Patient Convenience Study (RE-SONANCE): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Patient Convenience Study (RE-SONANCE) (NCT02684981), a registered phase not stated study. The primary outcome is Convenience PACT-Q2 Scores at Second and Last Assessment Between Treatment Groups.

2. Clinical Question

The study focused on patients’ perceptions of anticoagulant treatment rather than on a randomized comparison of clinical efficacy. Its stated purpose was to describe treatment perception and convenience among people receiving Pradaxa for stroke and systemic embolism prevention, alongside treatment with a vitamin K antagonist. That distinction matters: an observational description can characterize recorded experiences, but it cannot by itself establish that differences in experience were caused by the treatment rather than by patient characteristics, treatment history, or other factors.

The two cohorts also represent different treatment pathways. Cohort A consisted of existing vitamin K antagonist users who switched to Pradaxa. Cohort B consisted of newly diagnosed patients treated with either option. Those populations should not automatically be treated as interchangeable. In particular, the switch cohort does not provide a like-for-like control comparison, and allocation is not stated as randomized in the registry record.

3. Trial Design

RE-SONANCE is registered as a non-interventional study, not as a randomized controlled trial. The registry lists an enrollment of 9472 and a completed status. The study began on 2015-11-11, and its primary completion date was 2017-06-01. The sponsor was Boehringer Ingelheim. These record details describe the study’s scale and registration history, but do not establish how participants were recruited, how long each person was followed, or how treatment decisions were made.

The design includes two distinct cohorts. Cohort A consisted of patients with non-valvular atrial fibrillation already receiving a vitamin K antagonist who switched to Pradaxa. Cohort B consisted of newly diagnosed patients treated with Pradaxa or a vitamin K antagonist, with the registry describing a 1:1 treatment allocation within that cohort. The record does not state that this allocation was randomized. A planned balance between treatment groups is not equivalent to random assignment, so measured and unmeasured differences between groups may remain.

The primary outcome was PACT-Q2 convenience and satisfaction, assessed after treatment was ongoing. The registry describes assessments from Day 30 up to Day 210 and identifies the second and last assessments for between-group comparison. It also describes median changes from baseline to the initiation and continuation stages. The analysis population is defined as the Main Analysis set, comprising eligible patients meeting inclusion and exclusion criteria with known assigned treatment information.

The record lists 14 outcome measures and 9 analyses. It does not report the protocol’s sample-size justification, detailed recruitment procedures, treatment assignment mechanism, or full statistical analysis plan. The planning calculations associated with the posted results are illustrations based on an observed effect, not evidence that the original study was designed around those calculations.

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: All patients were screened for eligibility. All enrolled patients met all implemented inclusion/exclusion criteria. Out of 9472 enrolled patients, 7 patients with unknown study treatment were not included in the main analysis set. Total 9465 patients were included in the main analysis set and started the study.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Main Analysis set (MAS): This includes all eligible patients who met inclusion/exclusion criteria with known assigned treatment information.

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: Main Analysis set (MAS): This includes all eligible patients who met inclusion/exclusion crteria with known assigned treatment information.

6. Primary Endpoint

The registry lists the primary outcome as Convenience PACT-Q2 Scores at Second and Last Assessment Between Treatment Groups, measured over Day 30 up to Day 210.

The primary outcome concerns the PACT-Q2, a questionnaire administered once treatment is underway. Its individual questions were grouped into convenience and satisfaction domains, and a global score was calculated for each domain. Scores range from 0-100, with higher scores indicating a better outcome. The registry states that individual item scores were summed and then rescaled to this range.

The endpoint is intended to describe patients’ reported experience of treatment, rather than a clinical event such as stroke. Convenience and satisfaction can capture aspects of treatment that matter to patients but may not be represented by clinical outcomes alone. As a patient-reported measure, the score depends on participants’ answers and on the timing and completeness of questionnaire administration.

