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 Continuous Intravenous Lidocaine Infusion Versus Placebo for Rib Fracture Analgesia (NCT04140396), a randomized phase 4 study. The primary outcome is Cumulative Oral Morphine Milligram Equivalent (OME) Consumption at 24 Hours.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT04140396 |
| Phase | Phase 4 |
| Condition | Rib Fractures |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Single |
| Enrollment | 1 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Stanford University |
| Results posted | Yes |
2. Clinical Question
Population
Adults with acute traumatic rib fractures. The registry record does not provide further detail about eligibility criteria or the characteristics of the participants enrolled.
Intervention
Continuous intravenous lidocaine infusion. The study description frames the intervention as an approach to pain control alongside the opioid-based care described in the registry summary.
Comparator
Placebo infusion consisting of normal saline. The record identifies the comparator as the placebo arm.
Primary question
Whether lidocaine infusion is associated with lower cumulative oral morphine milligram equivalent consumption at 24 hours than placebo. The registry summary also describes an aim to assess OME consumption at 48 hours, but the registered primary endpoint is the measure at 24 hours.
The clinical question uses opioid consumption as an indicator of pain-control requirements. OME expresses opioid use in a common morphine-equivalent unit, allowing different opioid medications to be represented on the same scale. The stated primary measure is cumulative consumption, summarized as a mean with standard deviation, in MME after 24 hours of treatment.
The planned comparison is randomized and parallel, with a lidocaine infusion arm and a saline placebo arm. The registry record reports an enrollment of 1 and a terminated status. It does not include a comparative primary-outcome result, so the clinical question cannot be answered from the posted outcome data. A stated study aim is not evidence that the intervention changed OME consumption.
3. Trial Design
The registry describes a phase 4, randomized, single-masked, parallel trial comparing lidocaine infusion with saline placebo for rib fracture analgesia. In a parallel design, assigned groups are intended to receive different interventions rather than each participant receiving both in sequence. The record identifies both intervention arms but does not state who was masked; the masking role is not reported in the registry record.
The listed population is adults with acute traumatic rib fractures. The study’s stated purpose was to evaluate pain control using cumulative OME consumption, with the registry summary describing assessments at 24 and 48 hours. The registered primary outcome is cumulative OME consumption at 24 hours, expressed in MME and summarized as a mean and standard deviation. Other listed outcomes include pain score, incentive spirometry volumes, PIC score, length of hospital stay, inflammatory biomarkers, and pulmonary complication events.
The record reports an enrollment of 1 and a status of terminated. It gives a study start date of 2020-02-10 and a primary completion date of 2020-11-09. These registry fields describe the trial record, but the record does not explain why the trial was terminated or provide details about the circumstances of enrollment.
Although the design specifies randomized intervention arms, the posted primary outcome information does not support a comparison between them. The record flags that fewer than two arms are present in the primary outcome. The number assigned to each intervention and the participant flow through the trial are not reported in the registry record. Therefore, the planned design should be distinguished from the information available for interpreting outcomes.
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 | Placebo Comparator | Active Comparator |
|---|---|---|
| STARTED | 0 | 1 |
| COMPLETED | 0 | 1 |
| NOT COMPLETED | 0 | 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.
| Characteristic | Unit | Active Comparator |
|---|---|---|
| Participants analysed | 1 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 0 |
| Age, Categorical: >=65 years | Participants | 1 |
| Sex: Female, Male: Female | Participants | 0 |
| Sex: Female, Male: Male | Participants | 1 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 1 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 |
| Race (NIH/OMB): White | Participants | 1 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: United States | Participants | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Cumulative Oral Morphine Milligram Equivalent (OME) Consumption at 24 Hours, measured over After 24 hours of treatment.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | MME |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is cumulative oral morphine milligram equivalent consumption at 24 hours after treatment. OME converts opioid consumption to a common morphine-equivalent scale, and the registry identifies the unit as MME. The endpoint is continuous and is described using a mean and standard deviation.
The registry summary explains why the investigators selected opioid consumption: the study aimed to evaluate whether lidocaine infusion could provide improved pain control, demonstrated by decreased OME consumption at 24 and 48 hours compared with placebo. The registered primary endpoint focuses on the 24-hour measure. The listed 48-hour measure appears among the secondary outcomes.
