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 Assessment of the Safety and the Performance of the SAGITTA EVL R Stems in Hip Arthroplasties (NCT05153473), a registered phase not stated study. The primary outcome is Survival Rate of Stems.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05153473 |
| Phase | Phase not stated |
| Condition | Hip Arthropathy |
| Allocation | Not Stated |
| Design model | Not Stated |
| Masking | Not Stated |
| Enrollment | 120 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Societe dEtude, de Recherche et de Fabrication |
| Results posted | Yes |
2. Clinical Question
The study concerns the safety and performance of the SAGITTA EVL R stem in hip arthroplasties. Its primary question is whether stems remain unrevised at five years of follow-up among the patients included in the study. The registry describes a cohort of 120 patients and specifies that the primary endpoint applies to patients who reached their last follow-up.
Population
Patients in a study of hip arthroplasties, with Hip Arthropathy listed as the condition. The primary endpoint population is described as patients who reached their last follow-up. Further eligibility criteria and participant characteristics are not reported in the registry record.
Intervention
The device under evaluation is the SAGITTA EVL R stem. The registry lists Total Hip Arthroplasty Revision as the intervention and describes the study as assessing stem safety and performance.
Comparator
No comparator group is identified. The record describes an observational study and does not state an allocation method or a like-for-like control comparison. The findings therefore cannot be read as a randomized comparison between treatments.
Primary question
What percentage of stems are unrevised at five years of follow-up? The registry defines the endpoint as the survival rate of stems, expressed as the percentage of stems unrevised, among patients who reached their last follow-up. The endpoint result is not reported in the registry record.
The record also names patient satisfaction, functional improvement and pain release as secondary outcomes. It does not provide their results. Thus, the stated aims extend beyond stem revision status, but the posted information does not establish the size, precision or direction of any outcome change.
3. Trial Design
This is described as a retro-prospective and observational study of 120 patients. Its stated purpose is post-market clinical follow-up of the SAGITTA EVL R stem, with assessment of performance, safety and benefit–risk information. The registry marks the study as completed. The start date is 2019-06-24 and the primary completion date is 2019-06-26.
The design is not described as randomized, and allocation is not stated. The registry does not identify a control arm. As a result, this is not a like-for-like comparison of the device against another intervention. Its findings should be understood as observations from the described cohort rather than as a comparative treatment effect.
The primary outcome is stem survival, defined as the percentage of stems unrevised at five years of follow-up. The endpoint population is described as patients who reached their last follow-up. The registry also identifies patient satisfaction, functional improvement and pain release as secondary outcomes. It lists four outcome measures in total, but does not provide detailed definitions, measurement instruments or results for those outcomes.
The registry record does not describe the recruitment process, eligibility criteria, clinical setting beyond the reference to a specific care strategy in the study summary, or how retrospective and prospective observations were combined. It also does not report the follow-up schedule, the number of patients with complete follow-up, or the method used to ascertain revision. These details affect how representative and complete the observed cohort may be, but cannot be inferred from the design label alone.
No statistical analysis entries are listed. The protocol, analysis plan, sample-size justification and any interim analyses are not reported in the registry record. Completion status indicates the study is marked completed; it does not by itself provide evidence about the primary outcome or the completeness of its reporting.
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 | SAGITTA EVL R |
|---|---|
| STARTED | 120 |
| COMPLETED | 71 |
| NOT COMPLETED | 49 |
Reasons for not completing this period:
| Reason | SAGITTA EVL R |
|---|---|
| Death | 46 |
| Lost to Follow-up | 3 |
Analysis population for the primary outcome, as defined in the registry: Patient that have reached the last Follow-up.
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 | SAGITTA EVL R |
|---|---|---|
| Participants analysed | 120 | |
| Age, Continuous | years | 73.6 (SD 11.6) |
| Sex: Female, Male: Female | Participants | 64 |
| Sex: Female, Male: Male | Participants | 55 |
| Race and Ethnicity Not Collected | Participants | — |
| Weight | Kilograms | 77.5 (SD 20.7) |
6. Primary Endpoint
The registry lists the primary outcome as Survival Rate of Stems, measured over at 5 years follow-up.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Percentage of stem unrevised |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the survival rate of stems, expressed as the percentage of stems unrevised at five years of follow-up. In this context, “survival” refers to remaining unrevised; it is not a measure of patient survival. The registry defines the endpoint population as patients who reached their last follow-up.
