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 Selective Intraoperative Administration of Local Anesthesia in Breast Reconstruction (NCT02525718), a randomized phase 2 study. The primary outcome is Quality of Recovery Score.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02525718 |
| Phase | Phase 2 |
| Condition | Breast Cancer |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Double |
| Enrollment | 47 |
| Arms in the primary outcome | 2 |
| Lead sponsor | Northwestern University |
| Results posted | Yes |
2. Clinical Question
Population
People undergoing unilateral or bilateral mastectomy with immediate reconstruction involving insertion of a tissue expander were eligible for the study. The condition listed in the registry is breast cancer. The record gives an enrollment of 47, but further eligibility details and participant characteristics are not reported in the registry record.
Intervention
The intervention was selective administration during surgery of a local anesthetic solution containing 0.25 % bupivacaine (2.5 mg/ml), 1:100,000 epinephrine, and 4 mg dexamethasone. The injection was intended to cover intercostal nerves supplying the breast tissue.
Comparator
The comparator was saline, described as placebo, administered to the breast area to cover the intercostal nerves supplying the breast tissue during surgery. The registry classifies allocation as randomized, masking as double, and the study model as parallel.
Primary question
The primary outcome was the Quality of Recovery Score 24 hours after surgery. The clinical question was whether the posted recovery scores differed between the saline and local anesthetic groups. The registry also lists pain score using a 10-point Visual Analog Scale, opioid consumption, and length of hospital stay as secondary outcomes, but comparative results for those outcomes are not reported in the registry record.
3. Trial Design
This completed Phase 2 study is registered as NCT02525718, with the title “Selective Intraoperative Administration of Local Anesthesia in Breast Reconstruction.” It was sponsored by Northwestern University. The registry describes a randomized, double-blinded, parallel-group design and records enrollment of 47. The study start is listed as 2015-08, and primary completion as 2016-11.
Participants undergoing unilateral or bilateral mastectomy with immediate reconstruction involving a tissue expander were assigned to saline placebo or selective administration of the local anesthetic solution. The active solution contained 0.25 % bupivacaine (2.5 mg/ml), 1:100,000 epinephrine, and 4 mg dexamethasone. The placebo was saline administered to the breast area. The registry descriptions identify the intended nerve coverage but do not report further details about the injection procedure or the implementation of masking.
The primary outcome was the Global 40 Item Quality of Recovery survey score, measured 24 hours post-operatively. The registry describes the score as ranging from 40 to 200, with higher scores representing better reported recovery. Secondary outcomes listed are pain score using a 10-point Visual Analog Scale, opioid consumption, and length of hospital stay. The registry lists four outcome measures in total but provides primary-arm summaries only for the Quality of Recovery Score. Results for the secondary outcomes are not reported in the registry record.
Details of the randomization sequence, allocation concealment, sample-size justification, statistical analysis plan, and handling of protocol deviations are not reported in the registry record. The registry also does not give participant-flow details or baseline characteristics. These omissions limit what can be concluded about the design and analysis beyond the stated randomized, double-blinded, parallel structure.
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 | 0.25 % Bupivacaine w/ Epinephrine & 4mg Dexamethasone |
|---|---|---|
| STARTED | 23 | 24 |
| COMPLETED | 22 | 23 |
| NOT COMPLETED | 1 | 1 |
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 | Placebo | 0.25 % Bupivacaine w/ Epinephrine & 4mg Dexamethasone | Total |
|---|---|---|---|---|
| Participants analysed | 22 | 23 | 45 | |
| Age, Continuous | years | 50 (42 to 57) | 48 (43 to 58) | 49 (43 to 58) |
| Sex: Female, Male: Female | Participants | 22 | 23 | 45 |
| Sex: Female, Male: Male | Participants | 0 | 0 | 0 |
| Region of Enrollment: United States | participants | 22 | 23 | 45 |
6. Primary Endpoint
The registry lists the primary outcome as Quality of Recovery Score, measured over 24 hours post-operatively.
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | Inter-Quartile Range |
| Unit | score on a scale |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the Quality of Recovery Score at 24 hours after surgery. It comes from the Global 40 Item Quality of Recovery survey, a questionnaire covering emotional state, physical comfort, psychological support, physical independence, and pain. The registry describes the score as ranging from 40 to 200, where 40 represents very poor overall recovery and 200 represents the best possible recovery.
A recovery questionnaire can capture several aspects of patients’ postoperative experience in a single outcome. This is useful when the study question concerns recovery as a broad construct rather than a single symptom or clinical event. The score’s inclusion of pain means it reflects more than pain alone; it also incorporates other dimensions named in the registry description. The secondary outcomes of pain score, opioid consumption, and hospital stay address more specific aspects of postoperative recovery.
