Controlled Investigation to Evaluate Impact of dCBT on Psychological Symptom Burden in Adult Subjects With PF: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Controlled Investigation to Evaluate Impact of dCBT on Psychological Symptom Burden in Adult Subjects With PF (NCT05330312), a randomized na study. The primary outcome is Part 2 - Change From Baseline in Anxiety Symptom Severity Assessed by Generalized Anxiety Disorder 7-item (GAD-7) at Week 9..

2. Clinical Question

3. Trial Design

The registry describes a randomized, controlled, parallel-group clinical investigation with single masking. It lists 119 participants enrolled and a completed study. The listed start date is 2022-04-17, and the primary completion date is 2023-10-19. The phase is recorded as NA. The sponsor is Vicore Pharma AB.

The record distinguishes Part 1 from Part 2. Part 1 included a dCBT group described as receiving 4 weeks of therapy. In Part 2, one group received 9 weeks of dCBT and the control group received no intervention. The primary endpoint is specifically identified as a Part 2 outcome assessed from baseline to Week 9. The registry record does not report how the two parts were sequenced or whether participants in Part 1 also entered Part 2.

Randomized allocation indicates that assignment to groups was intended to occur by chance. A parallel-group design means the comparison is between groups assigned to different study conditions, rather than a design in which each participant receives both conditions. These are general descriptions of the design terms; the registry record does not report the allocation procedure, concealment methods, or randomization ratio.

Single masking is reported, but the record does not identify who was masked. It therefore does not establish whether participants, investigators, outcome assessors, or another group were unaware of assignment. The control condition was no intervention, rather than an active or attention-matched comparator. The record does not report additional details about the digital program, participant engagement, adherence, or the care received outside the study intervention.

The overall enrollment figure and the posted primary outcome counts describe different aspects of the record. The primary endpoint lists 54 participants in each Part 2 arm. The reason those arm counts do not represent the full enrollment is not reported in the registry record. The Part 1 group appears in the safety results, with 10 participants at risk for the reported safety categories. These distinctions matter when interpreting which participants contribute to each result.

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: This investigation consisted of two parts: Part 1 - A pilot phase with the key purpose of testing the functionality of dCBT-PF. Part 2 - A pivotal phase with the key purpose of evaluating the efficacy of dCBT-PF versus a control on patient-reported psychological symptom burden in patients with PF.

Pilot Investigation - Part 1

Reasons for not completing this period:

Pivotal Investigation - Part 2

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Qualitative information on functionality and experience was collected from 10 participants.

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: One subject randomised to dCBT-PF in Part 2 was not treated, as the subject was unable to download the app.

6. Primary Endpoint

The registry lists the primary outcome as Part 2 - Change From Baseline in Anxiety Symptom Severity Assessed by Generalized Anxiety Disorder 7-item (GAD-7) at Week 9., measured over Baseline to Week 9.

The primary endpoint is change from baseline to Week 9 in anxiety symptom severity, measured with the GAD-7. The questionnaire has 7 items, each scored from 0 to 3. The composite score ranges from 0 to 21, with higher scores indicating worse symptoms. The record identifies cut-off scores for mild, moderate, and severe anxiety symptoms as 5, 10, and 15, respectively.

A change score describes how a participant’s measured score differs from their own baseline measurement. In general, a negative change on a scale where higher scores mean worse symptoms indicates a lower measured score at follow-up, while a positive change indicates a higher score. This interpretation concerns the direction of the scale, not whether a difference is clinically important.

The GAD-7 is used to quantify anxiety symptoms consistently across participants and over time. A standardized questionnaire can make symptom measurement more structured than an informal description, while still relying on participant responses. The registry record does not report a threshold for a clinically meaningful change, a responder definition, or a rationale for choosing the GAD-7 as the primary measure. It also does not report baseline group means, so the posted change estimates cannot be read as the groups’ Week 9 scores.

The reported values are least-squares means with 95% confidence intervals. These are arm-specific summaries of change. The record does not report the model specification or a direct estimate comparing the two groups. Thus the endpoint definition is clear, but the posted values do not by themselves answer how far apart the assigned groups were at Week 9.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is a continuous measure: each participant’s GAD-7 score can take values across a numerical scale, and change is summarized as a mean. The registry identifies the reported summary as a least-squares mean and its uncertainty as a 95% confidence interval. These terms describe the form of the posted result, but do not disclose all the modeling choices used to obtain it.

