Post-Marketing Use Of CT-P13 (Infliximab) For Standard Of Care Treatment Of Inflammatory Bowel Disease: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Post-Marketing Use Of CT-P13 (Infliximab) For Standard Of Care Treatment Of Inflammatory Bowel Disease (NCT02539368), a registered phase not stated study. The primary outcome is Disease Characteristics of Participants: Disease Duration.

2. Clinical Question

3. Trial Design

CONNECT-IBD (NCT02539368) is described as a post-marketing observational cohort study of people with inflammatory bowel disease treated in usual clinical practice in the United States. Its full title identifies a cohort of patients treated with CT-P13 in usual clinical practice. The brief description also includes people prescribed Remicade. The study is marked completed. The registry record lists a start date of 2015-04-22, a primary completion date of 2018-10-31, and enrollment of 2565. Because the study is observational, treatment was not assigned through a randomized comparison. The record does not state how treatment choices were made, and it explicitly cautions that allocation is not stated and that the arms are not a like-for-like control comparison. This matters when interpreting differences between treatment groups: patient characteristics, clinical decisions, prior treatment, or switching may differ across groups. The record does not provide enough information to determine how such differences were handled analytically. The listed treatment groups are CT-P13, Remicade, switched from Remicade to CT-P13, switched from CT-P13 to Remicade, and multiple switchers. These categories reflect different treatment histories and should not be treated as interchangeable randomized arms. The registry description states objectives concerning treatment use, long-term safety, and effectiveness for Crohn's disease and ulcerative colitis. The primary outcome is disease duration measured at baseline. Other listed outcomes include clinical remission or relapse and disease activity measures for Crohn's disease and ulcerative colitis, as well as Crohn's disease classifications. The record lists 23 outcome measures and 0 analyses. Detailed recruitment procedures, follow-up schedules, treatment-selection criteria, and analysis methods 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: A total of 2565 participants were enrolled in the study, out of which 22 participants were not eligible to receive treatment for any of the treatment groups. Hence, only those participants who received treatment during the study observation period were included in the participants flow section.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Safety analysis population included all participants who received at least 1 dose of study drug during the observation period. Here, 'Overall number of participants analyzed' signifies number of participants evaluable for this outcome measure.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

Population: Safety analysis population included all participants who received at least 1 dose of study drug during the observation period.

6. Primary Endpoint

The registry lists the primary outcome as Disease Characteristics of Participants: Disease Duration, measured over Baseline (Day 1).

The primary outcome is disease duration, defined as the number of months from the initial diagnosis of inflammatory bowel disease, either Crohn's disease or ulcerative colitis, to the date of informed consent recorded at enrollment. It is measured at baseline (Day 1), and the planned summary is the median with the full range. The outcome is intended to describe how long participants had been living with their diagnosed disease when they entered the study. A median is a measure of the center of a distribution: it identifies the middle observation after values are ordered. It can be useful when a distribution is skewed or includes unusually low or high values, because extreme observations have less influence on the median than on the arithmetic mean. The full range describes the smallest and largest observed values, but does not show how values are distributed between those endpoints. These are general properties of the statistics, not claims about the actual distribution in this study. Disease duration is a baseline characteristic, not a measure of change after treatment or a comparison of treatment effectiveness. It can help characterize the participants and provide context for understanding the study population. The median, range, and number of participants evaluable for this outcome are not reported in the registry record, so the observed distribution and its precision cannot be assessed from the posted information.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the primary outcome summarize?

The primary outcome is a median, with the full range, for disease duration at baseline. In general, a median is the value at the center of an ordered set of observations. It is less affected by extreme observations than a mean, which can make it a useful summary when values are asymmetric. The full range gives the lowest and highest observed values, but it does not indicate whether most participants had values near the center or near either endpoint. The registry record defines disease duration as months from initial diagnosis to informed consent recorded at enrollment. It does not report the observed median, range, or evaluable count.

Why does the observational design matter?

In a randomized study, allocation by chance is intended to make treatment groups comparable, on average, with respect to measured and unmeasured characteristics. In an observational study, treatment is not allocated by randomization. In general, clinical and patient factors may influence which treatment is received, and those same factors may relate to outcomes. This is a potential source of confounding. The registry record states that allocation is not stated and that the groups are not a like-for-like control comparison. It does not report a statistical adjustment plan that would allow readers to assess how confounding was addressed.

The treatment categories also include switching histories. A group defined by switching from one treatment to another differs in its treatment history from a group listed simply as CT-P13 or Remicade. Such categories can be informative for describing real-world use, but they do not by themselves identify a causal effect of switching. The reasons for switching and the timing of treatment changes are not reported in the registry record.

How should estimates and uncertainty be read?

