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 Self-monitoring of Weight & Blood Pressure (Via patientMpower Platform) in Hemodialysis (NCT03403491), a randomized na study. The primary outcome is Patient Engagement With patientMpower App to Record Body Weight.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03403491 |
| Phase | NA |
| Condition | Renal Dialysis |
| Allocation | Randomized |
| Design model | Crossover |
| Masking | None (open label) |
| Enrollment | 43 |
| Arms in the primary outcome | n/a |
| Lead sponsor | patientMpower Ltd. |
| Results posted | Yes |
2. Clinical Question
Population
Ambulatory haemodialysis patients. The registry lists an enrollment of 43 and describes the primary endpoint population as patients who started the patientMpower observation period and recorded body weight at least once. The number included in that endpoint analysis is not reported in the registry record.
Intervention
The patientMpower electronic health journal, used with digital weighing scales and a blood pressure monitor. Patients could record body weight and other daily information, including blood pressure and fluid intake.
Comparator
A sham application without digital scales or a blood pressure monitor, alongside usual care. The two observation methods were given in randomized order after a usual-care run-in.
Primary question
During the patientMpower observation period, how many days did patients report body weight in the app over the 28-day timeframe? The endpoint is a measure of recorded engagement, not a direct measure of clinical benefit.
The trial also set out to examine clinical and behavioral outcomes, including ultrafiltration rate, interdialytic weight gain, pre-dialysis weight and blood pressure, medication adherence, daily recording, and unscheduled dialysis. Its brief summary also describes an objective concerning the app’s acceptability and utility from patient and healthcare professional perspectives. These objectives frame what the trial was designed to assess; the registry record does not report comparative estimates for them.
The primary question is narrower than whether self-monitoring changes health outcomes. It concerns use of the app for body-weight reporting among patients who began the relevant observation period and recorded weight at least once. That population definition excludes patients who did not meet those conditions, while the number meeting them is not reported in the registry record. The record also does not report the primary endpoint’s mean, standard deviation, or a comparison between observation periods.
3. Trial Design
The registry describes a prospective, randomized, open-label, sham-controlled, two-period crossover pilot. The listed enrollment is 43. Participants were assigned to one of two sequences. Each sequence began with usual care for 2 weeks and then included 4 weeks with each observation method. In one sequence, patientMpower preceded the sham application; in the other, the sham application preceded patientMpower. The stated total duration was 10 weeks.
A crossover design exposes participants to both observation methods in a randomized order. In general, this can allow within-person comparisons, because each participant may contribute information under both conditions. The registry record does not report the analysis method or indicate how any within-person correlation was handled. It also does not report whether period effects or possible carryover from the first observation period were assessed or addressed.
The study was open-label: the masking entry is “NONE.” The applications also differed in whether digital scales and a blood pressure monitor were included. This design therefore contrasts the patientMpower package with the sham application as described, rather than isolating the app’s software from the devices or the act of self-monitoring. The registry record does not report participant or staff blinding procedures beyond the masking entry.
The primary objective was to determine frequency of use of the patientMpower app in patients randomized to that observation method. The primary outcome is specified as the mean number of days body weight was reported, over a 28-day timeframe. Secondary outcomes include measures of ultrafiltration rate, interdialytic weight gain, pre-dialysis weight and blood pressure, and medication-adherence recording. The record lists 17 outcome measures overall.
The study is marked completed, with start and primary completion dates of 2018-11-07 and 2019-03-08. Completion status describes the trial’s recorded status, not whether results were posted. The analyses count is 0, and no outcome results are reported in the registry record. The protocol’s sample-size justification, randomization procedure details, and analysis plan 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.
