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 Study of Progression to Progressive Fibrosing Interstitial Lung Disease (PF-ILD) Incidence/Management and Treatment (NCT05875532), a registered phase not stated study. The primary outcome is Incidence Probability of Progression to Pulmonary Fibrosing-Interstitial Lung Disease (PF-ILDs).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05875532 |
| Phase | Phase not stated |
| Condition | Lung Diseases, Interstitial |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 34960 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Boehringer Ingelheim |
| Results posted | Yes |
2. Clinical Question
Population
Patients in Japan with fibrosing interstitial lung disease other than idiopathic pulmonary fibrosis, identified in the Medical Data Vision database. The record describes eligible database patients with an underlying pre-specified interstitial lung disease and a second diagnosis of fibrosing interstitial lung disease. The full eligibility description is not reported in the registry record.
Intervention
There is no assigned intervention. This is a real-world observational study of progression, management, and treatment in routine care. The record identifies one patient group rather than treatment arms assigned by the study.
Comparator
No comparator group is described. The study does not set up a randomized or like-for-like comparison of treatments. Its primary question concerns the estimated cumulative incidence of progression within the eligible patient population.
Primary question
What is the cumulative incidence probability of progression to progressive fibrosing interstitial lung disease at 6, 12, 18 and 24 months after the index date? The index date is the second diagnosis of fibrosing interstitial lung disease, within the stated date window. The registry also names secondary questions about treatment and management during follow-up.
3. Trial Design
NCT05875532 is a completed, non-randomized, real-world database study sponsored by Boehringer Ingelheim. Its stated primary objective is to investigate the incidence probability of progression to progressive fibrosing interstitial lung diseases among patients in Japan with fibrosing interstitial lung disease other than idiopathic pulmonary fibrosis. The secondary objective is to describe procedures for management and treatment in this population. The registry lists an enrollment of 34960, but this registry enrollment figure should not be assumed to be the number contributing to every endpoint or risk set.
The study uses the Medical Data Vision database. The arm description concerns patients with an interstitial lung disease other than idiopathic pulmonary fibrosis, with data available in the database and a second diagnosis of fibrosing interstitial lung disease. The full arm description is cut off in the registry record, so further eligibility details are not reported in the registry record. The primary endpoint specifies an index date between 01-Jan-2013 and 6 months before 28-May-2020. Follow-up is described as ending at 28-May-2020, the last encounter in the database, or in-hospital death, whichever occurs first.
The registry lists study start on 2023-04-20, primary completion on 2023-05-01, and status as completed. These administrative dates do not establish when every person’s database observations occurred; the endpoint description gives its own index-date and follow-up windows. No randomized allocation or treatment comparison is reported. The record lists three outcome measures, including the primary incidence outcome and secondary counts of patients receiving treatments and management of interest. The secondary outcome results 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: Patients that met all inclusion criteria and none of the exclusion criteria were followed from the day after of the second diagnosis of a fibrosing ILD other than IPF - index date - until the end of study period (28-May-2020), the last encounter in the MDV database or in-hospital death, whichever occurs first.
Overall Study
| Stage | Patients With an ILD Other Than IPF |
|---|---|
| STARTED | 34960 |
| COMPLETED | 34960 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: Full analysis set: Patients in Japan with data available in the Medical Data Vision (MDV) database, between 01-Jan-2012 to 28-May-2020, who met all inclusion criteria and none of the exclusion criteria. The number of patients analyzed displays the number of patients at risk of progression at the time of interest.
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: Full analysis set: Patients in Japan with data available in the Medical Data Vision (MDV) database, between 01-Jan-2012 to 28-May-2020, who met all inclusion criteria and none of the exclusion criteria.
| Characteristic | Unit | Patients With an ILD Other Than IPF |
|---|---|---|
| Participants analysed | 34960 | |
| Age, Continuous | Years | 71.13 (SD 12.16) |
| Sex: Female, Male: Female | Participants | 16597 |
| Sex: Female, Male: Male | Participants | 18363 |
| Race and Ethnicity Not Collected | Participants | — |
6. Primary Endpoint
The registry lists the primary outcome as Incidence Probability of Progression to Pulmonary Fibrosing-Interstitial Lung Disease (PF-ILDs), measured over At 6, 12, 18 and 24 months after the index date, defined between 01-Jan-2013 and 6 months before 28-May-2020.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | 95% Confidence Interval |
| Unit | Cumulative incidence probability |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the cumulative incidence probability of progression to progressive fibrosing interstitial lung disease at 6, 12, 18 and 24 months after the index date. The index date is defined as the second diagnosis of fibrosing interstitial lung disease. The registry says this probability is estimated as the complement of the Kaplan-Meier estimate, with Greenwood’s variance estimate used for a 95% confidence interval. The endpoint is therefore a time-to-event estimate across follow-up, rather than simply a count of people observed to progress by the end of the study.
