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 Sonoelastography: Ultrasound Method to Measure Liver Fibrosis (NCT01747772), a na na study. The primary outcome is Liver Elasticity Value Measured Using Sonoelastography (SE).
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01747772 |
| Phase | NA |
| Condition | Chronic Liver Disease, Non-Alcoholic Fatty Liver Disease, Hepatitis C Virus (HCV) Coinfection |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | Single |
| Enrollment | 180 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Massachusetts General Hospital |
| Results posted | Yes |
2. Clinical Question
Population
Adults with suspected diffuse liver disease who were scheduled for a non-focal liver biopsy as part of routine clinical care. The listed conditions include chronic liver disease, non-alcoholic fatty liver disease, hepatitis C virus coinfection, hepatitis B virus, and drug-induced liver injury.
Intervention
Shear-wave sonoelastography, an ultrasound-based assessment of liver stiffness measured in kilopascals (kPa).
Comparator
Liver biopsy results, read by a single pathologist and graded using the METAVIR fibrosis scale. This is a comparison with a tissue-based assessment, not a randomized control group.
Primary question
What mean liver elasticity value does sonoelastography measure, and how does the stiffness assessment relate to biopsy-based fibrosis grading? The registry also lists sensitivity and specificity for detecting and staging fibrosis among the study aims, but those results are not reported in the registry record.
The study’s stated hypothesis is that sonoelastography can provide quantitative measurements useful for staging liver fibrosis. It also aims to assess whether steatosis and inflammation affect the fibrosis estimate. These aims describe questions the investigators intended to examine; they do not establish what the study found. The posted results include a primary outcome description but no reported elasticity estimate, confidence interval, or diagnostic-accuracy result. Therefore, the record does not permit a numerical assessment of agreement between stiffness measurements and biopsy grades.
3. Trial Design
This completed study is registered as a single-group study of shear-wave sonoelastography. Allocation is listed as not applicable, and masking is listed as single; the registry record does not identify who was masked. There is no randomized comparison group described. The study enrolled 180 participants according to the registry, while the reported outcome population was restricted to participants who completed the study and had adequate sonoelastography and biopsy data.
Participants were scheduled for a non-focal liver biopsy as part of routine clinical care. Sonoelastography was performed in those patients, and stiffness was compared with the biopsy assessment. A single pathologist read biopsy results using the METAVIR scale, which distinguishes fibrosis grades from F0, no fibrosis, through F4, cirrhosis. The intervention is listed as a device, rather than a drug or a treatment assigned against a control.
The record lists the study start as 2010-02, primary completion as 2014-02-14, and status as completed. Massachusetts General Hospital is the sponsor. The study is registered as phase not applicable. The registry does not report the allocation method beyond NA, or provide a more detailed account of how participants entered the study.
Because the design is single-group, the study can describe measurements made in the enrolled participants and compare them with biopsy grades. It cannot, through a randomized between-group contrast, estimate the effect of assigning one intervention rather than another. The registry record does not report a detailed statistical analysis plan, a sample-size justification, or whether any interim analyses were performed.
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 | Shear Wave Sonoelastography for Fibrosis Assessment |
|---|---|
| STARTED | 180 |
| Analysis Population | 164 |
| COMPLETED | 171 |
| NOT COMPLETED | 9 |
Reasons for not completing this period:
| Reason | Shear Wave Sonoelastography for Fibrosis Assessment |
|---|---|
| SWE Data Not Obtainable Prior to Biopsy | 9 |
Analysis population for the primary outcome, as defined in the registry: The analysis population included all participants who completed the study and had adequate shear-wave sonoelastography (SWE) and liver biopsy data. 16 participants were excluded: 9 discontinued and 7 had inadequate SWE or biopsy data.
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: The analysis population included all participants who completed the study and had adequate shear-wave sonoelastography (SWE) and liver biopsy data. 16 participants were excluded: 9 discontinued and 7 had inadequate SWE or biopsy data.
| Characteristic | Unit | Shear Wave Sonoelastography for Fibrosis Assessment |
|---|---|---|
| Participants analysed | 164 | |
| Age, Continuous | years | 48 (SD 13) |
| Sex: Female, Male: Female | Participants | 81 |
| Sex: Female, Male: Male | Participants | 83 |
6. Primary Endpoint
The registry lists the primary outcome as Liver Elasticity Value Measured Using Sonoelastography (SE), measured over Day 1.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | kilopascals (kPa) |
| Endpoint classification | Continuous Endpoint |
The primary outcome is the mean liver elasticity value measured using sonoelastography, in kilopascals (kPa), with a 95% confidence interval. It is recorded at Day 1. The registry describes elasticity as a measure of liver stiffness and states that higher values correspond to greater stiffness and hepatic fibrosis. It gives approximately 5.5 kPa as a normal value and describes normal liver stiffness as ranging between 3.3-7.8 kPa.