As a statistical endpoint, cumulative consumption can describe the amount of opioid medication used over a defined period. A group mean describes the average in that group, while the standard deviation describes variability among observations. Neither statistic, by itself, indicates whether a difference between treatment groups is precisely estimated or compatible with chance variation. That assessment requires a comparative estimate and uncertainty measure, neither of which is reported for the primary endpoint.
The registry record does not provide observed group means, standard deviations, a treatment contrast, or a confidence interval for the primary outcome. Thus, the endpoint’s definition and rationale are available, but its observed result is not.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The trial’s intended comparison is clear: cumulative OME consumption at 24 hours in the lidocaine and saline placebo groups. The registry defines the primary measure, its unit, and its summary form. However, it does not post a result for that comparison. There is no reported group mean, standard deviation, between-group estimate, confidence interval, or test result for the primary endpoint.
The record reports an enrollment of 1 and a terminated status. It also flags that fewer than two arms are present in the primary outcome. These features prevent a comparative reading of the posted primary endpoint. Randomization describes the planned allocation approach; it does not create an interpretable treatment estimate when the outcome record lacks observations from both arms.
The registry lists secondary outcomes, including OME consumption at 48 hours, pain score, incentive spirometry volumes, PIC score, length of hospital stay, inflammatory biomarkers, and pulmonary complication events. It reports 0 analyses. Outcome definitions or a list of intended measures should not be mistaken for observed findings. No comparative results for these listed measures are reported in the registry record.
The enrollment entry is not a basis for inferring the number of participants in either arm, and the record does not provide a participant flow account. The adverse-event fields likewise contain only limited group-specific information and cannot establish comparative safety. They should not be generalized into a conclusion about the overall safety of either intervention.
In general, a treatment-effect estimate is most informative when interpreted together with its uncertainty. A confidence interval describes a range of effect values compatible with the data and the method used; it does not replace the estimate or resolve limitations in the underlying data. No confidence interval or other precision measure for the primary comparison appears in the registry record.
The appropriate statistical reading is therefore descriptive: the registry documents a randomized, single-masked, parallel trial that was terminated, with an enrollment of 1 and no posted primary comparison. The available record does not establish whether lidocaine was associated with lower, higher, or similar OME consumption than saline placebo. It also does not permit a conclusion that the interventions were equivalent or that any difference was absent.
9. Statistical Methods Explained
The registry identifies the trial as randomized, single-masked, and parallel. Randomization is a method for assigning participants to intervention groups according to a chance process. When implemented as planned, it aims to reduce systematic differences between groups at the point of assignment. It does not guarantee that groups will be balanced in every characteristic, and it cannot compensate for an outcome record that lacks a comparison between groups.
A parallel design assigns participants to one intervention group for the comparison. The listed interventions are lidocaine infusion and normal saline placebo. The registry identifies single masking but does not report which people were masked. It also does not describe the randomization procedure, allocation concealment, or procedures for maintaining masking; those details are not reported in the registry record.
The primary measure is a continuous outcome: cumulative OME consumption at 24 hours, expressed in MME. The specified summary is the mean with standard deviation. A mean describes the average outcome in a group. A standard deviation describes how spread out individual observations are around that group average. It is a description of variability, not a measure of uncertainty in the estimated treatment difference.
For a two-group comparison, the central quantity would ordinarily be a between-group contrast in mean OME consumption, accompanied by a measure of uncertainty. A confidence interval is a general statistical tool for expressing precision: it indicates a range of values compatible with the observed data under the assumptions of the method. A narrow interval indicates greater precision than a wide interval, but precision does not by itself establish clinical importance. The registry record does not report a contrast or confidence interval for the primary endpoint.
The record includes sample-size assumptions for a planning illustration: a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation, with the effect to detect described as a stated fraction of the observed effect. This is explicitly a planning illustration based on the observed effect, not the trial’s own design. No numerical planning results are available in the registry record, and no observed primary effect is posted to interpret. Such illustrations are not observed power and should not be read as evidence that the trial could detect a particular effect.
