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 Steroids in Total Knee Arthroplasty (NCT02219581), a randomized phase 4 study. The primary outcome is Pain Score.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02219581 |
| Phase | Phase 4 |
| Condition | Postoperative Pain, Inflammation, Osteoarthritis |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | Quadruple |
| Enrollment | 1 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Thomas L Bradbury |
| Results posted | Yes |
2. Clinical Question
Population
The registry describes people undergoing primary total knee arthroplasty. Its stated conditions include postoperative pain, inflammation, and osteoarthritis. The enrollment recorded is 1 participant, so the record describes a very small study rather than a dataset from which treatment-group comparisons can be read with confidence.
Intervention
The active regimens were two intravenous doses of dexamethasone, at either 10 mg or 20 mg. For both active regimens, the first dose was scheduled before surgery within 3 hours, and the second dose was scheduled 8 hours after the first in the inpatient setting. The descriptions also include standard multimodal postoperative pain management.
Comparator
The registry lists a placebo regimen alongside standard multimodal postoperative pain management. The record also lists standard multimodal pain management as an intervention. It does not report a complete allocation scheme or explain how the four listed intervention entries map onto the study arms.
Primary question
The primary outcome was pain score, assessed from baseline through the end of the hospital stay, up to 3 days, and at 1, 4, and 12 months after surgery. The study description asks whether intravenous steroids affect pain or pain-medication use and postoperative outcomes. The registry record contains no posted analyses that answer those questions.
3. Trial Design
The registry identifies this as a Phase 4, randomized, quadruple-masked, parallel study. These labels describe the recorded design, but the record does not explain who was masked, how randomization was generated or implemented, or how participants were assigned among the listed regimens. The allocation ratio and the intended number of study arms are not reported in the registry record.
The listed interventions include dexamethasone 10 mg, dexamethasone 20 mg, placebo, and a standard multimodal pain-management regimen. The descriptions for the active-dose groups specify two intravenous doses: the first before surgery within 3 hours, followed by a second dose 8 hours later in the inpatient setting. Those descriptions also include standard postoperative pain management. The placebo description states that placebo was given in addition to standard multimodal postoperative pain management, but its registry text is incomplete. The record does not clarify the comparison structure across all four intervention entries.
The study status is terminated, and the recorded enrollment is 1 participant. The registry lists a start date of 2014-10-16 and a primary completion date of 2015-12-01. It does not report why the study was terminated, whether enrollment ended as planned, or whether any participants completed follow-up. The planned sample size and the rationale for choosing it are not reported in the registry record.
The outcome list contains the primary pain score and secondary outcomes covering swelling, range of motion, physical-therapy clearance, antiemetic dose, blood glucose, health-status and knee-function scores, and hospital stay. Although 12 outcome measures are listed, the posted results contain no analyses. This page therefore describes the registered design and available record information, not a completed comparison of treatment effects.
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 | Dexamethasone 10 mg | Dexamethasone 20 mg |
|---|---|---|---|
| STARTED | 0 | 0 | 1 |
| COMPLETED | 0 | 0 | 1 |
| NOT COMPLETED | 0 | 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 | Dexamethasone 20 mg |
|---|---|---|
| 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 | — |
| Sex: Female, Male: Male | Participants | — |
| Region of Enrollment: United States | Participants | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Pain Score, measured over Baseline, end of hospital stay (up to 3 days), 1, 4, and 12 months post-operatively.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | units on a scale |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is a pain score measured with a visual analog scale. The registry describes a series of faces ranging from a happy face at 0, labelled “No hurt,” to a crying face at 10, labelled “Hurts worst.” Participants select the face that best represents their pain. Higher scores indicate greater pain intensity.
Pain is relevant to the study’s stated question because the registry describes evaluating steroid use in relation to pain and pain-medication use after knee replacement surgery. Repeated assessment was planned at baseline, at the end of the hospital stay up to 3 days, and at 1, 4, and 12 months after surgery. These time points span the immediate postoperative period and later follow-up, but the registry record does not report whether data were collected at each time point.
A score on a scale is an outcome measure, not a treatment-effect estimate by itself. To compare groups, an analysis would need to summarize the observed scores and account for the study design and available data. No group summaries, effect estimates, confidence intervals, or outcome analyses are posted in the registry record. The listed scale and time points therefore explain what the endpoint was intended to measure, but they do not establish what participants experienced or whether the regimens differed.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record does not provide an analyzed result for the primary pain outcome. It lists pain scores at baseline, at the end of the hospital stay up to 3 days, and at 1, 4, and 12 months after surgery, but it gives no group-level values or comparisons at those times. There is consequently no posted estimate of the size or direction of a difference between dexamethasone and placebo, and no confidence interval or statistical test for such a difference.