The registry describes comparisons between treatment groups at the second and last assessments, and also describes median change from baseline to the initiation stage and from baseline to the continuation stage. It reports that the data were non-normal and therefore specifies medians and full ranges rather than means and standard deviations of differences. The record does not report the numerical PACT-Q2 results, the score distributions, or the number of participants contributing at each assessment. Consequently, the endpoint’s definition is available, but the magnitude and precision of any observed treatment-group difference are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes the primary outcome in terms of PACT-Q2 domain scores and median changes. It says the data were non-normal and that results were presented using medians and full ranges rather than means and standard deviations of differences. The statistical tests, models, confidence intervals, and detailed procedures used for the primary comparison are not reported in the registry record.

Why use medians and ranges?

In general, a mean can be strongly influenced by unusually high or low observations. A median is based on the ordered position of observations and can be less sensitive to extremes. The range communicates the observed endpoints of the data, but it does not show the distribution between those endpoints and can be heavily affected by a single extreme observation. Medians and ranges are descriptive summaries; by themselves, they do not quantify uncertainty around a treatment-group difference.

For the PACT-Q2, the registry says each domain’s global score was created by summing individual item scores and rescaling the result to 0-100. A higher score indicates a better outcome. The stated comparisons concern the second and last assessments, with the outcome description also referring to median changes from baseline to the initiation and continuation stages. The registry does not specify the exact statistical test or model used to compare those summaries, nor does it report numerical estimates or confidence intervals for the primary outcome.

What does non-interventional mean for comparisons?

In general, random assignment helps balance measured and unmeasured characteristics across treatment groups. In a non-interventional study, treatment is not assigned through a randomized trial procedure. Differences between groups may therefore reflect how patients entered treatment, their prior care, or other characteristics as well as any treatment-related experience. The registry record does not state the treatment assignment mechanism for Cohort B beyond describing a 1:1 allocation, and it identifies the comparison as not randomized and not like-for-like.

Adjustment methods can sometimes account for recorded characteristics, but they cannot guarantee removal of confounding, particularly when relevant factors are not measured or are measured imperfectly. The registry record does not report which covariates, if any, were included in adjusted analyses, how confounding was addressed, or whether adjusted and unadjusted estimates were compared. A causal interpretation is therefore not supported by the design information reported.

How should uncertainty be understood?

In general, a confidence interval describes the range of estimates compatible with a statistical procedure and the observed data, under that procedure’s assumptions. Its width indicates precision: a wider interval represents greater uncertainty than a narrower one. A point estimate alone does not show this uncertainty. The registry record does not report confidence intervals for the primary PACT-Q2 outcome, so precision cannot be judged from the stated endpoint definition or the cohort sizes alone.

In general, a p-value evaluates how compatible observed data are with a specified null model, conditional on the assumptions of the test. It does not measure the probability that a treatment works, and it does not resolve confounding in a non-randomized comparison. The primary-outcome p-value and the test used are not reported in the registry record. No conclusion about statistical significance can be drawn from the endpoint description alone.

What are the planning calculations?

The posted planning illustrations use the observed effect as a basis for hypothetical sample-size calculations. The stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the target effect is expressed as a stated fraction of the observed effect. For time-to-event calculations, the output is a total number of events, while other calculations are expressed as participants per arm. These are planning illustrations, not the study’s original sample-size justification and not observed power. The registry record does not report the protocol’s sample-size justification or the design assumptions used when the study was planned.

In general, over-dispersion means that observed variability is greater than a model assumes. If a model ignores it, uncertainty estimates can be too small and tests can be misleading. The registry record does not identify an over-dispersion model for the primary PACT-Q2 analysis, so no claim about whether it was assessed or handled is warranted.

The record identifies a Main Analysis set of eligible patients meeting inclusion and exclusion criteria with known assigned treatment information. It does not describe the analysis software, model diagnostics, handling of repeated measurements, or sensitivity analyses. Those omissions limit independent assessment of how the stated summaries and any comparisons were obtained.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 14 outcome measures and 9 analyses. A study that examines multiple outcomes, time points, domains, or comparisons can produce many statistical tests. In general, the more tests conducted, the greater the chance that at least one result will appear unusual by chance. Common approaches include identifying a primary hypothesis in advance or adjusting inference for multiple testing, but the registry record does not report whether a multiplicity procedure was planned or used. It also does not describe a testing hierarchy or distinguish confirmatory from exploratory analyses.