The endpoint is reported as a median with interquartile-range bounds. A median describes the middle of the observed score distribution, while the interquartile range describes the spread of its central portion. These summaries communicate the typical observed score and some of its variability without relying on a mean and standard deviation. They do not, by themselves, establish whether a between-group difference is compatible with chance or how precisely that difference is estimated. The registry record does not report a comparative estimate or confidence interval for this endpoint.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
For the primary outcome at 24 hours post-operatively, the placebo group has a reported median Quality of Recovery Score of 165.0, with interquartile-range bounds of 143.0 and 179.0. The group receiving 0.25 % bupivacaine with epinephrine and 4 mg dexamethasone has a median of 169.0, with bounds of 155.0 and 182.0. These are descriptive summaries of the recorded scores in the two groups. They indicate the observed central scores and the spread represented by the reported bounds.
The registry lists 22 participants for the placebo outcome and 23 for the active-treatment outcome. The reported summaries do not provide the individual scores, and they do not show how the distributions overlap. A reader cannot infer the size or precision of a treatment contrast from the group medians alone. The registry record does not report a between-group estimate, confidence interval, or p-value for the primary outcome. It also does not report an analysis method for comparing the groups. Thus, the posted primary results support a descriptive account of the observed scores, but not an inferential conclusion about a group difference.
The record lists three secondary outcomes: pain score using a 10-point Visual Analog Scale, opioid consumption, and length of hospital stay. Their results are not reported in the registry record. The lack of those outcome results prevents a fuller comparison of pain, opioid use, and hospital stay between the randomized groups. It is also not possible to determine from this record whether secondary outcomes were measured but omitted, or whether results were unavailable for another reason.
The adverse-event record lists zero serious adverse events and zero other adverse events for each group, among the participants identified as at risk for those outcomes. This is a report of recorded event counts, not proof that no events occurred outside the registry’s reported categories or collection period. Death counts are not reported in the registry record.
No sponsor-reported comparative analysis is available in this record, and no recalculated comparison is listed. The posted arm summaries should therefore be read as descriptive results, not as evidence of statistical significance, equivalence, or a clinically important difference. Clinical importance cannot be judged from the reported medians alone; the registry record does not state a threshold for an important difference in the Quality of Recovery Score.
9. Statistical Methods Explained
What do the group summaries describe?
The primary outcome is summarized by a median and interquartile-range bounds. In general, the median is the middle value after observations are ordered. It is a measure of location that is less influenced by extreme observations than the mean. The interquartile range describes the spread between the central portions of a distribution; the posted bounds help readers see the range around the reported median. These summaries are descriptive. They do not show every score, identify the shape of the score distribution, or quantify uncertainty in a group comparison.
The registry reports the placebo median as 165.0, with bounds of 143.0 and 179.0, and the active-treatment median as 169.0, with bounds of 155.0 and 182.0. The record identifies interquartile range as the dispersion measure, but it does not report a separate comparative effect estimate. The medians and bounds cannot substitute for a confidence interval for the between-group effect: they describe each group, rather than the uncertainty around a specified contrast.
Why does the randomized design matter?
In general, random assignment aims to make the groups comparable at the start of a trial with respect to both measured and unmeasured characteristics. A parallel-group design assigns participants to a group and evaluates outcomes in that assigned group. Double masking is intended to limit the influence of knowledge about assignment on aspects of trial conduct or outcome assessment. These are general design principles, not confirmation of how masking or allocation procedures were implemented in this study. The registry does not report the sequence-generation method, allocation concealment, or which people were masked.
Randomization alone does not answer the statistical question. An analysis must define the outcome contrast, account for the trial design, and present an estimate with uncertainty. The registry record does not report a comparative analysis for the primary endpoint, and it lists zero analyses. It is therefore not possible to assess the analysis population, model assumptions, adjustment strategy, or treatment of protocol deviations from the posted record.
What would a confidence interval add?
In general, a confidence interval gives a range of values compatible with the observed data under a specified statistical procedure. It conveys uncertainty about an estimated effect, while a point estimate alone gives only the center of that estimate. A confidence interval would need to correspond to a clearly defined comparison and an appropriate analysis of the trial outcome. No confidence interval for the primary comparison is reported in the registry record. Nor is a p-value reported, so the registry results do not establish whether a formal hypothesis test was conducted or what its outcome was.
