Oxygen Therapy Use in Patients With Fibrotic Interstitial Lung Disease: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Oxygen Therapy Use in Patients With Fibrotic Interstitial Lung Disease (NCT05957198), a registered phase not stated study. The primary outcome is Time to Oxygen Therapy Initiation.

2. Clinical Question

3. Trial Design

The registry describes a completed, non-randomized study of oxygen therapy use in patients with fibrotic ILD. Its stated purpose is to describe initiation and use of oxygen therapy and assess the impact of oxygen therapy on clinical outcomes. Because treatment was not assigned at random in the record, the study is observational: oxygen use is examined as it occurred in the data rather than as an intervention allocated by the study.

The stated data sources are existing administrative claims and electronic health record data. Eligibility includes patients aged ≥18 years with at least 2 fibrosing ILD diagnoses and continuous medical and pharmacy coverage for 12 months before the diagnosis date through a commercial, Medicaid, or Medicare plan. The primary endpoint further restricts its population to newly diagnosed eligible patients without baseline oxygen therapy use. The registry enrollment is 114921, but the number included in this endpoint population is not reported in the registry record. Enrollment should not be treated as the endpoint denominator.

The primary endpoint timeframe refers to up to 2099 days and identifies the patient identification period as 01 October 2016 through 30 June 2022. The registry lists the study start as 2023-07-25, primary completion as 2023-09-26, and status as COMPLETED. These administrative dates do not supply the missing endpoint result or explain the relationship between the patient identification period and the study start date.

The registry lists 10 outcome measures and 0 analyses. It names secondary outcomes related to hypoxemia and acute exacerbations, but the numerical results for those outcomes are not reported in the registry record. The record does not state an allocation method; it is not a randomized treatment comparison.

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 subjects were screened for eligibility prior to participation in the trial.

Overall Study

Analysis population for the primary outcome, as defined in the registry: Population AIM 1 include patients newly diagnosed with fibrosing ILD during the patient identification period and met all the eligibility criteria. Population AIM 1 in this endpoint restricted to patients without baseline oxygen therapy use.

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: Patients aged ≥18 years with newly diagnosed fibrosing ILD were identified from 01 October 2016 through 30 June 2022 (patient identification period) in existing data from a commercial, Medicaid, or Medicare plan, using existing administrative claims and electronic health record (EHR) data in Optum's Market Clarity Integrated Claims + Clinical database.

6. Primary Endpoint

The registry lists the primary outcome as Time to Oxygen Therapy Initiation, measured over Up to 2099 days (from 01 October 2016 through 30 June 2022 (patient identification period))..

The primary endpoint is time from the fibrosing ILD diagnosis date to oxygen therapy initiation, expressed in months. It applies to the specified primary endpoint population, which excludes patients with baseline oxygen therapy use. This measure addresses the timing of treatment initiation after diagnosis, rather than the proportion of patients who ever receive oxygen or a comparison of treatment effects.

The registry specifies the median and inter-quartile range as the descriptive summaries. In general, the median is the central value when observations are ordered, and the inter-quartile range describes the spread of the middle portion of those observations. These summaries can be useful for elapsed-time data when the distribution is asymmetric or includes unusually long times. They describe the observed timing pattern; by themselves, they do not establish that oxygen therapy caused any later clinical outcome.

The endpoint timeframe is described as up to 2099 days, within the patient identification period from 01 October 2016 through 30 June 2022. The registry says descriptive statistics are rounded to one decimal place. However, neither the median time nor its inter-quartile range is reported in the registry record. The number of patients contributing to this endpoint, the handling of patients without a recorded initiation date, and any approach to incomplete follow-up are also not reported in the registry record. Without those details and the endpoint estimate, the timing question cannot be quantified from the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the median time describe?

The endpoint is a time interval beginning at the fibrosing ILD diagnosis date and ending at oxygen therapy initiation. It is reported in months. The median gives a central summary of the observed times, while the inter-quartile range describes their spread. In general, these summaries are less dominated by a small number of unusually long observations than a mean can be. They still depend on how the analysis defines the starting date, initiation date, eligible patients, and follow-up.

The registry names the endpoint and its descriptive summaries, but it does not give the median or inter-quartile range. It also does not report how records without a documented oxygen initiation date were handled. For elapsed-time outcomes, incomplete observation can matter: a patient may have no recorded initiation during the available period, or the available record may end before initiation. General methods for such data can account for differing observation time, but the registry record does not report whether or how such methods were used. It is therefore not possible to infer a survival-analysis estimate from the endpoint description alone.

What is the role of the timeframe?