The primary outcome includes convenience and satisfaction domains and assessments at different stages. The record describes the second and last assessments and median changes from baseline to the initiation and continuation stages. It does not report how the multiple domain and assessment comparisons were handled statistically, or whether any result was selected for emphasis after looking at the data. No assumption about such procedures can be made from the outcome description.

The record defines the Main Analysis set as eligible patients meeting inclusion and exclusion criteria with known assigned treatment information. It does not report the number with available PACT-Q2 responses at each assessment, the amount or pattern of missing questionnaire data, or how missing responses were handled. In general, missingness can affect a patient-reported outcome if the likelihood of responding is related to treatment experience or participant characteristics. Without response counts and a stated handling method, the impact of missing data cannot be assessed.

The registry record also does not report whether analyses followed a prespecified protocol, how protocol deviations were handled, or whether sensitivity analyses tested alternative assumptions about missing data. These are not evidence that a particular method was or was not used; they are details not reported in 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 serious adverse event terms

Serious events with the highest arm-level rate: death (0.1%), ischaemic stroke (0.1%), atrial fibrillation (0.1%), gastrointestinal haemorrhage (0.1%), cardiac failure (0.1%).

The registry lists serious adverse event counts for Cohort A, Cohort B-Pradaxa, Cohort B-VKA, and the combined Cohort B. For Cohort A, 4066 participants were listed at risk and 26 were affected by serious adverse events. For Cohort B-Pradaxa, the corresponding figures were 3164 and 25; for Cohort B-VKA, they were 2181 and 15. The combined Cohort B figures were 5345 and 40. The combined cohort includes its treatment groups and should not be read as a separate comparison group.

The reported death counts were 5 in Cohort A, 2 in Cohort B-Pradaxa, 4 in Cohort B-VKA, and 6 in Cohort B overall. The registry also reports zero participants affected by other adverse events in each listed group. Listed serious adverse event terms include Death, Ischaemic stroke, Atrial fibrillation, Gastrointestinal haemorrhage, Cardiac failure, and Transient ischaemic attack; each is shown as 0.1%.

These are registry counts, not adjusted comparative risks. The record does not provide group-specific exposure time or a detailed follow-up duration for interpreting rates. The groups also arise from a non-interventional design, so differences in counts cannot be attributed to treatment from these figures alone. The registry’s listed death counts and serious adverse event counts are separate summaries and should not be assumed to represent mutually exclusive people.

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

The study’s stated aim was to describe patient perceptions and convenience during anticoagulant treatment for non-valvular atrial fibrillation. Its primary outcome is patient-reported: PACT-Q2 convenience and satisfaction scores, measured after treatment was underway. That outcome addresses an aspect of treatment experience, rather than establishing comparative effects on stroke or another clinical endpoint.

The numerical primary-outcome results are not reported in the registry record. The endpoint description alone does not reveal whether scores differed between groups, how large any difference was, or how precisely it was estimated. No claim that one treatment was more or less convenient or satisfying is supported by the information reported for the primary outcome.

The design further limits causal interpretation. This was a non-interventional study, and the record states that the arms are not a like-for-like control comparison. Cohort A involved switching from a vitamin K antagonist to Pradaxa, whereas Cohort B involved newly diagnosed patients receiving either treatment. Group differences could reflect treatment history, patient selection, or other factors in addition to treatment. The registry information does not report enough detail about adjustment to determine how those factors were handled.

The safety counts provide descriptive information about serious adverse events and deaths among the listed groups. They do not establish comparative safety, because the groups were not described as randomized and the record does not provide exposure-adjusted rates or a detailed account of follow-up time. Counts should not be interpreted as proof of causation or as a complete comparison of treatment risks.