Progression is defined by a set of database-based criteria. These include 3 or more pulmonary function tests within 365 days, 3 or more tomographies within 365 days, or 1 or more claims during follow-up for oxygen therapy, respiratory hospitalization, palliative care, lung transplant, immunosuppressive drugs, oral corticosteroid, or Nintedanib. The criteria combine testing and clinical events with treatment or service claims. Meeting any criterion can therefore mark progression under the registry definition; the measure is not limited to a direct physiological measure of lung function.
Time-to-event methods are used because patients may have different follow-up lengths and may stop contributing observations before the end of the database period. The registry record does not report the endpoint estimates or confidence interval limits, so the magnitude and precision of the estimated incidence cannot be assessed from the posted results.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes how progression was to be measured, but it does not report the primary endpoint estimates. In particular, the cumulative incidence probabilities at 6, 12, 18 and 24 months, their 95% confidence intervals, and the corresponding numbers at risk are not reported in the registry record. The posted results therefore do not establish the observed frequency or timing of progression under the study’s definition, nor how precisely that frequency was estimated.
The reported enrollment is 34960. That figure is not interchangeable with the number of patients analyzed at each follow-up time. The endpoint description says the number analyzed displays the number at risk of progression at that time, but the actual risk-set counts are not reported in the registry record. The number eligible after applying the database criteria, and the number contributing information at each time point, are also not reported in the registry record.
Interpretation depends on the operational definition of progression. Testing frequency, hospitalization, oxygen therapy, palliative care, transplant, and medication claims are among the criteria. These events may reflect changes in disease, clinical practice, care access, or the recording of claims. The endpoint is thus a registry-defined composite proxy rather than a single direct clinical measurement. The record does not report the contribution of each criterion or how often multiple criteria were met.
The planned Kaplan-Meier complement estimates event probability over time while accounting for incomplete follow-up under its censoring assumptions. The record identifies last database encounter and in-hospital death as follow-up endpoints, but does not explain in the registry record how death was handled in the analysis. This matters because death can prevent subsequent observation of progression; treating it as ordinary censoring and treating it as a competing event answer different statistical questions.
The study has no reported comparator group and no assigned treatment. Its design can describe outcomes within the eligible database population, but cannot by itself estimate a causal treatment effect. The secondary outcomes are counts of patients with treatment or management of interest during follow-up; their results are not reported in the registry record. No analysis results are listed, so substantive conclusions about incidence, management patterns, or treatment patterns are not supported by the posted results.
9. Statistical Methods Explained
What does the Kaplan-Meier complement represent?
The Kaplan-Meier method estimates the probability of remaining free of the event over time while allowing follow-up to end at different times for different participants. Its complement expresses the estimated probability of having experienced the event by a specified time. In this study, the event is progression according to the registry’s criteria, and the specified times are 6, 12, 18 and 24 months after the index date.
This approach can use partial follow-up rather than requiring every participant to be observed through the same endpoint. A participant whose follow-up ends before progression is typically treated as censored at the last observed time. Censoring means that the event status is not observed after that point; it does not mean that progression did not occur later. For the estimate to be interpreted as intended, the handling of censoring and the assumptions about who remains observed matter. Those detailed analysis procedures are not reported in the registry record.
What does the confidence interval add?
A confidence interval describes statistical uncertainty around an estimated quantity. The registry specifies a 95% confidence interval and says Greenwood’s variance estimate is used. Greenwood’s method estimates the variance associated with the Kaplan-Meier curve, which can then be used to quantify uncertainty in the derived probability. A narrow interval would indicate greater precision than a wide interval, but interval width alone would not address bias from eligibility, measurement, or database coverage.
The actual estimates and confidence interval limits are not reported in the registry record. As a result, the statistical precision of the study’s primary result cannot be evaluated. The endpoint description also refers to the number at risk at each time, but those counts are not reported in the registry record.
How is progression operationalized?