The endpoint is relevant to the study’s stated purpose because the investigators sought a quantitative stiffness measure that could be assessed alongside fibrosis grades from biopsy. The biopsy grading uses the METAVIR scale from F0 through F4. The registry description identifies 7.6 kPa for significant fibrosis (F3) and gives 9.0-26 kPa for cirrhosis (F4). These descriptions provide context for interpreting the measure, but do not themselves report how participants’ measurements were distributed across biopsy grades.
The primary outcome is a continuous measurement summarized as a mean and confidence interval. However, the actual mean and confidence interval are not reported in the registry record. Nor does the record provide the outcome values by METAVIR grade. The endpoint description therefore explains what was intended to be measured, but does not provide the numerical result needed to judge its observed precision or relationship to biopsy findings.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies the study’s central measurement and its intended reference: shear-wave sonoelastography estimates of liver stiffness compared with biopsy-based METAVIR grades. The primary outcome is defined as a mean elasticity value with a 95% confidence interval, but neither the mean nor the interval is reported in the registry record. As a result, the posted information does not show the observed stiffness level or how precisely the mean was estimated.
The registry also describes aims to assess sensitivity and specificity for detecting and staging fibrosis, and to evaluate effects of steatosis and inflammation on fibrosis estimates. It does not report sensitivity, specificity, diagnostic thresholds derived from the study, or results stratified by fibrosis grade, steatosis, or inflammation. The study aims must therefore be distinguished from findings: stating that a measure was evaluated does not establish its diagnostic performance.
The biopsy was read by a single pathologist using the METAVIR scale. That gives the stated basis for grading fibrosis, but the record does not provide details on pathology reproducibility or independent review. The sonoelastography measure and biopsy grade are different forms of assessment; the record’s planned comparison is clinically and statistically distinct from a randomized treatment comparison.
The analysis population for the primary outcome included participants who completed the study and had adequate sonoelastography and biopsy data. The record says 16 participants were excluded: 9 discontinued and 7 had inadequate sonoelastography or biopsy data. This means the endpoint pertains to the eligible analysis population rather than all enrolled participants. The registry does not report whether those excluded differed in characteristics or outcomes from those included.
The record lists no analyses under its analyses field. It also does not report a detailed statistical plan or results for the stated diagnostic-accuracy aims. Consequently, readers cannot use this record alone to evaluate the magnitude, precision, or classification performance of the primary measurement. The absence of reported results in the registry should not be read as evidence that the measurement had a particular value or level of performance.
9. Statistical Methods Explained
The study uses a continuous measurement, liver elasticity in kPa, and identifies the mean as its primary summary. A mean describes the arithmetic center of a set of measurements. It is useful for conveying the average stiffness value in the analyzed population, but it does not describe how widely individual measurements vary or how well the measurement separates fibrosis grades.
What does a confidence interval convey?
A confidence interval expresses uncertainty around an estimated quantity, such as a mean. A narrower interval generally indicates greater precision in the estimate, while a wider interval indicates more uncertainty. It does not show the range containing most individual participants’ measurements, and it does not establish that a value is clinically important. The registry specifies a 95% confidence interval for the primary outcome, but the estimate and interval themselves are not reported in the registry record.
For this study, the intended interpretation is a mean stiffness measurement accompanied by an interval that reflects uncertainty in that mean. Without the reported estimate and interval, readers cannot judge either the measured average or its precision. The record also does not state the method used to calculate the interval, so no particular distributional assumption or calculation procedure can be attributed to the investigators.
How does the biopsy comparison work?
The registry describes comparing stiffness with biopsy results read by a single pathologist and classified using METAVIR. The scale orders fibrosis grades from F0, no fibrosis, to F4, cirrhosis. Such a comparison can examine whether measurements tend to differ across pathology grades or whether a stiffness threshold distinguishes selected grades. The record states aims involving sensitivity and specificity, but does not report those statistics or results by grade.
Sensitivity and specificity are general measures used to describe classification against a reference standard. Sensitivity concerns how often a test identifies cases meeting a chosen reference definition; specificity concerns how often it identifies cases that do not meet that definition. Their interpretation depends on the definition of a positive result and the reference classification. The registry’s description includes stiffness values associated with fibrosis categories, but does not report the study’s observed sensitivity or specificity, or the analysis details used to derive them.
