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 Cost Utility Analyses of Adalimumab Treatment in Patients With Rheumatoid Arthritis (RA) (NCT01078116), a registered phase not stated study. The primary outcome is Estimation of the Direct and Indirect Cost Incurred by Adalimumab Treatment.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01078116 |
| Phase | Phase not stated |
| Condition | Rheumatoid Arthritis |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 124 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Abbott |
| Results posted | Yes |
2. Clinical Question
Population
People with rheumatoid arthritis who were eligible for treatment with adalimumab. The registry describes an enrollment of 124 participants and says the cost analysis is based on the number completing assessments at each visit. Further details about eligibility criteria and the characteristics of participants are not reported in the registry record.
Intervention
Adalimumab treatment according to the approved Summary of Product Characteristics in the European Union. The study assessed costs before and after treatment initiation and also aimed to evaluate health-related quality of life. Treatment duration, adherence, dose, and any treatment changes are not reported in the registry record.
Comparator
No separate comparison group is described. The registry lists a single group of patients receiving adalimumab, with baseline observations before treatment initiation and later observations after initiation. Allocation is not stated, and the study is not a randomized comparison.
Primary question
How do direct and indirect costs associated with rheumatoid arthritis and its management compare between the baseline period before adalimumab initiation and subsequent assessments? The primary measure is mean cost in Euros, with standard deviation. The study also aimed to assess health-related quality of life and explore the relationship between costs and quality of life, but numerical results for these aims are not reported in the registry record.
The clinical question is framed around changes within a treated group, not around a randomized comparison of adalimumab with another treatment or with no treatment. Baseline costs cover the three-month period before treatment began. Later cost assessments were scheduled at month 3, month 6, and month 12. This before-and-after structure can describe how costs recorded in the same study population change over time, but by itself it cannot separate treatment-related change from other changes occurring over that period.
The registry’s stated broader rationale is that health-related quality of life and costs may give complementary perspectives on rheumatoid arthritis and its management. Cost information includes direct expenses and indirect costs attributed to loss of income due to disability. The primary endpoint described in the record is the cost measure; a formal primary endpoint for health-related quality of life is not reported in the registry record.
3. Trial Design
This completed study enrolled 124 participants with rheumatoid arthritis. The registry identifies a single group, titled Patients with Rheumatoid Arthritis, whose members received adalimumab according to the approved Summary of Product Characteristics in the European Union. A separate untreated or active-comparator arm is not described. Allocation is not stated, and the record explicitly identifies the study as not being a randomized comparison.
The schedule used an enrollment visit as baseline, before treatment initiation, followed by assessments at month 3, month 6, and month 12. Baseline costs refer to the three-month period before adalimumab began; the later assessments concern costs after initiation. The registry describes collection of health-related quality-of-life and cost information over a one-year period. The study began in 2007-11, reached primary completion in 2010-06, and is listed as completed.
The primary outcome is a continuous measure: mean direct and indirect per-participant cost in Euros, with standard deviation. The analysis population is described as participants completing assessments at each visit. This wording makes the available participants for a visit dependent on completing that assessment; the number assessed at each visit is not reported in the registry record.
The registry lists five outcome measures, but it does not report an analysis for any of them. The statistical analysis plan, the methods used to compare visits, and any adjustment for participant characteristics are not reported in the registry record. The study’s design therefore supports a description of repeated assessments in a treated cohort, but the record does not supply a statistical basis for a causal comparison or a numerical estimate of change in costs.
Other design details that would help interpret a longitudinal study are also not reported in the registry record. These include the eligibility criteria beyond the treatment description, the recruitment process, the number completing each assessment, handling of treatment discontinuation, and whether assessments were conducted consistently across participants. Without those details, the record gives the broad schedule and purpose but not a complete account of how the planned observations were obtained and analyzed.
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 | Adalimumab Treatment |
|---|---|
| STARTED | 124 |
| COMPLETED | 76 |
| NOT COMPLETED | 48 |
Reasons for not completing this period:
| Reason | Adalimumab Treatment |
|---|---|
| Lost to Follow-up | 17 |
| Adverse Event | 5 |
| Withdrawal by Subject | 8 |
| Lack of effectiveness | 15 |
| Case report form not completed | 3 |
Analysis population for the primary outcome, as defined in the registry: Analysis is based on the number of participants completing the assessments at each visit.