The enrollment recorded is 1 participant, and the study status is terminated. The record does not say which regimen that participant received, whether the participant completed the planned assessments, or whether outcome data were collected. Without those details, the enrollment count cannot be treated as evidence about pain outcomes in any group. It also does not support an estimate of variability or precision.
The study description identifies several questions: whether steroid use changes pain or pain-medication use, and whether participants receiving steroid have different pain control or postoperative outcomes. The listed secondary outcomes include swelling, range of motion, physical-therapy clearance, antiemetic dose, blood glucose, health-status and knee-function scores, and length of hospital stay. None of these outcomes has a posted analysis in the record. A list of outcomes is not a report of findings.
The registry describes the study as randomized and quadruple-masked, which are design features intended to support fair comparisons and reduce some sources of bias. Those labels do not substitute for outcome data, and the registry does not supply enough detail to assess how those procedures were implemented. The record also does not specify the analysis plan, the approach to repeated measurements, or how missing observations would be handled.
The record’s termination status should be read as a study-status entry, not as a statistical conclusion. The reason for termination and its relation to the study’s conduct or results are not reported in the registry record. Likewise, the absence of posted analyses is not evidence that treatments were equivalent, or that either regimen had a particular effect. The appropriate statistical reading is that the registered question and measurement schedule are visible, but the posted record does not permit an estimate of treatment effects or their precision.
Any sample-size illustrations shown elsewhere on the page are planning calculations, not observed power and not evidence about what this study found. In this record there are no posted outcome estimates from which to interpret a treatment effect. The illustrations cannot replace trial results, explain why enrollment was 1, or reveal the study’s original design rationale.
9. Statistical Methods Explained
What does randomization contribute?
In general, randomization assigns participants to study groups using a chance-based process. When implemented as intended, it can reduce systematic differences between groups at the start of a study. It does not guarantee that groups will be balanced, especially in a small study, and it does not ensure that participants complete follow-up or that outcomes are measured without error. The registry labels this study randomized, but the method used to generate and conceal assignments is not reported in the registry record. The enrollment recorded is 1 participant, and no group allocation is posted, so the record cannot show whether the intended groups were formed or how comparable they were.
What does quadruple masking mean?
Masking is intended to limit the influence of knowing a participant’s assigned treatment on care, outcome reporting, or assessment. The registry labels the study quadruple-masked, but it does not identify the four parties or roles that were masked, nor does it describe how masking was maintained or assessed. The label alone does not establish that masking was successful. No posted results allow readers to examine whether outcomes or treatment delivery could have been affected by knowledge of assignment.
How would the pain scale be interpreted?
The pain measure uses a visual analog scale with values anchored at 0 for “No hurt” and 10 for “Hurts worst”; higher values mean greater pain intensity. In general, an analysis might summarize scores by group and time point, or estimate a between-group contrast. A confidence interval would express the range of effect values compatible with the data under the model and assumptions used. A narrow interval generally indicates greater precision than a wide interval, but neither interval width nor an effect estimate is available. The registry record reports no pain summaries, contrasts, confidence intervals, or p-values.
Why do repeated measurements need an analysis plan?
Pain was scheduled for assessment at baseline, at the end of the hospital stay up to 3 days, and at 1, 4, and 12 months after surgery. Repeated observations from one participant are related rather than independent. In general, an analysis of repeated measures needs to account for that dependence and specify how time is represented, which comparisons are of interest, and how incomplete follow-up is handled. The registry record does not report the statistical model or the planned primary time-point comparison. Since no analyses are posted, readers cannot determine how these repeated observations were summarized or whether the planned schedule was completed.
What can be said about the analysis population?
Clinical-trial reports may describe analyses based on all randomized participants, participants who received the assigned regimen, or participants with particular outcome data. Those populations answer somewhat different questions and can be affected differently by missing observations or deviations from assigned treatment. The registry record does not identify an analysis population, describe participant flow, or report treatment receipt. With enrollment recorded as 1 and no posted analyses, there is no basis for reconstructing which population, if any, was used for an analysis.
What is over-dispersion, and does it apply?
