Feasibility of At-Home Handheld Spirometry: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Feasibility of At-Home Handheld Spirometry (NCT03284203), a na na study. The primary outcome is Comparison of KOKO Spirometry to SpiroPD Use.

2. Clinical Question

Thus, the clinical question combines a measurement question—whether handheld readings relate to bedside readings—with a practical question about consistent home use. The posted record does not include numerical results for the measurement comparison, adherence outcomes, or management-related hypotheses. It therefore does not establish the strength of the relationship between devices or the experience participants would have had using SpiroPD at home.

3. Trial Design

The registry identifies NCT03284203 as a study of handheld spirometry feasibility in COPD. It lists the study as a single-group device investigation, with allocation recorded as NA and masking recorded as none. The listed phase is NA. There is no separate randomized control group in the design information, so the study is not a head-to-head treatment trial and cannot support a randomized between-group treatment contrast.

The intervention was SpiroPD, a handheld spirometry device. The intended home procedure was daily use for 30 consecutive days. Measurements were to be stored by the device and synced over wifi to each participant’s associated online account. The primary outcome description also refers to comparison with bedside KoKo measurements at baseline and at a 30-day follow-up visit. The registry says that baseline KoKo measurements were compared with in-hospital SpiroPD use, but does not report the numerical results or the number of participants contributing to that comparison.

Enrollment was 8. The study start date is 2017-09-30, the primary completion date is 2017-11-20, and the status is listed as terminated. The reason for termination and any relationship between termination and study conduct are not reported in the registry record. No protocol details beyond the stated aims, device procedures, and outcome descriptions are reported.

The stated aims included assessing correlation between handheld and bedside lung-function measurements, feasibility and adherence to home testing, and preliminary management-related outcomes. The registry lists three outcome measures, but reports zero analyses. The record does not report a statistical analysis plan, a sample-size justification for the actual study, or results for the stated hypotheses. The study’s single-group structure and lack of home use are central to interpreting what can be learned from the posted 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: No participants were excluded from the study except those who did not meet the eligibility criteria.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: We have reported data from baseline KOKO spirometry measurements vs. in-hospital SpiroPD use. However, none of the 8 enrolled participants used the SpiroPD device at home and thus, no data from at-home spirometry exists for this analysis.

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.

6. Primary Endpoint

The registry lists the primary outcome as Comparison of KOKO Spirometry to SpiroPD Use, measured over 30 days from patient enrollment.

The primary outcome is titled “Comparison of KOKO Spirometry to SpiroPD Use.” It is a continuous measurement, reported as percentage of FVC, with the mean and standard deviation specified as the summary measures. Its timeframe is 30 days from patient enrollment. The description says daily SpiroPD measurements were intended to be collected over 30 days and compared with bedside KoKo measurements from baseline and the 30-day follow-up visit.

In general, a continuous outcome retains the measured values rather than reducing them to categories. A mean describes the central level of a set of measurements, while a standard deviation describes how dispersed those measurements are around the mean. These summaries can help describe device readings, but by themselves they do not establish whether two devices agree for individual measurements. The study’s stated measurement aim also refers to correlation. In general, correlation describes how measurements vary together; high correlation alone does not guarantee close agreement between devices.

The registry reports that participants used SpiroPD in hospital and that baseline KoKo measurements were compared with in-hospital handheld use. However, it gives no numerical mean, standard deviation, correlation estimate, confidence interval, or test result. It also states that none of the 8 enrolled participants used SpiroPD at home, leaving no at-home spirometry data for this analysis. The intended home-use period therefore describes the protocol objective, not an observed set of home measurements.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes an intended comparison of continuous lung-function measurements from a handheld device and bedside spirometry. It does not report the specific statistical methods used to analyze those measurements. The concepts below explain the types of methods relevant to the stated aims; they should not be read as a description of an analysis confirmed to have been performed.

What does a correlation measure?

The study’s first aim was to determine the correlation between SpiroPD and bedside KoKo measurements. In general, correlation measures the direction and strength of association between two sets of paired measurements. A positive association means that higher values on one measure tend to accompany higher values on the other; a weak association means that the paired values do not closely track one another. The registry record does not report a correlation coefficient, its confidence interval, or the method used to estimate it.

Correlation and agreement answer different questions. Two devices can rank people similarly while producing readings that differ systematically in level. Conversely, a comparison focused on agreement asks how close paired readings are, not merely whether they move together. In general, device evaluations may examine both association and the size and pattern of paired differences. The registry describes a comparison and states a correlation hypothesis, but the analysis approach for assessing agreement is not reported in the registry record.

What do the mean and standard deviation convey?