Statistical significance and clinical importance are different questions. A statistical test evaluates compatibility with a null hypothesis under its assumptions; it does not determine whether an observed difference matters to patients. Assessing clinical importance would require a justified threshold or other clinical context. The record does not report a threshold for an important Quality of Recovery Score difference.
How should planning calculations be read?
In general, a sample-size calculation explores how many participants might be needed under stated assumptions to detect a specified effect with a chosen error rate and power. The registry’s planning illustration is described as using the observed effect, a two-sided significance level of 0.05, equal allocation, and a normal approximation; the targeted effect is expressed as a fraction of the observed effect. Such an illustration is not the trial’s documented design justification unless the registry says that it was used to plan the study. The sample-size justification and the trial’s own statistical plan are not reported in the registry record.
Planning estimates depend on their assumptions, including the effect size chosen and the variability of the endpoint. An illustration based on an effect observed in the same trial is especially not a measure of the probability that the trial’s result is true. It should not be interpreted as observed power. Any planning output is a prospective design illustration, not an additional result from the participants enrolled in this trial.
What remains unreported?
The record does not describe an interim analysis, multiplicity adjustment, missing-data method, or analysis population. It does not state whether the primary comparison was adjusted for baseline measures or other covariates. Those details matter because they define how the observed data are converted into a treatment-effect estimate and how uncertainty is assessed. Without them, the available record supports a careful description of the outcome summaries but does not support reconstruction of the trial’s inferential analysis.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists the Quality of Recovery Score as the primary outcome and identifies pain score using a 10-point Visual Analog Scale, opioid consumption, and length of hospital stay as secondary outcomes. Considering several outcomes can raise a multiplicity question: if many tests are performed, the chance of at least one apparently unusual result can increase. In general, a trial may address this through a prespecified hierarchy, an adjustment procedure, or clear designation of which results are confirmatory and which are exploratory. The registry record does not report a multiplicity strategy, and it does not report comparative analyses for the listed secondary outcomes.
The registry lists four outcome measures but provides primary results only for the Quality of Recovery Score. It does not report how missing observations were handled, whether any outcome data were unavailable, or whether the posted summaries use all randomized participants. The analysis population and participant-flow details are not reported in the registry record. Consequently, the reader cannot determine whether the summaries represent an intention-to-treat analysis, a per-protocol analysis, or another population definition.
In general, missing outcome data can affect both the group summaries and the validity of a comparison, depending on why data are missing and how the analysis handles them. The registry record does not describe imputation, sensitivity analyses, or assumptions about missingness. It also does not report protocol deviations or withdrawals by group. These reporting gaps do not show that data were missing or that a particular analysis was used; they mean those details are not available 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 |
|---|---|---|---|
| Placebo | 0 | 22 | 0.0% |
| 0.25 % Bupivacaine w/ Epinephrine & 4mg Dexamethasone | 0 | 23 | 0.0% |
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 |
|---|---|
| Placebo | 0 of 22 |
| 0.25 % Bupivacaine w/ Epinephrine & 4mg Dexamethasone | 0 of 23 |
The adverse-event record gives separate counts for serious and other adverse events. In the placebo group, the record lists 22 at risk for serious events and 22 at risk for other events, with zero affected in each category. In the group receiving 0.25 % bupivacaine with epinephrine and 4 mg dexamethasone, it lists 23 at risk in each category, again with zero affected. The registry does not list serious adverse-event terms.
These figures describe what is recorded in the registry for the reported event categories. They should not be interpreted as proving that an intervention is free of risk. The record does not give event definitions, collection procedures, follow-up duration for adverse events, or details about how the counts were verified. The death counts are not reported in the registry record.
In general, an event count of zero is still an observation made within the study’s recorded population and follow-up, rather than evidence about every possible patient or setting. These safety entries also do not provide a formal comparison between groups. No such analysis is reported in the registry record.
12. What the Result Does, and Does Not, Mean
The posted primary results describe Quality of Recovery Scores 24 hours after surgery in a randomized comparison of saline with selective administration of a local anesthetic solution. The median is 165.0 in the placebo group and 169.0 in the active-treatment group. The reported interquartile-range bounds are 143.0 and 179.0 for placebo, and 155.0 and 182.0 for active treatment. These summaries show the observed central scores and their reported spread; they are not a test of whether the groups differ.
The registry record does not report a comparative effect estimate, confidence interval, or p-value. It therefore does not establish the precision of a treatment contrast or whether the observed medians are compatible with no difference under a specified statistical model. It also does not report a threshold for a clinically important difference. The numbers alone cannot establish whether any difference is meaningful to patients.
