Interscalene Nerve Blocks With Ropivacaine Alone, With Dexamethasone, Plus Systemic Dexamethasone: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Interscalene Nerve Blocks With Ropivacaine Alone, With Dexamethasone, Plus Systemic Dexamethasone (NCT00519584), a randomized na study. The primary outcome is the Duration of Analgesia.

2. Clinical Question

3. Trial Design

The registry identifies NCT00519584 as a randomized, quadruple-masked, parallel-group clinical study. It lists the phase as NA and the condition as pain. Enrollment is recorded as 218. The sponsor is The Cleveland Clinic. The study start is recorded as 2007-07, primary completion as 2009-03, and status as terminated. The reason for termination is not reported in the registry record.

The listed regimens combine a local interscalene block with either local or intravenous study medication. One arm is labelled Ropivacaine/Saline and is described as ropivacaine with local saline and intravenous saline. A second is labelled Ropivacaine/Dex and is described as ropivacaine mixed with dexamethasone, with intravenous saline. The other arm labels are Bupivacaine/Dex and Bupivacaine/Saline, but their descriptions specify ropivacaine as the local anesthetic. That inconsistency is part of the record and makes the intended local anesthetic for those two labelled arms unclear.

The primary outcome is the duration of analgesia, reported in hours as a median with an inter-quartile range. Its timeframe is surgical date to postoperative day 1 (pod 0 -1 day). The registry also lists three secondary outcomes: time to a significant increase in shoulder discomfort, maximum VRS pain scores at rest, and total opioid consumption. The record contains analyses for the primary outcome, but further details about randomization procedures, masking procedures, treatment adherence, and the reason for study termination are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

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.

6. Primary Endpoint

The registry lists the primary outcome as the Duration of Analgesia, measured over surgical date to postoperative day 1 (pod 0 -1 day).

The primary endpoint, described as the duration of analgesia, is the time interval between onset of sensory block and the initial PACU use of opioid analgesia for surgical-site pain. The recorded timeframe is surgical date to postoperative day 1 (pod 0 -1 day), and the unit is hours. The registry summarizes the endpoint using the median and inter-quartile range for each arm.

This is a time-to-event measure: the event is the first recorded use of opioid analgesia for surgical-site pain after the block. Describing the time to an event can preserve information about when it occurred, rather than treating every participant’s experience as a simple yes-or-no outcome. The median gives the time by which half of the observed times fall, while the inter-quartile range describes the middle portion of the distribution. These summaries are useful when the distribution of event times is not well represented by a mean alone.

The endpoint is a measure of analgesia duration under the study’s definition, not a direct measure of every aspect of pain or recovery. It depends on the recorded onset of sensory block and on when opioid analgesia was first used in the PACU. Details about how those times were assessed, whether participants who did not use an opioid before the end of follow-up were censored, and how such observations were handled are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is a time-to-event endpoint: the event is initial PACU opioid use for surgical-site pain, measured from sensory-block onset. Time-to-event methods are useful when the outcome concerns how long it takes for an event to occur. They can make use of event timing and can accommodate observations for which the event time is not fully observed, provided the analysis defines and handles censoring appropriately. The registry does not report whether censoring occurred or how it was handled.

What does a median time describe?

The registry reports a median for each arm, with an inter-quartile range. The median is the central point of the observed time distribution: half of the recorded times are at or below it and half are at or above it. The inter-quartile range describes the central spread of the observations. It is not a confidence interval for the median. The reported values are 22.2 hours (18.0 to 28.6) for Ropivacaine/Saline, 11.8 hours (9.7 to 13.8) for Ropivacaine/Dex, 14.8 hours (11.8 to 18.1) for Bupivacaine/Dex, and 22.4 hours (20.5 to 29.3) for Bupivacaine/Saline.

What does the log-rank analysis contribute?

The log-rank method compares event-time patterns between groups. It assesses evidence that the time-to-event distributions differ across the comparison, using the timing of events rather than only comparing the reported medians. The registry reports a hazard ratio alongside each log-rank analysis. A hazard ratio is a relative measure of event rates over time under the model used for the analysis. Interpretation depends on which group is in the numerator and which event is being modelled. The registry lists the groups but does not specify the hazard-ratio orientation or provide further model details; the values should therefore be reported with their stated comparisons rather than given an assumed direction.

How should the confidence intervals and p-values be read?

The 95% confidence interval represents uncertainty around the reported hazard ratio under the analysis assumptions. A narrower interval indicates more precision than a wider interval, while an interval spanning a broad range leaves more uncertainty about the size of the association. The interval is not a range containing 95% of individual participants’ outcomes. The reported results are 0.17 (95% confidence interval 0.08 to 0.39; p < 0.001) for Ropivacaine/Saline versus Ropivacaine/Dex, and 0.44 (95% confidence interval 0.23 to 0.83; p < 0.001) for Bupivacaine/Dex versus Bupivacaine/Saline.

