Evaluating Efficacy of Digital Health Technology in the Treatment of Congestive Heart Failure: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluating Efficacy of Digital Health Technology in the Treatment of Congestive Heart Failure (NCT04394754), a randomized na study. The primary outcome is Change in Quality of Life at 90 Days Post Enrollment.

2. Clinical Question

3. Trial Design

The registry describes a randomized, single-masked, parallel study of digital health technology in the management of congestive heart failure. Its four arms were usual care, BodyPort, Noom, and Conversa. Participants in the control arm received usual care and no digital health device; the other arms received the BodyPort device or a subscription to the Noom or Conversa platform. The registry reports overall enrollment of 182.

The study is listed as completed. Its recorded start date is 2020-09-21, and its primary completion date is 2021-09-20. The phase is listed as NA. The sponsor is Yale University. These administrative details describe the registry record, but do not establish how participants were recruited, how randomization was implemented, or how the products were delivered in practice.

Single masking indicates that the registry classifies the study as masked, but does not identify who was masked or explain how masking was maintained. Details of the allocation sequence, concealment, protocol deviations, adherence, and treatment exposure are not reported in the registry record. The parallel design indicates that the arms were concurrent study groups; it does not by itself establish that each arm received the same follow-up or had comparable outcome data.

The primary outcome was change in KCCQ quality-of-life score at day 90 after enrollment. The registry also lists secondary outcomes involving quality of life at day 180, hospital admission, guideline-directed medical therapy, and emergency department visits, among other measures. It records 29 outcome measures, but reports zero analyses. Numerical primary-outcome results and formal comparisons are not reported in the registry record, limiting what can be concluded about the study's findings.

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.

Overall Study

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 Change in Quality of Life at 90 Days Post Enrollment, measured over Day 90 after enrollment.

The primary endpoint is change in quality of life from baseline at enrollment to day 90, assessed with the Kansas City Cardiomyopathy Questionnaire (KCCQ). The registry describes the KCCQ as a 23-item self-administered instrument that captures a patient's perception of health status. Its domain scores are transformed to a range from 0 to 100. Higher score bands correspond to more favorable descriptions of health status: 0 to 24 is very poor to poor, 25 to 49 is poor to fair, 50 to 74 is fair to good, and 75 to 100 is good to excellent.

The instrument reports several related domains and summary scores. The Total Symptom score combines Symptom Frequency and Symptom Burden; the Overall Summary Score combines Physical Limitation, Total Symptom, Quality of Life, and Social Limitation; and the Clinical Summary score combines Physical Limitation and Total Symptom. These measures offer structured ways to describe patients' perceptions, rather than relying only on a single clinical event.

Quality of life is used as the primary endpoint because the registry's stated study purpose centers on improvement in quality of life. The registry specifies a median as the summary measure and an inter-quartile range as the measure of dispersion. It does not report the observed baseline or follow-up scores, the change estimates, or the exact KCCQ score or domain used for the primary analysis. Those results are not reported in the registry record, so the endpoint's observed magnitude and precision cannot be assessed.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies a randomized, parallel-group study with four arms and a primary outcome based on change in KCCQ score. The primary outcome summary is specified as a median with an inter-quartile range. This tells readers the intended descriptive form of the result, but it does not identify the model or test used to compare arms. The statistical analysis plan, including any adjusted or unadjusted comparisons, is not reported in the registry record.

What do the median and inter-quartile range convey?

As a general statistical explanation, the median is the central observation when values are ordered. It can be useful when a distribution is skewed or includes unusually high or low values because it is less sensitive to extremes than the mean. The inter-quartile range describes the spread of the central half of the observations. These summaries show where observations are concentrated and how much they vary, but they do not alone quantify the uncertainty of a comparison between groups.

For this study, the median and inter-quartile range are specified for the primary outcome, but their numerical values are not reported in the registry record. A reader therefore cannot assess the observed distribution of KCCQ change or determine whether the groups differed. The record also does not say whether the primary comparison was based on raw change scores, an adjusted model, or another procedure.

What does the KCCQ score represent?

The registry describes the KCCQ as a 23-item self-administered measure of perceived health status. Scores are transformed to a 0 to 100 range, and the listed score bands run from very poor to poor through good to excellent. The instrument includes symptom, physical limitation, quality-of-life, and social limitation domains, with specified combinations forming summary scores. These components make the outcome relevant to patients' reported experience, while also meaning that an analysis needs to identify which score or summary is used.

The primary outcome title refers to change in quality of life at day 90, while its description discusses several KCCQ domains and summary scores. The exact score used for the primary result is not reported in the registry record. Nor is there a reported estimate of change for any domain or summary. Thus, the scale description clarifies how KCCQ scores are interpreted but does not supply an outcome finding.