The study’s stated question includes postoperative pain and opioid requirement, and the registry lists pain score, opioid consumption, and length of hospital stay as secondary outcomes. Their results are not reported in the registry record. The primary recovery score includes several dimensions, among them pain, but it is not a substitute for the specific secondary outcomes. The available record therefore does not support conclusions about those outcomes.
The randomized, double-blinded design is relevant context, but a design label is not a substitute for reporting how the trial was conducted and analyzed. Randomization details, masking implementation, missing-data handling, and the statistical plan are not reported in the registry record. The zero adverse-event counts should likewise be read as registry-reported counts, not as a general guarantee of safety.
Overall, the record offers descriptive primary-outcome summaries and safety counts for this completed Phase 2 study. It does not provide enough comparative statistical information to determine the size, precision, or clinical importance of a group difference. It neither establishes benefit nor establishes lack of benefit.
13. Why This Trial Matters Statistically
This trial is statistically interesting because it evaluates a broad recovery measure alongside more specific postoperative outcomes. The Quality of Recovery Score combines emotional state, physical comfort, psychological support, physical independence, and pain into a single score. That breadth may be useful for describing recovery as a whole, while the listed secondary outcomes focus on pain, opioid consumption, and length of hospital stay. Together, the outcome choices illustrate why a study needs a clear primary endpoint and transparent reporting of other outcomes.
The randomized, double-blinded, parallel design is also relevant to interpretation. In general, random allocation can reduce systematic baseline differences, while masking can limit some influences of treatment knowledge. However, readers need operational details and a reported analysis to assess how well those design aims were carried out. The registry record gives the design classifications but not the randomization method, masking procedures, or statistical plan.
The posted primary summaries demonstrate the difference between descriptive and inferential reporting. Medians and interquartile-range bounds communicate observed group scores and spread. A comparative estimate and its uncertainty would be needed to evaluate the evidence for a between-group difference. Because these are not reported in the registry record, the summaries do not answer how precisely the groups differ.
The registry also makes visible the limits of outcome reporting: secondary outcomes are named, but their comparative results are not reported. This matters because a broad recovery score and individual pain or opioid outcomes answer related but distinct questions. The record is therefore a useful example of why readers should distinguish the trial’s design, its posted descriptive results, and the inferential conclusions that can be supported by the available reporting.
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 trial-specific limitation of the registry record is that it provides no comparative analysis for the primary endpoint. Group medians and interquartile-range bounds are posted, but an effect estimate, confidence interval, and p-value are not reported in the registry record. The statistical method used to compare the groups is also not reported. This prevents assessment of the size and precision of the primary contrast.
Although the registry lists pain score using a 10-point Visual Analog Scale, opioid consumption, and length of hospital stay as secondary outcomes, their results are not reported. As a result, the record does not allow readers to evaluate those aspects of postoperative recovery alongside the primary score. The registry’s listing of four outcome measures does not provide the missing comparative results.
Participant characteristics, eligibility criteria beyond the described surgical population, participant flow, withdrawals, and outcome-data completeness are not reported in the registry record. The analysis population and missing-data approach are also not reported. These omissions make it difficult to understand which participants contributed to the posted summaries or how incomplete observations, if any, were handled.
The registry classifies the study as randomized and double-blinded, but does not report sequence generation, allocation concealment, or masking implementation. It also does not report a sample-size justification, interim analyses, or a statistical analysis plan. These details cannot be inferred from the design labels or the enrollment record. The safety entries lack reported event definitions and follow-up details, and death counts are not reported in the registry record. Accordingly, the available record should be interpreted as a limited descriptive account rather than a complete report of trial conduct and analysis.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Selective Intraoperative Administration of Local Anesthesia in Breast Reconstruction — NCT02525718.
- Registry record last updated 2019-08-14; status last verified 2019-07.
- Results first posted 2019-08-14.
- 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
NCT02525718 is a completed Phase 2 randomized, double-blinded, parallel-group study sponsored by Northwestern University. The registry records enrollment of 47 and a study start of 2015-08, with primary completion in 2016-11. Participants undergoing unilateral or bilateral mastectomy with immediate tissue-expander reconstruction were assigned to saline placebo or selective administration of 0.25 % bupivacaine with epinephrine and 4 mg dexamethasone.
The primary outcome was the Quality of Recovery Score 24 hours after surgery. The registry reports group medians and interquartile-range bounds, but does not report a comparative analysis. Pain score, opioid consumption, and length of hospital stay are listed as secondary outcomes; their results are not reported in the registry record. Serious and other adverse-event counts are recorded as zero in both groups. Death counts are not reported in the registry record.