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 Treating Participants With Early Axial Spondyloarthritis (axSpA) Taking an Intense Treatment Approach Versus Routine Treatment (NCT02897115), a randomized phase 4 study. The primary outcome is Percentage of Participants With an Ankylosing Spondylitis Disease Activity Score (ASDAS) of Inactive Disease at Week 32.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02897115 |
| Phase | Phase 4 |
| Condition | Axial Spondyloarthritis |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 22 |
| Arms in the primary outcome | 2 |
| Lead sponsor | AbbVie |
| Results posted | Yes |
2. Clinical Question
Population
Participants had axial spondyloarthritis (axSpA). The trial title and summary describe the condition as early axSpA. The primary endpoint population was participants with available data at Week 32; the reported endpoint group sizes were 5 in the treat-to-target arm and 1 in the standard-of-care arm.
Intervention
The intervention was a treat-to-target (T2T) intense treatment approach. Its description states that participants initially received any non-steroidal anti-inflammatory drug (NSAID) at a full anti-inflammatory dose for 4 weeks. The description of what followed is cut off in the registry record, so the full treatment pathway is not reported there. Adalimumab is listed among the interventions, but the record does not specify its use by participant or the complete T2T sequence.
Comparator
The comparator was standard of care (SOC): treatment prescribed by the participant’s physician according to local standard of care. This is a routine-care comparator rather than a single fully specified regimen in the registry description. The particular treatments received in this arm are not reported in the registry record.
Primary question
The primary question was what percentage of participants had ASDAS-defined inactive disease at Week 32. Inactive disease was defined as an ASDAS below 1.3, calculated using CRP. The posted percentages are 80.0% for T2T and 0.0% for SOC, but the endpoint was available for 5 participants in T2T and 1 in SOC. The registry record does not report a statistical comparison of these percentages. The results therefore describe the available observations, rather than establishing a precise difference between the treatment approaches.
3. Trial Design
STRIKE was a Phase 4, randomized, parallel-group study comparing an intense treat-to-target approach with routine standard-of-care treatment in participants with axial spondyloarthritis. The official title describes it as a 1 Year Randomized Controlled Study. The registry record lists enrollment of 22 and a non-masked design. It does not report blinding, which is consistent with the masking field indicating none.
The T2T arm description says that participants initially received an NSAID at a full anti-inflammatory dose for 4 weeks. It then begins to describe a treatment change depending on disease activity or NSAID tolerability, but the text is truncated. The complete decision pathway, including the role and timing of adalimumab, is not reported in the registry record. In the SOC arm, treatment was prescribed by the physician according to local standard of care. Thus, the arms differed in their stated treatment strategy, but the exact individual treatments cannot be reconstructed from the record.
The registry lists a start date of 2016-09-12, a primary completion date of 2017-12-21, and a status of terminated. The reason for termination and the timing of the termination are not reported in the registry record. The trial’s status should be distinguished from the posted endpoint results: termination alone does not explain the size or direction of the available Week 32 observations.
The posted primary outcome is the percentage with ASDAS inactive disease at Week 32, among participants with available data at that time. The recorded endpoint denominators are 5 for T2T and 1 for SOC. They are not the enrollment figures for the full trial. The registry lists 33 outcome measures and 32 posted secondary outcomes, while the analysis count is zero. A detailed statistical analysis plan, allocation procedure, and explanation of how missing endpoint observations were handled 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 | Treat-to-Target (T2T) | Standard of Care (SOC) |
|---|---|---|
| STARTED | 14 | 8 |
| COMPLETED | 3 | 0 |
| NOT COMPLETED | 11 | 8 |
Reasons for not completing this period:
| Reason | Treat-to-Target (T2T) | Standard of Care (SOC) |
|---|---|---|
| Early termination of study by sponsor | 11 | 8 |
Analysis population for the primary outcome, as defined in the registry: Participants with available data at week 32
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 | Treat-to-Target (T2T) | Standard of Care (SOC) | Total |
|---|---|---|---|---|
| Participants analysed | 14 | 8 | 22 | |
| Age, Continuous | years | 37.0 (SD 9.49) | 29.6 (SD 7.96) | 34.3 (SD 9.49) |
| Sex: Female, Male: Female | Participants | 8 | 4 | 12 |
| Sex: Female, Male: Male | Participants | 6 | 4 | 10 |
| Race and Ethnicity Not Collected | Participants | — | — | 0 |
6. Primary Endpoint
The registry lists the primary outcome as Percentage of Participants With an Ankylosing Spondylitis Disease Activity Score (ASDAS) of Inactive Disease at Week 32, measured over Week 32.
| 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 ASDAS-defined inactive disease at Week 32. ASDAS combines participant-reported back pain, duration of morning stiffness, the participant’s global assessment of disease activity, assessment of peripheral joint pain and swelling, and an acute phase reactant: CRP or ESR. For this endpoint, the registry specifies the calculation using CRP. Inactive disease is defined as an ASDAS below 1.3.