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 | Adalimumab Treatment |
|---|---|---|
| Participants analysed | 121 | |
| Age Continuous | years | 56.2 (SD 12.9) |
| Sex: Female, Male: Female | Participants | 100 |
| Sex: Female, Male: Male | Participants | 21 |
| Region of Enrollment: Greece | participants | 121 |
6. Primary Endpoint
The registry lists the primary outcome as Estimation of the Direct and Indirect Cost Incurred by Adalimumab Treatment, measured over Enrollment visit (Baseline), month 3, month 6, month 12.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | Euros |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the estimated mean direct and indirect cost per participant, expressed in Euros. Direct costs cover pharmaceutical costs; diagnostic and monitoring tests; hospitalization; rheumatologist and social insurance rheumatologist costs; other specialists; physiotherapy; rehabilitation; home care; equipment; and transportation. Indirect costs refer to loss of income due to rheumatoid arthritis disability. The registry states that mean and standard deviation are the summary measures.
Costs are assessed at baseline and at month 3, month 6, and month 12. Baseline represents the three-month period before treatment initiation, while later assessments follow initiation. This structure permits the study to describe costs over time within the treated cohort. The standard deviation describes the spread of individual cost observations around the mean; it is not a measure of how precisely the mean has been estimated.
Cost measurement is relevant to the stated study objective because treatment-related pharmaceutical costs are only one part of the overall economic picture. Other direct costs and income loss may also contribute to the recorded burden. Combining cost information with health-related quality of life was intended to support an exploration of cost utility. However, a formal cost-utility method, including the health-related quality-of-life instrument, utility calculation, and time horizon for that calculation, is not reported in the registry record.
No numerical means, standard deviations, confidence intervals, or visit-to-visit comparisons for this endpoint are reported in the registry record. Consequently, the endpoint’s definition can be described, but the magnitude and precision of any cost change cannot be assessed from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record defines a clinically and economically relevant measurement plan, but it does not report numerical results for the primary cost endpoint. It describes mean direct and indirect per-participant costs in Euros at baseline, month 3, month 6, and month 12, with standard deviations. There are no reported visit-specific means or standard deviations, no estimated change from baseline, and no confidence interval or test result. The record therefore does not establish the direction, size, or precision of any observed cost change.
The enrollment of 124 participants is not the same as the number contributing data at every assessment. The record says that each visit’s analysis is based on participants completing that assessment, but does not report visit-specific counts. Without those counts, the extent of missing assessment data and the number of observations underlying any eventual summary cannot be evaluated. The number completing each visit is not reported in the registry record.
The single-group structure also limits what a before-and-after pattern could establish. Even if cost summaries were available, a change between baseline and follow-up would describe the experience of the treated cohort over time. Without a concurrent comparison group, it would not by itself distinguish changes associated with treatment from changes related to the course of rheumatoid arthritis, other care, or other circumstances. This is a general limitation of uncontrolled before-and-after comparisons, not a finding about what happened to participants in this study.
The registry lists five outcome measures but reports zero analyses. It does not give estimates, uncertainty intervals, statistical tests, or the methods used to compare measurements across visits. It also does not report a statistical analysis plan, a sample-size justification, or interim analyses. These omissions prevent an assessment of whether the intended comparisons were conducted as planned or how much uncertainty surrounds any result.
The study’s stated aims include health-related quality of life and an exploration of cost utility, in addition to costs. The primary outcome description focuses on costs. Numerical health-related quality-of-life results and a defined cost-utility estimate are not reported in the registry record. As a result, the economic objective is evident, but the relative value of costs and health outcomes cannot be evaluated from the registry information.
Safety figures are reported separately: 3 participants were affected by serious adverse events among 124 at risk, and 2 were affected by other adverse events among 124 at risk. The record also lists three leading serious-event terms, each at 0.8%. These counts describe the recorded safety data; they do not provide a comparison with another group. The death count is not reported in the registry record. No causal conclusion about treatment can be drawn from these figures alone.
Overall, the posted information is sufficient to identify the study’s question, setting, outcome definition, visit schedule, and broad design. It is not sufficient to determine the observed cost pattern, quantify uncertainty, assess the completeness of follow-up, or estimate a treatment effect relative to a comparator. Those distinctions matter when interpreting a registry entry that contains study objectives but no posted analyses.
