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 Non-Invasive Hemoglobin Monitoring in Patients With Hemorrhage (NCT01709786), a registered phase not stated study. The primary outcome is CBC Hemoglobin Measurement Compared to Non-invasive Radical-7 Measurement.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01709786 |
| Phase | Phase not stated |
| Condition | Hemorrhage |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 88 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Cincinnati |
| Results posted | Yes |
2. Clinical Question
Population
Patients with suspected hemorrhage who met the study’s inclusion and exclusion criteria. The registry record lists an enrollment of 88. Further details about eligibility criteria and participant characteristics are not reported in the registry record.
Intervention
Point-of-care hemoglobin measurement using the non-invasive Radical-7 method. The study also evaluated the CDC method. The registry describes taking measurements when blood was drawn for laboratory testing, using one drop of blood for the point-of-care measurements.
Comparator
Standard laboratory serum hemoglobin measurement, described in the primary outcome as CBC hemoglobin. The same set of measurements was taken in the study’s single group; this was not a comparison between separately assigned treatment groups.
Primary question
How do CBC hemoglobin measurements compare with non-invasive Radical-7 measurements in patients with suspected hemorrhage? The primary outcome is framed as a comparison of continuous measurements, with the outcome description specifying a mean and a 95% confidence interval. The estimates themselves are not reported in the registry record.
The study, NCT01709786, is titled “Non-Invasive Hemoglobin Monitoring in Patients With Hemorrhage.” Its brief summary describes evaluating the accuracy of two rapid hemoglobin measurement methods against standard laboratory measurements. The registry identifies hemorrhage as the condition and the University of Cincinnati as the sponsor.
The clinical question concerns measurement agreement, not whether one assigned treatment improves a health outcome relative to another. Participants were measured using methods intended to assess hemoglobin, and their measurements were compared with one another. Because the design has a single group, the data do not represent a randomized, like-for-like comparison of separate groups. The record does not report a clinical decision threshold or a patient outcome linked to a particular measurement result.
3. Trial Design
The registry record describes a completed, single-group study of patients with suspected hemorrhage. Enrollment is listed as 88. The study began in 2012-09, and primary completion is listed as 2013-09. Its stated aim was to evaluate the accuracy of two rapid hemoglobin measurement methods by comparing them with standard laboratory measurements.
There was a single group of eligible patients, rather than separate intervention and control arms. The same set of measurements was taken from each patient, and those measurements were compared with one another. The record does not describe random assignment; allocation is not stated. It would therefore be misleading to interpret the measurement methods as treatment arms or to treat the design as a randomized comparison.
The registry describes taking a point-of-care measurement with the CDC and Radical-7 methods whenever blood was drawn for laboratory measurement of serum hemoglobin. The primary outcome specifically names CBC hemoglobin compared with non-invasive Radical-7 measurement. The outcome description says that reported means use an equally weighted average of measurements on each device across all measurement occasions on all patients.
The primary outcome’s timeframe describes at least one measurement each day and use of all measurements from ICU Days 1-7 in Bland-Altman analysis, equally weighted. The exact number of measurement occasions per patient, the distribution of measurements over time, and the number of patients contributing measurements to each analysis are not reported in the registry record.
The record does not report the inclusion and exclusion criteria in detail, a sample-size justification for the study, or a prespecified statistical analysis plan. Planning illustrations use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a fraction of the observed effect. Those are planning assumptions, not a description of the single-group study design or its observed analysis. A numerical planning result is 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 | Patients With Suspected Hemorrhage |
|---|---|
| STARTED | 88 |
| COMPLETED | 88 |
| NOT COMPLETED | 0 |
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: Adult patients (\>18 years of age) with the potential for hemorrhage and who were admitted to the Surgical Intensive Care Unit of a tertiary referral, Level I verified trauma center.
| Characteristic | Unit | Patients With Suspected Hemorrhage |
|---|---|---|
| Participants analysed | 88 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 69 |
| Age, Categorical: >=65 years | Participants | 19 |
| Sex: Female, Male: Female | Participants | 35 |
| Sex: Female, Male: Male | Participants | 53 |
6. Primary Endpoint
The registry lists the primary outcome as CBC Hemoglobin Measurement Compared to Non-invasive Radical-7 Measurement, measured over n ≥ 1 measurements were taken each day. All measurements (n ≥ 7) from ICU Days 1-7 were used in Bland-Altman analysis, equally weighted..
