A Post-Marketing-Observational Study (PMOS) to Determine the Effectiveness of Combined Adalimumab Treatment and Active Supervised Training in Patients With Axial Spondyloarthritis (axSpA): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for A Post-Marketing-Observational Study (PMOS) to Determine the Effectiveness of Combined Adalimumab Treatment and Active Supervised Training in Patients With Axial Spondyloarthritis (axSpA) (NCT03258814), a registered phase not stated study. The primary outcome is Change Form Baseline in Bath Ankylosing Spondylitis Metrology Index (BASMI) at Month 6.

2. Clinical Question

The central statistical question is therefore not whether the posted results establish a difference between AST and SOC. The registry record contains no analyses, and the primary endpoint was unavailable. It does not provide a Month 6 BASMI estimate for either group or a between-group estimate. The study also included secondary measures of function, health status and disease activity, but the record does not report analyses of those outcomes. The record describes the study as observational and non-confirmatory, so its intended comparison should not be read as a randomized efficacy test.

3. Trial Design

This was a post-marketing observational study of people with axial spondyloarthritis treated with adalimumab. Its brief description calls it non-interventional, longitudinal and non-confirmatory. The intended comparison was between active supervised training and standard-of-care physiotherapy, with spinal mobility as the primary focus. Participants in both groups were described as receiving adalimumab according to the local product label and local standard of care. The AST program was supervised and standardized; SOC physiotherapy was determined according to the physiotherapist’s discretion.

The study began on 2017-12-08, and the registry lists primary completion as 2018-09-14. Its status is TERMINATED, and enrollment was 17. The record states that early termination meant no participants had a Month 6 visit, so the primary endpoint could not be assessed. It does not report the reason for termination.

The registry identifies AST and SOC groups, as well as a “Not Randomized” group in the safety record. It explicitly cautions that this was not a randomized comparison and that the arms are not a like-for-like control comparison. How participants entered the groups, and whether the groups differed at baseline, is not reported in the registry record. No adjusted comparison or other analysis is reported. Consequently, the group labels alone do not establish that participants receiving the two physiotherapy approaches were comparable at the start or during follow-up.

The listed secondary outcomes include BASMI at Month 3, BASFI, ASAS Health Index, BASDAI, BASDAI 50 response, ASDAS, ASDAS inactive disease and ASDAS low disease activity. The registry lists 24 outcome measures overall, but reports no analyses. Details such as the intended analysis populations and the statistical 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.

Before assignment: An enrollment period of treatment initiation and response assessment for 3 to 5 months preceded Randomization. This study was terminated early due to slow enrollment. Up to study termination 17 patients met all inclusion and none of the exclusion criteria and were enrolled in the study. A total of 7 of these patients were randomized into the study.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: No participants had a Month 6 visit due to early study termination, hence the primary endpoint could not be assessed.

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: All randomized participants

6. Primary Endpoint

The registry lists the primary outcome as Change Form Baseline in Bath Ankylosing Spondylitis Metrology Index (BASMI) at Month 6, measured over Baseline and Month 6.

The primary endpoint was change from baseline in BASMI at Month 6. BASMI measures spinal mobility using five clinical measurements: cervical rotation, tragus-to-wall distance, lumbar side flexion, lumbar flexion measured using the modified Schober’s method, and intermalleolar distance. The total score ranges from 0 to 10. The registry describes the score as reflecting mild to moderate disease activity and functional ability in the spinal column, with higher scores indicating more severe limitation of movement due to ankylosing spondylitis.

A change-from-baseline endpoint compares a participant’s follow-up score with their starting score. As a general statistical interpretation, a lower score at follow-up would indicate less movement limitation on this scale, while the estimated change and its uncertainty would be needed to judge the size and precision of any observed pattern. The registry record does not report a Month 6 score, a change estimate, or a measure of uncertainty.

BASMI was selected to address the study’s stated primary objective: improvement in spinal mobility after the training program. Its five measurements cover several aspects of spinal and related movement rather than relying on a single clinical measurement. However, no Month 6 visits occurred because of early study termination, so the primary endpoint could not be assessed. The record therefore offers no observed primary-endpoint result to interpret.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes an observational, longitudinal, non-confirmatory study. Those terms are important to the statistical interpretation. Observational means the record does not describe a randomized assignment to AST or SOC. Longitudinal indicates that outcomes were intended to be followed over time, including a primary assessment at Month 6. Non-confirmatory signals that the study was not described as a confirmatory test. The registry does not report a detailed statistical analysis plan, so the intended methods beyond the outcome descriptions cannot be established from the record.

What would a change-from-baseline estimate represent?

The primary outcome is change from baseline in BASMI at Month 6. In general, change-from-baseline analysis uses a follow-up measurement in relation to a participant’s initial measurement. It can describe whether scores moved over time, and a comparison of changes can describe how those movements differed between groups. A meaningful report would identify the analyzed participants, the estimate of change, and the uncertainty around it. The registry reports none of those results for Month 6. Because no participants had a Month 6 visit, the primary endpoint could not be assessed at all.