9. Statistical Methods Explained
The primary measure is a continuous outcome: cost per participant. For a continuous outcome, a mean gives the arithmetic average across the participants whose observations are included, while the standard deviation describes how dispersed those observations are. These summaries answer different questions. The mean describes the center of the observed cost distribution; the standard deviation describes variation among participants. Neither measure is reported numerically for this study in the registry record.
What would a visit comparison mean?
Because the same treated group was scheduled for baseline and follow-up assessments, a natural descriptive question is how the recorded mean costs differ across visits. A comparison of measurements from the same participant can account for the fact that repeated observations from that person are related. In general, an analysis of repeated measurements should make clear whether it compares within-participant changes, visit-specific averages, or both. The registry record does not report which approach was used.
Baseline is not an untreated comparison arm observed throughout the study. It is a measurement period before treatment initiation, and the later assessments occur after initiation. A within-group comparison can describe temporal change, but does not by itself provide the counterfactual comparison needed to determine what would have happened over the same period without the treatment. This is a general point about causal interpretation of uncontrolled before-and-after data.
How should a confidence interval be read?
In general, a confidence interval is a range of values compatible with the observed data under a specified statistical model and procedure. It communicates estimation uncertainty; it is not a range containing a fixed proportion of individual participants’ costs. A narrow interval generally indicates greater precision for the estimated quantity, while a wide interval indicates less precision. No confidence interval for the cost endpoint is reported in the registry record, so its precision cannot be assessed.
A p-value, when used, summarizes how unusual the data would be under a stated null hypothesis and assumptions. It does not measure the size or practical importance of a cost difference, and it does not establish causation. The registry record reports no p-values or hypothesis tests for the outcomes. It also does not state whether comparisons were prespecified or which hypotheses were primary for any outcome other than the stated cost endpoint.
Why can cost data need careful modeling?
As a general statistical matter, cost observations can be highly variable and may be concentrated at lower values with a smaller number of much larger costs. In such circumstances, the mean can be influenced by relatively costly observations, and model assumptions deserve scrutiny. Over-dispersion means that observed variability exceeds what a chosen model expects. If ignored, it can make uncertainty estimates unreliable. These are general considerations for cost analyses; the registry does not report the observed distribution of costs or a model used for this study.
Standard deviation is a descriptive measure of participant-level variability, not a substitute for a confidence interval around the mean. For a mean estimate, precision also depends on the amount of information in the analysis, including how many participants contributed and the variability in their costs. Since visit-specific participant counts and cost summaries are not reported, no assessment of the study’s precision is possible from the registry record.
What do the planning illustrations represent?
The posted planning illustrations are described as calculations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. They use a stated fraction of the observed effect as the effect to detect. These are planning assumptions, not evidence that the study itself randomized participants between two arms. The registry describes one treated group and no like-for-like control comparison.
Such calculations can illustrate how a hypothetical future comparison might be sized under chosen assumptions. They are not observed power, and they do not demonstrate that the completed study had a particular probability of detecting an effect. The record does not report a sample-size justification for the trial’s own design. The effect estimates and numerical planning results are not reported in the registry record, so no particular planning estimate can be interpreted from the registry description alone.
For time-to-event outcomes, planning calculations may use event counts; for other outcomes, they may use participant counts per arm. That general distinction does not change the design actually described for this study. The primary outcome is a continuous cost measure, and the record does not describe a randomized two-arm comparison. Planning outputs based on hypothetical assumptions should therefore remain separate from the study’s observed findings, which are not numerically reported.
What can be said about cost utility?
In general, cost-utility analysis combines costs with a measure of health-related utility over time, often to express the trade-off between resource use and health outcomes. Such an analysis requires clear definitions of the health measure, the method for assigning utility, the time horizon, and the approach to combining costs and outcomes. The registry states an aim to explore cost utility by combining health-related quality of life with direct and indirect costs, but does not describe those calculation methods. A numerical cost-utility result is not reported in the registry record.
These methods concepts explain what would be needed to interpret estimates, not what analyses were performed in this study. The registry record does not report the statistical model, handling of skewness, uncertainty method, covariate adjustment, or any sensitivity analyses. Accordingly, the definitions and general principles cannot be taken as evidence that a particular statistical procedure was used.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists five outcome measures and reports zero analyses. It does not describe how multiple outcomes or repeated visit comparisons were handled. When several outcomes or comparisons are examined, the chance of at least one apparently notable result can increase; multiplicity procedures are sometimes used to manage that issue. This is a general statistical consideration. Whether any adjustment was planned or applied is not reported in the registry record.