A p-value quantifies how incompatible the observed data are with a specified null hypothesis under the assumptions of the test. It is not the probability that the null hypothesis is true, nor does it measure the size or importance of a treatment effect. The record does not state whether the analyses were prespecified, whether they were adjusted, or how the tests relate to any broader analysis plan. The log-rank method and reported p-values should not be treated as a substitute for those missing details.

Why does the endpoint’s definition matter?

Use of opioid analgesia is a clinically relevant event in the context of postoperative pain management, but it is also influenced by the circumstances of measurement and care. The recorded duration ends at initial PACU opioid use for surgical-site pain. It does not encompass all subsequent pain experience, all later analgesic use, or a comprehensive measure of recovery. General statistical interpretation of a time-to-event endpoint also depends on consistent event definitions and follow-up across groups. The registry does not describe the assessment procedure, rules for opioid administration, or handling of participants without a recorded event by the end of the timeframe.

The sample-size assumptions described for planning illustrations use a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the effect to detect set as a stated fraction of the observed effect. For time-to-event outcomes, the planning illustration is based on the total number of events. These are planning assumptions, not the study’s reported design justification or observed power. The registry does not report the trial’s own sample-size justification, and no planning illustration values are available in the registry record.

10. Analyses Reported by the Sponsor

The registry reports two log-rank analyses with hazard ratios, 95% confidence intervals, and p-values. These are the posted analyses: 0.17 (95% confidence interval 0.08 to 0.39; p < 0.001) for the comparison of Ropivacaine/Saline with Ropivacaine/Dex, and 0.44 (95% confidence interval 0.23 to 0.83; p < 0.001) for the comparison of Bupivacaine/Dex with Bupivacaine/Saline. The record does not provide a separate recalculated hazard ratio or another unadjusted re-calculation to compare with these estimates.

No discrepancy is flagged between a sponsor analysis and a recalculation in the registry record. Because a recalculated estimate is not reported, there is no numerical comparison to make. Where a recalculation differs from an analysis reported by the sponsor, the sponsor’s own analysis takes precedence; that distinction does not create an additional estimate for this trial. Further details about the sponsor analysis, including its prespecification, covariates, censoring rules, and analytic population, are not reported in the registry record.

11. Multiplicity, Missing Data and Analysis Populations

The registry lists the duration of analgesia as the primary outcome and lists three secondary outcomes: time to a significant increase in shoulder discomfort, maximum VRS pain scores at rest, and total opioid consumption. It also reports two primary-outcome comparisons. When a study assesses multiple outcomes or contrasts, the chance of finding at least one apparently notable result can increase if the analyses are interpreted without accounting for multiplicity. Whether and how to adjust for multiple testing depends on the trial’s objectives and prespecified analysis plan.

The registry does not report a multiplicity strategy, a hierarchy for testing outcomes, or whether the two comparisons were jointly treated as confirmatory. It also does not provide results for the listed secondary outcomes in the record. Their absence from the posted results should not be read as evidence of no difference or as confirmation of any effect; their results are not reported in the registry record.

Missing-data methods and analysis populations are also not reported in the registry record. In a time-to-event analysis, information about follow-up completion and censoring can affect the interpretation of estimates. The record does not describe withdrawals, exclusions, missing outcome observations, deviations from assigned treatment, or whether the analysis followed an intention-to-treat approach. It is therefore not possible to establish from the posted information how completely the randomized groups were represented in the endpoint analysis.

The status is terminated, but no reason for termination or account of its effect on outcome collection is reported. Interim analyses and any statistical stopping rules are not reported in the registry record. Without these details, the reported p-values and confidence intervals can be described, but the completeness of the planned analysis and the handling of multiplicity and missing data cannot be independently assessed.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The adverse-event record lists zero participants affected by serious adverse events in each arm and zero affected by other adverse events in each arm. The at-risk counts are 54 for Ropivacaine/Saline, 54 for Ropivacaine/Dex, 54 for Bupivacaine/Dex, and 56 for Bupivacaine/Saline. No serious adverse-event terms are listed.

These entries describe what the registry reports; they should not be interpreted as proof that no adverse events occurred beyond the recorded categories or reporting period. The record does not provide event-level details, definitions, ascertainment methods, severity information, or a description of the observation period for adverse events. Death counts are recorded as null, which is not the same as reporting zero deaths. The registry also does not report whether safety data were collected for all participants through the same duration.

Safety comparisons require caution because the posted figures are limited to the recorded counts and provide no further context about completeness or uncertainty. The arm-label inconsistency affecting the local anesthetic descriptions also applies when identifying the regimens associated with the safety entries. The figures are descriptive registry entries, not a standalone assessment of comparative safety.