The endpoint description gives a timeframe of up to 2099 days and identifies the patient identification period as 01 October 2016 through 30 June 2022. The identification period tells the reader which diagnosis dates are relevant to cohort selection; it does not, by itself, state how long every patient was observed. The record does not explain the individual follow-up rules or the treatment of observation ending before oxygen initiation. Those details are important to interpreting a time-to-initiation summary.

The term “up to” indicates that the endpoint timeframe is not expressed as a single guaranteed observation period for every patient. General interpretation of time-to-event data distinguishes an event being observed from follow-up ending without an observed event. The method for handling that distinction is not reported in the registry record. No hazard ratio for this primary endpoint is reported in the registry record, and the stated primary result type is a median with an inter-quartile range, not a treatment-effect comparison.

Why does the observational design matter?

In general, random allocation can balance measured and unmeasured characteristics across treatment groups on average. This record does not describe random allocation and does not state an allocation method. It uses existing claims and electronic health record data, so treatment use is observed rather than assigned by the study. Comparisons based on observed oxygen use can be affected by differences in underlying health, disease severity, health care contact, or other factors. These are general sources of confounding in observational research; the registry record does not report which were measured or adjusted for in this study.

Claims and electronic health records are generated for care and administrative purposes. In general, a recorded diagnosis or treatment may depend on documentation and coding practices. The registry does not provide operational definitions for oxygen exposure or the listed clinical outcomes, nor does it describe validation of the data elements. Consequently, the record does not permit assessment of how exposure and outcome classification may affect estimates.

How should planning calculations be read?

General sample-size planning asks how many observations or events might be needed under stated assumptions to detect a chosen effect with specified statistical properties. The planning illustration assumptions in this record include a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of an observed effect. For time-to-event illustrations, the stated convention is to report the total number of events; other illustrations use participants per arm. These are planning conventions, not observed study results.

The record does not describe a randomized two-arm design, so equal allocation is an illustration assumption rather than a description of this study’s cohort. Planning figures do not show that a study actually achieved a particular power, and they do not replace the sponsor’s analysis. Sample sizes are planning illustrations, never observed power. If a recalculated estimate differs from the sponsor’s own analysis, the sponsor’s analysis takes precedence. The registry record does not report the numerical endpoint estimate needed to interpret an observed-effect-based planning illustration.

What statistical detail is absent?

The registry specifies descriptive rounding to one decimal place for the primary endpoint, but does not report the endpoint statistics. It lists 0 analyses, and does not report an inferential model, uncertainty interval, hypothesis test, covariate adjustment, missing-data approach, or sensitivity analysis. These details are not interchangeable: a descriptive median characterizes observed timing, while a model-based estimate or comparison would answer a different question and require additional assumptions. The primary endpoint description alone does not establish that such analyses were performed.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 10 outcome measures and identifies secondary outcomes concerning hypoxemia in baseline periods and acute exacerbations in baseline and follow-up periods. It reports 0 analyses. The numerical results for these outcomes are not reported in the registry record, and the record does not describe how the outcome measures were prioritized or analyzed together.

Multiplicity arises in general when several outcomes or comparisons are examined: the chance of at least one apparently notable finding can increase if no plan accounts for the number of analyses. Possible approaches include prespecifying a primary outcome, adjusting significance criteria, or treating secondary findings as exploratory. The registry record does not report whether any multiplicity strategy was specified or used. No multiplicity adjustment should be assumed.

The record does not report methods for missing data, incomplete follow-up, or patients lacking a recorded oxygen initiation date. It also does not describe whether missingness was assessed or whether sensitivity analyses were conducted. These omissions matter because the endpoint is based on elapsed time and existing records, where observation can vary across patients.

The primary endpoint population is defined as newly diagnosed eligible patients without baseline oxygen therapy use, but its size is not reported in the registry record. The registry enrollment of 114921 should not be substituted for that endpoint denominator. The record does not describe analysis populations beyond the endpoint eligibility language, including whether all eligible patients were analyzed or how exclusions after cohort selection were handled. Allocation is not stated, and the study is not described as randomized.

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

The record establishes the study’s intended descriptive focus and defines the primary endpoint: time from fibrosing ILD diagnosis to oxygen therapy initiation among eligible patients without baseline oxygen use. It also specifies a median and inter-quartile range as the summaries and identifies the relevant patient identification period. These details explain what the primary analysis is intended to describe.

The registry record does not report the median, inter-quartile range, or endpoint population size. It therefore does not establish how soon oxygen was initiated in the analyzed population or how much individual timing varied. It also does not provide results for the listed secondary outcomes or numerical comparisons of clinical outcomes by oxygen use. A study’s stated aim to assess impact should not be read as a finding that an impact was demonstrated.