What does a least-squares mean describe?

In general, a least-squares mean is a model-based estimate of an average. Unlike a simple arithmetic mean, it may reflect covariates or other features of a fitted statistical model. The registry’s choice to label the estimates as least-squares means does not reveal which covariates were included, how repeated measurements were handled, or what assumptions were made about the data. Those details are not reported in the registry record.

The posted least-squares means are -1.8 for dCBT and 0.9 for control. They summarize change from baseline to Week 9 within each group. They are not, by themselves, the treatment effect. In a randomized comparison, the effect of interest is commonly represented by a contrast between assigned groups. For a continuous outcome, such a contrast might be expressed as a difference in mean change or another model-based comparison. The registry record does not report a primary between-group contrast, so the comparative estimate and its uncertainty cannot be described from the posted values.

How should the confidence intervals be read?

A confidence interval is a range of values generated by a statistical procedure to convey uncertainty around an estimate. In general, a narrower interval indicates greater precision than a wider interval, all else being equal. The posted intervals are -5.9 to 2.4 for dCBT and -3.3 to 5.1 for control. Both span zero, so each interval is compatible with a negative or positive average change under the method used. The intervals apply to the arm-specific means, not to a comparison between arms.

It is important not to treat overlap between two arm-specific confidence intervals as a substitute for a formal comparison. The uncertainty in a difference depends on the estimates and their joint variability. A direct contrast with its own interval or test is the appropriate information for assessing the comparative result. Neither the contrast nor its uncertainty is reported in this registry record. No p-value for the primary comparison is posted.

Why does the outcome scale matter?

The GAD-7 consists of 7 questions scored from 0 to 3 points each, and the composite score ranges from 0 to 21. The registry states that higher scores mean worse symptoms and gives cut-off scores of 5, 10, and 15 for mild, moderate, and severe symptom levels. This makes the direction of the mean change interpretable: a negative change means the measured score is lower than baseline on average; a positive change means it is higher. It does not establish that an observed change is important to participants. A clinically meaningful threshold or responder rule is not reported in the registry record.

Scale cut-offs are useful for describing symptom levels, but they are not interchangeable with a treatment-effect threshold. A group mean change cannot show how many people crossed a cut-off, and the record does not report category transitions. Nor does the listed mean reveal the spread of participant-level changes. The posted confidence intervals quantify uncertainty in the estimated means, not the range of individual outcomes.

What can and cannot be inferred from the sample sizes?

The primary endpoint lists 54 participants in each Part 2 arm. Those counts indicate the group sizes associated with the posted outcome estimates. They do not, on their own, show how many participants were randomized, how many completed the intervention, or how many had missing endpoint measurements. Those details are not reported in the registry record.

Sample-size planning and observed results answer different questions. A planning calculation can illustrate how many participants per arm might be needed under stated assumptions; it does not show that a trial had a particular probability of detecting an effect after the results are observed. The registry’s planning description refers to a two-sided significance level of 0.05, equal allocation, a normal approximation, and effects defined as fractions of the observed effect. It states that the planning illustration is not the trial’s own design. A sample-size justification for the actual trial is not reported in the registry record. Such planning values should not be interpreted as observed power or as evidence that a particular result is reliable.

More broadly, over-dispersion is a concern when observed variability exceeds what a statistical model assumes. In general, that mismatch can make standard errors too small and confidence intervals too narrow if it is not handled appropriately. The endpoint is continuous and the record does not report a variance model or diagnostics, so there is no basis to say whether over-dispersion was assessed or relevant to this analysis. This is a general statistical consideration, not a claim about the trial’s data.

The registry identifies randomized allocation and a parallel-group model, which define the broad structure of the comparison. It does not report the analysis population, covariate adjustment, handling of repeated measures, missing-data assumptions, or sensitivity analyses. Those omissions prevent a full appraisal of how the posted least-squares means were estimated. The confidence intervals remain useful as reported uncertainty summaries, but their interpretation is limited to the method used, which is not described in detail.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 6 outcome measures and 4 secondary outcomes. The secondary outcomes include safety in Part 1, anxiety symptom severity on the Hamilton Anxiety Rating Scale in Part 2, and health-related quality-of-life measures from the King's Brief Interstitial Lung Disease questionnaire, including its Psychological Domain and Total Score. The primary outcome is GAD-7 change from baseline to Week 9. The registry record reports zero posted analyses, so it does not provide results for the listed secondary outcomes.