In general, a confidence interval is a range of values compatible with an estimate under the assumptions of the statistical method. Its width conveys precision: a wider interval indicates greater uncertainty than a narrower interval. A p-value addresses compatibility between the observed data and a specified null hypothesis under a statistical model; it is not a measure of effect size or clinical importance. There is no primary outcome estimate, confidence interval or p-value reported in the registry record, so these tools cannot be used to characterize a Month 6 BASMI comparison.

Why does the observational design matter?

In a randomized comparison, random assignment is intended to balance measured and unmeasured characteristics between groups on average. This registry does not describe a randomized comparison and explicitly says that the arms are not a like-for-like control comparison. As a general statistical matter, differences between groups in an observational study can reflect participant characteristics or treatment decisions as well as the intervention itself. An adjusted analysis can sometimes address measured differences, but it cannot automatically remove bias from unmeasured factors. The registry does not report an adjusted analysis, the variables that might have been used for adjustment, or baseline group comparisons.

The intervention descriptions also differ in how the physiotherapy was delivered. AST is described as supervised and standardized; SOC was delivered according to the physiotherapist’s discretion. That distinction defines the intended approaches but does not establish that the groups had similar exposure, adherence or follow-up. Such information is not reported in the registry record.

What do the planning illustrations mean?

The registry includes assumptions for planning illustrations: a two-sided significance level of 0.05, equal allocation between the two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. These assumptions describe planning calculations, not the study’s own design or an observed analysis. The record does not report the study’s sample-size justification. A planning illustration is not observed power and cannot compensate for the missing Month 6 outcome. No numerical planning results are interpreted.

As a general statistical point, sample-size calculations depend on the effect size, variability, analysis method and other assumptions. If an assumed effect is smaller, a larger sample is generally required to detect it with the same target power, all else equal. Such calculations are prospective planning aids; they do not establish that an observed result is reliable or that a study was adequately powered. In this study, the primary endpoint was not assessed, so a power interpretation of an observed primary effect is not available.

How should multiple outcomes be viewed?

The registry lists 24 outcome measures and several secondary outcomes spanning mobility, function, health status and disease activity. In general, examining many outcomes raises multiplicity concerns: the more statistical tests performed, the greater the chance of at least one apparently unusual result under a collection of null hypotheses. Researchers may address this through prespecified outcome hierarchies or adjustment procedures. The registry does not report a multiplicity strategy, and it reports zero analyses. It is therefore not possible to determine whether any adjustment was intended or applied.

Likewise, general methods for incomplete follow-up may include analyses restricted to observed outcomes, imputation, or models using available repeated measurements. Each relies on assumptions about why data are missing and how missing outcomes relate to observed information. The record says there were no Month 6 visits and that the primary endpoint could not be assessed; it does not report an approach to missing data. No method should be inferred from the endpoint description alone.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 24 outcome measures, including the primary Month 6 BASMI endpoint and secondary measures of mobility, function, health status and disease activity. When many outcomes are assessed, multiplicity can affect how readily an apparently notable result arises by chance. As a general statistical point, possible approaches include prespecifying a hierarchy among outcomes or adjusting inference across tests. The registry does not report a multiplicity plan. Because it reports zero analyses, there are no reported outcome tests to evaluate for multiplicity adjustment.

Missing follow-up is especially consequential for the primary endpoint. The registry states that no participants had a Month 6 visit because of early study termination, and that BASMI at Month 6 could not be assessed. This is not simply a small amount of missing information within an otherwise reported Month 6 comparison: the record supplies no primary endpoint estimate. It does not report an imputation method, a model for incomplete repeated measurements, or another missing-data strategy. The reason for early termination is not reported in the registry record.

The analysis populations are also not reported in the registry record. No participant flow for outcome analyses, inclusion criteria for a particular analysis, or handling of participants without follow-up is described. The registry does not report interim analyses, a detailed statistical plan, or a sample-size justification. These absences limit assessment of how the planned outcomes would have been analyzed, but they do not establish that any particular method was or was not used outside the registry record.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

Most frequent non-serious adverse event terms

The safety record separates participants into AST, SOC physiotherapy and Not Randomized groups. Among those at risk, the registry reports 0 serious adverse events in AST (4 at risk), 0 in SOC (3 at risk), and 0 in Not Randomized (10 at risk). It reports 0 deaths in each of the three groups. Other adverse events are reported for 2 participants in AST, 2 in SOC and 1 in Not Randomized, with 4, 3 and 10 participants at risk in those respective groups.

These are descriptive counts, not evidence of a comparative safety effect. The groups are not described as a randomized, like-for-like comparison, and their sizes differ. The record does not provide serious adverse event terms; the list of top serious terms is empty. The other adverse event counts do not describe event severity, timing or relationship to treatment in this record. In general, an absence of reported serious events in a small study does not establish that no such events could occur. These safety figures should be read as the events recorded during the study, not as a definitive comparison between physiotherapy approaches.