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | grams per deciliter |
| Endpoint classification | Continuous Endpoint |
The primary outcome is titled “CBC Hemoglobin Measurement Compared to Non-invasive Radical-7 Measurement.” It concerns a continuous measurement, expressed in grams per deciliter, and is described using a mean and a 95% confidence interval. Its purpose is to characterize how the laboratory measurement and the non-invasive device readings compare in patients with suspected hemorrhage.
The record says that whenever blood was drawn for laboratory measurement of serum hemoglobin, one drop of blood was used for point-of-care measurements with the CDC and Radical-7 methods. For reporting outcome measures, measurements on each device were averaged with equal weighting across all measurement occasions on all patients. Thus, the stated summary is based on measurement occasions, not on a description of a single reading from each patient.
The timeframe also describes Bland-Altman analysis using all measurements from ICU Days 1-7, equally weighted, with at least one measurement taken each day and at least seven measurements in that analysis. Bland-Altman analysis is used to examine agreement between methods by considering the differences between paired readings in relation to their measurement levels. It can reveal whether methods tend to differ systematically and how variable those differences are. This is a general explanation of the method, not a claim about the study’s actual findings.
The numerical mean, confidence interval, and Bland-Altman results are not reported in the registry record. Without those estimates, the direction and size of any difference and the precision of the comparison cannot be described from the record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a measurement-comparison study, but it does not report the numerical primary outcome estimates. In particular, the mean and 95% confidence interval for CBC hemoglobin compared with non-invasive Radical-7 measurement are not reported in the registry record. The reported record therefore does not establish the size or direction of the difference between the methods, nor how precisely that difference was estimated. The posted results do not include numerical Bland-Altman findings.
The endpoint is based on continuous measurements. In general, a mean gives a summary of the average value in the measurements being analyzed. A confidence interval conveys uncertainty around an estimate under the analysis assumptions; it is not itself a range containing every observed reading. A narrow interval would indicate greater precision for the estimated mean than a wide interval, but the actual interval cannot be characterized when its bounds are not reported.
For a method-comparison question, an average difference alone may not describe how closely the methods agree for individual readings. A small average difference can coexist with considerable variation between paired measurements. Bland-Altman analysis addresses this by examining paired differences and their variability across the range of measurement levels. The registry says this analysis used all measurements from ICU Days 1-7, with equal weighting. Its numerical estimates, graphical pattern, and uncertainty are not reported in the registry record, so agreement cannot be characterized from the available outcome details.
The record describes measurements from the same patients, not separate randomized groups. This structure is important: readings from one patient may be related to one another, and repeated measurement occasions do not automatically provide the same information as independent observations from different patients. The registry states that measurement occasions were equally weighted for reported means and for the specified Bland-Altman analysis. Whether and how the analysis accounted for within-patient dependence beyond that description is not reported in the registry record.
The enrollment figure is not a substitute for the number of observations contributing to an endpoint. The record describes repeated measurements and gives minimum measurement requirements, but it does not report the exact number of observations in the analysis or how missing measurements were handled. It also does not report subgroup estimates or a numerical comparison for the CDC method in the primary outcome.
Consequently, the defensible interpretation is limited to the study’s aim and stated analysis structure: it compared laboratory hemoglobin measurements with rapid point-of-care methods in a single group, and the primary outcome focused on CBC and Radical-7 measurements. Whether the observed readings were close enough for a particular use, whether there was systematic bias, and how much measurement variability occurred are not reported in the registry record. No conclusion about a clinical decision or patient outcome follows from the design description alone.