How should uncertainty be assessed?

In general, a confidence interval expresses the range of effect sizes compatible with the data and the method used to calculate it. Its width gives information about precision; it is not a probability statement that the true effect lies within a particular interval. A p-value, when used, describes the compatibility of the data with a specified null model under the analysis assumptions; it does not measure clinical importance. The registry record does not report a confidence interval or p-value for the primary outcome, and the comparison procedure is not reported.

Because there are four arms, interpretation would also require knowing which contrasts were planned and how the analysis handled multiple comparisons. A comparison of each product with usual care is a different question from comparisons among all arms. The registry does not report the planned contrast structure or a multiplicity adjustment. No particular test or model should be inferred from the randomized design, the choice of median, or the outcome title.

Why do distribution and allocation matter?

As a general statistical explanation, over-dispersion occurs when observed variability is greater than a model assumes. If an analysis treats observations as less variable than they are, uncertainty can be understated and inferences can become too confident. The registry does not report an over-dispersion assessment or a model for the primary outcome. Since the numerical results and analytic method are also not reported, it is not possible to evaluate whether distributional assumptions were appropriate.

Random allocation is intended to reduce systematic differences between groups at the start of a study. It does not ensure perfect balance in every characteristic, and it does not prevent missing outcome data or differences in adherence after assignment. Details of the randomization procedure and baseline characteristics are not reported in the registry record. The listed overall enrollment does not, by itself, describe the number included in each primary-outcome analysis.

What does the planning illustration mean?

The registry's sample-size assumptions describe a planning illustration based on the observed effect, using a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. These are planning assumptions, not a report of observed power. Such calculations describe a hypothetical future design under specified assumptions; they do not show the probability that this completed study detected an effect. The registry record does not report a sample-size justification from the trial's own design, and the primary outcome effect used as the illustration's basis is not reported in the registry record.

More broadly, the design classification and outcome definitions support understanding what was planned, while numerical estimates and a prespecified analysis are needed to assess findings. The registry lists zero analyses. The particular statistical methods actually used, any adjustments, diagnostic checks, and treatment of missing data are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry records 29 outcome measures, including a primary quality-of-life measure and secondary outcomes related to quality of life, hospital admissions, medical therapy, and emergency department visits. The stated purpose also refers to patient and provider satisfaction, clinical efficiency, and patient outcomes. Having multiple measured outcomes can create multiplicity: the more statistical comparisons examined, the greater the opportunity for apparently notable findings to arise by chance if testing is not planned or accounted for. This is a general statistical concern, not a claim about what occurred in this study.

The registry does not report a multiplicity strategy, a hierarchy among secondary outcomes, or which comparisons were designated confirmatory. It also records zero analyses. As a result, the registry record does not show whether any adjustment, outcome prioritization, or other approach was used. The repeated listing of prescribing of guideline-directed medical therapy among the secondary outcomes does not clarify which measure or analysis was intended.

Missing-data methods are not reported in the registry record. In general, the amount and pattern of missing follow-up data can affect both the precision and interpretation of a treatment comparison, especially when missingness differs between groups or relates to participants' outcomes. The record does not report the number with day-90 KCCQ data, reasons for missingness, imputation methods, or sensitivity analyses. Completion status does not establish completeness of outcome follow-up.

The analysis populations are also not reported in the registry record. It is therefore unclear from the registry whether results were intended to include all randomized participants, participants with available outcome data, or another defined population. The posted record provides no numerical primary results with which to examine these issues.

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 registry's safety entries show zero serious adverse events and zero other adverse events in each arm's recorded at-risk group. The at-risk counts are 44 for Control, 46 for BodyPort, 46 for Noom, and 46 for Conversa. These are the figures recorded in the safety section; they should not be interpreted as a complete account of every possible harm unless the registry establishes that all relevant events were captured and reported. The record does not describe event definitions, surveillance procedures, or the period covered by these entries.

Deaths are listed separately from serious and other adverse events: one for Control, two for BodyPort, zero for Noom, and two for Conversa. The registry does not state whether these deaths were considered related to a product, the study, or the underlying condition. A count alone cannot establish causation, and the record does not provide contextual details or a comparative safety analysis.

The zero entries for the two adverse-event categories do not mean that the study established absence of risk. They describe what was entered in those categories. The safety record also does not indicate whether the groups were compared statistically. The counts should therefore be read descriptively and alongside the limits of the registry's reporting, not as proof that any product is safe or unsafe.

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

The registry record establishes that a randomized, single-masked, parallel study evaluated BodyPort, Noom, and Conversa against usual care for people with congestive heart failure. It specifies change in KCCQ quality-of-life score at day 90 as the primary outcome, gives a description of the instrument, and lists additional outcomes. These details clarify the research question and the outcome framework.