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

The registry record establishes that the study was intended to compare active supervised training with standard-of-care physiotherapy among people with axial spondyloarthritis treated with adalimumab. It also establishes that the planned primary outcome was change from baseline in BASMI at Month 6. Because early termination meant no participants had a Month 6 visit, that primary outcome could not be assessed. No primary estimate or analysis is reported.

It follows that the posted results do not establish whether spinal mobility changed, how it changed, or whether change differed between AST and SOC. They do not show that the approaches were equivalent, that one was superior, or that either had no effect. Those conclusions would require outcome data and an analysis that are absent from the registry record. The same caution applies to the listed secondary outcomes: they are planned measures, not reported findings.

The design limits causal interpretation as well. The registry describes the study as non-interventional and explicitly states that the arms are not a like-for-like control comparison. As a general statistical point, even when observational studies report group differences, those differences may reflect factors other than the intervention. Here, there is no reported outcome comparison to interpret, and baseline comparability or adjustment is not described.

The safety record reports no serious adverse events and no deaths among participants at risk in the listed groups, alongside other adverse events. These are descriptive entries and do not resolve the missing primary outcome or establish comparative safety. Overall, the record documents the study question, planned measures, early termination and limited safety information, but it does not provide an analyzed answer to the primary clinical question.

13. Why This Trial Matters Statistically

This study matters statistically because it illustrates the difference between a planned endpoint and an analyzed result. BASMI at Month 6 was the primary measure, but the record states that no participants had a Month 6 visit after early study termination. Without that endpoint, there is no estimate to interpret, no precision to assess, and no basis for a statistical comparison of the two physiotherapy approaches on the primary question.

It also highlights why design labels are more than formal descriptions. The study was observational and non-confirmatory, and the registry warns that its groups are not a like-for-like control comparison. As a general statistical point, nonrandomized comparisons can be vulnerable to differences between groups that affect outcomes. The absence of reported baseline information and analyses means that readers cannot assess how such differences were handled.

The record lists a range of secondary outcomes and 24 outcome measures, yet reports zero analyses. This makes clear that an extensive outcome list is not itself evidence of findings. It also raises questions that a fuller statistical record would ordinarily help answer, including how multiple outcomes were prioritized and how incomplete follow-up would be handled. Those details are not reported in the registry record.

Finally, safety counts need to be interpreted in light of the small enrollment and the group-specific numbers at risk, without turning descriptive observations into comparative claims. The study’s value in the registry is therefore chiefly in documenting the intended question and the limits of the available results. It cannot support a conclusion about the planned Month 6 mobility comparison.

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 primary limitation is that the planned Month 6 BASMI endpoint could not be assessed: no participants had a Month 6 visit because of early study termination. The registry does not report the reason for termination. Consequently, the primary outcome has no reported estimate or analysis, and the record cannot answer the study’s main comparative question.

Enrollment was 17, and the registry reports no analyses of the primary or secondary outcomes. It does not describe an analysis population, participant flow for outcome assessments, or handling of missing data. Although secondary outcomes are listed, the record does not report results for them. Details of adherence, training exposure and follow-up before Month 6 are not reported in the registry record.

The registry describes the study as non-interventional and non-confirmatory, and cautions that the arms are not a like-for-like control comparison. Allocation details are not stated. Baseline characteristics and any adjustment for differences between groups are not reported, limiting assessment of comparability and potential confounding. The statistical analysis plan, multiplicity approach, interim analyses and sample-size justification are not reported in the registry record.

The safety record is descriptive and separates participants into AST, SOC and Not Randomized groups. It reports no serious adverse events or deaths, but the group sizes are limited and the record does not provide serious adverse event terms. These limitations mean that the available safety entries should not be treated as a precise comparative assessment. Taken together, the termination, unavailable primary endpoint, absence of analyses and observational design sharply constrain what can be concluded.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: A Post-Marketing-Observational Study (PMOS) to Determine the Effectiveness of Combined Adalimumab Treatment and Active Supervised Training in Patients With Axial Spondyloarthritis (axSpA) — NCT03258814.
• Registry record last updated 2019-10-02; status last verified 2019-08.
• Results first posted 2019-10-02.
• 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.

18. Record Summary

The registry record describes NCT03258814, a post-marketing observational study of active supervised training versus standard-of-care physiotherapy in people with axial spondyloarthritis treated with adalimumab. It was described as non-interventional, longitudinal and non-confirmatory. The sponsor was AbbVie; enrollment was 17. The study began on 2017-12-08, its primary completion date is listed as 2018-09-14, and its status is TERMINATED.

The primary endpoint was change from baseline in BASMI at Month 6. Early termination meant no participants had a Month 6 visit, so the endpoint could not be assessed. The record lists 24 outcome measures and reports zero analyses. It also includes descriptive adverse event counts by group, with no serious adverse events or deaths reported. The registry cautions that this was not a randomized comparison and that the arms are not a like-for-like control comparison.