailed event-coding or reporting rules. The listed serious-event terms include Coronary artery disease (1.9%), Anaemia (1.8%), Seizure (1.8%), Gastric ulcer (1.8%) and Sickel cell anaemia (1.8%). The denominator and group attribution for these term percentages are not reported in the registry record. Counts and terms describe what is recorded, but should not be interpreted as proving causation or as a complete account of safety.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a randomized, phase 2, active-control study compared two subcutaneous anakinra dose groups with intramuscular triamcinolone for acute gouty arthritis. It defines a primary pain endpoint based on the average of patient ratings at 24, 48 and 72 hours, relative to baseline. It also records selected adverse-event counts. Those details support a description of the study question and some aspects of its design and safety reporting.
They do not establish the size or direction of the primary treatment effect. No group-level endpoint results, between-group estimates, confidence intervals or p-values are reported in the registry record. As a result, it is not possible to judge whether the observed pain changes differed between groups, how precise a contrast was, or whether the results were compatible with a range of clinically relevant effects. The absence of those numerical results is not evidence that groups were the same.
More broadly, a statistical comparison is not, by itself, a complete account of clinical importance. In general, interpretation benefits from considering the magnitude and uncertainty of an estimate, the outcome’s meaning to patients, the study population, and the quality and completeness of the data. The registry record does not include enough primary efficacy information to make that assessment for this trial.
The safety counts likewise have limits. They report how many participants were affected in each category, but do not provide adjusted comparisons or establish whether an event was caused by treatment. The registry does not report the analysis populations, missing-data procedures, or multiplicity approach. Therefore, the record supports a cautious description of registered methods and selected counts, not a definitive interpretation of efficacy or comparative safety.
13. Why This Trial Matters Statistically
This study is statistically notable for the structure of its question: it compares two dose levels of anakinra with an active-control treatment, using patient-assessed pain as its primary endpoint. A randomized parallel-group design can support comparisons between assigned treatment groups when allocation and follow-up are implemented appropriately. The registry record gives the broad design and endpoint definitions needed to understand the intended comparison.
The endpoint also illustrates a common analytical choice. Pain is measured repeatedly during an early period, then summarized as an average across specified assessments. Such a summary can make the outcome easier to interpret as an overall measure across that period, while also reducing the separate interpretation burden of multiple time-specific outcomes. General statistical considerations include how repeated measurements relate to one another, how incomplete assessments are handled, and whether the summary captures changes over time. The registry record does not report the methods used to address these issues.
The study also registers several secondary outcomes, including time-to-event measures and physician assessments. These outcomes raise different analytical questions from a mean pain score and can create multiplicity concerns when many results are examined. The registry record does not report how those analyses were planned or interpreted.
Finally, the distinction between a defined endpoint and a reported endpoint result is important. The record gives a detailed primary outcome definition but no numerical primary comparison. This makes the study’s design understandable while leaving its principal efficacy result unavailable in the record described. That distinction is central to statistical reading: a registered question and a completed study do not, on their own, reveal the estimate, its precision or the analysis supporting it.
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.
A major limitation of the registry record is that it does not report the numerical results for the primary endpoint. Group-level changes, treatment contrasts, confidence intervals and p-values are absent, so the central comparison cannot be quantified or assessed for precision. The record also lists no analyses. Secondary outcome results are not reported in the information available for this account.
Important design and analysis details are unavailable. The record does not report the allocation ratio, treatment-group enrollment totals, full eligibility criteria, baseline participant characteristics, analysis populations, missing-data procedures, adjustment methods or multiplicity plan. It does not provide the sample-size justification or a detailed statistical analysis plan. These omissions make it difficult to assess the implementation of randomization, the representativeness of the analyzed groups, and the robustness of any potential estimates.
The primary endpoint combines assessments at 24, 48 and 72 hours. Although that definition is clear, the record does not explain how the average was calculated for participants with incomplete assessments, whether all time points were equally weighted, or how changes from baseline were analyzed. The masking entry and official title use different descriptions, and the roles masked are not specified.
Safety reporting is also limited to counts and listed terms. Comparative statistical analyses, exposure information, event duration, severity and causal assessments are not reported. These limitations concern what can be learned from the registry record; they do not establish that the underlying trial lacked additional documentation or analyses.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Study to Evaluate Efficacy and Safety of Anakinra in the Treatment of Acute Gouty Arthritis — NCT03002974.
- Registry record last updated 2020-07-15; status last verified 2020-06.
- Results first posted 2020-07-15.
- 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 record describes NCT03002974, a completed, randomized, parallel-group, phase 2 study sponsored by Swedish Orphan Biovitrum. It records enrollment of 165 and compares anakinra 100 mg and 200 mg with triamcinolone 40 mg for acute gouty arthritis. The official title describes a multicenter study and an extension period of up to 2 years.
The primary endpoint is change in patient-assessed index-joint pain from baseline, based on the average of assessments at 24, 48 and 72 hours on a 0-100 mm visual analogue scale. The registry record does not report the primary endpoint estimates or statistical analyses. It reports selected serious and other adverse-event counts and lists deaths as 0 in each group. Further details about missing data, analysis populations, multiplicity and the statistical plan are not reported in the registry record.