13. What the Result Does, and Does Not, Mean

The posted results describe the time from sensory-block onset to initial PACU opioid use for surgical-site pain, as defined by the registry. The medians are shorter in the dexamethasone-labelled arms than in their corresponding saline-labelled arms for both reported comparisons. The registry’s log-rank analyses report p < 0.001 for each comparison, together with hazard ratios and 95% confidence intervals. These are observations from the posted results and should be interpreted in light of the endpoint definition, the analysis details that are not reported, and the inconsistency in local anesthetic names for the arms labelled Bupivacaine.

The results do not establish a causal explanation for the observed time distributions beyond what the trial design and analyses can support. The record does not specify the direction convention for the hazard ratios, analytic population, censoring rules, or adjustment for other factors. The median summaries do not describe the whole distribution, and the hazard ratios do not directly state the absolute time until opioid use for an individual participant.

The results also do not answer every question about postoperative pain or recovery. The endpoint ends at initial PACU opioid use for surgical-site pain, while secondary outcomes are listed but their results are not reported in the registry record. The safety entries report zero affected participants for the adverse-event categories listed, but deaths are recorded as null and the safety reporting details are limited. Neither those entries nor the primary outcome alone provide a complete assessment of benefits and harms.

The trial status is terminated, and the reason is not reported. The results should be understood as the analyses and summaries recorded in the registry, not as a complete account of the study protocol or all results. No treatment recommendation follows from these statistics.

14. Why This Trial Matters Statistically

This trial illustrates how a time-to-event outcome can capture more than whether a participant eventually uses rescue analgesia: it records when the first use occurs relative to sensory-block onset. Reporting both medians with inter-quartile ranges and log-rank hazard ratios gives readers different views of the event-time data. The median summaries are directly interpretable in hours, while the hazard ratio summarizes a relative comparison over the follow-up period under the analysis assumptions.

It also illustrates why statistical estimates need to be read alongside their definitions and documentation. Here, the event is not a general pain score; it is initial PACU opioid use for surgical-site pain. That measure depends on the timing of block onset and medication use, and its interpretation would benefit from details about event assessment, follow-up, and censoring. Those details are not reported in the registry record.

The arm-name inconsistency is another statistical reporting issue with substantive implications. Two arms are labelled with bupivacaine, while their descriptions say ropivacaine. This makes it difficult to identify the intended treatment contrast precisely from the record alone. A result can be numerically precise while the intervention being compared remains ambiguously described.

Finally, the record demonstrates the distinction between a reported p-value and a complete analysis plan. The primary endpoint has two reported comparisons, but multiplicity handling, secondary-outcome results, missing-data procedures, and analysis populations are not reported. Such omissions constrain how comprehensively readers can assess the evidence, even when confidence intervals and p-values are available.

15. 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 record’s descriptions of the arms labelled Bupivacaine/Dex and Bupivacaine/Saline specify ropivacaine as the local anesthetic. This conflicts with the arm titles and with the trial title’s wording. The intended drug identity for those arms is not reported clearly in the registry record, so the precise treatment contrast cannot be resolved from the descriptions.

The reported analyses are limited to two comparisons for the primary endpoint. The registry does not report a separate recalculated estimate, adjustment details, hazard-ratio orientation, censoring rules, or the analysis population. It also does not report the trial’s sample-size justification, interim analyses, multiplicity plan, or a detailed statistical analysis plan. The three listed secondary outcomes have no results reported in the registry record.

Although enrollment is recorded as 218, the registry does not describe exclusions, withdrawals, protocol deviations, or how many observations contributed to each endpoint analysis beyond the arm-level counts. The reason for the terminated status is not reported, and its relationship to follow-up or outcome reporting is unclear. Details about eligibility, participant characteristics, event assessment, and treatment adherence are also not reported in the registry record.

Safety information is restricted to the reported counts for serious and other adverse events. The record does not describe ascertainment, observation duration, event definitions, or the meaning of the null entries for deaths. Taken together, these omissions do not invalidate the reported summaries, but they limit assessment of their precision, completeness, and applicability to the intended treatment contrasts.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Interscalene Nerve Blocks With Ropivacaine Alone, With Dexamethasone, Plus Systemic Dexamethasone — NCT00519584.
• Registry record last updated 2017-07-21; status last verified 2017-06.
• Results first posted 2017-07-21.
• 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.

19. Record Summary

NCT00519584 is recorded as a randomized, quadruple-masked, parallel-group study sponsored by The Cleveland Clinic, with enrollment of 218 and status listed as terminated. The primary outcome is duration of analgesia, defined as the interval from sensory-block onset to initial PACU opioid use for surgical-site pain. The registry reports median times and two log-rank comparisons.

In both reported comparisons, the median is lower in the dexamethasone-labelled arm than in the corresponding saline-labelled arm; both log-rank p-values are < 0.001. The record lists three secondary outcomes but does not report their results. It records zero participants affected by serious and other adverse events in each arm, while death counts are null. The reason for termination, detailed analysis methods, and several data-handling details are not reported in the registry record. A mismatch between two arm titles and their local anesthetic descriptions limits identification of those treatment regimens.