In general, over-dispersion occurs when observed variability in count data is greater than expected under a statistical model. If present, it can make model-based uncertainty too small unless the analysis accounts for that extra variability. This is a general concept, not a finding about this study. The registry identifies the primary endpoint as a pain score, not a count outcome, and provides no outcome distributions or fitted models. There is no posted evidence that over-dispersion was assessed or that it is relevant to an analysis of this endpoint.
What do the planning illustrations represent?
In general, a sample-size illustration asks how many participants might be needed under specified assumptions to detect an effect at a chosen significance level and power. Such a calculation depends on assumptions about the effect, variability, allocation, and analysis. The stated illustration framework uses a two-sided significance level of 0.05, equal allocation, a normal approximation, and an effect expressed as a fraction of an observed effect. These are planning assumptions, not evidence of the trial’s intended design or of its results. The registry record does not report the original sample-size justification. Because no analyzed outcome effect is posted, the illustrations should not be read as observed power or as a retrospective explanation for the recorded enrollment.
No inferential method can recover a treatment comparison that is absent from the posted results. The registry provides a design label, endpoint description, and outcome schedule, but not the data summaries or analytical outputs needed to assess an effect. Statistical concepts can clarify what a complete analysis would normally report; they cannot fill in the missing results or determine why the study ended.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary pain outcome with repeated measurement times and multiple secondary outcomes. When a study tests many outcomes, time points, or contrasts, the chance of finding at least one apparently notable result can increase if all are interpreted as separate tests. In general, a statistical plan may identify a primary comparison and specify whether and how other tests are adjusted or treated as exploratory. The registry record does not report a multiplicity strategy or identify a single primary time-point contrast.
The record lists 12 outcome measures and reports 0 analyses. There are no posted test results to interpret in light of multiple comparisons, and the list alone does not establish which outcomes were analyzed. The registry also does not explain whether the outcome list changed over time or how outcomes were prioritized.
Missing-data methods are not reported in the registry record. Although enrollment is recorded as 1, the record does not state whether that participant had measurements at baseline or at later visits, whether any observations were missing, or how missing values would be handled. In general, missingness can affect both the amount of information available and the interpretation of a comparison; the consequences depend on why data are missing and on the analysis assumptions. None of those details can be assessed.
The analysis populations are also not reported in the registry record. There is no participant-flow account or description of whether analyses were intended to follow randomized assignment, treatment received, or available observations. These omissions leave important uncertainties about outcome completeness, analysis choices, and the scope of any possible conclusions.
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 |
|---|---|---|---|
| Dexamethasone 20 mg | 0 | 1 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Dexamethasone 20 mg | 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 |
|---|---|
| Dexamethasone 20 mg | 0 of 1 |
The posted serious-adverse-event figures are limited to the group labelled Dexamethasone 20 mg. The record lists 1 participant at risk, 0 affected by a serious adverse event, 0 affected by other adverse events, and 0 deaths. These counts describe the information entered in the registry; they are not an estimate of a treatment effect or a comparison with placebo or the other dexamethasone dose.
A zero count in a group with 1 participant does not establish that an event cannot occur or that a regimen is free of risk. It means that the registry reports no affected participant among the 1 participant recorded at risk for that group. The record does not provide comparable adverse-event figures for the other listed groups, explain the period during which events were collected, or describe how events were defined and assessed.
The registry lists no top serious-adverse-event terms. That absence should not be interpreted as a detailed account of event types, since the posted safety information is very limited. With no comparative safety analysis and no complete group-level context, the figures should be read narrowly as registry counts only.
12. What the Result Does, and Does Not, Mean
This record establishes that a randomized, quadruple-masked, parallel Phase 4 study was registered to evaluate intravenous dexamethasone regimens around total knee arthroplasty. It identifies two active dose regimens, a placebo regimen, and standard multimodal pain management, and it names postoperative pain as the primary outcome. It also records the timing of planned pain assessments and a range of secondary outcomes. These details describe the research question and the intended measurement framework.
The record does not establish whether dexamethasone changed pain, pain-medication use, or any other postoperative outcome. No group summaries, effect estimates, confidence intervals, or statistical tests are posted. The single recorded participant cannot be used to infer a comparative effect, and the registry does not identify that participant’s assigned regimen or outcome data. The absence of a result is not evidence that the regimens had the same outcomes or that one performed better.