ASDAS is used to represent disease activity through a composite measure rather than a single symptom. Bringing patient-reported information together with an inflammatory marker can capture more than one aspect of the condition. The registry describes additional ASDAS states: moderate disease activity is from 1.3 to below 2.1, high disease activity is from 2.1 to 3.5, and very high disease activity is above 3.5. The overall score has no defined upper score.
Reporting the percentage below the inactive-disease threshold makes the endpoint a binary summary: each participant with an available Week 32 assessment either meets the threshold or does not. The endpoint does not show how far an individual score lies from the threshold, nor does it summarize change from baseline. Its interpretation depends on the available assessments and on how the threshold is applied. The registry record does not report additional endpoint-specific details about assessment timing or missing-data handling.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
At Week 32, the posted result for ASDAS inactive disease is 80.0% in the T2T arm and 0.0% in the SOC arm. These percentages are based on available data from 5 participants in T2T and 1 participant in SOC. The percentages are descriptive observations from those participants, not estimates accompanied by reported uncertainty. The registry record does not report confidence intervals, a p-value, or a formal between-group test.
The very small endpoint populations are central to reading these percentages. A percentage based on a handful of available observations can change substantially when the outcome for even one participant differs. The SOC percentage represents the observation from a single participant with available endpoint data; it cannot characterize the full SOC group with precision. The 80.0% result in T2T likewise describes only the available-data subset, not necessarily everyone randomized to that approach. No inference should be made about the outcomes of participants whose Week 32 data are not included.
The record reports enrollment of 22, but the endpoint denominators are much smaller. The flow of participants from enrollment to the Week 32 available-data population, by arm and by reason for missingness, is not reported in the registry record. Consequently, it is not possible to determine from these results whether the available participants represent the randomized groups, or whether missing endpoint data could affect the apparent pattern.
The record lists 33 outcome measures and 32 posted secondary outcomes, but no analyses are recorded. The posted percentages therefore should not be read as results of a reported inferential comparison. They also do not establish that one strategy caused better outcomes: randomization is part of the trial design, but the available endpoint data are too sparse to support a precise causal estimate from the information recorded.
The study is marked terminated, but the reason is not reported in the registry record. Termination does not by itself indicate whether the study stopped for operational, recruitment, safety, or other reasons. Nor does it establish that the posted primary endpoint was the reason for stopping. The results should be read narrowly: the registry reports these percentages for the participants with available Week 32 data, while important information needed to assess precision, missingness, and the planned comparison is not reported.
9. Statistical Methods Explained
Several statistical ideas help distinguish the observed percentages from evidence about a broader treatment effect. The explanations below are general, followed by their application to the registry record.
What does a percentage describe?
For a binary endpoint, a percentage describes the share of participants in the analysis population who meet the stated definition. In this trial, the definition is ASDAS below 1.3 at Week 32. The denominator matters as much as the percentage: the registry reports available endpoint data for 5 participants in T2T and 1 in SOC. These are the populations underlying the posted values. They are not interchangeable with the enrolled population, and they do not establish how participants without an available Week 32 result would have been classified.
General: a percentage is a point estimate, meaning one summary of the observed data. It does not, on its own, express precision. With very limited observations, a point estimate can be unstable. A confidence interval is a range generated by a statistical procedure to communicate uncertainty around an estimate. No confidence interval is reported for this endpoint in the registry record, so the precision cannot be assessed from a reported interval.
What would a between-group analysis add?
General: a treatment comparison typically estimates a contrast between outcomes in the groups and quantifies uncertainty in that contrast. A statistical test may also assess how compatible the data are with a specified null hypothesis under its assumptions. The estimate, interval, and test answer different questions: an estimate describes the contrast, an interval conveys precision, and a test summarizes evidence against a null model. None should substitute for the others.