The primary outcome description specifies cost estimates at baseline, month 3, month 6, and month 12. The analysis population is described as participants completing assessments at each visit. However, the number contributing at each visit, the amount and pattern of missing data, and reasons for missing assessments are not reported in the registry record. The record does not state whether missing values were excluded, imputed, or addressed with another method.
Using completers at each assessment can mean that the participants contributing to one visit’s summary differ from those contributing to another visit’s summary. If completion is related to participant characteristics or costs, the observed visit summaries may not represent the same underlying group in the same way. This is a general concern; the record does not provide information to assess whether it occurred in this study.
The registry does not describe analysis populations beyond the statement about participants completing each visit’s assessment. It does not report an intention-to-treat analysis, a per-protocol analysis, rules for handling treatment discontinuation, or a plan for participants with incomplete cost components. Methods for missing data, multiplicity, and analysis populations are therefore not reported in the registry record.
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 |
|---|---|---|---|
| Adalimumab Treatment | 3 | 124 | 2.4% |
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 |
|---|---|
| Adalimumab Treatment | 2 of 124 |
Most frequent serious adverse event terms
| Event term | Organ system | Adalimumab Treatment |
|---|---|---|
| Acute Myocardial Infarction/Coronary Artery Bypass Graft | Cardiac disorders | 1 of 124 |
| Muscular weakness | Musculoskeletal and connective tissue disorders | 1 of 124 |
| Cellulitis | Skin and subcutaneous tissue disorders | 1 of 124 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Adalimumab Treatment |
|---|---|---|
| Rash muculo-papular | Skin and subcutaneous tissue disorders | 1 of 124 |
| Hypersensitivity | Immune system disorders | 1 of 124 |
Serious events with the highest arm-level rate: acute myocardial infarction/coronary artery bypass graft (0.8%), muscular weakness (0.8%), cellulitis (0.8%).
The registry reports 3 participants affected by serious adverse events among 124 at risk in the adalimumab treatment group. It reports 2 participants affected by other adverse events among 124 at risk. These are the posted counts; they should not be interpreted as comparative estimates because the registry describes no separate control group.
The serious adverse event terms listed as the leading terms are Acute Myocardial Infarction/Coronary Artery Bypass Graft, Muscular weakness, and Cellulitis. Each term is reported at 0.8%. The record does not explain whether event terms could overlap within a participant, so the terms should not be added together or treated as necessarily representing distinct people.
The death field has no reported count. A missing count is not evidence that no deaths occurred. The death count is not reported in the registry record. The safety figures also do not provide event timing, severity details beyond the serious-event classification, relatedness assessments, or a comparison against background rates. Those details are not reported in the registry record.
Adverse-event counts describe what was recorded in the study; they do not establish that treatment caused an event or that an event was unrelated to treatment. With no comparison group and no additional event-level context, these figures are descriptive rather than comparative evidence.
12. What the Result Does, and Does Not, Mean
The record establishes that the study was designed to examine costs around adalimumab initiation in people with rheumatoid arthritis, with assessments at baseline, month 3, month 6, and month 12. It identifies mean direct and indirect cost in Euros as the primary measure and specifies standard deviation as the dispersion measure. It also describes an aim to assess health-related quality of life and explore cost utility.
What the record does not establish is the actual pattern of costs. It contains no numerical cost means or standard deviations, no estimated changes, and no interval estimates for precision. The registry lists five outcomes but reports zero analyses. Numerical results for health-related quality of life and cost utility are not reported in the registry record. It is therefore not possible to state whether costs increased, decreased, or stayed similar, or to quantify the uncertainty around any such pattern.
The single-group design means that even a reported change over time would not, by itself, isolate an effect of adalimumab. In general, a concurrent comparator can help account for changes that would occur over time irrespective of the treatment being studied. No such comparator is described. This limitation concerns the design’s capacity for causal interpretation and does not imply any particular direction or size of change.