The status is terminated, but the reason for termination is not reported in the registry record. The record does not state whether the study stopped because of enrollment, operational, safety, or other considerations; assigning a reason would be speculation. Nor does the available information reveal whether the protocol’s planned enrollment or analysis procedures were followed.
Where planning illustrations appear on the page, they should be read as hypothetical sample-size calculations under stated assumptions. They are not observed power, do not represent trial findings, and do not explain the small recorded enrollment. A calculation based on a presumed effect cannot replace a reported treatment comparison with uncertainty estimates.
The main conclusion for readers is therefore about the limits of the record: the trial’s registered question and some design features are documented, but the posted information does not provide an interpretable efficacy comparison or a complete safety comparison.
13. Why This Trial Matters Statistically
This study matters statistically because it illustrates the distinction between a registered trial question and an analyzable result. The record names a primary pain endpoint, a measurement scale, scheduled follow-up times, and several secondary outcomes. Those details can help readers understand what investigators intended to measure. They do not, by themselves, show what happened to participants or how treatment groups compared.
Randomization and masking are important design features in clinical research, but their value for interpretation depends on how they were implemented and on having outcome data to analyze. Here, the registry labels the study randomized and quadruple-masked, while details about assignment procedures and masked roles are not reported. The recorded enrollment is 1, and no analyses are posted. This makes it especially important not to treat design labels as substitutes for estimates, uncertainty, or a participant-flow account.
The record also highlights why outcome schedules and analysis plans matter. A pain score collected at several times can support different questions depending on which time point is primary and how repeated observations and missing data are handled. The registry does not report those analysis choices. With multiple secondary outcomes as well, the absence of a multiplicity plan leaves no basis for interpreting a set of statistical tests, even if results were available.
Finally, the record cautions against overreading a zero adverse-event count. A small count in one recorded group is descriptive and does not establish comparative safety. Statistical interpretation depends on context, denominators, definitions, follow-up, and uncertainty. In this case, the posted information is useful for documenting the registered design and the limits of what can be concluded, rather than for estimating treatment effects.
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 central limitation is that the registry record contains no posted outcome analyses. It reports 0 analyses and gives no pain-score summaries, treatment contrasts, confidence intervals, or statistical tests. As a result, the primary research question cannot be answered from this record.
Enrollment is recorded as 1 participant, and the study status is terminated. The record does not explain why the study ended, whether the participant completed follow-up, or which regimen the participant received. It also does not report participant flow, exclusions, adherence, or completion of the scheduled outcome assessments. The amount and completeness of the outcome data are therefore unknown.
The comparison structure is not fully clear. The interventions list dexamethasone 10 mg, dexamethasone 20 mg, placebo, and standard multimodal pain management, while the arm descriptions are incomplete and do not give a complete allocation scheme. The allocation ratio, planned number of arms, and randomization procedures are not reported in the registry record. The identities of the parties covered by quadruple masking and the procedures used to maintain masking are also not reported.
The statistical plan is not reported in the registry record. This includes the planned primary comparison, handling of repeated pain measurements, missing-data methods, analysis population, and approach to multiple outcomes and time points. The original sample-size justification is not reported either. These gaps prevent readers from assessing whether a planned analysis was followed or how much precision was intended.
Safety information is limited to one group, with 1 participant at risk and no recorded adverse events or deaths. There is no complete comparative safety account, and the record does not provide further event definitions or collection details. These limitations mean the posted registry information supports a description of the registered study, but not a reliable estimate of efficacy or a broad assessment of safety.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Steroids in Total Knee Arthroplasty — NCT02219581.
- Registry record last updated 2022-10-04; status last verified 2022-09.
- Results first posted 2022-10-04.
- 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
The registry describes a Phase 4, randomized, quadruple-masked, parallel study of intravenous dexamethasone regimens around total knee arthroplasty. The active regimens were two doses of dexamethasone 10 mg or 20 mg, alongside standard multimodal postoperative pain management; placebo was also listed. The primary outcome was pain on a visual analog scale, scheduled from baseline through 12 months after surgery.
The study status is terminated, and enrollment is recorded as 1 participant. The registry lists 12 outcome measures and 0 analyses. It reports no outcome comparisons or estimates of precision. The reason for termination, the analysis plan, and the original sample-size justification are not reported in the registry record. The safety entry covers the Dexamethasone 20 mg group only, with 1 participant at risk and 0 serious adverse events, other adverse events, or deaths recorded. The available information describes the registered study but does not establish treatment effects.