A revision-based endpoint is used to describe whether a stem has undergone revision by a specified follow-up point. It can summarize device performance in clinical practice, but its interpretation depends on how revisions are defined and recorded, how follow-up is handled, and how many patients have information available at the relevant time. Those operational details are not reported in the registry record.
For time-to-event outcomes generally, analysis may account for different lengths of follow-up and for people whose event status is not known through the full period. The statistical approach used for this endpoint is not reported in the registry record, so it is not possible to determine whether the posted endpoint was estimated using a time-to-event method or another approach.
No five-year percentage, event count, confidence interval or analysis result for stem survival is reported in the registry record. The endpoint definition therefore identifies what was intended to be assessed, but does not show the observed level of unrevised stems or the precision of an estimate.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes an observational cohort of 120 patients and names stem survival at five years as the primary outcome. It does not report the primary endpoint result. Consequently, no conclusion about the observed percentage of stems unrevised, the number of revisions, or the precision of the estimate can be drawn from the posted outcome information.
The record lists 0 serious adverse events among 120 at risk and 0 other adverse events among 120 at risk in the SAGITTA EVL R group. It also records 46 deaths in that group. These are separate registry counts; the record does not state the timing, causes or relationship to the device for the deaths. The adverse-event entries should not be treated as evidence that no safety events of any kind occurred, nor do the counts alone describe event ascertainment or follow-up completeness.
No analyses are listed in the registry record. There are no posted estimates, confidence intervals, p-values, or results for the secondary outcomes of patient satisfaction, functional improvement and pain release. The absence of an analysis entry is a reporting limitation, not proof that no analyses were performed outside the registry.
Because the study is observational and no comparator is identified, the design does not establish a causal contrast between the device and another treatment. Patient characteristics, care decisions and follow-up may influence observed outcomes in an observational cohort. The record does not report adjustment methods or enough detail to evaluate those influences.
Precision is also unknown. A confidence interval, when reported, describes the range of estimates compatible with the data under the stated statistical model; its width helps show how uncertain an estimate is. No interval is reported for stem survival or the other outcomes. Without the point estimate and its uncertainty, the magnitude and reliability of the primary outcome cannot be assessed.
These limitations mean the record supports description of the study’s purpose, design label, planned endpoint and selected safety counts, but not a quantitative assessment of five-year stem survival or the secondary outcomes. The completed status does not substitute for those results.
9. Statistical Methods Explained
What does an observational design allow?
In general, an observational study records outcomes under the care and exposure patterns that occur, rather than assigning participants randomly to competing treatments. It can describe what happened in the studied cohort, but differences in patient characteristics or care can complicate comparisons. Here, the registry describes a retro-prospective observational study and does not identify a control group or allocation method. The record therefore does not support interpreting the cohort as a randomized comparison.
The registry mentions a specific care strategy in its study summary, but does not give enough detail to characterize that strategy or determine how it affected outcome measurement. It also does not report recruitment, eligibility criteria, baseline characteristics or adjustment procedures. The scope of any conclusions is consequently limited to the cohort as described, with important details of its composition unavailable.
How should stem survival be understood?
The primary endpoint is the percentage of stems unrevised at five years of follow-up, among patients who reached their last follow-up. This is a binary status at a stated time if each stem is classified as revised or unrevised at that point. In general, time-to-event methods can use information about when a revision occurred and account for incomplete follow-up through censoring. Whether such a method was used is not reported in the registry record.
That distinction matters because a simple proportion and a time-to-event estimate can use follow-up information differently. A time-to-event estimate typically depends on event timing and assumptions about participants whose follow-up ends before the target time. The registry does not report the number followed to five years, censoring information, revision definitions or the estimator used. No method-specific result can therefore be reconstructed from the endpoint description.
What would uncertainty measures add?
In general, a confidence interval gives a range of values compatible with the observed data and statistical model, and its width conveys precision. A point estimate without an interval can conceal substantial uncertainty, particularly when the number of observed events or the amount of complete follow-up is limited. The registry record does not report a stem-survival estimate or its confidence interval. It also provides no p-value or other inferential result for the primary endpoint.
A p-value, in general, assesses how inconsistent data are with a specified null model under the assumptions of the analysis. It is not a measure of the probability that a hypothesis is true, nor does it describe clinical importance. No p-values are reported, and no hypothesis or statistical model is stated in the registry record. Accordingly, statistical significance cannot be evaluated from the posted information.