For STRIKE, the record posts the arm-specific percentages but records no analyses. It does not report a formal between-group estimate, confidence interval, or p-value. The displayed arm percentages therefore should not be interpreted as a completed test of the treatment strategies. No recalculated comparison is reported. This distinction is especially important when available endpoint data are limited, because a numerical difference between arm percentages does not alone show whether a population-level difference is estimated precisely.
Why does the analysis population matter?
General: an analysis population is the set of participants whose data contribute to a particular result. Trials may define populations based on randomization, treatment received, or availability of outcome measurements. These choices can change which participants are represented and may affect interpretation. A randomized comparison is generally intended to preserve the benefits of random assignment, but the method used to handle missing outcomes must be clear to understand whether the analyzed groups still support that comparison.
The endpoint definition explicitly restricts the result to participants with available Week 32 data. The registry record does not report an analysis-population definition beyond this, participant flow by arm, or a missing-data method. It is therefore not possible to tell whether missing outcomes were excluded without adjustment, imputed, or handled in another way. No such method should be presumed.
What does the planning illustration mean?
General: sample-size planning asks how many participants may be needed under chosen assumptions to detect a target effect with a specified probability, often called power. Such a calculation is prospective planning, not a measure of what a completed or terminated trial actually achieved. It depends on assumptions about the effect, outcome variability, allocation, significance level, and statistical method.
The registry record describes planning illustrations based on the observed effect, a two-sided significance level of 0.05, equal allocation, and a normal approximation; the illustrated target effects are stated as fractions of the observed effect. These calculations are planning illustrations, never observed power. With small observed endpoint populations, an effect estimated from the posted percentages may itself be unstable, so planning based on it should be treated cautiously. The registry record does not report the trial’s own sample-size justification or underlying planning assumptions. Any planning estimates should not be presented as evidence that the trial had adequate power or as a description of the design actually used.
Why can sparse binary data be difficult?
General: binary outcomes contain limited information when few observations are available, particularly when one group has very few observed outcomes or a very small denominator. Standard approximations used in statistical procedures may perform poorly with sparse data. Alternative methods may be considered, but the suitable method depends on the design and analysis plan. The registry record does not report a selected method for a treatment comparison, so it would be inappropriate to infer one from the percentages alone.
In this record, the most defensible statistical reading is therefore descriptive. The endpoint threshold and the available-data percentages are stated, but uncertainty, a formal comparison, the missing-data strategy, and the detailed statistical analysis plan are not reported in the registry record.
10. Exact Estimates for Each Arm
No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.
| Arm | Participants | Events | Observed % | Clopper-Pearson 95% CI | Wilson 95% CI | Bayesian 95% credible interval |
|---|---|---|---|---|---|---|
| Treat-to-Target (T2T) | 5 | 4 | 80.0% | 28.4% to 99.5% | 37.6% to 96.4% | 35.9% to 95.7% |
| Standard of Care (SOC) | 1 | 0 | 0.0% | 0.0% to 97.5% | 0.0% to 79.3% | 1.3% to 84.2% |
R code and output
arm <- c("Treat-to-Target (T2T)", "Standard of Care (SOC)")
n <- c(5, 1)
events <- c(4, 0)
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 Treat-to-Target (T2T) 5 4 80.0 28.4 99.5 37.6 96.4 35.9 95.7
ARM Standard of Care (SOC) 1 0 0.0 0.0 97.5 0.0 79.3 1.3 84.211. Multiplicity, Missing Data and Analysis Populations
The registry lists 33 outcome measures, including the primary endpoint and 32 posted secondary outcomes. Multiple outcomes create a general statistical issue: when many hypotheses are tested, the chance of at least one apparently notable result can increase if no adjustment or prespecified hierarchy is used. A multiplicity strategy may control that risk by setting an order of testing or adjusting the criteria for interpretation. This is a general consideration, not a claim that a particular adjustment was required or used in STRIKE.
The analysis count is recorded as zero. The registry record does not report a statistical analysis plan, a testing hierarchy, multiplicity adjustment, or p-values for the posted outcome results. It is therefore not possible to assess whether the secondary outcomes were treated as confirmatory, exploratory, or handled through any prespecified procedure. The number of outcomes alone does not establish that analyses were performed or that a multiplicity problem occurred.