The primary outcome specifies the mean and standard deviation for a continuous measure expressed as percentage of FVC. In general, the mean is an average that describes the center of the measured values, while the standard deviation describes their spread around that average. These summaries are most informative when read alongside the number of observations and the way measurements were collected. The record does not report numerical means, standard deviations, or analysis sample sizes for the device comparison.

Repeated daily measurements can also create multiple observations for one participant. In general, measurements from the same person are often related rather than independent. Analyses that treat repeated observations as unrelated can give misleading uncertainty estimates. Appropriate methods depend on the actual data structure and research question, such as whether the target is a participant-level summary, change over time, or the relationship between paired device readings. The registry record does not state how daily measurements were aggregated or modeled.

Why does variability matter?

In general, variability affects how precisely an average or association can be estimated. Greater dispersion among readings can make estimates less precise, especially when only a limited number of independent participants contribute data. Repeated measures may add information, but they do not necessarily provide the same information as measurements from additional independent participants because observations within a participant can be correlated. The enrollment count is 8, but the number of usable paired observations and the handling of repeated readings are not reported in the registry record.

Over-dispersion is a general issue for count outcomes when observed variability exceeds what a chosen statistical model expects. It can lead to uncertainty estimates that are too small if ignored. It is not identified as an issue for the continuous primary measure in this record, and the registry does not report count-outcome analyses. The concept therefore should not be taken as evidence that over-dispersion occurred in this study.

How should planning illustrations be understood?

Any sample-size figures associated with planning are illustrations, not results from the enrolled participants. The stated illustration assumptions are 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 the observed effect. For time-to-event outcomes, the stated convention is a total event count; for other outcomes, it is participants per arm. These are planning conventions and do not describe the actual single-group design, which has no two-arm allocation.

The registry does not report the observed effect estimate or the resulting planning counts in the information available for this analysis. The actual study enrollment was 8, and a planning calculation cannot change that enrollment or create observations. Sample-size planning estimates are not observed power. In general, post hoc power calculations based on an observed estimate are not a substitute for reporting an effect estimate with its uncertainty.

The record does not state whether an interim analysis was planned or conducted, what hypothesis-testing procedure was used, whether confidence intervals were calculated, or whether the primary analysis was adjusted for covariates. It also does not report a prespecified threshold for interpreting the size of correlation as substantial. These omissions limit reconstruction of the statistical analysis from the registry. No unadjusted recalculation or alternative estimate is reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists three outcome measures: the primary comparison of KoKo and SpiroPD spirometry and secondary measures concerning daily device adherence and consistent home use. The study description also states hypotheses about medication adherence and acute care utilization. The registry lists zero analyses and does not report outcome estimates for these measures.

When several outcomes or hypotheses are tested, multiplicity is a general concern: the chance of at least one apparently notable result can increase as more tests are considered. Researchers may prespecify a primary outcome, use an adjustment procedure, or treat secondary analyses as exploratory. The registry record does not report a multiplicity strategy or enough analysis detail to determine whether any adjustment was used. No result should therefore be interpreted as having a particular multiplicity control on the basis of this record.

Missing-data methods are also not reported. For the home component, the record states that none of the 8 enrolled participants used the device at home, so there are no at-home spirometry data for the analysis. This is an absence of home-use data, rather than a reported set of home readings with some values missing. The reason participants did not use the device at home is not reported.

The number of participants included in the in-hospital comparison, the handling of incomplete measurements, and any analysis population definitions are not reported in the registry record. It is also not reported whether all enrolled participants contributed to any particular outcome. Without those details, the enrolled count should not be assumed to be the analysis count for each measure.

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.

The adverse-event record lists 8 participants at risk in the SpiroPD group for serious adverse events and 8 at risk for other adverse events. It records 0 participants affected in each category and 0 deaths. No serious adverse-event terms are listed.

These are registry counts, not comparative estimates. The study is listed as single group, so the figures do not compare SpiroPD with a separate control group. A count of zero affected participants in this record means that no affected participants are recorded in the specified categories; it does not by itself establish that an event is impossible or characterize risk beyond the participants and reporting represented in the registry.

The record does not provide further detail about event definitions, observation time for safety reporting, event collection procedures, or whether any events were judged related to the device. The primary outcome’s 30-day timeframe should not be assumed to define the safety observation period, because a safety timeframe is not reported in the registry record. The figures should therefore be read as the posted adverse-event counts, without extending them to broader claims about safety.

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

The registry record documents a study intended to examine handheld spirometry use in hospital and at home, compare SpiroPD readings with bedside KoKo measurements, and assess feasibility and adherence. It reports that 8 participants enrolled and that none used the SpiroPD device at home. As a result, the record states that no at-home spirometry data exist for the analysis. That is the clearest finding about the home-use component.