9. Statistical Methods Explained
The primary outcome is a continuous measurement, and the registry describes the reported summary as a mean with a 95% confidence interval. The outcome description also specifies Bland-Altman analysis for measurements from ICU Days 1-7. These methods answer related but distinct questions: a mean summarizes a central value, while a method-agreement analysis examines how paired readings differ.
What does a mean summarize?
In general, the mean is an average of the values included in an analysis. For this outcome, the registry says measurements on each device were averaged with equal weighting across all measurement occasions on all patients. This means the stated summary uses measurement occasions as its basis. It is not described as an average of one value per patient. When patients contribute different numbers of occasions, an occasion-weighted summary can give more influence to patients with more recorded occasions than a summary that first averages within each patient. The registry states the weighting approach, but does not report the exact contribution of each patient or the resulting mean.
The mean is useful as a compact description, but it cannot show the full spread of readings or whether differences vary across measurement levels. For method comparison, the mean alone does not show whether paired measurements tend to agree closely for individual occasions. That is why the registry’s stated use of Bland-Altman analysis is relevant to the stated research question.
What does a 95% confidence interval convey?
In general, a confidence interval describes the uncertainty around an estimate under the statistical model and sampling assumptions used to construct it. It should be interpreted as an interval for an estimated quantity, rather than as a range that contains most individual measurements. Its width depends on the variability in the data and on the analysis structure. Repeated measurements from the same patient can be correlated, so treating every occasion as independent when that is not appropriate can misstate uncertainty. The registry identifies a 95% confidence interval as the dispersion measure for the primary outcome, but the interval’s bounds and the details of its calculation are not reported in the registry record.
How does Bland-Altman analysis address agreement?
In general, Bland-Altman analysis evaluates paired readings by calculating their differences and relating those differences to the readings’ average levels. The average difference can indicate systematic measurement bias: whether one method tends, on average, to read higher or lower than the other. The spread of differences indicates how much individual paired readings vary around that average. Limits of agreement are commonly used to describe the range within which differences are expected to fall under the method’s assumptions. These concepts help distinguish average alignment from the closeness of individual measurements.
The registry says the analysis used all measurements from ICU Days 1-7 and weighted them equally. It also reports at least one measurement per day and at least seven measurements for the specified analysis. Those details describe the intended analysis window and minimum measurement pattern; they do not give the observed differences, the average bias, the limits of agreement, or their uncertainty. Those numerical results are not reported in the registry record.
Why does repeated measurement matter?
Repeated observations within a patient may be more alike than observations from different patients because they share the same person and circumstances. This dependence matters for uncertainty estimates and for interpretation of how much information the data contain. A general statistical response may use methods that account for clustering or repeated measurements, but the registry does not report enough detail to determine whether such adjustments were used. Equal weighting of measurement occasions is stated; a complete account of dependence handling is not.
Repeated measurement can also help describe changes over time, but the listed primary outcome is a comparison of measurement methods, and the timeframe specifies ICU Days 1-7 for the Bland-Altman analysis. The record does not report a time-trend model or an analysis that separates changes in hemoglobin over time from differences between devices. It would therefore be inappropriate to infer that the reported analysis estimates a particular time course.
What can planning illustrations tell the reader?
The registry’s planning assumptions describe illustrations computed from the observed effect. They use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is expressed as a stated fraction of the observed effect. These are planning assumptions, not evidence that the study was designed with two randomized arms. The actual study description identifies a single group with repeated measurements. Any sample-size values in planning illustrations should be read as hypothetical planning quantities, not as observed power or as the study’s actual enrollment rationale. A sample-size justification and the numerical planning results are not reported in the registry record.