In general, an estimate describes a quantity calculated from the observed study data. A confidence interval describes a range of values compatible with the data under the statistical model and its assumptions. A wider interval indicates less precision than a narrower interval, although interval width alone does not establish whether a result is clinically important. No confidence interval for the primary outcome is reported in the registry record. The median and full range are also absent, so neither the central value nor its spread can be assessed.

For time-to-event outcomes, a hazard ratio is a relative comparison of event hazards over follow-up under the model used to estimate it. It is not the same as a difference in cumulative event probabilities. The registry entries identify a time-to-event type and state that only sponsor-reported hazard ratios are used, but no such estimates are included in the results available for interpretation. No hazard ratio should therefore be inferred from the adverse-event counts.

What do the planning illustrations mean?

The record describes sample-size illustrations based on the observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The illustrations consider the effect to detect as a stated fraction of the observed effect. For time-to-event calculations, the stated quantity is the total number of events; for other calculations, it is participants per arm. These are planning illustrations, not observed study findings and not the study's own design justification. The numerical illustration results and the observed effect they rely on are not reported in the registry record. Such calculations are not observed power and do not show the probability that the completed study found an effect.

In general, a sample-size calculation asks how much information a proposed design would need to detect a specified effect under stated assumptions. Its result depends on those assumptions, including the size of the effect the calculation aims to detect. If the assumed effect is smaller, more information is generally needed to distinguish it from random variation. An illustration based on an observed effect is not a substitute for a documented prospective design rationale. The registry record does not report a sample-size justification for the study itself.

Why can event counts be hard to compare?

Counts of participants affected by an event are not rates unless the relevant time at risk and denominator are accounted for. In general, people observed for different lengths of time have different opportunities for events to be recorded. A raw count also does not adjust for group differences in baseline health, treatment history, or other factors. The registry lists group-specific numbers at risk and affected, but the information available does not establish a common observation period or an adjusted comparison. The counts should therefore be read descriptively, not as a treatment contrast.

Over-dispersion is a general issue in count data: the observed variability can exceed what a simple model assumes. When that happens, standard errors from an overly restrictive model can be too small, making intervals appear more precise than warranted. The registry record does not identify a count-data model or report whether over-dispersion was assessed. This is a general methodological consideration, not a claim that over-dispersion occurred in CONNECT-IBD.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 23 outcome measures, including outcomes related to clinical remission, relapse, disease activity, and Crohn's disease classification. It lists 0 analyses. The available record does not explain which outcomes were tested, whether any were designated secondary or exploratory in the analysis, or how multiple comparisons were handled. A multiplicity strategy, such as adjusting significance thresholds or prioritizing a prespecified outcome hierarchy, is not reported in the registry record. Multiplicity matters because examining many outcomes can increase the chance that some results appear noteworthy through random variation alone. This general concern does not establish that any reported finding is false; it means that interpretation depends on knowing which analyses were planned and how they were handled. The record does not provide enough information to determine the implications for this study. Missing-data methods are not reported in the registry record. The record does not explain how missing baseline measures, incomplete follow-up, or participants with unavailable outcome assessments were handled. It also does not describe imputation, sensitivity analyses, or assumptions about why data might be missing. Without those details, the effect of missing observations on the reported outcome summaries cannot be assessed. The primary outcome description defines a safety analysis population as participants who received at least 1 dose during the observation period and says that the overall number analyzed means the number evaluable for that outcome. The evaluable count for disease duration is not reported. The record does not provide further detail on analysis populations for the listed outcomes, nor does it explain whether populations differed by outcome. These omissions limit assessment of how much of the enrolled cohort contributed to each result.

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 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: crohn's disease (3.0%), hypersensitivity (3.0%), colitis (1.5%), diverticulitis (1.5%), gastroenteritis (1.5%).

The registry lists serious adverse event counts by treatment group. For CT-P13, 256 of 1522 participants at risk were affected; for Remicade, 43 of 494; for participants switched from Remicade to CT-P13, 57 of 358; for participants switched from CT-P13 to Remicade, 10 of 67; and for multiple switchers, 15 of 102. The record also lists other adverse events: 442 of 1522, 100 of 494, 90 of 358, 7 of 67, and 21 of 102, respectively. Death counts are 4, 2, 1, 0, and 0 in the same group order. These are descriptive counts, not adjusted comparisons. The categories have different sizes and treatment histories, and the record does not report person-time or an adjusted analysis for these figures. A count of affected participants should not be treated as a rate or as evidence that treatment caused an event. The registry lists Crohn's disease and hypersensitivity at 3.0% each among the leading serious adverse event terms, and colitis, diverticulitis, gastroenteritis, and hepatitis C at 1.5% each. The denominator and further details for these term percentages are not reported in the registry record. The posted information does not support a like-for-like safety ranking.

