QL vs PENG for Analgesia After Hip Arthroplasty: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for QL vs PENG for Analgesia After Hip Arthroplasty (NCT05710107), a randomized na study. The primary outcome is Postoperative Cumulative Opioid Consumption.

2. Clinical Question

3. Trial Design

This was a prospective, randomized clinical trial with a parallel-group model and triple masking. The registry lists the study as completed and gives an enrollment of 106. The start date is 2023-02-07, and the primary completion date is 2023-11-12. The sponsor is the Medical University of South Carolina. The phase is listed as NA.

The planned participants were adults aged 18 years and older undergoing elective hip replacement with planned same-day discharge. Participants were randomized to receive either PENG + LFC blocks or a QL block before surgery. Random allocation is intended, in general, to make treatment groups comparable on average, including for factors that are not measured. It does not guarantee that groups will be balanced in any particular trial, and the registry record does not provide baseline comparisons with which to assess balance.

A parallel-group design assigns each participant to one treatment group for the comparison rather than comparing both treatments within the same participant. Triple masking indicates that masking was planned for three parties or roles, but the record does not identify them. It also does not describe allocation concealment, the masking procedures, or whether masking was successfully maintained.

The primary outcome was cumulative postoperative opioid consumption, with the stated timeframe of 0–72 hours after surgery. The record also describes average postoperative pain score as a secondary outcome. Its brief summary names other planned outcome areas, including ambulation, function and mobility, recovery-room duration, satisfaction, and opioid-related side effects. The record does not report results for those outcomes. It does not report a detailed statistical analysis plan, sample-size justification, or participant flow through follow-up.

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

Reasons for not completing this period:

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 Postoperative Cumulative Opioid Consumption, measured over 0-72 hours postoperatively.

The primary endpoint is postoperative cumulative opioid consumption, expressed in intravenous morphine milligram equivalents, over 0–72 hours after surgery. The description says consumption would be evaluated at the post-anesthesia care unit (PACU) and through 72 hours after surgery. The intended summary is a mean with a 95% confidence interval.

A cumulative measure represents opioid use across a stated period rather than at just one assessment time. Expressing consumption in morphine milligram equivalents places different opioid medications on a common scale for the purpose of describing total use. In general, this kind of endpoint can describe medication burden during recovery; it does not, by itself, describe pain intensity, function, or the reasons for medication use. Those are distinct outcomes.

A mean gives the average consumption in the analyzed group. A confidence interval communicates uncertainty around an estimated mean or contrast: narrower intervals indicate greater precision, while wider intervals indicate less precision. It does not show the range of individual participants’ consumption.

The registry record gives the endpoint definition and intended summary but does not report a primary-outcome mean, between-group contrast, or confidence interval. It also notes that the primary outcome has several categories or time points and was not reduced to one comparison. As a result, the posted record does not establish the observed magnitude, direction, or precision of a single primary comparison.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does randomization contribute?

Randomization assigns participants to treatment groups using a chance-based process. In general, this helps reduce systematic differences between groups at assignment, including differences in known and unknown characteristics. It does not ensure that every characteristic will be balanced in a particular trial. The record states that allocation was randomized, but does not describe the sequence-generation method or allocation concealment. Those details are not reported in the registry record.

The parallel model means participants were assigned to one of the compared approaches. This design supports a between-group comparison, provided the outcome data and analysis are available. Triple masking is recorded, but the identities of the masked roles, and the procedures used to keep assignments concealed during care or assessment, are not reported.

What does a mean describe?

The primary outcome is a continuous measure: cumulative opioid consumption in intravenous morphine milligram equivalents. A mean describes the arithmetic average for the observations included in an analysis. It is a compact summary, but does not show how individual observations are distributed. In general, a small number of unusually high values can affect a mean, and groups with the same mean can still differ in variability or distribution. The record does not provide outcome distributions, group means, or a description of how the analysis handled unusual values.

For repeated or cumulative measurements, the time definition is part of the endpoint. The registry names a 0–72-hour period and says consumption would be evaluated at PACU and through 72 hours after surgery. It does not specify whether the analysis would use a single cumulative value per participant, compare measurements at multiple times, or apply a particular repeated-measures model. The record notes that there are several categories or time points and no single comparison was selected for the posted primary outcome.

How should a confidence interval be read?

A confidence interval is an uncertainty summary for an estimate. In general, a 95% confidence procedure is constructed so that, under its statistical assumptions, intervals generated across repeated samples would cover the target value at the stated rate. For an individual study, the interval gives a range of estimates compatible with the data and method; it is not a range containing most individual participants’ outcomes, nor does it assign a probability to the fixed true value after the data have been observed. A narrower interval indicates more precise estimation than a wider interval, all else being equal.