A significance test, in general, evaluates how compatible data are with a specified null hypothesis under a statistical model. A p-value does not quantify the probability that a treatment works, nor does it measure the size or clinical importance of an effect. No primary-outcome test result is reported. The record also reports 0 analyses, so there is no posted analysis to interpret as a sponsor-reported test.
For continuous outcomes, the assumptions of a chosen method matter. A normal approximation is a general modeling approach that can be used for certain estimates and tests. Its appropriateness depends on the data and analysis context. The registry’s planning assumptions do not establish which method was used for a trial analysis. No analysis model, covariate adjustment, or handling of skewed outcome values is reported in the registry record.
Over-dispersion is a general concern when observed variability exceeds what a statistical model expects. If a model understates variability, uncertainty estimates can be too narrow and tests can appear more decisive than warranted. This concept may be relevant to some outcome types, but the record does not report an analysis of over-dispersion or provide data with which to assess it for this trial.
Recalculated comparisons from summary statistics would require usable group-level outcome summaries. The posted primary outcome does not provide those summaries, and the record indicates fewer than two arms in the primary outcome. No recalculated treatment effect or precision estimate can therefore be interpreted. The sponsor’s own analysis would take precedence if it conflicted with a simple recalculation, but no sponsor primary analysis is posted in the registry record.
In short, the registry supplies design labels and a defined endpoint but not the analysis details or results needed to evaluate a treatment contrast. General statistical methods explain what such an analysis could mean; they do not fill in the missing trial findings.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists several outcome measures beyond the primary 24-hour OME endpoint. These include cumulative OME consumption at 48 hours, pain score, incentive spirometry volumes, PIC score, length of hospital stay, inflammatory biomarkers, and pulmonary complication events. It reports 8 outcome measures and 0 analyses. The outcome list does not include posted comparative results.
When a study assesses multiple outcomes, the chance of at least one apparently unusual finding can increase if each is tested separately. Statistical methods can address multiplicity, but the choice depends on the analysis plan and the intended interpretation. Whether any adjustment was planned or used is not reported in the registry record. The registry also does not report a testing hierarchy or identify which secondary outcomes, if any, were analyzed.
Missing-data methods and analysis populations are not reported in the registry record. The record does not state how missing outcome measurements would be handled, which participants would be included in an analysis, or how deviations from assigned intervention would be treated. These omissions prevent assessment of whether an analysis would reflect the planned randomized comparison.
The enrollment entry, terminated status, and primary outcome flag do not provide a participant flow account or explain why outcome results are unavailable. The missing analysis details should not be replaced with assumptions about the protocol or conduct. Without a posted analysis, multiplicity, missingness, and analysis-population choices cannot be evaluated from the 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 |
|---|---|---|---|
| Active Comparator | 0 | 1 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Active Comparator | 0 of 1 |
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 |
|---|---|
| Active Comparator | 0 of 1 |
The registry’s adverse-event fields list the Active Comparator group with 1 at risk for serious adverse events, 0 affected, 1 at risk for other adverse events, 0 affected, and 0 deaths. No serious-event terms are listed. These figures are sparse and relate only to the group and entries shown in the record.
These counts should not be interpreted as a comparison between lidocaine and placebo. The adverse-event listing does not include a corresponding placebo group, and the registry record reports an enrollment of 1. The figures also do not establish that all possible events were collected or that the listed risk period covers the full study experience; those details are not reported in the registry record.
In general, an event count describes what was recorded under a defined collection process. A zero count does not demonstrate that an event cannot occur, and a small amount of safety information provides little basis for estimating event frequency or comparing groups. The posted fields therefore support only a narrow description of the entries, not a broad conclusion about safety.
12. What the Result Does, and Does Not, Mean
The registry record establishes that a randomized, single-masked, parallel study was registered to compare continuous intravenous lidocaine infusion with normal saline placebo for rib fracture analgesia. Its stated primary endpoint is cumulative OME consumption at 24 hours. The record also describes a study aim involving OME consumption at 48 hours.
What the record does not establish is the result of the primary comparison. It contains no reported group summaries or estimate of the difference in OME consumption. The enrollment entry is 1, the status is terminated, and the primary outcome is flagged as having fewer than two arms. Without an interpretable comparison, the posted information cannot show whether consumption was lower, higher, or similar between the intervention groups.