How should event counts and planning calculations be read?
For count outcomes, the number of events and the population in which events were monitored are both important. The registry lists no serious adverse events and no other adverse events in the group, with 120 at risk for each category. In general, observing no recorded events does not establish that the underlying event risk is zero. Interpretation also depends on the event definitions, length and completeness of surveillance, and how events were collected; those details are not reported.
General sample-size illustrations can be useful for planning, but they are not observed power and do not establish what the study was designed to detect. The registry’s stated illustration assumptions include a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation and an effect defined as a fraction of the observed effect. For time-to-event outcomes, the illustration is based on total events; other outcomes are expressed as participants per arm. These are planning assumptions, not evidence that the observational study used two arms or was designed with that allocation. The trial’s own sample-size justification is not reported in the registry record.
Over-dispersion is a general issue for count data: if variation exceeds what a simple count model assumes, standard errors may be too small and intervals too narrow unless the model accommodates that extra variation. The registry does not report an over-dispersion assessment or a count-data model, and the posted adverse-event counts do not permit those methods to be evaluated.
What can be said about the analysis plan?
The registry lists 0 analyses. The statistical methods, prespecified analysis populations, missing-data procedures, handling of multiple outcomes and any interim analyses are not reported in the registry record. These omissions mean the reader cannot check whether methods were selected before outcomes were known, how incomplete observations were handled, or whether analyses were adjusted for multiple testing. They should be treated as unavailable information, not filled in by assumption.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists four outcome measures in total and identifies patient satisfaction, functional improvement and pain release as secondary outcomes alongside stem survival as the primary outcome. It does not report results for the secondary outcomes or describe how they were measured. The statistical plan, including whether any multiplicity adjustment was intended, is not reported in the registry record.
In general, testing multiple outcomes can increase the chance of finding at least one apparently unusual result by chance. A prespecified approach may address that issue, but the appropriate method depends on the questions and analysis plan. No adjustment or hierarchy among outcomes is described, and no outcome-specific analyses are listed. There is therefore no basis to infer whether multiplicity was considered.
Missing-data handling is also not reported. The primary endpoint population is described as patients who reached their last follow-up, but the record does not state how many patients did so, how many were unavailable, or how missing outcome observations were treated. The five-year timeframe does not establish that every participant was observed through five years. The method for handling incomplete follow-up, withdrawals or other unavailable observations is not stated.
The record does not define analysis populations or state whether outcomes were analyzed for all enrolled patients, only those with available data, or another group. It also lists 0 analyses. This means the posted registry record does not permit evaluation of analysis-population choices, missing-data assumptions or the relationship between the intended and analyzed populations. These gaps limit interpretation of both the outcome estimates and their precision.
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 |
|---|---|---|---|
| SAGITTA EVL R | 0 | 120 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| SAGITTA EVL R | 46 of 120 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| SAGITTA EVL R | 0 of 120 |
For the SAGITTA EVL R group, the registry records 0 serious adverse events among 120 at risk and 0 other adverse events among 120 at risk. It also records 46 deaths. The record does not specify the timing or causes of death, or whether any death was considered related to the device or study.
These entries are counts, not a complete safety analysis. The registry does not report the event definitions, surveillance period, collection procedures, severity grading details or a breakdown by event term. No top serious adverse-event terms are listed. In general, a count of zero means no events were recorded in that category in the stated group; it does not prove that the true event rate is zero or that all events were captured.
The death count should be read separately from the adverse-event counts. The record does not explain whether deaths were included in an adverse-event category, how they affected follow-up, or how many participants remained available for the five-year stem-survival assessment. No causal interpretation is supported by these figures alone.
12. What the Result Does, and Does Not, Mean
The record establishes that the study was intended to assess the safety and performance of SAGITTA EVL R stems in hip arthroplasties, with a primary endpoint defined as the percentage of stems unrevised at five years. It describes a cohort of 120 patients, an observational retro-prospective design, and a completed status. It also records 0 serious adverse events and 0 other adverse events in the group, alongside 46 deaths.
It does not report the five-year stem-survival result, the number of revisions, or the precision of an estimate. It also does not report results for patient satisfaction, functional improvement or pain release. As a result, the record does not establish the observed performance level or summarize the secondary outcomes quantitatively.
The observational design and absence of a comparator mean that the record cannot estimate a randomized treatment contrast. Even if an outcome estimate were available, a cohort result would describe what was observed in that cohort and would not by itself separate device effects from other patient, clinical-care or follow-up factors. The record does not provide adjustment methods that would resolve such concerns.