The endpoint description specifies a 95% confidence interval, but the registry record does not post one for the primary outcome. Thus the intended form of reporting can be described, but its realized precision cannot be evaluated. The record also does not report a between-group estimate or a test statistic.

Why do multiple outcomes and time points matter?

When a study examines multiple endpoints, time points, or comparisons, the chance of finding at least one apparently unusual result can increase if each is interpreted as a separate confirmatory test. Statistical methods can address this issue by defining a primary comparison in advance, controlling the overall error rate, or treating secondary analyses as exploratory. The registry record lists seven outcome measures, but does not report a multiplicity procedure or identify how any adjustment would be applied. Its note that the primary outcome has several categories or time points reinforces that the exact comparison is not specified in the posted results.

The record names average postoperative pain score as a secondary outcome. Its brief summary also describes pain scores across the postoperative period and additional areas such as ambulation, mobility, recovery-room duration, satisfaction, and opioid-related side effects. These outcome domains are not substitutes for the primary opioid-consumption endpoint, and the record does not provide their estimates or analysis methods.

What do the planning assumptions mean?

The sample-size material is described as a planning illustration computed from an observed effect, not as the trial’s original design justification. The stated assumptions are a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation; the effect to detect is described as a fraction of the observed effect. In general, a planning calculation asks how many participants would be needed under specified assumptions to detect a chosen effect with a chosen power. Such an illustration is prospective and conditional: it does not indicate the probability that the completed trial detected an effect, and it is not observed power.

Because the registry record does not post the primary effect estimate, the illustration cannot be evaluated from this record as a transparent recalculation of that effect. The sample-size justification used when the trial was designed is not reported. No inference about the trial’s statistical power or adequacy should be drawn from the planning assumptions alone.

What statistical details are unavailable?

The registry record does not describe an inferential model, covariate adjustment, handling of repeated observations, missing-data method, or analysis population. These choices can affect how an estimate is calculated and what population it represents. Without the analysis record and outcome results, readers cannot check whether the reported analysis followed an intended plan or assess model assumptions. General statistical considerations, such as whether a continuous outcome is skewed or whether observations vary more than a model expects, are relevant only if the data and method are known; the registry record does not supply that information.

10. Multiplicity, Missing Data and Analysis Populations

The record lists seven outcome measures and identifies postoperative cumulative opioid consumption as the primary outcome. It does not report a multiplicity strategy for the primary outcome’s several categories or time points, or for the other outcomes. The registry notes that the primary outcome was not reduced to one comparison. Without a defined comparison and a stated approach to multiplicity, the role of any possible time-specific or secondary findings cannot be assessed as confirmatory from this entry.

Missing-data information is not reported in the registry record. The record does not state whether primary-outcome measurements were missing, how much data were available at each time point, why measurements might be missing, or how missing observations would be handled. The absence of those details should not be read as evidence that all enrolled participants had complete outcome data.

The analysis population is also not reported. The registry does not say whether the intended analysis would include participants according to randomized assignment, treatment received, or another rule. These approaches can answer different questions, especially if treatment assignment and treatment received do not coincide. No method for protocol deviations or withdrawals is described.

Finally, the registry record does not report a detailed statistical analysis plan, interim analysis plan, or sample-size justification. These omissions limit assessment of prespecification and of how the reported outcome choices would be interpreted. They do not establish that such procedures were absent from the study conduct; they are simply not reported in the registry record.

11. Safety Results

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

Deaths

Other (non-serious) adverse events

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

Most frequent non-serious adverse event terms

The registry record lists zero serious adverse events among 50 participants at risk in the PENG + LFC group and zero among 51 at risk in the QL group. It also lists zero deaths in each group. For other adverse events, the record lists 30 affected among 50 at risk in the PENG + LFC group and 28 affected among 51 at risk in the QL group.

These figures describe what the registry reports; they do not by themselves establish that the groups had equivalent safety outcomes. A zero count of serious events does not prove that such events cannot occur, and the record does not provide confidence intervals or a comparative statistical analysis for these counts. The nature, definitions, severity, timing, and ascertainment rules for the other adverse events are not reported in the registry record. The counts should therefore be read as recorded event summaries, not as a complete account of the safety profile or as proof of a treatment effect.

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

The registry record supports a description of the trial question and design: adults undergoing elective hip replacement with planned same-day discharge were to be randomized to PENG + LFC blocks or a QL block, and the primary outcome was cumulative opioid consumption over 0–72 hours after surgery. It also reports adverse-event counts for the two groups.