The endpoint uses several claims and care-process criteria. It includes frequent pulmonary function tests or tomographies within a stated 365-day window, and one or more claims for specified interventions, services, or events during follow-up. The criteria are not all equivalent measures: some indicate diagnostic monitoring, while others indicate treatment or a clinical event. A patient can meet the registry definition through any one of the listed criteria. The record does not report separate estimates by criterion, so it is not possible to determine which components most often accounted for the outcome.
Using administrative data can make it possible to study routine-care populations, but claims reflect recorded services and diagnoses. Testing frequency may be affected by clinical practice, and treatment claims depend on care being delivered and captured in the database. The endpoint should therefore be read as progression under the registry’s composite definition, not as a direct, uniform measure of biological change.
What role does follow-up play?
The registry specifies follow-up from 1-Jan-2013 to 28-May-2020, the last encounter in the Medical Data Vision database, or in-hospital death, whichever occurs first. The primary endpoint also specifies an index-date window from 01-Jan-2013 to 6 months before 28-May-2020. Because people can enter at different index dates and have different lengths of observation, a time-to-event method is relevant. However, the registry record does not report the distribution of follow-up, the amount of censoring, or how in-hospital death was treated in the calculations.
In general, competing-risk methods distinguish an event of interest from an event that prevents it from occurring or being observed. A Kaplan-Meier complement that treats a competing event as censoring may not estimate the same quantity as a cumulative incidence function that accounts for competing events. The record identifies the Kaplan-Meier complement but does not report a competing-risk analysis or further detail about death handling. It is therefore important not to infer an unreported analysis choice.
What do planning calculations mean?
Any sample-size calculation based on an observed effect is a planning illustration, not observed power. The stated illustration assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is 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 general planning conventions, not evidence that this observational study had two assigned arms or used that design for its primary analysis. The record does not report a trial-specific sample-size justification, and no analysis result or comparison effect is reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry identifies one primary outcome and two secondary outcomes: the number of patients with treatment of interest during follow-up and the number with management of interest during follow-up. It does not report the statistical analysis plan for these outcomes, including whether any multiplicity adjustment was planned. When several outcomes or time points are examined, multiplicity is a general concern because repeated statistical testing can increase the chance of a chance finding. No adjustment method or decision rule is reported in the registry record, and the outcome results themselves are not reported.
The primary endpoint is evaluated at 6, 12, 18 and 24 months. The record does not explain whether these estimates were treated as separate inferential tests or as descriptive estimates of a single time course. It also does not report any interim analysis plan, stopping rule, or prespecified hierarchy among the time points. Those details should not be inferred from the listed endpoint schedule.
The population description names a full analysis set consisting of patients meeting inclusion criteria and none of the exclusion criteria. The complete eligibility criteria are not reported in the registry record, and the number entering that analysis set is not reported. The record says that the number analyzed displays the number at risk at each endpoint time, but those counts are unavailable.
Missing-data procedures are not reported in the registry record. This includes procedures for missing or incomplete diagnosis, claims, testing, or follow-up information. The endpoint description gives rules for ending follow-up, but does not describe how missing data within an otherwise observed period were handled. The record also does not report sensitivity analyses assessing alternative missing-data or censoring assumptions. Consequently, the possible effect of missingness on the estimates cannot be assessed from the posted results.
11. What the Result Does, and Does Not, Mean
The primary outcome is an estimate of progression under a specific registry definition among eligible patients recorded in a Japanese medical database. It is not a treatment-effect estimate. No treatment was assigned, no comparator group is described, and the record does not report results for the secondary treatment and management outcomes. The study design therefore does not support a conclusion that a particular treatment caused a change in progression.
The endpoint combines testing frequency, medical events, and claims for treatments or services. This can capture several ways that progression may become apparent in routine care, but it also means that the outcome is influenced by clinical decisions and claims recording. A patient meeting one listed criterion counts as having progressed under the stated definition; the registry record does not report component-specific results to show which criteria drove the overall outcome.
The cumulative-incidence framing is intended to describe how estimated risk changes over time after the index diagnosis. A confidence interval would show uncertainty around each estimate, but the estimates and interval limits are not reported in the registry record. Without them, readers cannot determine the observed incidence, compare precision across follow-up times, or assess whether the data support meaningful differences over time.