For an unadjusted recalculation from summary statistics, the sponsor’s own analysis takes precedence if a discrepancy is identified. The registry record does not provide numerical primary outcome estimates for a recalculation in this account, and no recalculated result can be stated. Planning quantities cannot fill that gap: they do not show the observed agreement or precision of the measurement comparison.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists two outcome measures and two analyses. The primary outcome is identified as CBC hemoglobin measurement compared with non-invasive Radical-7 measurement. The record’s description also refers to the CDC measurement method. The titles and complete analysis details for all outcomes and analyses, and the role of any additional analysis in relation to the primary outcome, are not reported in the registry record.
Multiplicity arises in general when several outcomes, comparisons, or analyses are examined, because the chance of finding an apparently notable result can increase as more questions are tested. Statistical approaches can address this in different ways, but the registry does not report whether a multiplicity adjustment was planned or used, nor does it give a statistical analysis plan. The two listed outcomes and two listed analyses alone do not establish that a particular adjustment was needed or applied.
The record describes repeated measurements and minimum measurement requirements, but it does not report the exact number of observations included in each analysis, the number of patients contributing to each outcome, or the handling of missing or unusable readings. It does not describe whether measurements were excluded for technical reasons, whether missingness was assessed, or whether any imputation method was used. These details are not reported in the registry record.
Analysis populations are also not described in sufficient detail. The record identifies patients who satisfied inclusion and exclusion criteria and gives the enrollment figure, but it does not state a separate population definition for each analysis or explain how incomplete measurement sequences were treated. The outcome summary’s equal weighting of occasions is reported; the treatment of missing data and any sensitivity analyses are not. Without these details, the extent to which the reported analysis population may differ from the enrolled group cannot be assessed.
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 |
|---|---|---|---|
| Radical-7 vs. CBC | 0 | 88 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Radical-7 vs. CBC | 0 of 88 |
The registry lists a safety comparison labeled “Radical-7 vs. CBC.” It records 88 at risk and 0 affected for serious adverse events, and 88 at risk and 0 affected for other adverse events. The listed serious adverse event terms are empty. Deaths are not reported in the registry record.
These figures should be read as registry counts, not as proof that no adverse events occurred in any broader sense. The record does not describe how events were defined, collected, reviewed, or attributed to a measurement method. In a single-group measurement study, the label naming two methods does not establish separate randomized safety groups. The counts therefore do not support a causal comparison of safety between Radical-7 and CBC.
The risk denominators in the safety record do not establish how many patients contributed valid readings to the primary outcome or how many measurement occasions were analyzed. The registry also does not report the duration or completeness of safety surveillance. The listed zero affected counts describe what was entered in those registry fields; they should not be extended beyond the reported safety information.
12. What the Result Does, and Does Not, Mean
The study addresses a practical statistical question: how measurements from rapid hemoglobin methods compare with standard laboratory measurements in patients with suspected hemorrhage. Its single-group design and repeated-measurement approach allow paired measurements to be compared within the study population. The registry’s primary outcome focuses on CBC and non-invasive Radical-7 measurements, while the study description also identifies the CDC method as an evaluated point-of-care method.
The record establishes the intended measurement process and analysis framing. It says measurements were obtained when blood was drawn for laboratory testing, that device measurements were summarized with equal weighting across occasions, and that Bland-Altman analysis used measurements from ICU Days 1-7. This describes how the comparison was intended to be organized; it does not state the numerical degree of agreement.
The record does not report the mean estimate, its 95% confidence interval, or the Bland-Altman results. As a result, it does not show whether the non-invasive readings tended to be higher or lower than CBC measurements, how variable the paired differences were, or how precisely any estimated bias was measured. It also does not establish whether the measurement differences would be acceptable for a particular clinical purpose. Such a judgment would require a relevant standard or decision threshold, which is not reported in the registry record.
The study is not a randomized comparison of treatment strategies, and its results cannot be interpreted as evidence about the effect of a treatment on patient outcomes. The design compares measurement methods within a single group. It also does not, from the information recorded, establish how performance may vary in different patient subgroups or settings. The study’s enrollment and completion status do not substitute for outcome estimates, uncertainty intervals, or a detailed account of missing measurements.