In general, patient-reported outcomes can complement clinical outcomes by describing experiences that matter to patients. They remain dependent on questionnaire response, assessment timing, and the way scores are summarized. Since the registry record does not report response completeness, numerical score distributions, or uncertainty estimates for the primary outcome, the strength and precision of any difference cannot be assessed. The record supports understanding the study question and design, but it does not support a treatment recommendation or a causal conclusion.

13. Why This Trial Matters Statistically

This study is statistically notable because it focuses on a patient-reported treatment experience in a non-interventional setting. The PACT-Q2 asks about convenience and satisfaction, which are distinct from clinical event outcomes. Such measures can add descriptive context about how people experience treatment, but comparisons require careful attention to who entered each treatment group and when assessments were made.

The cohort structure illustrates why an overall treatment comparison can be difficult to interpret. Cohort A comprises patients switching from a vitamin K antagonist to Pradaxa, while Cohort B comprises newly diagnosed patients treated with either option. These pathways differ by treatment history and population definition. The registry record states that treatment allocation was not randomized and that the arms are not a like-for-like control comparison. Those features make confounding and selection important considerations.

The registry also demonstrates the difference between defining an endpoint and reporting evidence about it. The PACT-Q2 scale, score direction, assessment period, and summary approach are described, but numerical primary-outcome results and their uncertainty are not reported in the registry record. Without those estimates, readers cannot judge the magnitude or precision of the patient-reported findings.

Finally, the distinction between a study’s design and later planning illustrations matters. Calculations based on an observed effect can help illustrate hypothetical future sample-size requirements under stated assumptions. They do not establish what the original investigators planned, nor do they turn an observational comparison into a randomized one. The registry record does not report its own sample-size justification. This makes it important to separate descriptive findings, planning exercises, and causal claims.

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 numerical results for the primary PACT-Q2 outcome. It therefore does not allow assessment of the score differences, median changes, distributions, or precision for convenience and satisfaction. Although the outcome description gives the assessment period as Day 30 up to Day 210, it does not state how many participants contributed responses at each assessment.

The study is non-interventional, and the registry cautions that the arms are not a like-for-like control comparison. Allocation is not stated as randomized. The switch cohort and newly diagnosed cohort also represent different treatment histories and populations. These design features limit causal comparison, and the registry record does not report the covariates or adjustment methods, if any, used to address confounding.

The registry record does not report the detailed statistical analysis plan, the tests or models used for the primary outcome, confidence intervals, or procedures for multiple comparisons. It lists 14 outcome measures and 9 analyses, but does not explain whether multiplicity was addressed. It also does not report missing-data amounts, reasons for missing assessments, or methods for handling missing questionnaire responses.

For safety, the record gives counts but does not report exposure-adjusted rates or detailed group-specific follow-up duration. The available counts cannot establish comparative risks, particularly in a non-randomized study. The protocol’s sample-size justification is not reported; planning illustrations based on an observed effect are not a substitute. These omissions describe limits of the registry record and do not establish that a method was absent from the full study documentation.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Patient Convenience Study (RE-SONANCE) — NCT02684981.
• Registry record last updated 2019-07-24; status last verified 2019-05.
• Results first posted 2019-07-24.
• 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

NCT02684981, titled Patient Convenience Study (RE-SONANCE), is a completed non-interventional study sponsored by Boehringer Ingelheim. The registry lists an enrollment of 9472, a start date of 2015-11-11, and a primary completion date of 2017-06-01. The study concerns patients with non-valvular atrial fibrillation receiving Pradaxa or a vitamin K antagonist.

Cohort A includes patients who switched from a vitamin K antagonist to Pradaxa. Cohort B includes newly diagnosed patients treated with Pradaxa or a vitamin K antagonist. The primary outcome is PACT-Q2 convenience and satisfaction, described using medians and full ranges over assessments from Day 30 up to Day 210. Numerical primary-outcome findings are not reported in the registry record.

The registry lists 14 outcome measures and 9 analyses. It describes the analysis population as eligible patients meeting inclusion and exclusion criteria with known assigned treatment information. Treatment assignment is not stated as randomized, and the arms are explicitly not described as a like-for-like control comparison. Serious adverse event and death counts are reported descriptively.