Missing data are also important. The primary endpoint population is described as participants with available data at Week 32, with 5 participants in T2T and 1 in SOC. The registry record does not report the number or characteristics of participants without endpoint data in each arm, reasons for missingness, or the method used to address missing values. General: if outcome availability is related to a participant’s health, treatment, or other factors, an available-case result may differ from the result that would have been observed with complete follow-up. That possibility cannot be evaluated from the registry record.
The record does not report whether the primary analysis was intended to include all randomized participants or another defined population. It also does not report sensitivity analyses for missing data. These omissions limit assessment of both the primary result and the wider set of posted outcomes.
12. 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 |
|---|---|---|---|
| Standard of Care (SOC) | 0 | 8 | 0.0% |
| Treat-to-Target (T2T) | 1 | 14 | 7.1% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Standard of Care (SOC) | 0 of 8 |
| Treat-to-Target (T2T) | 0 of 14 |
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 |
|---|---|
| Standard of Care (SOC) | 6 of 8 |
| Treat-to-Target (T2T) | 12 of 14 |
Most frequent serious adverse event terms
| Event term | Organ system | Standard of Care (SOC) | Treat-to-Target (T2T) |
|---|---|---|---|
| CHOLECYSTITIS CHRONIC | Hepatobiliary disorders | 0 of 8 | 1 of 14 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Standard of Care (SOC) | Treat-to-Target (T2T) |
|---|---|---|---|
| NASOPHARYNGITIS | Infections and infestations | 3 of 8 | 4 of 14 |
| AXIAL SPONDYLOARTHRITIS | Musculoskeletal and connective tissue disorders | 3 of 8 | 2 of 14 |
| ABDOMINAL PAIN UPPER | Gastrointestinal disorders | 1 of 8 | 3 of 14 |
| GASTROENTERITIS | Infections and infestations | 2 of 8 | 1 of 14 |
| GASTRITIS | Gastrointestinal disorders | 0 of 8 | 2 of 14 |
| NAUSEA | Gastrointestinal disorders | 0 of 8 | 2 of 14 |
| CYSTITIS | Infections and infestations | 1 of 8 | 1 of 14 |
| BACK PAIN | Musculoskeletal and connective tissue disorders | 0 of 8 | 2 of 14 |
| HEADACHE | Nervous system disorders | 0 of 8 | 2 of 14 |
| LYMPHADENOPATHY | Blood and lymphatic system disorders | 0 of 8 | 1 of 14 |
Serious events with the highest arm-level rate: cholecystitis chronic (7.1%).
The registry reports serious adverse event figures by arm using the listed at-risk groups. In SOC, 0 serious adverse events were reported among 8 participants at risk. In T2T, 1 serious adverse event was reported among 14 participants at risk. The record reports 0 deaths in each arm. These are descriptive counts; no statistical comparison or uncertainty interval for the safety figures is reported in the registry record.
For other adverse events, the record lists 6 affected participants among 8 at risk in SOC and 12 among 14 at risk in T2T. These figures should not be conflated with serious adverse events: the registry reports the categories separately. It lists “CHOLECYSTITIS CHRONIC” as a top serious-event term with 7.1%. The record does not provide enough context in this entry to interpret that term as a comparative rate or to connect it with a particular arm.
General: adverse-event counts depend on the period of observation, event definitions, and completeness of reporting. The registry record does not provide enough detail to assess exposure time or to determine whether participants had comparable observation periods. These counts describe what was posted, not the overall safety profile of either approach.
13. What the Result Does, and Does Not, Mean
The posted primary result says that 80.0% of the T2T participants with available Week 32 data met the ASDAS inactive-disease definition, compared with 0.0% of the available SOC participants. The data underlying those percentages come from 5 participants in T2T and 1 in SOC. The appropriate interpretation is descriptive: these are the reported outcomes among the available participants, not a precise estimate of what would happen across the full randomized groups.
The result does not establish that T2T caused a higher rate of inactive disease. The registry record does not report a statistical comparison, confidence interval, or p-value, and it does not explain how unavailable Week 32 observations were handled. Without those details, the size and precision of any treatment-group contrast cannot be established from the posted endpoint figures. The small available-data population makes that limitation particularly important.