The enrollment figure of 34960 describes registry enrollment, not necessarily the number of patients at risk at each time or the number included in the analytic population. The number of patients contributing to each estimate is not reported in the registry record. Nor are detailed data on follow-up completeness or the handling of death. These omissions limit assessment of both precision and potential bias.
Accordingly, the posted registry information describes the research question and endpoint construction, but not the empirical answer. It does not establish the probability of progression in the population, the effectiveness of any treatment, or the prevalence of particular management practices. Those conclusions require results and analysis details not reported in the registry record.
12. Why This Trial Matters Statistically
Real-world database studies can address questions about disease course and care patterns in populations observed in routine practice. This study’s stated focus is fibrosing interstitial lung disease other than idiopathic pulmonary fibrosis in Japan, with an incidence question framed around progression after a second diagnosis. The approach makes the definition of progression central: the result would describe events captured by the selected diagnosis, testing, treatment, and service criteria.
The time-to-event framing is statistically relevant because the database follow-up ends at the last encounter, the end of the specified observation period, or in-hospital death. Methods that use follow-up time can accommodate observation that ends at different points, but interpretation relies on how censoring and death are handled. The registry names the Kaplan-Meier complement and Greenwood’s variance estimate, while leaving important implementation details unreported.
The record also illustrates why an enrollment number alone is not enough to interpret an observational estimate. The analysis population, risk sets at each follow-up time, and outcome counts are needed to understand how much information supports the estimates. Those results are not reported in the registry record. Likewise, claims-based composite outcomes can be useful for describing care-linked progression, yet they combine components with different meanings and possible influences from clinical practice.
Statistically, the study raises an important distinction between describing incidence and estimating treatment effects. The registry’s objectives include treatment and management patterns, but no comparator or treatment assignment is described. Without reported analyses, there is no basis to draw a treatment-effect conclusion. The record is informative about the intended observational question and methods, but its missing outcome results prevent evaluation of the empirical findings.
13. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The primary limitation for interpretation is that the registry record does not report the incidence estimates, confidence intervals, event counts, or numbers at risk. It also does not report results for the named secondary outcomes. Thus, the posted information cannot establish the size or precision of the observed progression probability or describe the treatment and management patterns measured by the study.
The study uses a claims-based progression definition that combines diagnostic testing frequency with claims for clinical events, services, and medications. These components may reflect different aspects of disease and care. The registry does not report component-specific frequencies or validation of the composite definition. As a result, readers cannot assess whether the endpoint was driven mainly by testing activity, clinical events, or treatment claims.
Eligibility and population details are incomplete in the registry record. The arm description is truncated, and the complete inclusion and exclusion criteria are not reported. Although the registry lists enrollment of 34960, the number in the full analysis set and the risk-set counts at each assessment time are not reported. The reach and representativeness of the database population cannot be assessed from the available record.
The record does not report detailed procedures for missing data, censoring, or handling of in-hospital death. These issues may affect time-to-event estimates, particularly when follow-up ends for reasons related to health status. No sensitivity analyses are reported in the registry record to assess robustness to these choices.
Finally, there is no randomized comparison or comparator group described. Observational associations in this setting would not, on their own, establish causal effects of treatment. The registry status is completed, but completion does not substitute for posted endpoint results or a detailed statistical analysis plan.
14. Related Tutorials
15. Related Statistical Calculators
16. Sources
- ClinicalTrials.gov: Study of Progression to Progressive Fibrosing Interstitial Lung Disease (PF-ILD) Incidence/Management and Treatment — NCT05875532.
- Registry record last updated 2024-09-19; status last verified 2024-04.
- Results first posted 2024-09-19.
- 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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17. Record Summary
NCT05875532, titled “Study of Progression to Progressive Fibrosing Interstitial Lung Disease (PF-ILD) Incidence/Management and Treatment,” is a completed study sponsored by Boehringer Ingelheim. The registry lists enrollment of 34960, a study start date of 2023-04-20, and primary completion on 2023-05-01. The research concerns patients in Japan with fibrosing interstitial lung disease other than idiopathic pulmonary fibrosis, using data from the Medical Data Vision database.
The primary outcome is cumulative incidence probability of progression at 6, 12, 18 and 24 months after the index date, estimated as the complement of Kaplan-Meier estimates with a 95% confidence interval. Secondary outcomes concern counts of patients receiving treatments and management of interest during follow-up. The registry record does not report the endpoint estimates, confidence limits, or secondary outcome results. It also does not report detailed missing-data, multiplicity, or death-handling procedures.