Overall Study
| Stage | Sequence 1 | Sequence 2 |
|---|---|---|
| STARTED | 20 | 23 |
| COMPLETED | 17 | 18 |
| NOT COMPLETED | 3 | 5 |
Analysis population for the primary outcome, as defined in the registry: All patients who started patientMpower observation period and who recorded weight at least once
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: All randomised patients who started the study observations
| Characteristic | Unit | All Patients |
|---|---|---|
| Participants analysed | 43 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 37 |
| Age, Categorical: >=65 years | Participants | 6 |
| Age, Continuous | years | 51.42 (SD 13.98) |
| Sex: Female, Male: Female | Participants | 15 |
| Sex: Female, Male: Male | Participants | 28 |
| Race/Ethnicity, Customized: white | Participants | 39 |
| Race/Ethnicity, Customized: black | Participants | 3 |
| Race/Ethnicity, Customized: Asian | Participants | 1 |
| Region of Enrollment: Ireland | participants | 43 |
| time since first-ever hemodialysis | years | 3.44 (SD 3.71) |
| vascular access modality: permcath | Participants | 25 |
| vascular access modality: arteriovenous fistula | Participants | 18 |
6. Primary Endpoint
The registry lists the primary outcome as Patient Engagement With patientMpower App to Record Body Weight, measured over 28 days.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | days |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the actual number of days on which a patient reported body weight through the patientMpower app. Its timeframe is 28 days, and the registry specifies that it is summarized as a mean with a standard deviation. The endpoint population is patients who started the patientMpower observation period and recorded weight at least once.
This measure is intended to describe engagement with the self-monitoring tool: it counts days with a weight report, rather than measuring the amount of weight change or a clinical event. Recording frequency can indicate whether the intended data-entry behavior occurred during the observation period. As a measure of use, it may also help distinguish the availability of a digital tool from its actual uptake by participants.
There is an important population qualification. Requiring at least one weight entry means the stated endpoint population does not include patients who started the period but never recorded weight. The registry record does not report how many patients met the endpoint definition, how missing days were treated, or whether any other data-quality rules were applied.
The endpoint does not by itself establish whether recorded weights were accurate, whether monitoring altered clinical management, or whether a clinical outcome changed. Those are different questions. The record names additional clinical and behavioral outcomes, but it does not report their estimates or the primary endpoint’s mean and standard deviation. Thus, the endpoint definition is available, while its observed result is not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record specifies a primary measure of engagement but does not post its result. It gives the endpoint definition, unit, summary type, timeframe, and analysis population, but no mean number of reporting days, standard deviation, confidence interval, or test result. The record also lists 0 analyses. Consequently, there is no registry-reported estimate from which to describe the amount or precision of app use, and no reported comparative estimate for the primary outcome.
The crossover structure matters when interpreting any comparison. In general, a crossover study can compare observations from the same participant under each condition, but that comparison depends on the way the data are analyzed. The registry record does not report whether a within-participant analysis was used, how period effects were handled, or whether possible carryover was considered. Without the analysis details and results, the planned design cannot be translated into a claim about the direction or size of any difference.
The endpoint is also conditional on having started the patientMpower observation period and recorded weight at least once. This makes the endpoint a description of reporting among the defined population, not necessarily a summary of all enrolled participants. The number who met that definition and the number with missing or unusable observations are not reported in the registry record. A reader therefore cannot assess how the endpoint population compares with the enrolled population.
The trial’s brief summary names further objectives: proportions of haemodialysis sessions meeting specified ultrafiltration-rate and interdialytic-weight-gain thresholds, pre-dialysis weight and blood pressure, medication adherence, daily recording, unscheduled dialysis, and acceptability and utility. The secondary-outcome list also includes relative and absolute interdialytic weight gain and several other measures. These are stated objectives and outcomes, not reported findings. Their estimates, uncertainty, and analysis populations are not reported in the registry record.
Safety figures are recorded for the sham and patientMpower observation periods, including serious adverse event counts and deaths. These descriptive counts do not supply a treatment-effect estimate, and the registry record does not report an inferential comparison for safety. The small pilot-scale setting and crossover structure also mean that counts should be interpreted in the context of the recorded observation periods, rather than as evidence of a definitive between-group effect.