This absence of a result is not evidence that the treatments had the same effect. It is also not evidence that lidocaine improved pain control or reduced opioid consumption. Equivalence and absence of an effect require appropriate data and analysis; neither can be inferred from a missing comparison.
The stated aim and outcome definitions describe what the trial was designed to investigate, not what it found. The listed secondary outcomes likewise do not establish findings. With 0 analyses reported, there are no posted outcome analyses from which to assess effect size, precision, or consistency across measures.
The safety entries are also limited: the record lists only the Active Comparator group and does not provide a safety comparison with placebo. The available counts cannot support a general conclusion about the relative safety of lidocaine and saline.
Accordingly, the record is informative about the planned question and the status of the study but does not provide evidence to resolve that question. Any conclusion about treatment effects would go beyond the posted results.
13. Why This Trial Matters Statistically
This trial poses a clinically recognizable statistical question: whether a lidocaine infusion changes opioid consumption, measured as cumulative OME, compared with saline placebo. Defining the endpoint, unit, and assessment time is an important part of making a comparison interpretable. Here, the primary measure is specified as a continuous outcome in MME at 24 hours, with a mean and standard deviation as the planned summary.
The record also illustrates why trial design and trial results must be read separately. Randomization and a parallel structure describe how a comparison was intended to be organized. They do not, on their own, provide evidence about the direction or size of an effect. For that, the record needs outcome observations from the groups and a suitable analysis with uncertainty information.
The registry’s enrollment of 1, terminated status, absence of analyses, and flag that fewer than two arms appear in the primary outcome make the distinction particularly important. A stated research aim is not a result, and an endpoint definition is not an estimate. A statistical interpretation must account for whether the evidence needed for the comparison is actually present.
The record also raises general issues about planning and inference. Sample-size planning illustrations based on an observed effect are not observed power, and they cannot substitute for trial results. Likewise, a list of secondary measures does not reveal which findings were analyzed or how multiplicity was handled. These are essential distinctions when assessing what a registry entry can support.
The main statistical value of the record is therefore in showing the intended estimand and the limitations of the available evidence. It does not supply a treatment-effect estimate, but it makes clear why conclusions about efficacy, equivalence, or comparative safety cannot be drawn from the posted outcome information.
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 is that the registry does not report a comparative result for the registered primary endpoint. No group means, standard deviations, treatment contrast, confidence interval, or test result are available. The record flags fewer than two arms in the primary outcome, so the intended comparison cannot be reconstructed from the posted results.
The registry reports an enrollment of 1 and a terminated status, but does not explain the termination or provide a participant flow account. The numbers assigned to each arm and the extent of outcome collection are not reported in the registry record. It is therefore not possible to determine how the enrollment entry relates to the intended randomized comparison.
Analysis details are also unavailable. The record does not report the analysis population, missing-data approach, covariate adjustment, or statistical model used for any outcome. It reports 0 analyses. Multiplicity procedures for the listed outcomes are not reported in the registry record.
The masking field identifies the study as single-masked but does not specify who was masked. Further details about randomization and allocation procedures are not reported. The adverse-event fields list only the Active Comparator group, limiting their use for comparative safety interpretation.
These limitations arise from what is available in the registry record. They do not establish why results or methods are absent, and they do not justify assumptions about the trial’s conduct.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Continuous Intravenous Lidocaine Infusion Versus Placebo for Rib Fracture Analgesia — NCT04140396.
- Registry record last updated 2023-11-30; status last verified 2023-11.
- Results first posted 2023-11-30.
- 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
The registry record describes a phase 4, randomized, single-masked, parallel trial of continuous intravenous lidocaine infusion versus normal saline placebo for rib fracture analgesia. The stated primary outcome is cumulative OME consumption at 24 hours, measured in MME and summarized as a mean with standard deviation. The study summary also describes OME consumption at 48 hours as an aim.
The record lists an enrollment of 1, a terminated status, a start date of 2020-02-10, and a primary completion date of 2020-11-09. It lists 8 outcome measures and reports 0 analyses. The primary outcome is flagged as having fewer than two arms. No comparative primary result or complete safety comparison is reported in the registry record.