Accordingly, the result’s meaning is limited by the outcome information available in the registry record. The record supports describing the study’s purpose, measurement design, and specified analyses. It does not support a conclusion that either method agrees sufficiently or insufficiently with laboratory measurement, and it cannot establish the clinical consequences of using either method. The missing numerical estimates are central to interpreting the comparison.
13. Why This Trial Matters Statistically
Measurement studies raise a different statistical question from trials that compare assigned treatments. The relevant issue is not simply whether two group averages differ, but whether measurements from different methods are close enough across the range of readings and how uncertain that assessment is. The registry’s choice to identify Bland-Altman analysis signals attention to agreement and variation in paired differences, rather than relying only on a mean summary.
The repeated-measurement structure also matters. Readings from the same patient may be dependent, and the number of measurement occasions can differ across patients. The registry explicitly describes equal weighting across measurement occasions. Understanding that weighting is important because an occasion-based summary and a patient-based summary answer different questions. The record does not give enough detail to assess the impact of that choice or the handling of within-patient dependence.
This study’s single-group design makes the comparison structure especially important to communicate. CBC and non-invasive device measurements are compared within patients; the named methods are not randomized arms. Treating them as separate intervention and control groups would misstate the design. Clear separation of the population, measurement methods, paired structure, and analysis target helps prevent that error.
The record also illustrates why a stated endpoint is not the same as an interpretable result. It specifies the unit, summary type, confidence level, and analysis window, but the numerical estimates needed to assess bias, variability, and precision are not reported in the registry record. Without them, the analysis method can be explained, but the observed measurement performance cannot be characterized. This distinction is important when reading registry entries: design and analysis descriptions do not replace outcome estimates and their uncertainty.
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 primary limitation for interpreting this study from the registry record is that the numerical outcome results are not reported. The mean and 95% confidence interval for the primary comparison are absent, as are the numerical results of the stated Bland-Altman analysis. Thus, the magnitude, direction, variability, and precision of the measurement comparison cannot be assessed from the record.
The description identifies repeated measurement occasions and equal weighting, but does not give the exact number of readings analyzed, the number of patients contributing to each analysis, or how many measurements were missing or unusable. The approach to within-patient dependence is not reported in detail. These omissions limit assessment of the effective information in the analysis and the uncertainty attached to the estimates.
The study has one group and no stated allocation to separate arms. Its measurements are compared within patients, so it does not provide a randomized comparison of measurement strategies or a treatment-effect estimate. The detailed eligibility criteria, participant characteristics, and study setting beyond the description of suspected hemorrhage and ICU measurement days are not reported in the registry record.
The record lists two outcome measures and two analyses but does not provide a full statistical analysis plan or explain whether multiplicity was considered. It does not describe the handling of missing data, prespecified exclusions, or sensitivity analyses. Nor does it report a clinical threshold for acceptable agreement. Without that context, even numerical agreement estimates would need careful interpretation; in this registry record, those estimates are not reported.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Non-Invasive Hemoglobin Monitoring in Patients With Hemorrhage — NCT01709786.
- Registry record last updated 2016-08-09; status last verified 2016-05.
- Results first posted 2016-08-09.
- 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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18. Record Summary
NCT01709786, “Non-Invasive Hemoglobin Monitoring in Patients With Hemorrhage,” is a completed, single-group measurement study sponsored by the University of Cincinnati. The registry lists enrollment of 88 and describes patients with suspected hemorrhage undergoing laboratory and point-of-care hemoglobin measurements. The study evaluated CDC and Radical-7 methods against standard laboratory measurement.
The primary outcome compares CBC hemoglobin with non-invasive Radical-7 measurement, reports a mean with a 95% confidence interval, and specifies Bland-Altman analysis using measurements from ICU Days 1-7. The registry describes equal weighting across measurement occasions. Numerical outcome estimates, detailed missing-data methods, and a complete statistical analysis plan are not reported in the registry record. Safety fields list 0 serious adverse events and 0 other adverse events, with deaths not reported in the registry record.