The result also does not determine whether the treatment strategies are equivalent, whether routine care is inferior, or whether a different result would be expected in another setting. A lack of a reported analysis is not evidence of no difference; conversely, a visible difference between descriptive percentages is not proof of a treatment effect. Both conclusions require more information than these arm-specific values provide.
The record does not report the reason the study was terminated, the complete T2T treatment algorithm, or a detailed analysis plan. Those gaps prevent a fuller account of how the intervention was implemented and how the endpoint was intended to be interpreted. The number of listed outcome measures also means the secondary outcomes should be considered in light of the unreported analysis strategy, rather than treated as a coherent set of confirmed findings.
In short, the registry documents a randomized study and posts a Week 32 endpoint pattern in the participants whose data were available. It does not report the information needed to quantify uncertainty around that pattern or to determine whether it represents a reliable difference between treatment strategies.
14. Why This Trial Matters Statistically
This trial is statistically instructive because its design and posted endpoint results illustrate why group percentages should always be read alongside their denominators. The primary result is not just a pair of percentages: it is a pair based on 5 available observations in T2T and 1 in SOC. The SOC value is particularly limited as a description of that arm because only 1 participant contributes endpoint data. The percentages alone can make a comparison seem more definitive than the underlying information allows.
STRIKE also shows the distinction between randomization and the analysis population. Random allocation can help make treatment groups comparable at the start of a study. But a result based on participants with available data at a later visit may not preserve that comparability if availability differs or is related to outcomes. The registry record does not report participant flow or a missing-data analysis, so this issue cannot be resolved from the posted endpoint entry.
The record’s analysis count of zero is another reason to separate descriptive reporting from inferential conclusions. An arm-specific percentage is not itself a test of a treatment strategy. To judge an estimated contrast, readers need information about the analysis method and uncertainty, as well as a clear account of which participants were included.
Finally, the trial is marked terminated, and the reason is not reported in the registry record. That status matters when considering the completeness and scope of the results, but it does not explain the outcome pattern on its own. Taken together, the record offers a useful example of the limits of interpreting sparse, available-case binary data without a reported comparison or missing-data plan.
15. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The primary endpoint is reported only for participants with available Week 32 data, and the recorded endpoint populations are 5 in T2T and 1 in SOC. The registry record does not report the participant flow from enrollment to this available-data population, reasons for missing outcome data, or a method for handling missingness. This makes it difficult to judge how representative the endpoint observations are of the randomized groups.
No formal analysis is recorded for the primary comparison. Confidence intervals, p-values, and an estimated between-group effect are not reported in the registry record. As a result, the precision of the percentages and the strength of evidence for a difference cannot be assessed from the posted primary result. The planning assumptions described in the record do not replace an analysis of the observed trial data.
The T2T treatment description is truncated after the initial NSAID treatment and a statement about later treatment changes. Although adalimumab is listed as an intervention, the full treatment sequence and its use in the arms are not reported. This limits reproducibility and makes it difficult to understand precisely what treatment strategy was implemented. SOC is described as physician-prescribed local care, but the actual treatments received are not reported.
The record lists 33 outcomes, including 32 secondary outcomes, but does not report an analysis plan or multiplicity approach. It is not clear how the secondary outcomes were prioritized or whether they were intended as confirmatory. The study status is terminated, but the reason for termination is not reported. These limitations are specific to the available registry information and should not be filled in by assumption.
16. Related Tutorials
17. Related Statistical Calculators
18. Sources
- ClinicalTrials.gov: A Study Treating Participants With Early Axial Spondyloarthritis (axSpA) Taking an Intense Treatment Approach Versus Routine Treatment — NCT02897115.
- Registry record last updated 2019-07-05; status last verified 2018-11.
- Results first posted 2019-07-05.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
19. Record Summary
STRIKE (NCT02897115) is a randomized, non-masked, parallel-group Phase 4 study comparing a treat-to-target approach with standard-of-care treatment for axial spondyloarthritis. The registry lists enrollment of 22, a start date of 2016-09-12, a primary completion date of 2017-12-21, and a terminated status.
The primary endpoint is the percentage with ASDAS inactive disease at Week 32, defined as ASDAS below 1.3 using CRP. The posted percentages are 80.0% for T2T and 0.0% for SOC, based on available endpoint data from 5 and 1 participants, respectively. No formal analysis is recorded. The registry does not report a confidence interval, p-value, missing-data method, reason for termination, or complete T2T treatment pathway.