Dexmedetomidine-ketamine in Femur Proximal Fracture Patients: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Dexmedetomidine-ketamine in Femur Proximal Fracture Patients (NCT02150759), a randomized na study. The primary outcome is Pain Score Using Five Scales.

2. Clinical Question

The clinical question concerns pain during a specific procedural position, rather than a general measure of pain over an extended period. The registry describes the assessment as occurring at an average of 10-20 minutes and defines a five-level score: 0 is calm, 1 is facial grimacing, 2 is moaning, 3 is screaming, and 4 is restlessness or agitation such that the procedure cannot proceed.

The record identifies the trial as randomized and parallel, with the two groups receiving regimens that share dexmedetomidine and differ in the other named drug. It does not report drug doses, administration details, or the exact timing and procedures used to assess pain beyond the stated timeframe. Those details therefore cannot be used to refine the clinical question.

Although the registry lists a primary outcome and a secondary outcome called Quality of Patient Positioning, it does not post results for either outcome in a form that permits a comparison. The primary outcome spans several categories or time points and has not been reduced to a single comparison in the registry record. Consequently, the question is clear, but the available posted results do not establish how the groups differed in pain or positioning quality.

3. Trial Design

The registry describes a randomized, parallel-group trial comparing dexmedetomidine-ketamine with dexmedetomidine-fentanyl in patients with proximal femur fractures. The masking field is listed as quadruple. The record does not explain which people were masked, how masking was maintained, or whether it was successful. The study phase is listed as NA, and the status is completed.

Enrollment is reported as 46. The registry gives a start date of 2014-05 and a primary completion date of 2017-11. Inje University is listed as the sponsor. These record details describe the trial as registered; they do not, by themselves, establish how many participants contributed data to any particular outcome. The analyzed sample sizes and analysis populations are not reported in the registry record.

The brief description places the comparison in the context of lateral positioning for spinal anesthesia. The primary outcome is titled Pain Score Using Five Scales, and its timeframe is average 10-20 minutes. The listed scale runs from calm to restlessness or agitation that prevents proceeding, with intermediate descriptions of facial grimacing, moaning, and screaming. Quality of Patient Positioning is listed as a secondary outcome.

The registry record does not report the allocation sequence method, concealment procedures, drug doses, detailed administration protocol, sample-size justification, or statistical analysis plan. It also does not report outcome results that would support a between-group estimate. Thus the design fields establish the broad randomized comparison and masking label, but important operational and analytical details remain unavailable. The record lists 2 outcome measures and 0 analyses; these registry entries do not supply a primary-outcome effect estimate or a test of the treatment groups.

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 Pain Score Using Five Scales, measured over average 10-20 minutes.

The primary endpoint is titled Pain Score Using Five Scales. It is described as a participant-level assessment of pain while patients are in the lateral position for spinal anesthesia, at an average of 10-20 minutes. The categories range from 0, calm, to 4, restlessness or agitation that makes it impossible to proceed. Intermediate categories describe facial grimacing, moaning, and screaming.

Such an endpoint is intended to capture the patient's observable response during positioning, when pain may affect whether the procedure can proceed. The ordered categories also distinguish different levels of observed distress rather than recording only whether any pain is present. That is a general explanation of why a graded measure can be useful; the registry does not report how the scale was developed, validated, or applied by assessors.

The record identifies the outcome parameter as a count of participants, but does not provide category-specific participant counts or a comparison between groups. It also notes that the primary outcome has several categories or time points and was not reduced to one comparison. Without those results, it is not possible to determine the distribution of scores, the direction or size of any difference, or the precision of a between-group estimate. The reason for choosing this endpoint over other possible measures is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does randomization mean?

In general, randomization assigns participants to study groups using a chance-based process. Its statistical purpose is to limit systematic differences in participant characteristics between groups at assignment. It does not guarantee that groups will be identical, especially in a trial with limited enrollment, and it does not eliminate the need to report outcome data and analysis methods. The registry identifies this trial's allocation as randomized but does not report how the sequence was generated, how assignments were concealed, or how the allocation process was implemented.

What does the masking label tell us?

The registry lists masking as quadruple. In general, masking aims to reduce the influence that knowledge of group assignment can have on participants, caregivers, assessors, or other people involved in a study. The label alone does not identify which roles were masked or whether masking remained intact. Those details are not reported in the registry record, so the practical meaning of the label cannot be assessed further.

How should the pain scale be understood?

The primary outcome describes five ordered categories, from 0 for calm to 4 for restlessness or agitation when the procedure cannot proceed. The intermediate descriptions are facial grimacing, moaning, and screaming. In general, an ordered categorical outcome ranks observations, but the category labels do not necessarily imply equal distances between adjacent scores. That distinction matters: an analysis of the full category distribution answers a different question from an analysis that treats scores as though equal numerical steps were meaningful.