It does not provide a primary-outcome comparison, group means, confidence interval, or statistical test. Consequently, the record cannot establish the size or direction of any observed difference in opioid consumption, or how precisely such a difference was estimated. The status of completed does not fill this gap. Nor does the planned use of a mean and confidence interval amount to a result.

The record also does not report results for the secondary pain outcome or the additional outcome areas described in the brief summary. The adverse-event figures are limited to the categories and counts recorded; details about event definitions and follow-up are unavailable. A zero serious-event count is not proof of no risk, and the available counts do not establish equivalence between groups.

More generally, a registry entry is a record of study information and posted results, not a substitute for a complete analysis report. Information about missing data, analysis populations, the statistical model, multiplicity, and deviations from the planned approach is not reported. Those details would be needed for a fuller appraisal of the analysis. The appropriate conclusion is that the registry describes a randomized comparison but does not report enough primary-outcome evidence to determine what the observed comparison showed.

13. Why This Trial Matters Statistically

This trial addresses a concrete statistical comparison: two regional block approaches were randomized in the setting of elective hip arthroplasty, and postoperative opioid consumption over a defined period was designated as the primary outcome. Randomization and a prespecified outcome can make a treatment comparison more interpretable when the analysis is reported with enough detail to connect the design to the estimate.

The endpoint also illustrates why outcome definition matters. Cumulative consumption over 0–72 hours is not the same quantity as a pain score at one assessment, mobility, or time to first ambulation. Each outcome captures a different aspect of postoperative experience, and results should be interpreted in relation to the outcome actually measured. The record’s description of several time points or categories highlights the importance of specifying which comparison is primary.

Statistically, an estimate and its uncertainty are essential complements. A group contrast describes the observed difference, while its confidence interval conveys precision. Without those results, the randomized design alone cannot answer whether the groups differed in the recorded outcome or how uncertain the comparison is. Likewise, safety counts are informative descriptions but require adequate definitions and uncertainty context for comparative interpretation.

The registry entry is therefore useful for identifying the study question, design, timing, and planned outcome, while also showing the limits of the posted analysis record. It is not possible to draw a primary-outcome conclusion from design details alone. Clear outcome reporting, analysis populations, missing-data accounting, and an explicit approach to multiple times and outcomes are important for turning a trial design into interpretable statistical evidence.

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 most important trial-specific limitation of the registry record is that it does not report a primary-outcome estimate or a single comparison, despite identifying cumulative opioid consumption as the primary endpoint. The record says the outcome spans several categories or time points and was not reduced to one comparison. It therefore does not allow assessment of the direction, magnitude, or precision of the primary result.

The registry does not report analysis results for the named secondary outcome or the other outcome areas in its brief summary. It also does not describe the statistical model, multiplicity handling, analysis population, missing-data methods, or participant flow. These gaps restrict assessment of how the randomized design was carried through to the analysis.

Several design details are also not reported: the roles included in triple masking, the methods for generating and concealing allocation, full eligibility criteria, and complete block-procedure details. The safety summaries lack event definitions, timing, and comparative uncertainty information. Those omissions prevent a detailed appraisal of safety ascertainment or the clinical meaning of the non-serious event counts.

The enrollment figure and completed status do not resolve these limitations. Nor can a planning illustration based on an observed effect substitute for the original sample-size justification or the trial’s reported analysis. These are limitations of the information in the registry record; they should not be treated as proof that the study team did not collect or analyze information that is not posted there.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: QL vs PENG for Analgesia After Hip Arthroplasty — NCT05710107.
• Registry record last updated 2024-12-20; status last verified 2024-11.
• Results first posted 2024-12-20.
• 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.

18. Record Summary

The registry record describes NCT05710107, titled QL vs PENG for Analgesia After Hip Arthroplasty. It is a completed, prospective randomized trial with a parallel model and triple masking, sponsored by the Medical University of South Carolina. Enrollment is 106. The study dates listed are 2023-02-07 for start and 2023-11-12 for primary completion.

The comparison is PENG + LFC block versus QL block in adults undergoing elective hip replacement with planned same-day discharge. The primary outcome is cumulative postoperative opioid consumption in intravenous morphine milligram equivalents over 0–72 hours, intended to be summarized as a mean with a 95% confidence interval. Average postoperative pain score is listed as a secondary outcome.

The registry record does not post a primary-outcome comparison or analysis results. It also does not report the detailed statistical plan, missing-data handling, or analysis population. Serious adverse-event and death counts are zero in both groups; other adverse-event counts are listed, but event definitions and comparative analyses are not reported.