In general, confidence intervals communicate the range of values compatible with an estimate under the statistical model. No confidence interval is reported for the primary endpoint in the registry record. The record therefore does not establish whether any estimated difference would be precise, imprecise, or compatible with a broad range of possibilities. It supports description of the intended question and design, but not a conclusion about the magnitude or certainty of an outcome.
9. Statistical Methods Explained
The registry describes a randomized crossover comparison, but it does not report the statistical analysis methods used. The following concepts explain how such a design and the listed summary measures are generally interpreted; they are not claims about procedures used in this trial.
What does a crossover design compare?
In a crossover study, participants receive the compared conditions in different orders. A within-person comparison can account for stable characteristics that differ between people, because observations from the same person are related. That benefit depends on appropriate analysis and on the design assumptions being reasonable. Measurements from a person under different conditions are not independent observations. Treating them as if they came from unrelated groups can misstate uncertainty.
Time and order can also matter. Outcomes may change over the course of a study for reasons unrelated to the assigned observation method. A period effect is a change associated with the period in which an observation is made. Carryover refers to an influence of an earlier condition that persists into a later period. In general, a crossover analysis may need to account for such features. The registry record does not report whether the trial assessed period effects or carryover, or how its analysis addressed them.
What does the primary summary describe?
The primary outcome is a continuous count of reporting days, summarized using a mean and standard deviation. A mean describes the average value in the analyzed population. A standard deviation describes the spread of individual values around that average; it is not the uncertainty of the mean. The record does not report either statistic for this endpoint. It also does not report a confidence interval or test result.
A confidence interval is a statistical range expressing uncertainty around an estimate under a stated method and assumptions. It is not a guarantee that the true value lies within the interval. If a comparison estimate and interval were reported, the estimate would describe the direction and size of the contrast, while the interval would show how precisely it was estimated. Neither is reported for the primary endpoint in the registry record, so no numerical interpretation of a contrast is available.
Why might the outcome distributions matter?
General statistical reasoning also depends on the outcome’s distribution and analysis population. Reporting days are bounded by the observation timeframe and may not follow a normal distribution, especially if many participants have similar or extreme reporting patterns. A mean and standard deviation can still be useful descriptive summaries, but additional distributional information may help readers understand whether values cluster or vary. No distribution plots or participant-level data are described in the registry record, and no alternative summary or modeling method is reported.
For session-level proportions, the observations within a participant may be related. In general, a statistical method that accounts for clustering can be more suitable than treating every session as independent. Over-dispersion occurs when the variability in count or proportion data exceeds what a chosen model expects. If present, it can make standard errors too small when ignored. The registry names several outcomes based on proportions, but the analysis methods and any assessment of over-dispersion are not reported in the registry record.
How should the safety counts be read?
Adverse-event summaries are descriptive counts of affected participants or events, depending on the registry’s reporting convention. They do not automatically establish that an observation method caused an event. In a crossover study, the same participant may contribute exposure to both observation periods, so period-level counts should not be treated as independent sets of people without information on event timing and participant overlap. The registry record does not report those details or a statistical safety comparison.
What do planning calculations mean?
In general, sample-size calculations use assumptions about the effect to detect, outcome variability, allocation, significance level, and desired power. Planning illustrations are conditional on those assumptions and are not observed power, nor do they show that a trial was adequately sized for every outcome. The registry record does not report the trial’s own sample-size justification or power calculation. It also does not report the underlying estimates and analysis details needed to assess the precision of an outcome comparison.
Because the record lists 0 analyses and no outcome estimates, there are no reported recalculated comparisons to interpret. A statistical method cannot recover an outcome result from a design description alone. Any conclusion about an effect, its size, or its uncertainty would require results and analysis information that are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The record lists 17 outcome measures and several objectives, but does not report a multiplicity plan. When a study examines multiple outcomes or contrasts, the chance of at least one apparently notable result can increase if each is assessed separately without an adjustment or prespecified hierarchy. In general, a multiplicity strategy can define which outcomes are confirmatory, how comparisons are ordered, or how uncertainty is adjusted. The registry record does not report whether such a strategy was used.