When a study examines multiple outcomes or makes multiple statistical comparisons, the chance of at least one apparently notable result arising by chance can increase. In general, a prespecified testing hierarchy or a multiplicity adjustment can address this issue, depending on the trial’s aims. The registry record does not report whether a multiplicity strategy was planned or used. With no posted analysis results for the secondary outcomes, it is not possible to assess how their findings were interpreted relative to the primary endpoint.

The record does not report how missing GAD-7 measurements were handled, whether participants were analyzed according to randomized assignment, or which analysis population was used. It does not report participant flow through the study, reasons for withdrawal, or sensitivity analyses examining assumptions about missing data. These details matter because analyses can differ depending on who contributes outcome data and how missing measurements are treated.

Interim analyses and any stopping rules are not reported in the registry record. The protocol’s statistical analysis plan, including model specification and outcome hierarchy, is also not reported. These omissions do not establish that such methods were absent; they mean that the registry record does not document them. The arm-specific primary estimates can be read descriptively, but the missing analysis details and absence of a posted between-group result limit formal interpretation.

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: death (3.7%), atrioventricular block complete (1.9%), oxygen saturation decreased (1.9%), urosepsis (1.9%), aspiration (1.9%).

Safety results are reported for three groups: Part 2 dCBT, Part 2 control, and Part 1 dCBT. For serious adverse events, the record lists 5 affected participants among 53 at risk in Part 2 dCBT, 9 among 54 at risk in Part 2 control, and 0 among 10 at risk in Part 1 dCBT. For other adverse events, it lists 3 among 53, 4 among 54, and 1 among 10, respectively. Death counts are listed as 1, 4, and 0 for those same groups.

These are participant counts in the registry’s safety categories. They should not be treated as a comparison of risks without considering the group sizes, study period, event definitions, and analysis approach. The record does not report whether events were judged related to the intervention, their timing, or the criteria used to classify seriousness. A count of participants with an event also does not necessarily equal a count of individual events.

The listed serious adverse event terms include Death at 3.7%, Atrioventricular block complete at 1.9%, Oxygen saturation decreased at 1.9%, Urosepsis at 1.9%, Aspiration at 1.9%, and Idiopathic pulmonary fibrosis at 1.9%. These percentages are registry-reported term frequencies; the record does not specify their group attribution in this listing. They should not be interpreted as evidence that the study intervention caused an event. The registry record does not report further event narratives or causal assessments.

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

The posted results provide a limited description of the primary endpoint. They show the estimated average change in GAD-7 score from baseline to Week 9 for each Part 2 arm and the confidence interval around each estimate. The point estimate is negative for dCBT and positive for control, but both arm-specific intervals extend across zero. This conveys uncertainty about the direction and size of each group’s average change.

The results do not provide the direct comparison needed to quantify the difference between the randomized groups. No between-group estimate, confidence interval for that estimate, or primary comparison p-value is reported. Comparing the signs or apparent locations of the two arm means does not replace that analysis. Nor does the overlap of their individual confidence intervals constitute a formal test of the difference.

The registry record also does not report a threshold for a clinically meaningful GAD-7 change, the distribution of individual changes, or the number of participants whose symptoms changed by a specified amount. The mean score change cannot establish how many participants improved, worsened, or experienced an important change. The scale’s symptom cut-offs describe score levels, not by themselves the meaning of a change between assessments.

The study is identified as randomized and parallel-group, but key details needed for a fuller appraisal are not reported in the registry record. These include the allocation procedure, who was masked, the statistical model, the analysis population, missing-data handling, and whether multiplicity was addressed. The record lists secondary outcomes but no posted analyses for them. As a result, the available registry results support a description of the arm-specific primary estimates and safety counts, but not a complete assessment of comparative efficacy or the robustness of the analyses.