The registry names the endpoint as a count of participants, but the posted results do not provide participant counts for each score category by group. The record also says the primary outcome has several categories or time points and has not been reduced to one comparison. Consequently, no particular statistical model, summary measure, or contrast can be inferred from the endpoint title alone.

What can a confidence interval say?

In general, a confidence interval describes the uncertainty around an estimated effect under the assumptions of the statistical method used. A narrow interval indicates greater precision than a wide interval; an interval that includes effects in different directions may leave the direction uncertain. A confidence interval does not correct for biased measurement, missing data, or an unsuitable analysis. No primary-outcome estimate or confidence interval is reported in the registry record, so precision cannot be evaluated for the pain comparison.

What do statistical tests and significance levels contribute?

In general, a statistical test evaluates how compatible observed data are with a specified null hypothesis under a model. A p-value is not the probability that the null hypothesis is true, nor does it convey the size or practical importance of an effect. Interpretation is strongest when a test is accompanied by an effect estimate and its uncertainty, and when the analysis was planned in advance. The registry record does not report a primary-outcome test, p-value, or analysis plan.

The registry describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. It states that the effect to detect is a stated fraction of the observed effect. No numeric planning results are reported in the record, and the primary-outcome effect needed to interpret that premise is not posted. Such planning illustrations are not observed power and do not provide evidence about the trial's outcome.

Why can over-dispersion matter?

In general, over-dispersion occurs when observed variability in count data is greater than a statistical model expects. If it is ignored, uncertainty estimates can be too small and statistical tests can appear more decisive than warranted. This trial's primary outcome is described in terms of participant counts across a graded score, not as a reported event-rate analysis. The registry does not report a model or dispersion estimate, so there is no basis for saying whether over-dispersion was assessed or relevant to the analysis actually used.

What is needed to assess the analysis?

A transparent analysis report would identify the outcome summary, the contrast between groups, the method used to estimate uncertainty, and the participants included. It would also explain how missing observations and multiple outcomes or comparisons were handled. These are general reporting considerations, not claims about this trial's protocol. The registry lists 0 analyses and does not report these details. Therefore, the analytical approach cannot be reconstructed from the posted record, and no recalculated primary comparison is available.

10. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when a study evaluates multiple outcomes, time points, groups, or statistical comparisons. In general, testing many hypotheses can increase the chance of finding a seemingly unusual result by chance, so an analysis plan may define a primary comparison or specify how multiple tests will be handled. The registry identifies a primary pain outcome and a secondary outcome called Quality of Patient Positioning. It also notes that the primary outcome has several categories or time points and has not been reduced to one comparison.

The record does not report a multiplicity strategy, a hierarchy of tests, or which time point or summary would be used for a primary comparison. It lists 2 outcome measures and 0 analyses, so the posted record does not establish how any multiplicity issue was addressed. These omissions do not demonstrate that the original investigators did or did not use a particular method; the details are not reported in the registry record.

Missing-data methods are also not reported. The registry does not give the number of missing pain assessments, explain whether participants withdrew or were excluded from particular analyses, or describe any imputation or sensitivity analyses. The enrollment figure does not establish the number contributing to each outcome. Analysis populations, such as whether an analysis included all randomized participants or only participants with observed measurements, are not reported either.

These gaps make it difficult to judge whether the reported outcomes, if available elsewhere, would reflect the planned analysis or whether missing observations could have influenced the comparison. No conclusion about the handling of multiplicity, missing data, or analysis populations can be drawn from 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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: postoperative cardiopulmonary resuscitation (4.8%).

The registry lists serious adverse events for 22 participants at risk in the dexmedetomidine-ketamine group, with 0 affected, and for 21 participants at risk in the dexmedetomidine-fentanyl group, with 1 affected. It lists other adverse events for 22 participants at risk in the dexmedetomidine-ketamine group, with 21 affected, and for 21 participants at risk in the dexmedetomidine-fentanyl group, with 20 affected. Deaths are listed as 0 and 1, respectively.

The registry also identifies postoperative cardiopulmonary resuscitation as a top serious-event term and reports 4.8%. The record does not specify in that entry which group the term belongs to or provide further context for interpreting the percentage. The group-level serious-event counts should therefore be distinguished from this term listing.

These are descriptive registry counts. They do not include a posted comparative safety analysis, and the record does not explain event definitions, collection procedures, follow-up duration, or the relationship between event counts and affected participants. Serious events, other events, and deaths are distinct entries and should not be combined or treated as interchangeable. The counts alone do not establish whether a difference is statistically persuasive or whether the groups' safety profiles are equivalent.

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

The registry record shows that a randomized parallel-group study was designed to compare dexmedetomidine-ketamine with dexmedetomidine-fentanyl for pain during lateral positioning for spinal anesthesia in patients with proximal femur fractures. It describes a five-category primary pain scale and identifies Quality of Patient Positioning as a secondary outcome. Those details clarify the clinical question and the type of observation the investigators intended to assess.