The record does not report numerical primary-outcome results, an estimate of the difference between any intervention and usual care, or uncertainty around such a difference. It also does not report analyses of the listed secondary outcomes. As a result, the record cannot show whether quality of life changed, how large any change was, or how precisely an arm comparison was estimated. It cannot establish that the products improved quality of life or that they had no effect.

Study completion and enrollment are administrative and design details, not efficacy findings. Similarly, an outcome's presence in the registry indicates that it was listed for measurement, not that a result was published in the record. The safety entries report zero serious and other adverse events in each arm's recorded at-risk group, along with separately listed deaths. They do not establish causal attribution or comparative safety.

In general, a treatment effect is interpreted using an estimate, its uncertainty, the design and analysis assumptions, and the clinical meaning of the outcome. The registry record does not provide enough result-level information to make that assessment for the primary question. Missing details about analysis populations, missing data, multiplicity, and the statistical methods further limit interpretation. These limitations apply to what can be concluded from the registry record; they are not proof that no analyses or results exist elsewhere.

13. Why This Trial Matters Statistically

This study raises a useful statistical question about evaluating several digital health products against usual care when the central outcome is patient-reported quality of life. The KCCQ offers a structured measure of health status, with domains covering symptoms, physical limitation, quality of life, and social limitation. A focus on a reported health-status measure differs from relying exclusively on hospital admissions or other clinical events, and it calls for clear reporting of the chosen score and its interpretation.

The four-arm design also makes the comparison strategy important. The research question could involve separate comparisons of each product with usual care, comparisons among digital products, or a broader assessment across arms. Those choices determine which estimates readers need and how multiple comparisons should be interpreted. The registry identifies the arms but does not report the planned contrasts or analysis strategy.

Outcome breadth is another statistical consideration. The registry lists 29 outcome measures, spanning quality of life, hospital admission, medical therapy, and emergency department visits. For readers to distinguish primary from exploratory findings, reporting should make clear which outcomes and contrasts were prespecified, how uncertainty was quantified, and how multiplicity was addressed. Those analysis details are not reported in the registry record.

The record is also a reminder that a detailed outcome description is not a substitute for numerical results. Naming the instrument, time point, and summary measure helps define what was intended to be assessed, but readers need the arm-level estimates, comparison estimates, and precision to understand the findings. Since the primary results and analyses are not reported, the registry supports discussion of the trial's statistical design and reporting needs, but not a conclusion about the comparative effects of the products.

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.

Several limitations are specific to the available registry record. The primary outcome is described as quality-of-life change at day 90, but numerical arm-level summaries and between-arm comparisons are not reported. Although the primary outcome specifies median and inter-quartile range, the record does not state which KCCQ score or domain posted the primary result. Because the KCCQ description includes multiple domains and summary scores, the precise endpoint cannot be identified beyond the general quality-of-life change description.

The study has four arms, but the record does not describe the planned comparison strategy, randomization implementation, allocation concealment, or who was masked. It does not provide group-level baseline characteristics or clarify how many participants contributed to each outcome analysis. Overall enrollment is reported, but that alone does not establish the analysis population or follow-up completeness.

The registry lists 29 outcome measures and zero analyses. It does not report a statistical analysis plan, multiplicity procedures, missing-data methods, or sensitivity analyses. The secondary outcome list includes repeated wording for prescribing of guideline-directed medical therapy, without enough detail in the record to determine how the entries relate to distinct measurements or analyses.

For safety, the registry lists event counts and at-risk groups, but does not define event ascertainment, provide causal attribution for deaths, or describe a comparative safety analysis. The record's completed status does not resolve these reporting gaps. These limitations constrain conclusions drawn from the registry record and do not establish what may have been reported in other sources.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Evaluating Efficacy of Digital Health Technology in the Treatment of Congestive Heart Failure — NCT04394754.
• Registry record last updated 2023-05-18; status last verified 2023-04.
• Results first posted 2022-12-23.
• 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 describes a completed randomized, single-masked, parallel study sponsored by Yale University, with enrollment of 182 and a listed phase of NA. The study evaluated the BodyPort device, Noom platform, and Conversa platform against usual care for congestive heart failure. The recorded start date is 2020-09-21, and the primary completion date is 2021-09-20.

The primary outcome was change in KCCQ quality-of-life score at day 90, summarized by median and inter-quartile range. The record lists 29 outcome measures and zero analyses. Numerical primary and secondary outcome findings, analysis methods, missing-data procedures, and multiplicity plans are not reported in the registry record. Safety entries list zero serious and zero other adverse events in each recorded at-risk group, with deaths listed separately by arm.