A continuous measurement can also be summarized without converting it into a positive or negative classification. That is why the primary mean and the diagnostic-accuracy aims answer different questions. A mean describes the average stiffness in the analyzed population. Sensitivity and specificity describe performance under a classification rule. Neither type of result can be inferred from the other, and the record does not provide the values needed for either interpretation.
Why can variability matter?
Measurements may vary between participants even when they share a biopsy grade. General statistical reasoning treats this spread as important because a difference in average values does not necessarily imply clear separation of individual values. Over-dispersion, in general, means that observed variability is greater than a model assumes. If present, it can make uncertainty estimates or classification performance based on a simpler model misleading. The registry record does not report a dispersion estimate for the primary endpoint or identify a model that would allow assessment of over-dispersion.
The primary outcome specifies a mean and confidence interval, while the record does not provide individual-level data, distributions, or grade-specific summaries. It is therefore not possible to assess skewness, outliers, overlap between fibrosis groups, or whether a mean is representative of the observed measurements. These are general considerations for continuous diagnostic measurements, not claims about the distribution in this study.
What does the analysis population mean?
The outcome population consists of participants who completed the study and had adequate sonoelastography and biopsy data. The record identifies exclusions related to discontinuation and inadequate data. Restricting an analysis to complete, adequate paired measurements allows comparison of the two assessments for those included, but can affect interpretation if excluded participants differ systematically from included participants. The record does not provide information that would establish whether such differences occurred.
The study is single-group, not a randomized comparison. Its analysis is therefore about measurements and their relation to biopsy grades in the included population, rather than a treatment contrast between assigned groups. The registry record does not report a detailed statistical analysis plan, methods for handling missing data, or methods for accounting for participant characteristics. No adjusted analysis or specific modeling approach can be assumed.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one primary outcome measure and no analyses under its analyses field. The record does not describe a prespecified hierarchy of tests, an adjustment for multiple comparisons, or how the several stated study aims were handled statistically. It is therefore not possible to determine from the registry record whether multiplicity was addressed in the investigators’ analysis. In general, examining multiple outcomes, subgroups, or thresholds can increase the chance of a seemingly notable result arising by chance; statistical plans often specify how such examinations will be interpreted. That general concern does not establish that a particular error occurred in this study.
The primary outcome population included participants who completed the study and had adequate sonoelastography and biopsy data. The registry reports 16 exclusions, consisting of 9 who discontinued and 7 with inadequate sonoelastography or biopsy data. It does not report the reasons for discontinuation, the characteristics of excluded participants, or whether missing measurements were related to stiffness or fibrosis grade.
These exclusions matter because a complete-measurement analysis describes participants with usable paired data. If missingness is related to participant characteristics or measurements, the analyzed group may not represent all enrolled participants. That is a general possibility, not a finding established by this record. The registry does not report imputation, sensitivity analyses for missing data, or another approach to account for incomplete measurements.
The record also does not report a detailed analysis plan, interim analyses, or a sample-size justification. The available information therefore supports describing the analysis population and missing-data counts, but not evaluating whether the analysis choices were prespecified or whether missingness altered the results.
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 |
|---|---|---|---|
| Shear Wave Sonoelastography for Fibrosis Assessment | 0 | 164 | 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 |
|---|---|
| Shear Wave Sonoelastography for Fibrosis Assessment | 0 of 164 |
The registry reports serious adverse events for the single listed group, “Shear Wave Sonoelastography for Fibrosis Assessment.” The number at risk is 164, and the number affected by serious adverse events is 0. The other adverse-event figures also list 164 at risk and 0 affected. These figures describe the registry’s reported counts for this group; they are not a comparison with a control group.
The record does not list serious adverse-event terms. Deaths are recorded as null, which means the registry record does not report a death count in that field; it should not be interpreted as a count of zero. The listed adverse-event counts are descriptive and do not, by themselves, establish that no harms occurred outside the events captured and reported in this record.
Because this is a single-group study, the safety figures cannot estimate a difference in adverse-event risk between assigned interventions. The record does not provide further details on event definitions, observation duration, or how events were collected. The adverse-event figures should therefore be read within the limits of the registry’s reported group and fields, rather than as a comparative safety analysis.
12. What the Result Does, and Does Not, Mean
This record describes an investigation of shear-wave sonoelastography as a quantitative measure of liver stiffness, with comparison to biopsy-based METAVIR fibrosis grades. It makes clear what the primary outcome was intended to measure and identifies related aims concerning fibrosis classification, steatosis, and inflammation. It also identifies the population used for the outcome analysis and the reported exclusions.