What the posted results do not show is the primary outcome distribution by group or an estimated between-group difference. As a result, they do not establish whether one group had lower or higher pain scores, whether any difference was large or small, or how precisely such a difference was estimated. They also do not support a conclusion that the groups were equivalent. A missing comparison is not evidence of no effect.

In general, interpretation of a randomized trial requires more than knowing the assignment method and outcome definition. Readers need group-specific results, an appropriate effect estimate, uncertainty, and enough information about missing data and analysis choices to understand how the estimate was obtained. The registry does not report those elements for the primary outcome. It also does not report a statistical analysis plan or analysis populations.

The adverse-event counts offer descriptive safety information, but they do not answer the pain question and should not be interpreted as a formal comparison. The record does not provide enough detail to assess event ascertainment or comparative uncertainty. Similarly, a planning illustration is not a trial result: the registry describes assumptions for such an illustration but posts no numeric planning results or primary effect estimate.

Accordingly, the record supports a description of the study's design and intended outcomes, but not an estimate of the relative analgesic effect. Any stronger conclusion about efficacy, statistical significance, or clinical importance would require results and methods not reported in the registry record.

13. Why This Trial Matters Statistically

This trial is statistically notable because its primary outcome is a graded observation tied to whether patients can proceed with positioning for spinal anesthesia. The registry's scale distinguishes calm behavior, observable signs of distress, and restlessness or agitation that prevents proceeding. Such an endpoint raises an important general analytical question: should results be expressed as the distribution across ordered categories, as a summary score, or by some other prespecified contrast? Those approaches can answer different questions, and the registry does not state which was used.

The comparison also illustrates the difference between a registered study design and an interpretable treatment-effect result. Randomization and a masking label describe intended design features, but they are not substitutes for outcome counts, effect estimates, or uncertainty. The record identifies the treatments and the clinical setting, yet the primary results are not reported in a form that permits a statistical comparison.

The listed planning assumptions provide another useful distinction. In general, sample-size planning concerns the ability to detect an anticipated effect under specified assumptions, while observed trial results concern the data actually collected. The registry describes a planning illustration based on a fraction of an observed effect, but it does not report numeric planning results or the primary effect itself. A planning illustration cannot be read as evidence that an effect was observed or that the study had any particular achieved power.

Finally, the registry has descriptive adverse-event counts but no posted comparative analysis and limited contextual detail. This underscores a broad statistical lesson: counts need denominators and clear definitions, while comparisons require methods and uncertainty. The record is useful for understanding the intended randomized comparison, but its available results do not answer the primary statistical question.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The main limitation for interpreting this specific trial is that the registry record does not report the primary pain results as a comparison between groups. It describes the five score categories and timeframe, but not the group-specific distribution, an effect estimate, a confidence interval, or a statistical test. The direction, magnitude, and precision of the primary result therefore cannot be assessed.

The outcome description notes several categories or time points and says they have not been reduced to one comparison. The record does not explain which category summary or time point would be the principal comparison. It also does not report results for the secondary outcome, Quality of Patient Positioning. The number of participants contributing to each outcome is not given, so the enrollment total cannot establish outcome-specific denominators.

Important design and analysis details are absent, including the allocation-sequence method, concealment, the roles covered by quadruple masking, drug doses, the analysis plan, analysis populations, and the approach to missing data. The reason for the sample size and any prespecified handling of multiple outcomes or comparisons are not reported in the registry record. These omissions limit appraisal of the trial's conduct and analysis, but they do not establish that any particular procedure was or was not used.

The safety entries are also limited: event definitions, ascertainment, follow-up, and comparative analyses are not reported. The top serious-event term is accompanied by a percentage without enough detail to assign it to a group. Taken together, the posted registry information supports a broad description of the trial but does not permit a complete assessment of its primary outcome or the robustness of any treatment comparison.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Dexmedetomidine-ketamine in Femur Proximal Fracture Patients — NCT02150759.
• Registry record last updated 2019-04-29; status last verified 2019-04.
• Results first posted 2019-04-29.
• 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

NCT02150759 is a completed randomized, parallel-group trial sponsored by Inje University. The registry reports enrollment of 46, a start date of 2014-05, primary completion in 2017-11, and quadruple masking. It compares dexmedetomidine-ketamine with dexmedetomidine-fentanyl in patients with proximal femur fractures undergoing lateral positioning for spinal anesthesia.

The primary outcome is Pain Score Using Five Scales at an average of 10-20 minutes. Quality of Patient Positioning is listed as a secondary outcome. The registry describes the pain categories but does not report a group-level primary comparison or results for the secondary outcome. It lists 2 outcome measures and 0 analyses.

Descriptive adverse-event counts and a serious-event term are recorded, but the registry does not provide a comparative safety analysis. The primary treatment-effect estimate, its precision, the analysis plan, and analysis-population details are not reported in the registry record.