The enrollment count of 124 should not be read as the number analyzed at every assessment. The registry defines the analysis population by assessment completion but does not report visit-specific counts or missing-data methods. That leaves uncertainty about how much follow-up information was available and whether the people contributing at each visit were comparable.
The posted adverse-event counts provide descriptive safety information for the treated group, including 3 participants affected by serious adverse events and 2 affected by other adverse events, each among 124 at risk. They do not provide a comparative risk estimate. The death count is not reported in the registry record.
In short, the registry describes the question, population, treatment context, measurement schedule, and endpoint definition. It does not report enough numerical or analytical information to support a conclusion about cost changes, health-related quality of life, cost utility, or comparative treatment effects.
13. Why This Trial Matters Statistically
This study is statistically notable because it treats rheumatoid arthritis management as both a health-outcome and resource-use question. Its stated objective goes beyond recording pharmaceutical expense: direct costs include multiple forms of medical and support care, while indirect costs concern lost income attributed to disability. Considering these categories together can make an economic assessment broader than a medication-cost summary alone.
The repeated schedule provides a framework for examining costs before and after treatment initiation. The baseline period is defined as the three months before initiation, and follow-up assessments were planned at month 3, month 6, and month 12. Repeated measurements can describe how outcomes evolve within participants, but interpretation depends on consistent measurement, adequate follow-up, and an analysis that accounts for within-person dependence. The registry does not report the analysis used.
The study also illustrates why a well-defined objective is not the same as a reported result. The record specifies the cost endpoint and its units and summary measures, yet provides no numerical cost estimates or analyses. Without those, readers cannot assess magnitude, precision, or whether the data support a cost-utility conclusion. This distinction is important for registry interpretation: plans and objectives identify what investigators intended to study, while results require estimates and methods.
Finally, the single treated group underscores the difference between longitudinal description and comparative inference. A before-and-after pattern can be informative about observed experience, but it cannot alone show what would have happened under another treatment or without treatment. The study’s economic question is important, while the registry record’s missing analyses and comparator information limit what can be concluded statistically.
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.
Several limitations specific to this study follow from the design and the detail available in the registry. The record describes a single group of participants receiving adalimumab, with no separate comparator. Allocation is not stated, and the study is not a randomized comparison. Consequently, the planned baseline-to-follow-up observations do not create a controlled estimate of treatment effect.
The primary endpoint aggregates diverse cost categories, from pharmaceuticals and hospitalization to transportation and income loss due to disability. The registry defines these components but does not provide their individual contributions, costing procedures, or rules for handling incomplete cost information. It is therefore not possible to determine which components dominate the mean or whether cost collection was comparable across visits.
The analysis is based on participants completing assessments at each visit, but the number completing each assessment is not reported. The record also does not describe reasons for non-completion or how missing measurements were handled. This limits assessment of attrition and of whether visit-specific estimates represent a consistent cohort.
Although health-related quality of life and cost utility are stated aims, the record does not identify the instrument, utility derivation, or calculation method. It also does not report numerical results for either aim. The primary cost measure alone cannot establish a cost-utility result.
The registry reports zero analyses, so statistical methods, estimates, uncertainty, multiplicity handling, and sensitivity analyses are not available. A sample-size justification, interim analyses, and a detailed statistical analysis plan are not reported in the registry record. These limitations concern the information available for interpretation; they do not establish that no analyses or methods existed outside the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Cost Utility Analyses of Adalimumab Treatment in Patients With Rheumatoid Arthritis (RA) — NCT01078116.
- Registry record last updated 2011-08-11; status last verified 2011-08.
- Results first posted 2011-07-25.
- 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 a completed study of adalimumab treatment in rheumatoid arthritis, sponsored by Abbott, with enrollment of 124 participants. It lists one treated group and a schedule of baseline, month 3, month 6, and month 12 assessments. Baseline costs cover the three-month period before treatment initiation.
The primary measure is mean direct and indirect per-participant cost in Euros, with standard deviation. Direct costs span medical, support, and transportation categories; indirect costs refer to loss of income due to rheumatoid arthritis disability. The study also aimed to assess health-related quality of life and explore cost utility.
Numerical cost outcomes and statistical analyses are not reported in the registry record. The record lists five outcome measures and zero analyses. Serious adverse events affected 3 of 124 participants at risk; other adverse events affected 2 of 124. The death count is not reported in the registry record. No separate comparison group is described.