The record does not report numerical results for the in-hospital device comparison. It provides no correlation estimate, mean, standard deviation, confidence interval, or p-value. Therefore, the size and precision of the relationship between SpiroPD and KoKo measurements cannot be assessed from the posted information. The study hypothesis that the device measurements would be substantially correlated should not be confused with an observed result.

The absence of home readings also means that the registry cannot establish how consistently participants would adhere to daily home spirometry under the intended procedure. The planned assessments of medication adherence and acute care utilization are not accompanied by reported results. The record does not show whether these outcomes changed, nor does it explain why home use did not occur.

In general, feasibility studies can inform whether intended procedures are implemented and what data are available, while estimates of measurement performance require reported observations and uncertainty. Here, the registry supports interpretation of implementation as documented, but not a quantitative assessment of device performance or management outcomes. It also does not establish how findings would generalize to other participants or settings.

The status is terminated, but the reason is not reported in the registry record. That status should not be treated as evidence of a particular outcome or cause. The appropriate conclusion is limited to the documented enrollment, the absence of at-home use, the listed design, and the lack of posted numerical analyses.

13. Why This Trial Matters Statistically

This trial raises an important statistical distinction between a planned measurement study and an evaluable comparison. The objective was to compare handheld spirometry with bedside measurements, but interpreting that objective requires paired observations, a clearly described analysis, and numerical estimates with uncertainty. The registry states that an in-hospital comparison was reported, yet supplies no numerical comparison results or analysis details. Without those, readers cannot judge the size or precision of the relationship between devices.

The home-use component illustrates a different issue: data availability depends on whether the intended procedure actually occurs. The stated daily home-testing plan was for 30 consecutive days, but none of the 8 enrolled participants used the device at home. The resulting absence of at-home readings is not repaired by a statistical method. It changes which study questions can be answered from the collected data.

Feasibility outcomes and measurement outcomes are related but not interchangeable. A device may be assessed for whether people can use it consistently, while its readings are separately assessed against another measurement method. In general, both questions need explicit definitions and suitable observations. The registry identifies these aims, but does not report the outcome estimates needed to assess them quantitatively.

The record also demonstrates why study status and study results should be read separately. It is listed as terminated, but the reason is not reported. Neither that status nor a planning illustration establishes a treatment or measurement effect. Statistical interpretation depends on observed data, analysis methods, and uncertainty; the record does not report enough of these elements to support broad claims about device performance or clinical consequences.

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 main trial-specific limitation is that no enrolled participant used SpiroPD at home. This leaves the planned home spirometry assessment without at-home readings and prevents evaluation of the intended daily home-use procedure from those data. The reason for nonuse is not reported, so the record does not identify whether this reflected participant preference, logistics, device issues, study conduct, or another cause.

Enrollment was 8, and the registry does not report the number of participants with usable data for the in-hospital comparison. It reports no numerical primary outcome results, including a correlation estimate or mean and standard deviation. There are also no reported confidence intervals or p-values. Consequently, the precision of the in-hospital comparison cannot be evaluated from the registry record.

The record does not report details of the statistical analysis, the handling of repeated daily measurements, missing-data procedures, analysis populations, or multiplicity. The reason for the terminated status is also not reported. Although the study description states intended aims and procedures, it does not report whether all were completed or how each outcome was analyzed.

The single-group design does not include a randomized control arm. It is therefore not suited to a randomized comparison of separate groups, and the posted design should not be interpreted as if it had such a comparator. These limitations are specific to the information recorded for this study and constrain conclusions about feasibility, measurement performance, adherence, and management-related outcomes.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Feasibility of At-Home Handheld Spirometry — NCT03284203.
• Registry record last updated 2023-05-31; status last verified 2023-05.
• Results first posted 2023-05-31.
• 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

NCT03284203, titled “Feasibility of At-Home Handheld Spirometry,” is a single-group device study in COPD, sponsored by the University of Chicago. The registry lists 8 enrolled participants, allocation as NA, masking as none, and status as terminated. The listed study start date is 2017-09-30, and the primary completion date is 2017-11-20.

The intervention was SpiroPD, intended for daily home use over 30 consecutive days. The primary outcome concerned comparison of KoKo spirometry with SpiroPD measurements, expressed as percentage of FVC and summarized by mean and standard deviation. The record reports baseline KoKo versus in-hospital SpiroPD data but includes no numerical analysis results. None of the 8 participants used the device at home, and no at-home spirometry data exist for the analysis.

The registry lists three outcome measures and zero analyses. It records 0 participants affected by serious adverse events, 0 affected by other adverse events, and 0 deaths among 8 at risk in each adverse-event category. The reason for termination and the detailed statistical analysis plan are not reported in the registry record.