These limits should not be converted into a claim that dCBT did or did not affect anxiety. The record’s numerical information is too incomplete for that conclusion. The appropriate statistical reading is that the primary outcome is reported for each group, with substantial uncertainty represented by the intervals, while a direct comparative result is not reported in the registry record.

13. Why This Trial Matters Statistically

This trial is statistically informative as an example of why a randomized design and a reported treatment comparison are not the same thing. Random assignment can support a fair comparison in principle, but readers still need the estimate of the difference between assigned groups, together with its uncertainty, to interpret the result. Here, the primary endpoint is reported as separate arm-specific least-squares mean changes. Those summaries do not directly quantify the contrast that answers the comparative question.

The confidence intervals also illustrate the distinction between an estimate and its precision. A point estimate gives one summary of the observed data, while an interval communicates uncertainty under the analysis method. Both intervals include positive and negative changes, and the model details are not reported. The intervals therefore warrant a cautious reading and cannot establish a precise direction of change for either group.

The record also separates the study’s outcome plan from the results that are posted. It lists several secondary outcomes, but no analyses are posted. This makes outcome completeness and multiplicity important considerations. Without posted secondary analyses, a testing hierarchy, or a statistical analysis plan, readers cannot determine how the full set of outcomes was handled.

Finally, the safety results show why counts need context. The record lists serious and other adverse events across groups with different numbers at risk, as well as death counts and serious-event terms. Those figures are useful descriptions, but do not establish causes or provide a complete comparative safety analysis. Overall, the trial highlights the value of transparent reporting of the between-group estimate, analysis methods, participant flow, and event attribution alongside arm-level summaries.

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 endpoint results are incomplete for evaluating the randomized comparison. The registry reports arm-specific least-squares mean changes and confidence intervals, but a between-group estimate and its uncertainty are not reported in the registry record. The model used to produce the least-squares means is also not reported, limiting assessment of covariate adjustment, repeated-measure handling, and assumptions.

The record lists 119 participants enrolled, while the primary endpoint lists 54 participants in each Part 2 arm. The reasons for the reported endpoint counts and the relationship of Part 1 to Part 2 are not reported in the registry record. Part 1 has separate safety results for 10 participants at risk. Participant flow, completion, withdrawals, and the number with missing primary outcome data are not reported, so the primary endpoint counts cannot be interpreted as a full account of enrollment or follow-up.

The control condition was no intervention. As a design consideration, that comparator does not by itself distinguish effects specific to the digital therapy from effects associated with receiving an intervention or engaging with study materials. This is not a claim that such effects occurred; it describes what the comparator can and cannot isolate. The registry does not report whether other care was received or whether it differed between groups.

Single masking is stated, but the masked parties are not identified. Details of eligibility criteria, baseline characteristics, intervention adherence, digital engagement, and concomitant care are not reported in the registry record. The record also does not report a clinically meaningful change threshold, missing-data procedures, analysis populations, multiplicity methods, interim analyses, or sensitivity analyses. Together, these omissions limit assessment of generalizability, analysis robustness, and the interpretation of the posted safety counts.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Controlled Investigation to Evaluate Impact of dCBT on Psychological Symptom Burden in Adult Subjects With PF — NCT05330312.
• Registry record last updated 2024-09-24; status last verified 2024-09.
• Results first posted 2024-09-24.
• 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

The registry record describes a completed, randomized, controlled, parallel-group investigation of digital cognitive behavioural therapy in adults with pulmonary fibrosis. It lists 119 participants enrolled, single masking, and a phase of NA. The study began on 2022-04-17, with primary completion on 2023-10-19; Vicore Pharma AB is the sponsor.

Part 1 included a 4-week dCBT group. Part 2 compared 9 weeks of dCBT with no intervention. The primary outcome was change from baseline to Week 9 in GAD-7 score. The posted Part 2 least-squares mean changes were -1.8 for dCBT and 0.9 for control, each with a 95% confidence interval that spans zero and a listed group size of 54. A direct between-group estimate is not reported in the registry record.

The record lists 4 secondary outcomes and 6 outcome measures, with zero analyses posted. It also reports adverse-event counts for the Part 1 and Part 2 groups. Analysis methods, missing-data handling, and the identities of those masked are not reported in the registry record.