The safety counts likewise have a limited meaning. No adverse events are recorded in the listed categories, but event definitions and surveillance details are unavailable, and deaths are recorded without timing or cause. These counts do not show whether events were completely ascertained or what their relationship to the device was.
Overall, the registry information identifies the study question and several design and safety details, but leaves the primary efficacy-style outcome and other clinical outcomes unreported. The completed status should not be mistaken for a posted result, and the absence of a reported result should not be interpreted as evidence of either favorable or unfavorable performance.
13. Why This Trial Matters Statistically
Post-market observational studies can contribute evidence about how a medical device is followed in clinical practice. Their value depends not only on the number of enrolled patients, but also on clear outcome definitions, complete follow-up, transparent analysis methods and accessible results. This registry record identifies a five-year unrevised-stem endpoint and a cohort of 120 patients, making the intended performance question clear.
Statistically, the central limitation is that the primary endpoint result is not reported. Without an estimate and its precision, readers cannot judge the observed level of stem survival or how uncertain that estimate may be. The record also does not give the number of participants who reached the relevant follow-up, the number of revisions or the method used to account for incomplete follow-up.
The observational design is important when framing the question. With no identified comparator and no stated allocation, the study is suited to describing its cohort rather than providing a randomized contrast. This distinction prevents a descriptive result from being interpreted as a causal comparison. It also makes information about patient characteristics and clinical context especially relevant; those details are not reported in the registry record.
The safety entries illustrate why counts need context. The registry records zero events in the two adverse-event categories and 46 deaths, but does not provide timing, causes, definitions or ascertainment details. These figures cannot substitute for a complete account of safety outcomes.
Finally, no analysis entries are listed, and the statistical plan and missing-data methods are not reported. Transparent reporting of these elements would help readers assess bias, precision and the credibility of outcome estimates. In their absence, the main statistical contribution of the record is to define the study’s intended question and make the limits of the posted results visible.
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.
Several trial-specific details needed to interpret the primary endpoint are not reported in the registry record. These include the observed five-year unrevised-stem percentage, the number of revisions, a confidence interval, the estimator or model used, and the number of participants with follow-up at the relevant time. The endpoint population is limited by its definition to patients who reached their last follow-up, but the record does not quantify that population.
The study is observational, and no comparator or allocation method is identified. Participant selection, eligibility criteria, baseline characteristics and the clinical setting are not described sufficiently to assess representativeness or potential confounding. The summary refers to a specific care strategy, but does not provide details that would allow its effects to be evaluated.
Outcome definitions and measurement procedures are not reported for stem revision or the secondary outcomes. The record names patient satisfaction, functional improvement and pain release, but gives no instruments, assessment times or results. It also does not explain how retrospective and prospective information was combined.
Safety reporting is limited to counts. Event definitions, observation duration, ascertainment procedures, timing and causes of the 46 deaths are not reported. The registry also does not state how deaths or incomplete follow-up affected assessment of stem survival.
Finally, the registry lists 0 analyses and does not report the statistical plan, analysis populations, missing-data methods, multiplicity approach or interim analyses. The study’s own sample-size justification is not reported in the registry record. These omissions make it difficult to assess precision, bias and the relationship between the intended outcomes and any analyses conducted.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Assessment of the Safety and the Performance of the SAGITTA EVL R Stems in Hip Arthroplasties — NCT05153473.
- Registry record last updated 2024-11-29; status last verified 2022-09.
- Results first posted 2024-11-29.
- 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.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
18. Record Summary
The registry record identifies NCT05153473 as a completed retro-prospective observational study of 120 patients assessing the safety and performance of SAGITTA EVL R stems in hip arthroplasties. The sponsor is Societe dEtude, de Recherche et de Fabrication. The recorded start date is 2019-06-24, and the primary completion date is 2019-06-26.
The primary outcome is stem survival, defined as the percentage of stems unrevised at five years of follow-up among patients who reached their last follow-up. Secondary outcomes are patient satisfaction, functional improvement and pain release. No comparator is identified, and allocation is not stated.
The record lists 0 serious adverse events and 0 other adverse events among 120 at risk in the SAGITTA EVL R group, and records 46 deaths. It lists 0 analyses. The primary endpoint result, secondary outcome results and statistical analysis methods are not reported in the registry record.