It does not report the primary mean elasticity value or its 95% confidence interval. It also does not report sensitivity, specificity, or results relating stiffness to individual METAVIR grades. Consequently, the record does not establish the observed size or precision of the measurement, how well it classified fibrosis, or whether steatosis or inflammation affected estimates.
The registry’s description of normal values and values associated with fibrosis categories provides context, not a study result. Those descriptions cannot substitute for the missing outcome estimates. Similarly, the study’s hypothesis and aims indicate what investigators set out to evaluate, not what the posted data demonstrate.
The design is single-group and does not include a randomized control comparison. The study can be understood as evaluating measurements against biopsy assessments among participants with adequate paired data, but the record does not support a causal comparison between treatments or devices. The reported adverse-event counts are also descriptive, not comparative. Overall, the record documents the study question and design more fully than it documents the numerical findings needed to assess measurement performance.
13. Why This Trial Matters Statistically
This study poses a measurement question that is distinct from a treatment-effect question: whether an ultrasound-based stiffness value can be assessed alongside biopsy-based fibrosis grades. That distinction matters statistically because a continuous measure, a pathology grade, and a diagnostic classification are different kinds of outcomes. Each requires suitable summaries and interpretation.
The registry identifies a continuous primary measure and a confidence-interval summary, while also describing diagnostic-accuracy aims. This makes clear why reporting the numerical endpoint and the classification results is important. A mean alone would not show how much measurements overlap across fibrosis grades; sensitivity and specificity would address classification under defined rules, but would not replace a description of the underlying continuous measurements.
The analysis population also matters. The primary outcome uses participants with completed studies and adequate paired sonoelastography and biopsy data. Reporting the reasons and extent of exclusions allows readers to understand which observations contribute to an estimate and to consider whether incomplete data might affect interpretation. The registry provides some exclusion counts, but not enough detail to assess the characteristics or results of those excluded.
Finally, the record illustrates a key limitation of registry results: a clearly stated question and endpoint do not amount to a reported finding. Without the primary estimate, its interval, or the diagnostic-accuracy results, readers cannot judge the magnitude, precision, or classification performance observed in the study. That distinction is central to sound statistical interpretation.
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 limitation for interpreting this registry record is that the primary outcome is described without its numerical result. The mean liver elasticity value and 95% confidence interval are not reported in the registry record. The stated sensitivity and specificity aims are also not accompanied by results. This prevents assessment of the observed measurement, its precision, and its diagnostic performance.
The record describes a single-group design and does not identify a randomized control group. The study therefore does not provide a randomized between-group contrast. The registry lists masking as single but does not say who was masked. It also does not report detailed allocation procedures beyond NA.
The primary outcome population excludes participants who discontinued or had inadequate sonoelastography or biopsy data. The record gives the number and broad reasons for exclusions, but does not describe the excluded participants or report analyses addressing missing data. As a result, the degree to which the analysis population represents all enrolled participants cannot be assessed from the record.
Biopsy results were read by a single pathologist. The record does not report independent readings, agreement between readers, or other information on pathology reproducibility. It also does not provide grade-specific stiffness summaries, a detailed statistical analysis plan, or results evaluating steatosis and inflammation. These absences limit evaluation of measurement variability, classification performance, and the robustness of conclusions.
The registry does not report a sample-size justification or interim-analysis details. These aspects should not be inferred from the enrollment figure or from the stated study aims. The available information supports a description of the study’s planned measurement and analysis population, but not a full appraisal of the numerical evidence.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Sonoelastography: Ultrasound Method to Measure Liver Fibrosis — NCT01747772.
- Registry record last updated 2017-06-14; status last verified 2017-05.
- Results first posted 2017-06-14.
- 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
NCT01747772 is a completed, single-group study sponsored by Massachusetts General Hospital. It evaluated shear-wave sonoelastography in adults with suspected diffuse liver disease scheduled for non-focal liver biopsy. The primary outcome was mean liver elasticity in kPa with a 95% confidence interval at Day 1, compared with biopsy grading using the METAVIR scale.
The registry reports an enrollment of 180 and says the outcome population included participants who completed the study and had adequate sonoelastography and biopsy data. It reports 16 exclusions: 9 discontinued and 7 had inadequate sonoelastography or biopsy data. The mean outcome, confidence interval, and diagnostic-accuracy results are not reported in the registry record. Serious adverse events are listed as 0 among 164 at risk; the death field is null and does not report a count.