Missing-data procedures are also not reported in the registry record. The primary endpoint population is restricted to patients who started the patientMpower period and recorded weight at least once. This definition does not tell readers how days without a recorded weight were treated, whether there were withdrawals, or how incomplete endpoint data were handled. The number of participants meeting the endpoint definition is not reported.
The record does not report analysis populations for the secondary outcomes, nor whether all randomized participants were included in any analysis. It does not specify an intention-to-treat, per-protocol, or other analysis population. Such labels describe which participants contribute to an analysis and can affect interpretation, particularly when eligibility for an endpoint depends on having data recorded.
Since the analyses count is 0 and results are not reported, readers cannot assess missingness patterns, compare analysis populations, or determine whether sensitivity analyses were conducted. The approach to missing data, multiplicity, and analysis-population definitions is not reported in the registry record.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Sham Observation Period | 1 | 43 | 2.3% |
| patientMpower Observation Period | 2 | 43 | 4.7% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Sham Observation Period | 0 of 43 |
| patientMpower Observation Period | 0 of 43 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Sham Observation Period | 0 of 43 |
| patientMpower Observation Period | 1 of 43 |
Most frequent serious adverse event terms
| Event term | Organ system | Sham Observation Period | patientMpower Observation Period |
|---|---|---|---|
| leg fracture | Musculoskeletal and connective tissue disorders | 1 of 43 | 0 of 43 |
| hypertension | Cardiac disorders | 0 of 43 | 1 of 43 |
| alcohol withdrawal seizure | Injury, poisoning and procedural complications | 0 of 43 | 1 of 43 |
| arteriovenous fistula thrombosis | Injury, poisoning and procedural complications | 0 of 43 | 1 of 43 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Sham Observation Period | patientMpower Observation Period |
|---|---|---|---|
| fall | General disorders | 0 of 43 | 1 of 43 |
Serious events with the highest arm-level rate: leg fracture (2.3%), hypertension (2.3%), alcohol withdrawal seizure (2.3%), arteriovenous fistula thrombosis (2.3%).
The registry reports serious adverse events separately for the sham observation period and the patientMpower observation period. In each period, the number at risk is 43. The sham period lists 1 serious adverse event and 0 other adverse events; the patientMpower period lists 2 serious adverse events and 1 other adverse event. Deaths are listed as 0 in both periods.
The serious-event terms listed include leg fracture, hypertension, alcohol withdrawal seizure, and arteriovenous fistula thrombosis, each shown as 2.3%. These are registry safety entries; the record does not provide event narratives, timing, attribution, or a statistical comparison. The listed percentage should be read as reported, not recalculated or treated as evidence of a causal relationship with either observation method.
Because this is a crossover study, participants may have contributed to both observation periods. Period-level entries therefore should not be interpreted as independent participant groups. The record does not explain whether any participant experienced events in both periods or how event overlap was handled. The counts describe the recorded safety experience; they do not establish comparative risk or causation.
12. What the Result Does, and Does Not, Mean
The registry record shows that this was a completed pilot-scale randomized crossover study of self-monitoring with patientMpower and a sham application in ambulatory haemodialysis patients. It describes an engagement-focused primary endpoint: the number of days body weight was reported through the app over 28 days, summarized as a mean and standard deviation. It also specifies a population that had started the patientMpower observation period and recorded weight at least once.
What the record does not show is the result for that endpoint. It reports no mean, standard deviation, confidence interval, or comparative estimate, and lists 0 analyses. It therefore does not establish how often participants recorded weight, how much use varied, or how app-period reporting compared with another condition. It also does not report estimates for the listed clinical and behavioral secondary outcomes.
Even if engagement results were available, reporting frequency would not by itself establish that the app improved health outcomes. Recording a measurement is distinct from changing a clinical measure, a treatment decision, or an event rate. Likewise, the listed safety counts do not establish that either observation method caused or prevented an event. These are separate questions that require outcome data and suitable analyses.