Even if outcome comparisons were available, the observational design would limit causal interpretation. In general, people receiving a treatment may differ from those not receiving it for reasons related to both treatment and outcome. The record does not provide enough information about comparison groups, adjustment, or missing data to judge whether such differences were addressed. No conclusion that oxygen therapy caused a change in an outcome follows from the purpose statement or endpoint definition.

The registry status is COMPLETED, but completion status does not supply missing results. The listed enrollment is 114921; it is not the same as a reported endpoint analysis count. The record’s planning assumptions also do not establish observed power or an observed treatment effect. Overall, the registry provides a study description but not the numerical findings needed to quantify the primary result or evaluate outcome associations.

12. Why This Trial Matters Statistically

Statistically, this study illustrates the difference between defining an outcome and reporting its result. A time-to-initiation endpoint requires a specified starting point, event definition, eligible population, and approach to follow-up. The registry gives the starting event and the intended summary measures, but does not report the estimate or the population count contributing to it. Without those quantities, the primary question remains unquantified.

The study also raises a common interpretive issue in clinical research: data describing treatment use are not equivalent to randomized evidence about treatment effects. Existing claims and electronic health record data can describe patterns of care across a broad eligible population. But comparisons involving treatment use may reflect patient and disease differences as well as treatment. The record’s lack of reported comparison and adjustment details prevents assessment of that distinction.

The registry enrollment of 114921 can appear informative at first glance, but it does not establish the size of the primary endpoint population. Eligibility criteria and exclusion of baseline oxygen use define a more specific group, whose size is not reported in the registry record. Keeping enrollment separate from the endpoint denominator is essential when interpreting precision and representativeness.

Finally, the record lists multiple outcome measures but no analyses. That makes the distinction between planned outcomes and available evidence especially important. A listed outcome is not a reported finding, and planning calculations are not observed power. The record is useful for understanding the intended study question and design, while its missing endpoint and analysis results constrain what can be concluded statistically.

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 principal limitation of the registry record is that it does not report the primary endpoint estimate. Although time to oxygen therapy initiation is defined and the median and inter-quartile range are specified, neither value appears in the record. The endpoint population size is also not reported. This prevents assessment of the observed timing pattern and its precision.

The eligibility description relies on fibrosing ILD diagnoses and continuous medical and pharmacy coverage. The record does not report the operational diagnosis definitions, how oxygen initiation was identified, or whether these measures were validated. It does not describe data completeness, missingness, follow-up rules, or the handling of patients without an observed initiation date. These are specific uncertainties for a study using existing claims and electronic health record data.

The registry does not state allocation and does not describe randomization. It does not report comparison-group definitions, covariates, adjustment methods, or sensitivity analyses for outcomes associated with oxygen use. Thus, the record does not allow evaluation of confounding or of the robustness of any association. Numerical results for the listed secondary outcomes are also not reported in the registry record.

The adverse-event summary lists 21503 deaths for the group titled Patients With Fibrotic Interstitial Lung Disease (ILD). The relationship of this count to the primary endpoint population, study follow-up, and any particular analysis is not reported in the registry record. It should not be interpreted as a primary endpoint result or as evidence about oxygen therapy’s effect. The record lists 10 outcome measures and 0 analyses, leaving the statistical treatment of those outcomes unclear.

14. Related Tutorials

15. Related Statistical Calculators

16. Sources

• ClinicalTrials.gov: Oxygen Therapy Use in Patients With Fibrotic Interstitial Lung Disease — NCT05957198.
• Registry record last updated 2024-11-21; status last verified 2024-09.
• Results first posted 2024-11-21.
• 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.

17. Record Summary

NCT05957198, titled “Oxygen Therapy Use in Patients With Fibrotic Interstitial Lung Disease,” is listed as COMPLETED. The registry identifies Boehringer Ingelheim as sponsor, a study start of 2023-07-25, primary completion of 2023-09-26, and enrollment of 114921.

The study uses existing administrative claims and electronic health record data. Its primary endpoint is time from fibrosing ILD diagnosis to oxygen therapy initiation, reported as a median in months with an inter-quartile range, among eligible patients without baseline oxygen use. The endpoint timeframe is up to 2099 days, within the identification period from 01 October 2016 through 30 June 2022.

The registry lists 10 outcome measures and 0 analyses. The primary endpoint estimate, endpoint population count, secondary outcome results, missing-data methods, and analysis details are not reported in the registry record. The study is observational and is not described as a randomized comparison.