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

The study addresses CT-P13 use in routine care for people with Crohn's disease or ulcerative colitis and places that use in the context of Remicade treatment. Its observational design is relevant to the interpretation: the treatment groups were not created by stated random allocation, and the record cautions that they are not a like-for-like control comparison. Descriptive results can characterize who was studied and which events were recorded, but they cannot on their own establish that treatment caused an outcome or explain differences between groups. The primary outcome, disease duration at baseline, describes the time from diagnosis to enrollment. It is not a measure of treatment response. The outcome definition is available, but the median, full range, and evaluable count are not reported in the registry record. As a result, readers cannot assess the observed baseline distribution from the information available. The record states that the study aimed to assess effectiveness and explore long-term safety. Those aims should be distinguished from results. The listed effectiveness-related outcomes include remission or relapse and measures of disease activity, but the numerical findings and analysis details needed to interpret treatment effects are not reported in the information. The safety counts provide a descriptive account by treatment category, but lack the time-at-risk and adjustment information needed for a comparative interpretation. The registry entry therefore contributes information about the study question, its observational structure, the defined baseline outcome, and selected adverse-event counts. It does not establish comparative effectiveness, prove equivalence between treatments, or establish that one treatment is safer than another. Those conclusions would require results and analytic details not reported in the registry record.

13. Why This Trial Matters Statistically

Observational studies can describe how treatments are used in usual clinical practice and can include participants whose treatment histories are not represented by a simple randomized contrast. CONNECT-IBD is framed as a post-marketing cohort study involving people with Crohn's disease or ulcerative colitis treated with CT-P13 or Remicade. Its objectives include describing treatment use, exploring long-term safety, and assessing effectiveness. Those questions are relevant to understanding treatment in routine care, while the observational design requires care in distinguishing description from causal comparison. Statistically, the record illustrates the importance of matching an endpoint to the question being asked. Disease duration at baseline characterizes the population; it does not estimate a treatment effect. The listed adverse-event counts describe affected participants by treatment category, but raw counts do not account for differences in time at risk or group composition. The record's explicit warning that the arms are not a like-for-like control comparison is central to interpretation. The entry also shows why outcome definitions and numerical results must be considered together. A clear definition specifies what a measure is intended to capture, but without its observed value and evaluable count, readers cannot assess its distribution or precision. Likewise, a list of outcomes and stated study objectives does not replace reported analyses. The registry lists 23 outcome measures and 0 analyses, leaving important details about statistical methods and results unreported in the registry record. The study's statistical value is therefore best understood through its design and reporting context: it identifies a real-world observational question and provides some descriptive safety information, while also illustrating the limits of drawing treatment comparisons from non-randomized groups without fuller outcome and analysis reporting.

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 registry record does not report the primary outcome's median, full range, or evaluable count. Although the definition and baseline timing are stated, the observed disease-duration distribution cannot be interpreted. The record also lists 23 outcome measures and 0 analyses, and does not include the numerical effectiveness results or statistical analysis details needed to evaluate those objectives. The study is observational, allocation is not stated, and the record explicitly says the arms are not a like-for-like control comparison. The listed categories include groups with different switching histories. Reasons for treatment selection or switching, group comparability, and methods for controlling confounding are not reported in the registry record. This prevents a confident causal interpretation of differences between groups. For safety, the record provides counts of participants at risk and affected, along with deaths and selected serious adverse event terms. It does not report event rates adjusted for time at risk, the details needed to assess the term percentages, or an adjusted comparison. The counts are therefore limited as evidence for relative safety. Further limitations include the absence of reported methods for missing data, outcome-specific analysis populations, multiplicity, and sample-size justification. The record describes planning illustrations, but their numerical results and underlying observed effect are not reported in the registry record. It also does not report detailed follow-up schedules or event ascertainment methods. These gaps limit assessment of precision, bias, and the extent to which the posted results answer the stated study objectives.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Post-Marketing Use Of CT-P13 (Infliximab) For Standard Of Care Treatment Of Inflammatory Bowel Disease — NCT02539368.
• Registry record last updated 2020-02-13; status last verified 2020-01.
• Results first posted 2020-02-13.
• 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

CONNECT-IBD (NCT02539368) is a completed post-marketing observational cohort study of CT-P13 and Remicade use in Crohn's disease and ulcerative colitis. The registry lists enrollment of 2565, a start date of 2015-04-22, and primary completion on 2018-10-31. Treatment categories include CT-P13, Remicade, and groups defined by switching between them. The record states that allocation is not stated and the groups are not a like-for-like control comparison. The primary outcome is median disease duration at baseline, defined from initial diagnosis to informed consent, with full range as the dispersion measure. Its result and evaluable count are not reported in the registry record. The record lists 23 outcome measures and 0 analyses. It includes descriptive adverse-event counts by group, but these do not establish comparative safety or causation. Missing-data methods, multiplicity handling, and detailed analysis methods are not reported in the registry record.