The study’s randomized order and crossover structure could support within-person comparisons in general, but interpretation would depend on the analysis and assumptions, including treatment of period effects and carryover. Those analysis details are not reported in the registry record. The number included in the primary endpoint analysis and the handling of missing observations are also not reported.
The appropriate reading is therefore limited: the registry record describes what the trial intended to compare and how the primary measure was defined, but it does not provide the results needed to judge the magnitude, precision, or direction of an outcome difference. It supports no conclusion that the app did or did not change engagement or clinical outcomes.
13. Why This Trial Matters Statistically
This trial raises a practical statistical distinction between offering a monitoring tool and observing whether people use it. Its primary endpoint counts days with a body-weight report, making engagement the central recorded measure rather than a clinical endpoint. For digital self-monitoring studies, that distinction matters: implementation and use can be measured separately from downstream clinical outcomes.
The crossover design is also statistically relevant. In general, within-person comparisons can reduce the influence of stable differences between participants, but they require methods that respect the relationship between repeated observations. Sequence, period, and possible carryover can affect interpretation. The registry record describes randomized order but does not report how these features were analyzed.
The design contrasts a package that includes an app, scales, and a blood pressure monitor with a sham application without those devices. This makes the study question relevant to the combined self-monitoring approach, while limiting what the comparison could distinguish about the individual contribution of the software, devices, or monitoring behavior. The record does not report a design intended to separate those components.
Finally, the trial illustrates why a clear endpoint definition does not substitute for a reported result. The primary measure has a stated timeframe and population, but the registry lists 0 analyses and does not report an estimate. Without the number analyzed, missing-data approach, or uncertainty measure, readers cannot evaluate the endpoint’s observed level or precision. The statistical value of the design can be described, but its empirical findings cannot be judged from the registry record.
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 trial-specific limitations follow from the registry information. The study is described as pilot-scale and has an enrollment of 43, but the number included in the primary endpoint population is not reported. Since that population requires starting the patientMpower observation period and recording weight at least once, its size and relation to enrollment cannot be assessed.
The record does not report primary or secondary outcome estimates, confidence intervals, or test results, and lists 0 analyses. It therefore does not support evaluation of effect size or precision. The number of outcome measures is 17, while the multiplicity approach is not reported. Missing-data handling and analysis-population definitions are also not reported in the registry record.
The open-label design and the difference between the applications are relevant to interpretation. The patientMpower condition includes digital scales and a blood pressure monitor, while the sham application does not. The comparison therefore concerns the described package and does not isolate the effect of software alone. The record does not report additional blinding procedures.
Although randomized order and a crossover structure are described, the analysis method and handling of within-person correlation, period effects, and carryover are not reported. The record also does not report the randomization procedure or allocation concealment. The acceptability and utility objective is described, but corresponding results are not reported. These omissions limit assessment of both the intended comparisons and how robustly they were analyzed.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Study of Self-monitoring of Weight & Blood Pressure (Via patientMpower Platform) in Hemodialysis — NCT03403491.
- Registry record last updated 2020-06-16; status last verified 2020-06.
- Results first posted 2020-06-16.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
NCT03403491 is a completed, randomized, open-label, two-period crossover pilot of the patientMpower application with digital weighing scales and a blood pressure monitor compared with a sham application, alongside usual care. The listed enrollment is 43. The registry describes a 10-week design, including a 2-week usual-care run-in followed by two 4-week observation periods in randomized order.
The primary endpoint is the mean number of days body weight was reported in the app over 28 days among patients who started the patientMpower period and recorded weight at least once. The record lists 17 outcome measures and 0 analyses. It does not report the primary endpoint result, comparative estimates, analysis methods, missing-data procedures, multiplicity plan, or the trial’s sample-size justification. Safety counts are recorded for each observation period, but a statistical comparison and event attribution are not reported in the registry record.